stb_truetype.h

// stb_truetype.h - v1.26 - public domain
// authored from 2009-2021 by Sean Barrett / RAD Game Tools
//
// =======================================================================
//
//    NO SECURITY GUARANTEE -- DO NOT USE THIS ON UNTRUSTED FONT FILES
//
// This library does no range checking of the offsets found in the file,
// meaning an attacker can use it to read arbitrary memory.
//
// =======================================================================
//
//   This library processes TrueType files:
//        parse files
//        extract glyph metrics
//        extract glyph shapes
//        render glyphs to one-channel bitmaps with antialiasing (box filter)
//        render glyphs to one-channel SDF bitmaps (signed-distance field/function)
//
//   Todo:
//        non-MS cmaps
//        crashproof on bad data
//        hinting? (no longer patented)
//        cleartype-style AA?
//        optimize: use simple memory allocator for intermediates
//        optimize: build edge-list directly from curves
//        optimize: rasterize directly from curves?
//
// ADDITIONAL CONTRIBUTORS
//
//   Mikko Mononen: compound shape support, more cmap formats
//   Tor Andersson: kerning, subpixel rendering
//   Dougall Johnson: OpenType / Type 2 font handling
//   Daniel Ribeiro Maciel: basic GPOS-based kerning
//
//   Misc other:
//       Ryan Gordon
//       Simon Glass
//       github:IntellectualKitty
//       Imanol Celaya
//       Daniel Ribeiro Maciel
//
//   Bug/warning reports/fixes:
//       "Zer" on mollyrocket       Fabian "ryg" Giesen   github:NiLuJe
//       Cass Everitt               Martins Mozeiko       github:aloucks
//       stoiko (Haemimont Games)   Cap Petschulat        github:oyvindjam
//       Brian Hook                 Omar Cornut           github:vassvik
//       Walter van Niftrik         Ryan Griege
//       David Gow                  Peter LaValle
//       David Given                Sergey Popov
//       Ivan-Assen Ivanov          Giumo X. Clanjor
//       Anthony Pesch              Higor Euripedes
//       Johan Duparc               Thomas Fields
//       Hou Qiming                 Derek Vinyard
//       Rob Loach                  Cort Stratton
//       Kenney Phillis Jr.         Brian Costabile
//       Ken Voskuil (kaesve)
//
// VERSION HISTORY
//
//   1.26 (2021-08-28) fix broken rasterizer
//   1.25 (2021-07-11) many fixes
//   1.24 (2020-02-05) fix warning
//   1.23 (2020-02-02) query SVG data for glyphs; query whole kerning table (but only kern not GPOS)
//   1.22 (2019-08-11) minimize missing-glyph duplication; fix kerning if both 'GPOS' and 'kern' are defined
//   1.21 (2019-02-25) fix warning
//   1.20 (2019-02-07) PackFontRange skips missing codepoints; GetScaleFontVMetrics()
//   1.19 (2018-02-11) GPOS kerning, STBTT_fmod
//   1.18 (2018-01-29) add missing function
//   1.17 (2017-07-23) make more arguments const; doc fix
//   1.16 (2017-07-12) SDF support
//   1.15 (2017-03-03) make more arguments const
//   1.14 (2017-01-16) num-fonts-in-TTC function
//   1.13 (2017-01-02) support OpenType fonts, certain Apple fonts
//   1.12 (2016-10-25) suppress warnings about casting away const with -Wcast-qual
//   1.11 (2016-04-02) fix unused-variable warning
//   1.10 (2016-04-02) user-defined fabs(); rare memory leak; remove duplicate typedef
//   1.09 (2016-01-16) warning fix; avoid crash on outofmem; use allocation userdata properly
//   1.08 (2015-09-13) document stbtt_Rasterize(); fixes for vertical & horizontal edges
//   1.07 (2015-08-01) allow PackFontRanges to accept arrays of sparse codepoints;
//                     variant PackFontRanges to pack and render in separate phases;
//                     fix stbtt_GetFontOFfsetForIndex (never worked for non-0 input?);
//                     fixed an assert() bug in the new rasterizer
//                     replace assert() with STBTT_assert() in new rasterizer
//
//   Full history can be found at the end of this file.
//
// LICENSE
//
//   See end of file for license information.
//
// USAGE
//
//   Include this file in whatever places need to refer to it. In ONE C/C++
//   file, write:
//      #define STB_TRUETYPE_IMPLEMENTATION
//   before the #include of this file. This expands out the actual
//   implementation into that C/C++ file.
//
//   To make the implementation private to the file that generates the implementation,
//      #define STBTT_STATIC
//
//   Simple 3D API (don't ship this, but it's fine for tools and quick start)
//           stbtt_BakeFontBitmap()               -- bake a font to a bitmap for use as texture
//           stbtt_GetBakedQuad()                 -- compute quad to draw for a given char
//
//   Improved 3D API (more shippable):
//           #include "stb_rect_pack.h"           -- optional, but you really want it
//           stbtt_PackBegin()
//           stbtt_PackSetOversampling()          -- for improved quality on small fonts
//           stbtt_PackFontRanges()               -- pack and renders
//           stbtt_PackEnd()
//           stbtt_GetPackedQuad()
//
//   "Load" a font file from a memory buffer (you have to keep the buffer loaded)
//           stbtt_InitFont()
//           stbtt_GetFontOffsetForIndex()        -- indexing for TTC font collections
//           stbtt_GetNumberOfFonts()             -- number of fonts for TTC font collections
//
//   Render a unicode codepoint to a bitmap
//           stbtt_GetCodepointBitmap()           -- allocates and returns a bitmap
//           stbtt_MakeCodepointBitmap()          -- renders into bitmap you provide
//           stbtt_GetCodepointBitmapBox()        -- how big the bitmap must be
//
//   Character advance/positioning
//           stbtt_GetCodepointHMetrics()
//           stbtt_GetFontVMetrics()
//           stbtt_GetFontVMetricsOS2()
//           stbtt_GetCodepointKernAdvance()
//
//   Starting with version 1.06, the rasterizer was replaced with a new,
//   faster and generally-more-precise rasterizer. The new rasterizer more
//   accurately measures pixel coverage for anti-aliasing, except in the case
//   where multiple shapes overlap, in which case it overestimates the AA pixel
//   coverage. Thus, anti-aliasing of intersecting shapes may look wrong. If
//   this turns out to be a problem, you can re-enable the old rasterizer with
//        #define STBTT_RASTERIZER_VERSION 1
//   which will incur about a 15% speed hit.
//
// ADDITIONAL DOCUMENTATION
//
//   Immediately after this block comment are a series of sample programs.
//
//   After the sample programs is the "header file" section. This section
//   includes documentation for each API function.
//
//   Some important concepts to understand to use this library:
//
//      Codepoint
//         Characters are defined by unicode codepoints, e.g. 65 is
//         uppercase A, 231 is lowercase c with a cedilla, 0x7e30 is
//         the hiragana for "ma".
//
//      Glyph
//         A visual character shape (every codepoint is rendered as
//         some glyph)
//
//      Glyph index
//         A font-specific integer ID representing a glyph
//
//      Baseline
//         Glyph shapes are defined relative to a baseline, which is the
//         bottom of uppercase characters. Characters extend both above
//         and below the baseline.
//
//      Current Point
//         As you draw text to the screen, you keep track of a "current point"
//         which is the origin of each character. The current point's vertical
//         position is the baseline. Even "baked fonts" use this model.
//
//      Vertical Font Metrics
//         The vertical qualities of the font, used to vertically position
//         and space the characters. See docs for stbtt_GetFontVMetrics.
//
//      Font Size in Pixels or Points
//         The preferred interface for specifying font sizes in stb_truetype
//         is to specify how tall the font's vertical extent should be in pixels.
//         If that sounds good enough, skip the next paragraph.
//
//         Most font APIs instead use "points", which are a common typographic
//         measurement for describing font size, defined as 72 points per inch.
//         stb_truetype provides a point API for compatibility. However, true
//         "per inch" conventions don't make much sense on computer displays
//         since different monitors have different number of pixels per
//         inch. For example, Windows traditionally uses a convention that
//         there are 96 pixels per inch, thus making 'inch' measurements have
//         nothing to do with inches, and thus effectively defining a point to
//         be 1.333 pixels. Additionally, the TrueType font data provides
//         an explicit scale factor to scale a given font's glyphs to points,
//         but the author has observed that this scale factor is often wrong
//         for non-commercial fonts, thus making fonts scaled in points
//         according to the TrueType spec incoherently sized in practice.
//
// DETAILED USAGE:
//
//  Scale:
//    Select how high you want the font to be, in points or pixels.
//    Call ScaleForPixelHeight or ScaleForMappingEmToPixels to compute
//    a scale factor SF that will be used by all other functions.
//
//  Baseline:
//    You need to select a y-coordinate that is the baseline of where
//    your text will appear. Call GetFontBoundingBox to get the baseline-relative
//    bounding box for all characters. SF*-y0 will be the distance in pixels
//    that the worst-case character could extend above the baseline, so if
//    you want the top edge of characters to appear at the top of the
//    screen where y=0, then you would set the baseline to SF*-y0.
//
//  Current point:
//    Set the current point where the first character will appear. The
//    first character could extend left of the current point; this is font
//    dependent. You can either choose a current point that is the leftmost
//    point and hope, or add some padding, or check the bounding box or
//    left-side-bearing of the first character to be displayed and set
//    the current point based on that.
//
//  Displaying a character:
//    Compute the bounding box of the character. It will contain signed values
//    relative to <current_point, baseline>. I.e. if it returns x0,y0,x1,y1,
//    then the character should be displayed in the rectangle from
//    <current_point+SF*x0, baseline+SF*y0> to <current_point+SF*x1,baseline+SF*y1).
//
//  Advancing for the next character:
//    Call GlyphHMetrics, and compute 'current_point += SF * advance'.
//
//
// ADVANCED USAGE
//
//   Quality:
//
//    - Use the functions with Subpixel at the end to allow your characters
//      to have subpixel positioning. Since the font is anti-aliased, not
//      hinted, this is very import for quality. (This is not possible with
//      baked fonts.)
//
//    - Kerning is now supported, and if you're supporting subpixel rendering
//      then kerning is worth using to give your text a polished look.
//
//   Performance:
//
//    - Convert Unicode codepoints to glyph indexes and operate on the glyphs;
//      if you don't do this, stb_truetype is forced to do the conversion on
//      every call.
//
//    - There are a lot of memory allocations. We should modify it to take
//      a temp buffer and allocate from the temp buffer (without freeing),
//      should help performance a lot.
//
// NOTES
//
//   The system uses the raw data found in the .ttf file without changing it
//   and without building auxiliary data structures. This is a bit inefficient
//   on little-endian systems (the data is big-endian), but assuming you're
//   caching the bitmaps or glyph shapes this shouldn't be a big deal.
//
//   It appears to be very hard to programmatically determine what font a
//   given file is in a general way. I provide an API for this, but I don't
//   recommend it.
//
//
// PERFORMANCE MEASUREMENTS FOR 1.06:
//
//                      32-bit     64-bit
//   Previous release:  8.83 s     7.68 s
//   Pool allocations:  7.72 s     6.34 s
//   Inline sort     :  6.54 s     5.65 s
//   New rasterizer  :  5.63 s     5.00 s

//
//  Incomplete text-in-3d-api example, which draws quads properly aligned to be lossless.
//  See "tests/truetype_demo_win32.c" for a complete version.
#if 0
#define STB_TRUETYPE_IMPLEMENTATION // force following include to generate implementation
#include "stb_truetype.h"
 
unsigned char ttf_buffer[1<<20];
unsigned char temp_bitmap[512*512];
 
stbtt_bakedchar cdata[96]; // ASCII 32..126 is 95 glyphs
GLuint ftex;
 
void my_stbtt_initfont(void)
{
  fread(ttf_buffer, 1, 1<<20, fopen("c:/windows/fonts/times.ttf", "rb"));
  stbtt_BakeFontBitmap(ttf_buffer, 0, 32.0, temp_bitmap, 512, 512, 32, 96, cdata); // no guarantee this fits!
  // can free ttf_buffer at this point
  glGenTextures(1, &ftex);
  glBindTexture(GL_TEXTURE_2D, ftex);
  glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, 512, 512, 0, GL_ALPHA, GL_UNSIGNED_BYTE, temp_bitmap);
  // can free temp_bitmap at this point
  glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
}
 
void my_stbtt_print(float x, float y, char *text)
{
   // assume orthographic projection with units = screen pixels, origin at top left
  glEnable(GL_BLEND);
  glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
  glEnable(GL_TEXTURE_2D);
  glBindTexture(GL_TEXTURE_2D, ftex);
  glBegin(GL_QUADS);
  while (*text) {
    if (*text >= 32 && *text < 128) {
      stbtt_aligned_quad q;
      stbtt_GetBakedQuad(cdata, 512, 512, *text-32, &x, &y, &q, 1);//1=opengl & d3d10+,0=d3d9
      glTexCoord2f(q.s0, q.t0); glVertex2f(q.x0, q.y0);
      glTexCoord2f(q.s1, q.t0); glVertex2f(q.x1, q.y0);
      glTexCoord2f(q.s1, q.t1); glVertex2f(q.x1, q.y1);
      glTexCoord2f(q.s0, q.t1); glVertex2f(q.x0, q.y1);
    }
    ++text;
  }
  glEnd();
}
#endif
//
//
//
// Complete program (this compiles): get a single bitmap, print as ASCII art
//
#if 0
#include <stdio.h>
#define STB_TRUETYPE_IMPLEMENTATION // force following include to generate implementation
#include "stb_truetype.h"
 
char ttf_buffer[1<<25];
 
int main(int argc, char **argv)
{
  stbtt_fontinfo font;
  unsigned char *bitmap;
  int w, h, i, j, c = (argc > 1 ? atoi(argv[1]) : 'a'), s = (argc > 2 ? atoi(argv[2]) : 20);
 
  fread(ttf_buffer, 1, 1<<25, fopen(argc > 3 ? argv[3] : "c:/windows/fonts/arialbd.ttf", "rb"));
 
  stbtt_InitFont(&font, ttf_buffer, stbtt_GetFontOffsetForIndex(ttf_buffer, 0));
  bitmap = stbtt_GetCodepointBitmap(&font, 0, stbtt_ScaleForPixelHeight(&font, s), c, &w, &h, 0, 0);
 
  for (j = 0; j < h; ++j) {
    for (i = 0; i < w; ++i)
      putchar(" .:ioVM@"[bitmap[j*w+i]>>5]);
    putchar('\n');
  }
  return 0;
}
#endif
//
// Output:
//
//     .ii.
//    @@@@@@.
//   V@Mio@@o
//   :i.  V@V
//     :oM@@M
//   :@@@MM@M
//   @@o  o@M
//  :@@.  M@M
//   @@@o@@@@
//   :M@@V:@@.
//
//
// Complete program: print "Hello World!" banner, with bugs
//
#if 0
char buffer[24<<20];
unsigned char screen[20][79];
 
int main(int arg, char **argv)
{
  stbtt_fontinfo font;
  int i, j, ascent, baseline, ch = 0;
  float scale, xpos = 2; // leave a little padding in case the character extends left
  char *text = "Heljo World!"; // intentionally misspelled to show 'lj' brokenness
 
  fread(buffer, 1, 1000000, fopen("c:/windows/fonts/arialbd.ttf", "rb"));
  stbtt_InitFont(&font, buffer, 0);
 
  scale = stbtt_ScaleForPixelHeight(&font, 15);
  stbtt_GetFontVMetrics(&font, &ascent, 0, 0);
  baseline = static_cast<int>(ascent*scale);
 
  while (text[ch]) {
    int advance, lsb, x0, y0, x1, y1;
    float x_shift = xpos - (float)floor(xpos);
    stbtt_GetCodepointHMetrics(&font, text[ch], &advance, &lsb);
    stbtt_GetCodepointBitmapBoxSubpixel(&font, text[ch], scale, scale, x_shift, 0, &x0, &y0, &x1, &y1);
    stbtt_MakeCodepointBitmapSubpixel(&font, &screen[baseline + y0][static_cast<int>(xpos) + x0], x1-x0, y1-y0, 79, scale, scale, x_shift, 0, text[ch]);
    // note that this stomps the old data, so where character boxes overlap (e.g. 'lj') it's wrong
    // because this API is really for baking character bitmaps into textures. if you want to render
    // a sequence of characters, you really need to render each bitmap to a temp buffer, then
    // "alpha blend" that into the working buffer
    xpos += (advance * scale);
    if (text[ch+1])
      xpos += scale*stbtt_GetCodepointKernAdvance(&font, text[ch], text[ch+1]);
    ++ch;
  }
 
  for (j = 0; j < 20; ++j) {
    for (i = 0; i < 78; ++i)
      putchar(" .:ioVM@"[screen[j][i]>>5]);
    putchar('\n');
  }
 
  return 0;
}
#endif

#ifndef DOXYGEN_SHOULD_SKIP_THIS
 
#ifdef STB_TRUETYPE_IMPLEMENTATION
// #define your own (u)stbtt_int8/16/32 before including to override this
#ifndef stbtt_uint8
typedef unsigned char stbtt_uint8;
typedef signed char stbtt_int8;
typedef unsigned short stbtt_uint16;
typedef signed short stbtt_int16;
typedef unsigned int stbtt_uint32;
typedef signed int stbtt_int32;
#endif
 
typedef char stbtt__check_size32[sizeof(stbtt_int32) == 4 ? 1 : -1];
typedef char stbtt__check_size16[sizeof(stbtt_int16) == 2 ? 1 : -1];
 
// e.g. #define your own STBTT_ifloor/STBTT_iceil() to avoid math.h
#ifndef STBTT_ifloor
#include <math.h>
#define STBTT_ifloor(x) ((int)floor(x))
#define STBTT_iceil(x) ((int)ceil(x))
#endif
 
#ifndef STBTT_sqrt
#include <math.h>
#define STBTT_sqrt(x) sqrt(x)
#define STBTT_pow(x, y) pow(x, y)
#endif
 
#ifndef STBTT_fmod
#include <math.h>
#define STBTT_fmod(x, y) fmod(x, y)
#endif
 
#ifndef STBTT_cos
#include <math.h>
#define STBTT_cos(x) cos(x)
#define STBTT_acos(x) acos(x)
#endif
 
#ifndef STBTT_fabs
#include <math.h>
#define STBTT_fabs(x) fabs(x)
#endif
 
// #define your own functions "STBTT_malloc" / "STBTT_free" to avoid malloc.h
#ifndef STBTT_malloc
#include <stdlib.h>
#define STBTT_malloc(x, u) ((void)(u), malloc(x))
#define STBTT_free(x, u) ((void)(u), free(x))
#endif
 
#ifndef STBTT_assert
#include <assert.h>
#define STBTT_assert(x) assert(x)
#endif
 
#ifndef STBTT_strlen
#include <string.h>
#define STBTT_strlen(x) strlen(x)
#endif
 
#ifndef STBTT_memcpy
#include <string.h>
#define STBTT_memcpy memcpy
#define STBTT_memset memset
#endif
#endif

 
#ifndef __STB_INCLUDE_STB_TRUETYPE_H__
#define __STB_INCLUDE_STB_TRUETYPE_H__
 
#ifdef STBTT_STATIC
#define STBTT_DEF static
#else
#define STBTT_DEF extern
#endif
 
#ifdef __cplusplus
extern "C" {
#endif
 
// private structure
  typedef struct
  {
    unsigned char *data;
    int cursor;
    int size;
  } stbtt__buf;

  //
  // TEXTURE BAKING API
  //
  // If you use this API, you only have to call two functions ever.
  //
 
  typedef struct
  {
    unsigned short x0, y0, x1, y1; // coordinates of bbox in bitmap
    float xoff, yoff, xadvance;
  } stbtt_bakedchar;
 
  STBTT_DEF int stbtt_BakeFontBitmap(const unsigned char *data, int offset, // font location (use offset=0 for plain .ttf)
                                     float pixel_height,                    // height of font in pixels
                                     unsigned char *pixels, int pw, int ph, // bitmap to be filled in
                                     int first_char, int num_chars,         // characters to bake
                                     stbtt_bakedchar *chardata);            // you allocate this, it's num_chars long
  // if return is positive, the first unused row of the bitmap
  // if return is negative, returns the negative of the number of characters that fit
  // if return is 0, no characters fit and no rows were used
  // This uses a very crappy packing.
 
  typedef struct
  {
    float x0, y0, s0, t0; // top-left
    float x1, y1, s1, t1; // bottom-right
  } stbtt_aligned_quad;
 
  STBTT_DEF void stbtt_GetBakedQuad(const stbtt_bakedchar *chardata, int pw, int ph, // same data as above
                                    int char_index,                                  // character to display
                                    float *xpos, float *ypos, // pointers to current position in screen pixel space
                                    stbtt_aligned_quad *q,    // output: quad to draw
                                    int opengl_fillrule);     // true if opengl fill rule; false if DX9 or earlier
  // Call GetBakedQuad with char_index = 'character - first_char', and it
  // creates the quad you need to draw and advances the current position.
  //
  // The coordinate system used assumes y increases downwards.
  //
  // Characters will extend both above and below the current position;
  // see discussion of "BASELINE" above.
  //
  // It's inefficient; you might want to c&p it and optimize it.
 
  STBTT_DEF void stbtt_GetScaledFontVMetrics(const unsigned char *fontdata, int index, float size, float *ascent,
                                             float *descent, float *lineGap);
  // Query the font vertical metrics without having to create a font first.

  //
  // NEW TEXTURE BAKING API
  //
  // This provides options for packing multiple fonts into one atlas, not
  // perfectly but better than nothing.
 
  typedef struct
  {
    unsigned short x0, y0, x1, y1; // coordinates of bbox in bitmap
    float xoff, yoff, xadvance;
    float xoff2, yoff2;
  } stbtt_packedchar;
 
  typedef struct stbtt_pack_context stbtt_pack_context;
  typedef struct stbtt_fontinfo stbtt_fontinfo;
#ifndef STB_RECT_PACK_VERSION
  typedef struct stbrp_rect stbrp_rect;
#endif
 
  STBTT_DEF int stbtt_PackBegin(stbtt_pack_context *spc, unsigned char *pixels, int width, int height,
                                int stride_in_bytes, int padding, void *alloc_context);
  // Initializes a packing context stored in the passed-in stbtt_pack_context.
  // Future calls using this context will pack characters into the bitmap passed
  // in here: a 1-channel bitmap that is width * height. stride_in_bytes is
  // the distance from one row to the next (or 0 to mean they are packed tightly
  // together). "padding" is the amount of padding to leave between each
  // character (normally you want '1' for bitmaps you'll use as textures with
  // bilinear filtering).
  //
  // Returns 0 on failure, 1 on success.
 
  STBTT_DEF void stbtt_PackEnd(stbtt_pack_context *spc);
  // Cleans up the packing context and frees all memory.
 
#define STBTT_POINT_SIZE(x) (-(x))
 
  STBTT_DEF int stbtt_PackFontRange(stbtt_pack_context *spc, const unsigned char *fontdata, int font_index,
                                    float font_size, int first_unicode_char_in_range, int num_chars_in_range,
                                    stbtt_packedchar *chardata_for_range);
  // Creates character bitmaps from the font_index'th font found in fontdata (use
  // font_index=0 if you don't know what that is). It creates num_chars_in_range
  // bitmaps for characters with unicode values starting at first_unicode_char_in_range
  // and increasing. Data for how to render them is stored in chardata_for_range;
  // pass these to stbtt_GetPackedQuad to get back renderable quads.
  //
  // font_size is the full height of the character from ascender to descender,
  // as computed by stbtt_ScaleForPixelHeight. To use a point size as computed
  // by stbtt_ScaleForMappingEmToPixels, wrap the point size in STBTT_POINT_SIZE()
  // and pass that result as 'font_size':
  //       ...,                  20 , ... // font max minus min y is 20 pixels tall
  //       ..., STBTT_POINT_SIZE(20), ... // 'M' is 20 pixels tall
 
  typedef struct
  {
    float font_size;
    int first_unicode_codepoint_in_range; // if non-zero, then the chars are continuous, and this is the first codepoint
    int *array_of_unicode_codepoints;     // if non-zero, then this is an array of unicode codepoints
    int num_chars;
    stbtt_packedchar *chardata_for_range;     // output
    unsigned char h_oversample, v_oversample; // don't set these, they're used internally
  } stbtt_pack_range;
 
  STBTT_DEF int stbtt_PackFontRanges(stbtt_pack_context *spc, const unsigned char *fontdata, int font_index,
                                     stbtt_pack_range *ranges, int num_ranges);
  // Creates character bitmaps from multiple ranges of characters stored in
  // ranges. This will usually create a better-packed bitmap than multiple
  // calls to stbtt_PackFontRange. Note that you can call this multiple
  // times within a single PackBegin/PackEnd.
 
  STBTT_DEF void stbtt_PackSetOversampling(stbtt_pack_context *spc, unsigned int h_oversample, unsigned int v_oversample);
  // Oversampling a font increases the quality by allowing higher-quality subpixel
  // positioning, and is especially valuable at smaller text sizes.
  //
  // This function sets the amount of oversampling for all following calls to
  // stbtt_PackFontRange(s) or stbtt_PackFontRangesGatherRects for a given
  // pack context. The default (no oversampling) is achieved by h_oversample=1
  // and v_oversample=1. The total number of pixels required is
  // h_oversample*v_oversample larger than the default; for example, 2x2
  // oversampling requires 4x the storage of 1x1. For best results, render
  // oversampled textures with bilinear filtering. Look at the readme in
  // stb/tests/oversample for information about oversampled fonts
  //
  // To use with PackFontRangesGather etc., you must set it before calls
  // call to PackFontRangesGatherRects.
 
  STBTT_DEF void stbtt_PackSetSkipMissingCodepoints(stbtt_pack_context *spc, int skip);
  // If skip != 0, this tells stb_truetype to skip any codepoints for which
  // there is no corresponding glyph. If skip=0, which is the default, then
  // codepoints without a glyph recived the font's "missing character" glyph,
  // typically an empty box by convention.
 
  STBTT_DEF void stbtt_GetPackedQuad(const stbtt_packedchar *chardata, int pw, int ph, // same data as above
                                     int char_index,                                   // character to display
                                     float *xpos, float *ypos, // pointers to current position in screen pixel space
                                     stbtt_aligned_quad *q,    // output: quad to draw
                                     int align_to_integer);
 
  STBTT_DEF int stbtt_PackFontRangesGatherRects(stbtt_pack_context *spc, const stbtt_fontinfo *info,
                                                stbtt_pack_range *ranges, int num_ranges, stbrp_rect *rects);
  STBTT_DEF void stbtt_PackFontRangesPackRects(stbtt_pack_context *spc, stbrp_rect *rects, int num_rects);
  STBTT_DEF int stbtt_PackFontRangesRenderIntoRects(stbtt_pack_context *spc, const stbtt_fontinfo *info,
                                                    stbtt_pack_range *ranges, int num_ranges, stbrp_rect *rects);
  // Calling these functions in sequence is roughly equivalent to calling
  // stbtt_PackFontRanges(). If you more control over the packing of multiple
  // fonts, or if you want to pack custom data into a font texture, take a look
  // at the source to of stbtt_PackFontRanges() and create a custom version
  // using these functions, e.g. call GatherRects multiple times,
  // building up a single array of rects, then call PackRects once,
  // then call RenderIntoRects repeatedly. This may result in a
  // better packing than calling PackFontRanges multiple times
  // (or it may not).
 
  // this is an opaque structure that you shouldn't mess with which holds
  // all the context needed from PackBegin to PackEnd.
  struct stbtt_pack_context
  {
    void *user_allocator_context;
    void *pack_info;
    int width;
    int height;
    int stride_in_bytes;
    int padding;
    int skip_missing;
    unsigned int h_oversample, v_oversample;
    unsigned char *pixels;
    void *nodes;
  };

  //
  // FONT LOADING
  //
  //
 
  STBTT_DEF int stbtt_GetNumberOfFonts(const unsigned char *data);
  // This function will determine the number of fonts in a font file.  TrueType
  // collection (.ttc) files may contain multiple fonts, while TrueType font
  // (.ttf) files only contain one font. The number of fonts can be used for
  // indexing with the previous function where the index is between zero and one
  // less than the total fonts. If an error occurs, -1 is returned.
 
  STBTT_DEF int stbtt_GetFontOffsetForIndex(const unsigned char *data, int index);
  // Each .ttf/.ttc file may have more than one font. Each font has a sequential
  // index number starting from 0. Call this function to get the font offset for
  // a given index; it returns -1 if the index is out of range. A regular .ttf
  // file will only define one font and it always be at offset 0, so it will
  // return '0' for index 0, and -1 for all other indices.
 
  // The following structure is defined publicly so you can declare one on
  // the stack or as a global or etc, but you should treat it as opaque.
  struct stbtt_fontinfo
  {
    void *userdata;
    unsigned char *data; // pointer to .ttf file
    int fontstart;       // offset of start of font
 
    int numGlyphs; // number of glyphs, needed for range checking
 
    int loca, head, glyf, hhea, hmtx, kern, gpos, svg; // table locations as offset from start of .ttf
    int index_map;                                     // a cmap mapping for our chosen character encoding
    int indexToLocFormat;                              // format needed to map from glyph index to glyph
 
    stbtt__buf cff;         // cff font data
    stbtt__buf charstrings; // the charstring index
    stbtt__buf gsubrs;      // global charstring subroutines index
    stbtt__buf subrs;       // private charstring subroutines index
    stbtt__buf fontdicts;   // array of font dicts
    stbtt__buf fdselect;    // map from glyph to fontdict
  };
 
  STBTT_DEF int stbtt_InitFont(stbtt_fontinfo *info, const unsigned char *data, int offset);
  // Given an offset into the file that defines a font, this function builds
  // the necessary cached info for the rest of the system. You must allocate
  // the stbtt_fontinfo yourself, and stbtt_InitFont will fill it out. You don't
  // need to do anything special to free it, because the contents are pure
  // value data with no additional data structures. Returns 0 on failure.

  //
  // CHARACTER TO GLYPH-INDEX CONVERSIOn
 
  STBTT_DEF int stbtt_FindGlyphIndex(const stbtt_fontinfo *info, int unicode_codepoint);
  // If you're going to perform multiple operations on the same character
  // and you want a speed-up, call this function with the character you're
  // going to process, then use glyph-based functions instead of the
  // codepoint-based functions.
  // Returns 0 if the character codepoint is not defined in the font.

  //
  // CHARACTER PROPERTIES
  //
 
  STBTT_DEF float stbtt_ScaleForPixelHeight(const stbtt_fontinfo *info, float pixels);
  // computes a scale factor to produce a font whose "height" is 'pixels' tall.
  // Height is measured as the distance from the highest ascender to the lowest
  // descender; in other words, it's equivalent to calling stbtt_GetFontVMetrics
  // and computing:
  //       scale = pixels / (ascent - descent)
  // so if you prefer to measure height by the ascent only, use a similar calculation.
 
  STBTT_DEF float stbtt_ScaleForMappingEmToPixels(const stbtt_fontinfo *info, float pixels);
  // computes a scale factor to produce a font whose EM size is mapped to
  // 'pixels' tall. This is probably what traditional APIs compute, but
  // I'm not positive.
 
  STBTT_DEF void stbtt_GetFontVMetrics(const stbtt_fontinfo *info, int *ascent, int *descent, int *lineGap);
  // ascent is the coordinate above the baseline the font extends; descent
  // is the coordinate below the baseline the font extends (i.e. it is typically negative)
  // lineGap is the spacing between one row's descent and the next row's ascent...
  // so you should advance the vertical position by "*ascent - *descent + *lineGap"
  //   these are expressed in unscaled coordinates, so you must multiply by
  //   the scale factor for a given size
 
  STBTT_DEF int stbtt_GetFontVMetricsOS2(const stbtt_fontinfo *info, int *typoAscent, int *typoDescent, int *typoLineGap);
  // analogous to GetFontVMetrics, but returns the "typographic" values from the OS/2
  // table (specific to MS/Windows TTF files).
  //
  // Returns 1 on success (table present), 0 on failure.
 
  STBTT_DEF void stbtt_GetFontBoundingBox(const stbtt_fontinfo *info, int *x0, int *y0, int *x1, int *y1);
  // the bounding box around all possible characters
 
  STBTT_DEF void stbtt_GetCodepointHMetrics(const stbtt_fontinfo *info, int codepoint, int *advanceWidth,
                                            int *leftSideBearing);
  // leftSideBearing is the offset from the current horizontal position to the left edge of the character
  // advanceWidth is the offset from the current horizontal position to the next horizontal position
  //   these are expressed in unscaled coordinates
 
  STBTT_DEF int stbtt_GetCodepointKernAdvance(const stbtt_fontinfo *info, int ch1, int ch2);
  // an additional amount to add to the 'advance' value between ch1 and ch2
 
  STBTT_DEF int stbtt_GetCodepointBox(const stbtt_fontinfo *info, int codepoint, int *x0, int *y0, int *x1, int *y1);
  // Gets the bounding box of the visible part of the glyph, in unscaled coordinates
 
  STBTT_DEF void stbtt_GetGlyphHMetrics(const stbtt_fontinfo *info, int glyph_index, int *advanceWidth,
                                        int *leftSideBearing);
  STBTT_DEF int stbtt_GetGlyphKernAdvance(const stbtt_fontinfo *info, int glyph1, int glyph2);
  STBTT_DEF int stbtt_GetGlyphBox(const stbtt_fontinfo *info, int glyph_index, int *x0, int *y0, int *x1, int *y1);
  // as above, but takes one or more glyph indices for greater efficiency
 
  typedef struct stbtt_kerningentry
  {
    int glyph1; // use stbtt_FindGlyphIndex
    int glyph2;
    int advance;
  } stbtt_kerningentry;
 
  STBTT_DEF int stbtt_GetKerningTableLength(const stbtt_fontinfo *info);
  STBTT_DEF int stbtt_GetKerningTable(const stbtt_fontinfo *info, stbtt_kerningentry *table, int table_length);
  // Retrieves a complete list of all of the kerning pairs provided by the font
  // stbtt_GetKerningTable never writes more than table_length entries and returns how many entries it did write.
  // The table will be sorted by (a.glyph1 == b.glyph1)?(a.glyph2 < b.glyph2):(a.glyph1 < b.glyph1)

  //
  // GLYPH SHAPES (you probably don't need these, but they have to go before
  // the bitmaps for C declaration-order reasons)
  //
 
#ifndef STBTT_vmove // you can predefine these to use different values (but why?)
  enum { STBTT_vmove = 1, STBTT_vline, STBTT_vcurve, STBTT_vcubic };
#endif
 
#ifndef stbtt_vertex            // you can predefine this to use different values
                                // (we share this with other code at RAD)
#define stbtt_vertex_type short // can't use stbtt_int16 because that's not visible in the header file
  typedef struct
  {
    stbtt_vertex_type x, y, cx, cy, cx1, cy1;
    unsigned char type, padding;
  } stbtt_vertex;
#endif
 
  STBTT_DEF int stbtt_IsGlyphEmpty(const stbtt_fontinfo *info, int glyph_index);
  // returns non-zero if nothing is drawn for this glyph
 
  STBTT_DEF int stbtt_GetCodepointShape(const stbtt_fontinfo *info, int unicode_codepoint, stbtt_vertex **vertices);
  STBTT_DEF int stbtt_GetGlyphShape(const stbtt_fontinfo *info, int glyph_index, stbtt_vertex **vertices);
  // returns # of vertices and fills *vertices with the pointer to them
  //   these are expressed in "unscaled" coordinates
  //
  // The shape is a series of contours. Each one starts with
  // a STBTT_moveto, then consists of a series of mixed
  // STBTT_lineto and STBTT_curveto segments. A lineto
  // draws a line from previous endpoint to its x,y; a curveto
  // draws a quadratic bezier from previous endpoint to
  // its x,y, using cx,cy as the bezier control point.
 
  STBTT_DEF void stbtt_FreeShape(const stbtt_fontinfo *info, stbtt_vertex *vertices);
  // frees the data allocated above
 
  STBTT_DEF unsigned char *stbtt_FindSVGDoc(const stbtt_fontinfo *info, int gl);
  STBTT_DEF int stbtt_GetCodepointSVG(const stbtt_fontinfo *info, int unicode_codepoint, const char **svg);
  STBTT_DEF int stbtt_GetGlyphSVG(const stbtt_fontinfo *info, int gl, const char **svg);
  // fills svg with the character's SVG data.
  // returns data size or 0 if SVG not found.

  //
  // BITMAP RENDERING
  //
 
  STBTT_DEF void stbtt_FreeBitmap(unsigned char *bitmap, void *userdata);
  // frees the bitmap allocated below
 
  STBTT_DEF unsigned char *stbtt_GetCodepointBitmap(const stbtt_fontinfo *info, float scale_x, float scale_y,
                                                    int codepoint, int *width, int *height, int *xoff, int *yoff);
  // allocates a large-enough single-channel 8bpp bitmap and renders the
  // specified character/glyph at the specified scale into it, with
  // antialiasing. 0 is no coverage (transparent), 255 is fully covered (opaque).
  // *width & *height are filled out with the width & height of the bitmap,
  // which is stored left-to-right, top-to-bottom.
  //
  // xoff/yoff are the offset it pixel space from the glyph origin to the top-left of the bitmap
 
  STBTT_DEF unsigned char *stbtt_GetCodepointBitmapSubpixel(const stbtt_fontinfo *info, float scale_x, float scale_y,
                                                            float shift_x, float shift_y, int codepoint, int *width,
                                                            int *height, int *xoff, int *yoff);
  // the same as stbtt_GetCodepoitnBitmap, but you can specify a subpixel
  // shift for the character
 
  STBTT_DEF void stbtt_MakeCodepointBitmap(const stbtt_fontinfo *info, unsigned char *output, int out_w, int out_h,
                                           int out_stride, float scale_x, float scale_y, int codepoint);
  // the same as stbtt_GetCodepointBitmap, but you pass in storage for the bitmap
  // in the form of 'output', with row spacing of 'out_stride' bytes. the bitmap
  // is clipped to out_w/out_h bytes. Call stbtt_GetCodepointBitmapBox to get the
  // width and height and positioning info for it first.
 
  STBTT_DEF void stbtt_MakeCodepointBitmapSubpixel(const stbtt_fontinfo *info, unsigned char *output, int out_w,
                                                   int out_h, int out_stride, float scale_x, float scale_y, float shift_x,
                                                   float shift_y, int codepoint);
  // same as stbtt_MakeCodepointBitmap, but you can specify a subpixel
  // shift for the character
 
  STBTT_DEF void stbtt_MakeCodepointBitmapSubpixelPrefilter(const stbtt_fontinfo *info, unsigned char *output, int out_w,
                                                            int out_h, int out_stride, float scale_x, float scale_y,
                                                            float shift_x, float shift_y, int oversample_x,
                                                            int oversample_y, float *sub_x, float *sub_y, int codepoint);
  // same as stbtt_MakeCodepointBitmapSubpixel, but prefiltering
  // is performed (see stbtt_PackSetOversampling)
 
  STBTT_DEF void stbtt_GetCodepointBitmapBox(const stbtt_fontinfo *font, int codepoint, float scale_x, float scale_y,
                                             int *ix0, int *iy0, int *ix1, int *iy1);
  // get the bbox of the bitmap centered around the glyph origin; so the
  // bitmap width is ix1-ix0, height is iy1-iy0, and location to place
  // the bitmap top left is (leftSideBearing*scale,iy0).
  // (Note that the bitmap uses y-increases-down, but the shape uses
  // y-increases-up, so CodepointBitmapBox and CodepointBox are inverted.)
 
  STBTT_DEF void stbtt_GetCodepointBitmapBoxSubpixel(const stbtt_fontinfo *font, int codepoint, float scale_x,
                                                     float scale_y, float shift_x, float shift_y, int *ix0, int *iy0,
                                                     int *ix1, int *iy1);
  // same as stbtt_GetCodepointBitmapBox, but you can specify a subpixel
  // shift for the character
 
  // the following functions are equivalent to the above functions, but operate
  // on glyph indices instead of Unicode codepoints (for efficiency)
  STBTT_DEF unsigned char *stbtt_GetGlyphBitmap(const stbtt_fontinfo *info, float scale_x, float scale_y, int glyph,
                                                int *width, int *height, int *xoff, int *yoff);
  STBTT_DEF unsigned char *stbtt_GetGlyphBitmapSubpixel(const stbtt_fontinfo *info, float scale_x, float scale_y,
                                                        float shift_x, float shift_y, int glyph, int *width, int *height,
                                                        int *xoff, int *yoff);
  STBTT_DEF void stbtt_MakeGlyphBitmap(const stbtt_fontinfo *info, unsigned char *output, int out_w, int out_h,
                                       int out_stride, float scale_x, float scale_y, int glyph);
  STBTT_DEF void stbtt_MakeGlyphBitmapSubpixel(const stbtt_fontinfo *info, unsigned char *output, int out_w, int out_h,
                                               int out_stride, float scale_x, float scale_y, float shift_x, float shift_y,
                                               int glyph);
  STBTT_DEF void stbtt_MakeGlyphBitmapSubpixelPrefilter(const stbtt_fontinfo *info, unsigned char *output, int out_w,
                                                        int out_h, int out_stride, float scale_x, float scale_y,
                                                        float shift_x, float shift_y, int oversample_x, int oversample_y,
                                                        float *sub_x, float *sub_y, int glyph);
  STBTT_DEF void stbtt_GetGlyphBitmapBox(const stbtt_fontinfo *font, int glyph, float scale_x, float scale_y, int *ix0,
                                         int *iy0, int *ix1, int *iy1);
  STBTT_DEF void stbtt_GetGlyphBitmapBoxSubpixel(const stbtt_fontinfo *font, int glyph, float scale_x, float scale_y,
                                                 float shift_x, float shift_y, int *ix0, int *iy0, int *ix1, int *iy1);
 
  // @TODO: don't expose this structure
  typedef struct
  {
    int w, h, stride;
    unsigned char *pixels;
  } stbtt__bitmap;
 
  // rasterize a shape with quadratic beziers into a bitmap
  STBTT_DEF void stbtt_Rasterize(stbtt__bitmap *result,        // 1-channel bitmap to draw into
                                 float flatness_in_pixels,     // allowable error of curve in pixels
                                 stbtt_vertex *vertices,       // array of vertices defining shape
                                 int num_verts,                // number of vertices in above array
                                 float scale_x, float scale_y, // scale applied to input vertices
                                 float shift_x, float shift_y, // translation applied to input vertices
                                 int x_off, int y_off,         // another translation applied to input
                                 int invert,                   // if non-zero, vertically flip shape
                                 void *userdata);              // context for to STBTT_MALLOC

  //
  // Signed Distance Function (or Field) rendering
 
  STBTT_DEF void stbtt_FreeSDF(unsigned char *bitmap, void *userdata);
  // frees the SDF bitmap allocated below
 
  STBTT_DEF unsigned char *stbtt_GetGlyphSDF(const stbtt_fontinfo *info, float scale, int glyph, int padding,
                                             unsigned char onedge_value, float pixel_dist_scale, int *width, int *height,
                                             int *xoff, int *yoff);
  STBTT_DEF unsigned char *stbtt_GetCodepointSDF(const stbtt_fontinfo *info, float scale, int codepoint, int padding,
                                                 unsigned char onedge_value, float pixel_dist_scale, int *width,
                                                 int *height, int *xoff, int *yoff);
  // These functions compute a discretized SDF field for a single character, suitable for storing
  // in a single-channel texture, sampling with bilinear filtering, and testing against
  // larger than some threshold to produce scalable fonts.
  //        info              --  the font
  //        scale             --  controls the size of the resulting SDF bitmap, same as it would be creating a regular
  //        bitmap glyph/codepoint   --  the character to generate the SDF for padding           --  extra "pixels" around
  //        the character which are filled with the distance to the character (not 0),
  //                                 which allows effects like bit outlines
  //        onedge_value      --  value 0-255 to test the SDF against to reconstruct the character (i.e. the isocontour of
  //        the character) pixel_dist_scale  --  what value the SDF should increase by when moving one SDF "pixel" away
  //        from the edge (on the 0..255 scale)
  //                                 if positive, > onedge_value is inside; if negative, < onedge_value is inside
  //        width,height      --  output height & width of the SDF bitmap (including padding)
  //        xoff,yoff         --  output origin of the character
  //        return value      --  a 2D array of bytes 0..255, width*height in size
  //
  // pixel_dist_scale & onedge_value are a scale & bias that allows you to make
  // optimal use of the limited 0..255 for your application, trading off precision
  // and special effects. SDF values outside the range 0..255 are clamped to 0..255.
  //
  // Example:
  //      scale = stbtt_ScaleForPixelHeight(22)
  //      padding = 5
  //      onedge_value = 180
  //      pixel_dist_scale = 180/5.0 = 36.0
  //
  //      This will create an SDF bitmap in which the character is about 22 pixels
  //      high but the whole bitmap is about 22+5+5=32 pixels high. To produce a filled
  //      shape, sample the SDF at each pixel and fill the pixel if the SDF value
  //      is greater than or equal to 180/255. (You'll actually want to antialias,
  //      which is beyond the scope of this example.) Additionally, you can compute
  //      offset outlines (e.g. to stroke the character border inside & outside,
  //      or only outside). For example, to fill outside the character up to 3 SDF
  //      pixels, you would compare against (180-36.0*3)/255 = 72/255. The above
  //      choice of variables maps a range from 5 pixels outside the shape to
  //      2 pixels inside the shape to 0..255; this is intended primarily for apply
  //      outside effects only (the interior range is needed to allow proper
  //      antialiasing of the font at *smaller* sizes)
  //
  // The function computes the SDF analytically at each SDF pixel, not by e.g.
  // building a higher-res bitmap and approximating it. In theory the quality
  // should be as high as possible for an SDF of this size & representation, but
  // unclear if this is true in practice (perhaps building a higher-res bitmap
  // and computing from that can allow drop-out prevention).
  //
  // The algorithm has not been optimized at all, so expect it to be slow
  // if computing lots of characters or very large sizes.

  //
  // Finding the right font...
  //
  // You should really just solve this offline, keep your own tables
  // of what font is what, and don't try to get it out of the .ttf file.
  // That's because getting it out of the .ttf file is really hard, because
  // the names in the file can appear in many possible encodings, in many
  // possible languages, and e.g. if you need a case-insensitive comparison,
  // the details of that depend on the encoding & language in a complex way
  // (actually underspecified in truetype, but also gigantic).
  //
  // But you can use the provided functions in two possible ways:
  //     stbtt_FindMatchingFont() will use *case-sensitive* comparisons on
  //             unicode-encoded names to try to find the font you want;
  //             you can run this before calling stbtt_InitFont()
  //
  //     stbtt_GetFontNameString() lets you get any of the various strings
  //             from the file yourself and do your own comparisons on them.
  //             You have to have called stbtt_InitFont() first.
 
  STBTT_DEF int stbtt_FindMatchingFont(const unsigned char *fontdata, const char *name, int flags);
  // returns the offset (not index) of the font that matches, or -1 if none
  //   if you use STBTT_MACSTYLE_DONTCARE, use a font name like "Arial Bold".
  //   if you use any other flag, use a font name like "Arial"; this checks
  //     the 'macStyle' header field; i don't know if fonts set this consistently
#define STBTT_MACSTYLE_DONTCARE 0
#define STBTT_MACSTYLE_BOLD 1
#define STBTT_MACSTYLE_ITALIC 2
#define STBTT_MACSTYLE_UNDERSCORE 4
#define STBTT_MACSTYLE_NONE 8 // <= not same as 0, this makes us check the bitfield is 0
 
  STBTT_DEF int stbtt_CompareUTF8toUTF16_bigendian(const char *s1, int len1, const char *s2, int len2);
  // returns 1/0 whether the first string interpreted as utf8 is identical to
  // the second string interpreted as big-endian utf16... useful for strings from next func
 
  STBTT_DEF const char *stbtt_GetFontNameString(const stbtt_fontinfo *font, int *length, int platformID, int encodingID,
                                                int languageID, int nameID);
  // returns the string (which may be big-endian double byte, e.g. for unicode)
  // and puts the length in bytes in *length.
  //
  // some of the values for the IDs are below; for more see the truetype spec:
  //     http://developer.apple.com/textfonts/TTRefMan/RM06/Chap6name.html
  //     http://www.microsoft.com/typography/otspec/name.htm
 
  enum
  { // platformID
    STBTT_PLATFORM_ID_UNICODE = 0,
    STBTT_PLATFORM_ID_MAC = 1,
    STBTT_PLATFORM_ID_ISO = 2,
    STBTT_PLATFORM_ID_MICROSOFT = 3
  };
 
  enum
  { // encodingID for STBTT_PLATFORM_ID_UNICODE
    STBTT_UNICODE_EID_UNICODE_1_0 = 0,
    STBTT_UNICODE_EID_UNICODE_1_1 = 1,
    STBTT_UNICODE_EID_ISO_10646 = 2,
    STBTT_UNICODE_EID_UNICODE_2_0_BMP = 3,
    STBTT_UNICODE_EID_UNICODE_2_0_FULL = 4
  };
 
  enum
  { // encodingID for STBTT_PLATFORM_ID_MICROSOFT
    STBTT_MS_EID_SYMBOL = 0,
    STBTT_MS_EID_UNICODE_BMP = 1,
    STBTT_MS_EID_SHIFTJIS = 2,
    STBTT_MS_EID_UNICODE_FULL = 10
  };
 
  enum
  { // encodingID for STBTT_PLATFORM_ID_MAC; same as Script Manager codes
    STBTT_MAC_EID_ROMAN = 0,
    STBTT_MAC_EID_ARABIC = 4,
    STBTT_MAC_EID_JAPANESE = 1,
    STBTT_MAC_EID_HEBREW = 5,
    STBTT_MAC_EID_CHINESE_TRAD = 2,
    STBTT_MAC_EID_GREEK = 6,
    STBTT_MAC_EID_KOREAN = 3,
    STBTT_MAC_EID_RUSSIAN = 7
  };
 
  enum
  { // languageID for STBTT_PLATFORM_ID_MICROSOFT; same as LCID...
   // problematic because there are e.g. 16 english LCIDs and 16 arabic LCIDs
    STBTT_MS_LANG_ENGLISH = 0x0409,
    STBTT_MS_LANG_ITALIAN = 0x0410,
    STBTT_MS_LANG_CHINESE = 0x0804,
    STBTT_MS_LANG_JAPANESE = 0x0411,
    STBTT_MS_LANG_DUTCH = 0x0413,
    STBTT_MS_LANG_KOREAN = 0x0412,
    STBTT_MS_LANG_FRENCH = 0x040c,
    STBTT_MS_LANG_RUSSIAN = 0x0419,
    STBTT_MS_LANG_GERMAN = 0x0407,
    STBTT_MS_LANG_SPANISH = 0x0409,
    STBTT_MS_LANG_HEBREW = 0x040d,
    STBTT_MS_LANG_SWEDISH = 0x041D
  };
 
  enum
  { // languageID for STBTT_PLATFORM_ID_MAC
    STBTT_MAC_LANG_ENGLISH = 0,
    STBTT_MAC_LANG_JAPANESE = 11,
    STBTT_MAC_LANG_ARABIC = 12,
    STBTT_MAC_LANG_KOREAN = 23,
    STBTT_MAC_LANG_DUTCH = 4,
    STBTT_MAC_LANG_RUSSIAN = 32,
    STBTT_MAC_LANG_FRENCH = 1,
    STBTT_MAC_LANG_SPANISH = 6,
    STBTT_MAC_LANG_GERMAN = 2,
    STBTT_MAC_LANG_SWEDISH = 5,
    STBTT_MAC_LANG_HEBREW = 10,
    STBTT_MAC_LANG_CHINESE_SIMPLIFIED = 33,
    STBTT_MAC_LANG_ITALIAN = 3,
    STBTT_MAC_LANG_CHINESE_TRAD = 19
  };
 
#ifdef __cplusplus
}
#endif
 
#endif // __STB_INCLUDE_STB_TRUETYPE_H__

 
#ifdef STB_TRUETYPE_IMPLEMENTATION
 
#ifndef STBTT_MAX_OVERSAMPLE
#define STBTT_MAX_OVERSAMPLE 8
#endif
 
#if STBTT_MAX_OVERSAMPLE > 255
#error "STBTT_MAX_OVERSAMPLE cannot be > 255"
#endif
 
typedef int stbtt__test_oversample_pow2[(STBTT_MAX_OVERSAMPLE & (STBTT_MAX_OVERSAMPLE - 1)) == 0 ? 1 : -1];
 
#ifndef STBTT_RASTERIZER_VERSION
#define STBTT_RASTERIZER_VERSION 2
#endif
 
#ifdef _MSC_VER
#define STBTT__NOTUSED(v) (void)(v)
#else
#define STBTT__NOTUSED(v) (void)sizeof(v)
#endif

//
// stbtt__buf helpers to parse data from file
//
 
static stbtt_uint8 stbtt__buf_get8(stbtt__buf *b)
{
  if (b->cursor >= b->size)
    return 0;
  return b->data[b->cursor++];
}
 
static stbtt_uint8 stbtt__buf_peek8(stbtt__buf *b)
{
  if (b->cursor >= b->size)
    return 0;
  return b->data[b->cursor];
}
 
static void stbtt__buf_seek(stbtt__buf *b, int o)
{
  STBTT_assert(!(o > b->size || o < 0));
  b->cursor = (o > b->size || o < 0) ? b->size : o;
}
 
static void stbtt__buf_skip(stbtt__buf *b, int o) { stbtt__buf_seek(b, b->cursor + o); }
 
static stbtt_uint32 stbtt__buf_get(stbtt__buf *b, int n)
{
  stbtt_uint32 v = 0;
  int i;
  STBTT_assert(n >= 1 && n <= 4);
  for (i = 0; i < n; i++)
    v = (v << 8) | stbtt__buf_get8(b);
  return v;
}
 
static stbtt__buf stbtt__new_buf(const void *p, size_t size)
{
  stbtt__buf r;
  STBTT_assert(size < 0x40000000);
  r.data = (stbtt_uint8 *)p;
  r.size = (int)size;
  r.cursor = 0;
  return r;
}
 
#define stbtt__buf_get16(b) stbtt__buf_get((b), 2)
#define stbtt__buf_get32(b) stbtt__buf_get((b), 4)
 
static stbtt__buf stbtt__buf_range(const stbtt__buf *b, int o, int s)
{
  stbtt__buf r = stbtt__new_buf(nullptr, 0);
  if (o < 0 || s < 0 || o > b->size || s > b->size - o)
    return r;
  r.data = b->data + o;
  r.size = s;
  return r;
}
 
static stbtt__buf stbtt__cff_get_index(stbtt__buf *b)
{
  int count, start, offsize;
  start = b->cursor;
  count = stbtt__buf_get16(b);
  if (count) {
    offsize = stbtt__buf_get8(b);
    STBTT_assert(offsize >= 1 && offsize <= 4);
    stbtt__buf_skip(b, offsize * count);
    stbtt__buf_skip(b, stbtt__buf_get(b, offsize) - 1);
  }
  return stbtt__buf_range(b, start, b->cursor - start);
}
 
static stbtt_uint32 stbtt__cff_int(stbtt__buf *b)
{
  int b0 = stbtt__buf_get8(b);
  if (b0 >= 32 && b0 <= 246)
    return b0 - 139;
  else if (b0 >= 247 && b0 <= 250)
    return (b0 - 247) * 256 + stbtt__buf_get8(b) + 108;
  else if (b0 >= 251 && b0 <= 254)
    return -(b0 - 251) * 256 - stbtt__buf_get8(b) - 108;
  else if (b0 == 28)
    return stbtt__buf_get16(b);
  else if (b0 == 29)
    return stbtt__buf_get32(b);
  STBTT_assert(0);
  return 0;
}
 
static void stbtt__cff_skip_operand(stbtt__buf *b)
{
  int v, b0 = stbtt__buf_peek8(b);
  STBTT_assert(b0 >= 28);
  if (b0 == 30) {
    stbtt__buf_skip(b, 1);
    while (b->cursor < b->size) {
      v = stbtt__buf_get8(b);
      if ((v & 0xF) == 0xF || (v >> 4) == 0xF)
        break;
    }
  }
  else {
    stbtt__cff_int(b);
  }
}
 
static stbtt__buf stbtt__dict_get(stbtt__buf *b, int key)
{
  stbtt__buf_seek(b, 0);
  while (b->cursor < b->size) {
    int start = b->cursor, end, op;
    while (stbtt__buf_peek8(b) >= 28)
      stbtt__cff_skip_operand(b);
    end = b->cursor;
    op = stbtt__buf_get8(b);
    if (op == 12)
      op = stbtt__buf_get8(b) | 0x100;
    if (op == key)
      return stbtt__buf_range(b, start, end - start);
  }
  return stbtt__buf_range(b, 0, 0);
}
 
static void stbtt__dict_get_ints(stbtt__buf *b, int key, int outcount, stbtt_uint32 *out)
{
  int i;
  stbtt__buf operands = stbtt__dict_get(b, key);
  for (i = 0; i < outcount && operands.cursor < operands.size; i++)
    out[i] = stbtt__cff_int(&operands);
}
 
static int stbtt__cff_index_count(stbtt__buf *b)
{
  stbtt__buf_seek(b, 0);
  return stbtt__buf_get16(b);
}
 
static stbtt__buf stbtt__cff_index_get(stbtt__buf b, int i)
{
  int count, offsize, start, end;
  stbtt__buf_seek(&b, 0);
  count = stbtt__buf_get16(&b);
  offsize = stbtt__buf_get8(&b);
  STBTT_assert(i >= 0 && i < count);
  STBTT_assert(offsize >= 1 && offsize <= 4);
  stbtt__buf_skip(&b, i * offsize);
  start = stbtt__buf_get(&b, offsize);
  end = stbtt__buf_get(&b, offsize);
  return stbtt__buf_range(&b, 2 + (count + 1) * offsize + start, end - start);
}

//
// accessors to parse data from file
//
 
// on platforms that don't allow misaligned reads, if we want to allow
// truetype fonts that aren't padded to alignment, define ALLOW_UNALIGNED_TRUETYPE
 
#define ttBYTE(p) (*(stbtt_uint8 *)(p))
#define ttCHAR(p) (*(stbtt_int8 *)(p))
#define ttFixed(p) ttLONG(p)
 
static stbtt_uint16 ttUSHORT(stbtt_uint8 *p) { return p[0] * 256 + p[1]; }
static stbtt_int16 ttSHORT(stbtt_uint8 *p) { return p[0] * 256 + p[1]; }
static stbtt_uint32 ttULONG(stbtt_uint8 *p) { return (p[0] << 24) + (p[1] << 16) + (p[2] << 8) + p[3]; }
static stbtt_int32 ttLONG(stbtt_uint8 *p) { return (p[0] << 24) + (p[1] << 16) + (p[2] << 8) + p[3]; }
 
#define stbtt_tag4(p, c0, c1, c2, c3) ((p)[0] == (c0) && (p)[1] == (c1) && (p)[2] == (c2) && (p)[3] == (c3))
#define stbtt_tag(p, str) stbtt_tag4(p, str[0], str[1], str[2], str[3])
 
static int stbtt__isfont(stbtt_uint8 *font)
{
  // check the version number
  if (stbtt_tag4(font, '1', 0, 0, 0))
    return 1; // TrueType 1
  if (stbtt_tag(font, "typ1"))
    return 1; // TrueType with type 1 font -- we don't support this!
  if (stbtt_tag(font, "OTTO"))
    return 1; // OpenType with CFF
  if (stbtt_tag4(font, 0, 1, 0, 0))
    return 1; // OpenType 1.0
  if (stbtt_tag(font, "true"))
    return 1; // Apple specification for TrueType fonts
  return 0;
}
 
// @OPTIMIZE: binary search
static stbtt_uint32 stbtt__find_table(stbtt_uint8 *data, stbtt_uint32 fontstart, const char *tag)
{
  stbtt_int32 num_tables = ttUSHORT(data + fontstart + 4);
  stbtt_uint32 tabledir = fontstart + 12;
  stbtt_int32 i;
  for (i = 0; i < num_tables; ++i) {
    stbtt_uint32 loc = tabledir + 16 * i;
    if (stbtt_tag(data + loc + 0, tag))
      return ttULONG(data + loc + 8);
  }
  return 0;
}
 
static int stbtt_GetFontOffsetForIndex_internal(unsigned char *font_collection, int index)
{
  // if it's just a font, there's only one valid index
  if (stbtt__isfont(font_collection))
    return index == 0 ? 0 : -1;
 
  // check if it's a TTC
  if (stbtt_tag(font_collection, "ttcf")) {
    // version 1?
    if (ttULONG(font_collection + 4) == 0x00010000 || ttULONG(font_collection + 4) == 0x00020000) {
      stbtt_int32 n = ttLONG(font_collection + 8);
      if (index >= n)
        return -1;
      return ttULONG(font_collection + 12 + index * 4);
    }
  }
  return -1;
}
 
static int stbtt_GetNumberOfFonts_internal(unsigned char *font_collection)
{
  // if it's just a font, there's only one valid font
  if (stbtt__isfont(font_collection))
    return 1;
 
  // check if it's a TTC
  if (stbtt_tag(font_collection, "ttcf")) {
    // version 1?
    if (ttULONG(font_collection + 4) == 0x00010000 || ttULONG(font_collection + 4) == 0x00020000) {
      return ttLONG(font_collection + 8);
    }
  }
  return 0;
}
 
static stbtt__buf stbtt__get_subrs(stbtt__buf cff, stbtt__buf fontdict)
{
  stbtt_uint32 subrsoff = 0, private_loc[2] = { 0, 0 };
  stbtt__buf pdict;
  stbtt__dict_get_ints(&fontdict, 18, 2, private_loc);
  if (!private_loc[1] || !private_loc[0])
    return stbtt__new_buf(nullptr, 0);
  pdict = stbtt__buf_range(&cff, private_loc[1], private_loc[0]);
  stbtt__dict_get_ints(&pdict, 19, 1, &subrsoff);
  if (!subrsoff)
    return stbtt__new_buf(nullptr, 0);
  stbtt__buf_seek(&cff, private_loc[1] + subrsoff);
  return stbtt__cff_get_index(&cff);
}
 
// since most people won't use this, find this table the first time it's needed
static int stbtt__get_svg(stbtt_fontinfo *info)
{
  stbtt_uint32 t;
  if (info->svg < 0) {
    t = stbtt__find_table(info->data, info->fontstart, "SVG ");
    if (t) {
      stbtt_uint32 offset = ttULONG(info->data + t + 2);
      info->svg = t + offset;
    }
    else {
      info->svg = 0;
    }
  }
  return info->svg;
}
 
static int stbtt_InitFont_internal(stbtt_fontinfo *info, unsigned char *data, int fontstart)
{
  stbtt_uint32 cmap, t;
  stbtt_int32 i, numTables;
 
  info->data = data;
  info->fontstart = fontstart;
  info->cff = stbtt__new_buf(nullptr, 0);
 
  cmap = stbtt__find_table(data, fontstart, "cmap");       // required
  info->loca = stbtt__find_table(data, fontstart, "loca"); // required
  info->head = stbtt__find_table(data, fontstart, "head"); // required
  info->glyf = stbtt__find_table(data, fontstart, "glyf"); // required
  info->hhea = stbtt__find_table(data, fontstart, "hhea"); // required
  info->hmtx = stbtt__find_table(data, fontstart, "hmtx"); // required
  info->kern = stbtt__find_table(data, fontstart, "kern"); // not required
  info->gpos = stbtt__find_table(data, fontstart, "GPOS"); // not required
 
  if (!cmap || !info->head || !info->hhea || !info->hmtx)
    return 0;
  if (info->glyf) {
    // required for truetype
    if (!info->loca)
      return 0;
  }
  else {
 // initialization for CFF / Type2 fonts (OTF)
    stbtt__buf b, topdict, topdictidx;
    stbtt_uint32 cstype = 2, charstrings = 0, fdarrayoff = 0, fdselectoff = 0;
    stbtt_uint32 cff;
 
    cff = stbtt__find_table(data, fontstart, "CFF ");
    if (!cff)
      return 0;
 
    info->fontdicts = stbtt__new_buf(nullptr, 0);
    info->fdselect = stbtt__new_buf(nullptr, 0);
 
    // @TODO this should use size from table (not 512MB)
    info->cff = stbtt__new_buf(data + cff, 512 * 1024 * 1024);
    b = info->cff;
 
    // read the header
    stbtt__buf_skip(&b, 2);
    stbtt__buf_seek(&b, stbtt__buf_get8(&b)); // hdrsize
 
    // @TODO the name INDEX could list multiple fonts,
    // but we just use the first one.
    stbtt__cff_get_index(&b); // name INDEX
    topdictidx = stbtt__cff_get_index(&b);
    topdict = stbtt__cff_index_get(topdictidx, 0);
    stbtt__cff_get_index(&b); // string INDEX
    info->gsubrs = stbtt__cff_get_index(&b);
 
    stbtt__dict_get_ints(&topdict, 17, 1, &charstrings);
    stbtt__dict_get_ints(&topdict, 0x100 | 6, 1, &cstype);
    stbtt__dict_get_ints(&topdict, 0x100 | 36, 1, &fdarrayoff);
    stbtt__dict_get_ints(&topdict, 0x100 | 37, 1, &fdselectoff);
    info->subrs = stbtt__get_subrs(b, topdict);
 
    // we only support Type 2 charstrings
    if (cstype != 2)
      return 0;
    if (charstrings == 0)
      return 0;
 
    if (fdarrayoff) {
      // looks like a CID font
      if (!fdselectoff)
        return 0;
      stbtt__buf_seek(&b, fdarrayoff);
      info->fontdicts = stbtt__cff_get_index(&b);
      info->fdselect = stbtt__buf_range(&b, fdselectoff, b.size - fdselectoff);
    }
 
    stbtt__buf_seek(&b, charstrings);
    info->charstrings = stbtt__cff_get_index(&b);
  }
 
  t = stbtt__find_table(data, fontstart, "maxp");
  if (t)
    info->numGlyphs = ttUSHORT(data + t + 4);
  else
    info->numGlyphs = 0xffff;
 
  info->svg = -1;
 
  // find a cmap encoding table we understand *now* to avoid searching
  // later. (todo: could make this installable)
  // the same regardless of glyph.
  numTables = ttUSHORT(data + cmap + 2);
  info->index_map = 0;
  for (i = 0; i < numTables; ++i) {
    stbtt_uint32 encoding_record = cmap + 4 + 8 * i;
    // find an encoding we understand:
    switch (ttUSHORT(data + encoding_record)) {
    case STBTT_PLATFORM_ID_MICROSOFT:
      switch (ttUSHORT(data + encoding_record + 2)) {
      case STBTT_MS_EID_UNICODE_BMP:
      case STBTT_MS_EID_UNICODE_FULL:
        // MS/Unicode
        info->index_map = cmap + ttULONG(data + encoding_record + 4);
        break;
      }
      break;
    case STBTT_PLATFORM_ID_UNICODE:
      // Mac/iOS has these
      // all the encodingIDs are unicode, so we don't bother to check it
      info->index_map = cmap + ttULONG(data + encoding_record + 4);
      break;
    }
  }
  if (info->index_map == 0)
    return 0;
 
  info->indexToLocFormat = ttUSHORT(data + info->head + 50);
  return 1;
}
 
STBTT_DEF int stbtt_FindGlyphIndex(const stbtt_fontinfo *info, int unicode_codepoint)
{
  stbtt_uint8 *data = info->data;
  stbtt_uint32 index_map = info->index_map;
 
  stbtt_uint16 format = ttUSHORT(data + index_map + 0);
  if (format == 0) { // apple byte encoding
    stbtt_int32 bytes = ttUSHORT(data + index_map + 2);
    if (unicode_codepoint < bytes - 6)
      return ttBYTE(data + index_map + 6 + unicode_codepoint);
    return 0;
  }
  else if (format == 6) {
    stbtt_uint32 first = ttUSHORT(data + index_map + 6);
    stbtt_uint32 count = ttUSHORT(data + index_map + 8);
    if ((stbtt_uint32)unicode_codepoint >= first && (stbtt_uint32)unicode_codepoint < first + count)
      return ttUSHORT(data + index_map + 10 + (unicode_codepoint - first) * 2);
    return 0;
  }
  else if (format == 2) {
    STBTT_assert(0); // @TODO: high-byte mapping for japanese/chinese/korean
    return 0;
  }
  else if (format == 4) { // standard mapping for windows fonts: binary search collection of ranges
    stbtt_uint16 segcount = ttUSHORT(data + index_map + 6) >> 1;
    stbtt_uint16 searchRange = ttUSHORT(data + index_map + 8) >> 1;
    stbtt_uint16 entrySelector = ttUSHORT(data + index_map + 10);
    stbtt_uint16 rangeShift = ttUSHORT(data + index_map + 12) >> 1;
 
    // do a binary search of the segments
    stbtt_uint32 endCount = index_map + 14;
    stbtt_uint32 search = endCount;
 
    if (unicode_codepoint > 0xffff)
      return 0;
 
    // they lie from endCount .. endCount + segCount
    // but searchRange is the nearest power of two, so...
    if (unicode_codepoint >= ttUSHORT(data + search + rangeShift * 2))
      search += rangeShift * 2;
 
    // now decrement to bias correctly to find smallest
    search -= 2;
    while (entrySelector) {
      stbtt_uint16 end;
      searchRange >>= 1;
      end = ttUSHORT(data + search + searchRange * 2);
      if (unicode_codepoint > end)
        search += searchRange * 2;
      --entrySelector;
    }
    search += 2;
 
    {
      stbtt_uint16 offset, start, last;
      stbtt_uint16 item = (stbtt_uint16)((search - endCount) >> 1);
 
      start = ttUSHORT(data + index_map + 14 + segcount * 2 + 2 + 2 * item);
      last = ttUSHORT(data + endCount + 2 * item);
      if (unicode_codepoint < start || unicode_codepoint > last)
        return 0;
 
      offset = ttUSHORT(data + index_map + 14 + segcount * 6 + 2 + 2 * item);
      if (offset == 0)
        return (stbtt_uint16)(unicode_codepoint + ttSHORT(data + index_map + 14 + segcount * 4 + 2 + 2 * item));
 
      return ttUSHORT(data + offset + (unicode_codepoint - start) * 2 + index_map + 14 + segcount * 6 + 2 + 2 * item);
    }
  }
  else if (format == 12 || format == 13) {
    stbtt_uint32 ngroups = ttULONG(data + index_map + 12);
    stbtt_int32 low, high;
    low = 0;
    high = (stbtt_int32)ngroups;
    // Binary search the right group.
    while (low < high) {
      stbtt_int32 mid = low + ((high - low) >> 1); // rounds down, so low <= mid < high
      stbtt_uint32 start_char = ttULONG(data + index_map + 16 + mid * 12);
      stbtt_uint32 end_char = ttULONG(data + index_map + 16 + mid * 12 + 4);
      if ((stbtt_uint32)unicode_codepoint < start_char)
        high = mid;
      else if ((stbtt_uint32)unicode_codepoint > end_char)
        low = mid + 1;
      else {
        stbtt_uint32 start_glyph = ttULONG(data + index_map + 16 + mid * 12 + 8);
        if (format == 12)
          return start_glyph + unicode_codepoint - start_char;
        else // format == 13
          return start_glyph;
      }
    }
    return 0; // not found
  }
  // @TODO
  STBTT_assert(0);
  return 0;
}
 
STBTT_DEF int stbtt_GetCodepointShape(const stbtt_fontinfo *info, int unicode_codepoint, stbtt_vertex **vertices)
{
  return stbtt_GetGlyphShape(info, stbtt_FindGlyphIndex(info, unicode_codepoint), vertices);
}
 
static void stbtt_setvertex(stbtt_vertex *v, stbtt_uint8 type, stbtt_int32 x, stbtt_int32 y, stbtt_int32 cx,
                            stbtt_int32 cy)
{
  v->type = type;
  v->x = (stbtt_int16)x;
  v->y = (stbtt_int16)y;
  v->cx = (stbtt_int16)cx;
  v->cy = (stbtt_int16)cy;
}
 
static int stbtt__GetGlyfOffset(const stbtt_fontinfo *info, int glyph_index)
{
  int g1, g2;
 
  STBTT_assert(!info->cff.size);
 
  if (glyph_index >= info->numGlyphs)
    return -1; // glyph index out of range
  if (info->indexToLocFormat >= 2)
    return -1; // unknown index->glyph map format
 
  if (info->indexToLocFormat == 0) {
    g1 = info->glyf + ttUSHORT(info->data + info->loca + glyph_index * 2) * 2;
    g2 = info->glyf + ttUSHORT(info->data + info->loca + glyph_index * 2 + 2) * 2;
  }
  else {
    g1 = info->glyf + ttULONG(info->data + info->loca + glyph_index * 4);
    g2 = info->glyf + ttULONG(info->data + info->loca + glyph_index * 4 + 4);
  }
 
  return g1 == g2 ? -1 : g1; // if length is 0, return -1
}
 
static int stbtt__GetGlyphInfoT2(const stbtt_fontinfo *info, int glyph_index, int *x0, int *y0, int *x1, int *y1);
 
STBTT_DEF int stbtt_GetGlyphBox(const stbtt_fontinfo *info, int glyph_index, int *x0, int *y0, int *x1, int *y1)
{
  if (info->cff.size) {
    stbtt__GetGlyphInfoT2(info, glyph_index, x0, y0, x1, y1);
  }
  else {
    int g = stbtt__GetGlyfOffset(info, glyph_index);
    if (g < 0)
      return 0;
 
    if (x0)
      *x0 = ttSHORT(info->data + g + 2);
    if (y0)
      *y0 = ttSHORT(info->data + g + 4);
    if (x1)
      *x1 = ttSHORT(info->data + g + 6);
    if (y1)
      *y1 = ttSHORT(info->data + g + 8);
  }
  return 1;
}
 
STBTT_DEF int stbtt_GetCodepointBox(const stbtt_fontinfo *info, int codepoint, int *x0, int *y0, int *x1, int *y1)
{
  return stbtt_GetGlyphBox(info, stbtt_FindGlyphIndex(info, codepoint), x0, y0, x1, y1);
}
 
STBTT_DEF int stbtt_IsGlyphEmpty(const stbtt_fontinfo *info, int glyph_index)
{
  stbtt_int16 numberOfContours;
  int g;
  if (info->cff.size)
    return stbtt__GetGlyphInfoT2(info, glyph_index, nullptr, nullptr, nullptr, nullptr) == 0;
  g = stbtt__GetGlyfOffset(info, glyph_index);
  if (g < 0)
    return 1;
  numberOfContours = ttSHORT(info->data + g);
  return numberOfContours == 0;
}
 
static int stbtt__close_shape(stbtt_vertex *vertices, int num_vertices, int was_off, int start_off, stbtt_int32 sx,
                              stbtt_int32 sy, stbtt_int32 scx, stbtt_int32 scy, stbtt_int32 cx, stbtt_int32 cy)
{
  if (start_off) {
    if (was_off)
      stbtt_setvertex(&vertices[num_vertices++], STBTT_vcurve, (cx + scx) >> 1, (cy + scy) >> 1, cx, cy);
    stbtt_setvertex(&vertices[num_vertices++], STBTT_vcurve, sx, sy, scx, scy);
  }
  else {
    if (was_off)
      stbtt_setvertex(&vertices[num_vertices++], STBTT_vcurve, sx, sy, cx, cy);
    else
      stbtt_setvertex(&vertices[num_vertices++], STBTT_vline, sx, sy, 0, 0);
  }
  return num_vertices;
}
 
static int stbtt__GetGlyphShapeTT(const stbtt_fontinfo *info, int glyph_index, stbtt_vertex **pvertices)
{
  stbtt_int16 numberOfContours;
  stbtt_uint8 *endPtsOfContours;
  stbtt_uint8 *data = info->data;
  stbtt_vertex *vertices = 0;
  int num_vertices = 0;
  int g = stbtt__GetGlyfOffset(info, glyph_index);
 
  *pvertices = nullptr;
 
  if (g < 0)
    return 0;
 
  numberOfContours = ttSHORT(data + g);
 
  if (numberOfContours > 0) {
    stbtt_uint8 flags = 0, flagcount;
    stbtt_int32 ins, i, j = 0, m, n, next_move, was_off = 0, off, start_off = 0;
    stbtt_int32 x, y, cx, cy, sx, sy, scx, scy;
    stbtt_uint8 *points;
    endPtsOfContours = (data + g + 10);
    ins = ttUSHORT(data + g + 10 + numberOfContours * 2);
    points = data + g + 10 + numberOfContours * 2 + 2 + ins;
 
    n = 1 + ttUSHORT(endPtsOfContours + numberOfContours * 2 - 2);
 
    m = n + 2 * numberOfContours; // a loose bound on how many vertices we might need
    vertices = (stbtt_vertex *)STBTT_malloc(m * sizeof(vertices[0]), info->userdata);
    if (vertices == 0)
      return 0;
 
    next_move = 0;
    flagcount = 0;
 
    // in first pass, we load uninterpreted data into the allocated array
    // above, shifted to the end of the array so we won't overwrite it when
    // we create our final data starting from the front
 
    off = m - n; // starting offset for uninterpreted data, regardless of how m ends up being calculated
 
    // first load flags
 
    for (i = 0; i < n; ++i) {
      if (flagcount == 0) {
        flags = *points++;
        if (flags & 8)
          flagcount = *points++;
      }
      else
        --flagcount;
      vertices[off + i].type = flags;
    }
 
    // now load x coordinates
    x = 0;
    for (i = 0; i < n; ++i) {
      flags = vertices[off + i].type;
      if (flags & 2) {
        stbtt_int16 dx = *points++;
        x += (flags & 16) ? dx : -dx; // ???
      }
      else {
        if (!(flags & 16)) {
          x = x + (stbtt_int16)(points[0] * 256 + points[1]);
          points += 2;
        }
      }
      vertices[off + i].x = (stbtt_int16)x;
    }
 
    // now load y coordinates
    y = 0;
    for (i = 0; i < n; ++i) {
      flags = vertices[off + i].type;
      if (flags & 4) {
        stbtt_int16 dy = *points++;
        y += (flags & 32) ? dy : -dy; // ???
      }
      else {
        if (!(flags & 32)) {
          y = y + (stbtt_int16)(points[0] * 256 + points[1]);
          points += 2;
        }
      }
      vertices[off + i].y = (stbtt_int16)y;
    }
 
    // now convert them to our format
    num_vertices = 0;
    sx = sy = cx = cy = scx = scy = 0;
    for (i = 0; i < n; ++i) {
      flags = vertices[off + i].type;
      x = (stbtt_int16)vertices[off + i].x;
      y = (stbtt_int16)vertices[off + i].y;
 
      if (next_move == i) {
        if (i != 0)
          num_vertices = stbtt__close_shape(vertices, num_vertices, was_off, start_off, sx, sy, scx, scy, cx, cy);
 
        // now start the new one
        start_off = !(flags & 1);
        if (start_off) {
          // if we start off with an off-curve point, then when we need to find a point on the curve
          // where we can start, and we need to save some state for when we wraparound.
          scx = x;
          scy = y;
          if (!(vertices[off + i + 1].type & 1)) {
            // next point is also a curve point, so interpolate an on-point curve
            sx = (x + (stbtt_int32)vertices[off + i + 1].x) >> 1;
            sy = (y + (stbtt_int32)vertices[off + i + 1].y) >> 1;
          }
          else {
         // otherwise just use the next point as our start point
            sx = (stbtt_int32)vertices[off + i + 1].x;
            sy = (stbtt_int32)vertices[off + i + 1].y;
            ++i; // we're using point i+1 as the starting point, so skip it
          }
        }
        else {
          sx = x;
          sy = y;
        }
        stbtt_setvertex(&vertices[num_vertices++], STBTT_vmove, sx, sy, 0, 0);
        was_off = 0;
        next_move = 1 + ttUSHORT(endPtsOfContours + j * 2);
        ++j;
      }
      else {
        if (!(flags & 1)) { // if it's a curve
          if (was_off)      // two off-curve control points in a row means interpolate an on-curve midpoint
            stbtt_setvertex(&vertices[num_vertices++], STBTT_vcurve, (cx + x) >> 1, (cy + y) >> 1, cx, cy);
          cx = x;
          cy = y;
          was_off = 1;
        }
        else {
          if (was_off)
            stbtt_setvertex(&vertices[num_vertices++], STBTT_vcurve, x, y, cx, cy);
          else
            stbtt_setvertex(&vertices[num_vertices++], STBTT_vline, x, y, 0, 0);
          was_off = 0;
        }
      }
    }
    num_vertices = stbtt__close_shape(vertices, num_vertices, was_off, start_off, sx, sy, scx, scy, cx, cy);
  }
  else if (numberOfContours < 0) {
 // Compound shapes.
    int more = 1;
    stbtt_uint8 *comp = data + g + 10;
    num_vertices = 0;
    vertices = 0;
    while (more) {
      stbtt_uint16 flags, gidx;
      int comp_num_verts = 0, i;
      stbtt_vertex *comp_verts = 0, *tmp = 0;
      float mtx[6] = { 1, 0, 0, 1, 0, 0 }, m, n;
 
      flags = ttSHORT(comp);
      comp += 2;
      gidx = ttSHORT(comp);
      comp += 2;
 
      if (flags & 2) {   // XY values
        if (flags & 1) { // shorts
          mtx[4] = ttSHORT(comp);
          comp += 2;
          mtx[5] = ttSHORT(comp);
          comp += 2;
        }
        else {
          mtx[4] = ttCHAR(comp);
          comp += 1;
          mtx[5] = ttCHAR(comp);
          comp += 1;
        }
      }
      else {
     // @TODO handle matching point
        STBTT_assert(0);
      }
      if (flags & (1 << 3)) { // WE_HAVE_A_SCALE
        mtx[0] = mtx[3] = ttSHORT(comp) / 16384.0f;
        comp += 2;
        mtx[1] = mtx[2] = 0;
      }
      else if (flags & (1 << 6)) { // WE_HAVE_AN_X_AND_YSCALE
        mtx[0] = ttSHORT(comp) / 16384.0f;
        comp += 2;
        mtx[1] = mtx[2] = 0;
        mtx[3] = ttSHORT(comp) / 16384.0f;
        comp += 2;
      }
      else if (flags & (1 << 7)) { // WE_HAVE_A_TWO_BY_TWO
        mtx[0] = ttSHORT(comp) / 16384.0f;
        comp += 2;
        mtx[1] = ttSHORT(comp) / 16384.0f;
        comp += 2;
        mtx[2] = ttSHORT(comp) / 16384.0f;
        comp += 2;
        mtx[3] = ttSHORT(comp) / 16384.0f;
        comp += 2;
      }
 
      // Find transformation scales.
      m = (float)STBTT_sqrt(mtx[0] * mtx[0] + mtx[1] * mtx[1]);
      n = (float)STBTT_sqrt(mtx[2] * mtx[2] + mtx[3] * mtx[3]);
 
      // Get indexed glyph.
      comp_num_verts = stbtt_GetGlyphShape(info, gidx, &comp_verts);
      if (comp_num_verts > 0) {
        // Transform vertices.
        for (i = 0; i < comp_num_verts; ++i) {
          stbtt_vertex *v = &comp_verts[i];
          stbtt_vertex_type x, y;
          x = v->x;
          y = v->y;
          v->x = (stbtt_vertex_type)(m * (mtx[0] * x + mtx[2] * y + mtx[4]));
          v->y = (stbtt_vertex_type)(n * (mtx[1] * x + mtx[3] * y + mtx[5]));
          x = v->cx;
          y = v->cy;
          v->cx = (stbtt_vertex_type)(m * (mtx[0] * x + mtx[2] * y + mtx[4]));
          v->cy = (stbtt_vertex_type)(n * (mtx[1] * x + mtx[3] * y + mtx[5]));
        }
        // Append vertices.
        tmp = (stbtt_vertex *)STBTT_malloc((num_vertices + comp_num_verts) * sizeof(stbtt_vertex), info->userdata);
        if (!tmp) {
          if (vertices)
            STBTT_free(vertices, info->userdata);
          if (comp_verts)
            STBTT_free(comp_verts, info->userdata);
          return 0;
        }
        if (num_vertices > 0 && vertices)
          STBTT_memcpy(tmp, vertices, num_vertices * sizeof(stbtt_vertex));
        STBTT_memcpy(tmp + num_vertices, comp_verts, comp_num_verts * sizeof(stbtt_vertex));
        if (vertices)
          STBTT_free(vertices, info->userdata);
        vertices = tmp;
        STBTT_free(comp_verts, info->userdata);
        num_vertices += comp_num_verts;
      }
      // More components ?
      more = flags & (1 << 5);
    }
  }
  else {
 // numberOfCounters == 0, do nothing
  }
 
  *pvertices = vertices;
  return num_vertices;
}
 
typedef struct
{
  int bounds;
  int started;
  float first_x, first_y;
  float x, y;
  stbtt_int32 min_x, max_x, min_y, max_y;
 
  stbtt_vertex *pvertices;
  int num_vertices;
} stbtt__csctx;
 
#define STBTT__CSCTX_INIT(bounds)                                                                                      \
  {                                                                                                                    \
    bounds, 0, 0, 0, 0, 0, 0, 0, 0, 0, nullptr, 0                                                                         \
  }
 
static void stbtt__track_vertex(stbtt__csctx *c, stbtt_int32 x, stbtt_int32 y)
{
  if (x > c->max_x || !c->started)
    c->max_x = x;
  if (y > c->max_y || !c->started)
    c->max_y = y;
  if (x < c->min_x || !c->started)
    c->min_x = x;
  if (y < c->min_y || !c->started)
    c->min_y = y;
  c->started = 1;
}
 
static void stbtt__csctx_v(stbtt__csctx *c, stbtt_uint8 type, stbtt_int32 x, stbtt_int32 y, stbtt_int32 cx,
                           stbtt_int32 cy, stbtt_int32 cx1, stbtt_int32 cy1)
{
  if (c->bounds) {
    stbtt__track_vertex(c, x, y);
    if (type == STBTT_vcubic) {
      stbtt__track_vertex(c, cx, cy);
      stbtt__track_vertex(c, cx1, cy1);
    }
  }
  else {
    stbtt_setvertex(&c->pvertices[c->num_vertices], type, x, y, cx, cy);
    c->pvertices[c->num_vertices].cx1 = (stbtt_int16)cx1;
    c->pvertices[c->num_vertices].cy1 = (stbtt_int16)cy1;
  }
  c->num_vertices++;
}
 
static void stbtt__csctx_close_shape(stbtt__csctx *ctx)
{
  if (ctx->first_x != ctx->x || ctx->first_y != ctx->y)
    stbtt__csctx_v(ctx, STBTT_vline, (int)ctx->first_x, (int)ctx->first_y, 0, 0, 0, 0);
}
 
static void stbtt__csctx_rmove_to(stbtt__csctx *ctx, float dx, float dy)
{
  stbtt__csctx_close_shape(ctx);
  ctx->first_x = ctx->x = ctx->x + dx;
  ctx->first_y = ctx->y = ctx->y + dy;
  stbtt__csctx_v(ctx, STBTT_vmove, (int)ctx->x, (int)ctx->y, 0, 0, 0, 0);
}
 
static void stbtt__csctx_rline_to(stbtt__csctx *ctx, float dx, float dy)
{
  ctx->x += dx;
  ctx->y += dy;
  stbtt__csctx_v(ctx, STBTT_vline, (int)ctx->x, (int)ctx->y, 0, 0, 0, 0);
}
 
static void stbtt__csctx_rccurve_to(stbtt__csctx *ctx, float dx1, float dy1, float dx2, float dy2, float dx3, float dy3)
{
  float cx1 = ctx->x + dx1;
  float cy1 = ctx->y + dy1;
  float cx2 = cx1 + dx2;
  float cy2 = cy1 + dy2;
  ctx->x = cx2 + dx3;
  ctx->y = cy2 + dy3;
  stbtt__csctx_v(ctx, STBTT_vcubic, (int)ctx->x, (int)ctx->y, (int)cx1, (int)cy1, (int)cx2, (int)cy2);
}
 
static stbtt__buf stbtt__get_subr(stbtt__buf idx, int n)
{
  int count = stbtt__cff_index_count(&idx);
  int bias = 107;
  if (count >= 33900)
    bias = 32768;
  else if (count >= 1240)
    bias = 1131;
  n += bias;
  if (n < 0 || n >= count)
    return stbtt__new_buf(nullptr, 0);
  return stbtt__cff_index_get(idx, n);
}
 
static stbtt__buf stbtt__cid_get_glyph_subrs(const stbtt_fontinfo *info, int glyph_index)
{
  stbtt__buf fdselect = info->fdselect;
  int nranges, start, end, v, fmt, fdselector = -1, i;
 
  stbtt__buf_seek(&fdselect, 0);
  fmt = stbtt__buf_get8(&fdselect);
  if (fmt == 0) {
    // untested
    stbtt__buf_skip(&fdselect, glyph_index);
    fdselector = stbtt__buf_get8(&fdselect);
  }
  else if (fmt == 3) {
    nranges = stbtt__buf_get16(&fdselect);
    start = stbtt__buf_get16(&fdselect);
    for (i = 0; i < nranges; i++) {
      v = stbtt__buf_get8(&fdselect);
      end = stbtt__buf_get16(&fdselect);
      if (glyph_index >= start && glyph_index < end) {
        fdselector = v;
        break;
      }
      start = end;
    }
  }
  if (fdselector == -1)
    stbtt__new_buf(nullptr, 0);
  return stbtt__get_subrs(info->cff, stbtt__cff_index_get(info->fontdicts, fdselector));
}
 
static int stbtt__run_charstring(const stbtt_fontinfo *info, int glyph_index, stbtt__csctx *c)
{
  int in_header = 1, maskbits = 0, subr_stack_height = 0, sp = 0, v, i, b0;
  int has_subrs = 0, clear_stack;
  float s[48];
  stbtt__buf subr_stack[10], subrs = info->subrs, b;
  float f;
 
#define STBTT__CSERR(s) (0)
 
  // this currently ignores the initial width value, which isn't needed if we have hmtx
  b = stbtt__cff_index_get(info->charstrings, glyph_index);
  while (b.cursor < b.size) {
    i = 0;
    clear_stack = 1;
    b0 = stbtt__buf_get8(&b);
    switch (b0) {
    // @TODO implement hinting
    case 0x13: // hintmask
    case 0x14: // cntrmask
      if (in_header)
        maskbits += (sp / 2); // implicit "vstem"
      in_header = 0;
      stbtt__buf_skip(&b, (maskbits + 7) / 8);
      break;
 
    case 0x01: // hstem
    case 0x03: // vstem
    case 0x12: // hstemhm
    case 0x17: // vstemhm
      maskbits += (sp / 2);
      break;
 
    case 0x15: // rmoveto
      in_header = 0;
      if (sp < 2)
        return STBTT__CSERR("rmoveto stack");
      stbtt__csctx_rmove_to(c, s[sp - 2], s[sp - 1]);
      break;
    case 0x04: // vmoveto
      in_header = 0;
      if (sp < 1)
        return STBTT__CSERR("vmoveto stack");
      stbtt__csctx_rmove_to(c, 0, s[sp - 1]);
      break;
    case 0x16: // hmoveto
      in_header = 0;
      if (sp < 1)
        return STBTT__CSERR("hmoveto stack");
      stbtt__csctx_rmove_to(c, s[sp - 1], 0);
      break;
 
    case 0x05: // rlineto
      if (sp < 2)
        return STBTT__CSERR("rlineto stack");
      for (; i + 1 < sp; i += 2)
        stbtt__csctx_rline_to(c, s[i], s[i + 1]);
      break;
 
      // hlineto/vlineto and vhcurveto/hvcurveto alternate horizontal and vertical
      // starting from a different place.
 
    case 0x07: // vlineto
      if (sp < 1)
        return STBTT__CSERR("vlineto stack");
      goto vlineto;
    case 0x06: // hlineto
      if (sp < 1)
        return STBTT__CSERR("hlineto stack");
      for (;;) {
        if (i >= sp)
          break;
        stbtt__csctx_rline_to(c, s[i], 0);
        i++;
      vlineto:
        if (i >= sp)
          break;
        stbtt__csctx_rline_to(c, 0, s[i]);
        i++;
      }
      break;
 
    case 0x1F: // hvcurveto
      if (sp < 4)
        return STBTT__CSERR("hvcurveto stack");
      goto hvcurveto;
    case 0x1E: // vhcurveto
      if (sp < 4)
        return STBTT__CSERR("vhcurveto stack");
      for (;;) {
        if (i + 3 >= sp)
          break;
        stbtt__csctx_rccurve_to(c, 0, s[i], s[i + 1], s[i + 2], s[i + 3], (sp - i == 5) ? s[i + 4] : 0.0f);
        i += 4;
      hvcurveto:
        if (i + 3 >= sp)
          break;
        stbtt__csctx_rccurve_to(c, s[i], 0, s[i + 1], s[i + 2], (sp - i == 5) ? s[i + 4] : 0.0f, s[i + 3]);
        i += 4;
      }
      break;
 
    case 0x08: // rrcurveto
      if (sp < 6)
        return STBTT__CSERR("rcurveline stack");
      for (; i + 5 < sp; i += 6)
        stbtt__csctx_rccurve_to(c, s[i], s[i + 1], s[i + 2], s[i + 3], s[i + 4], s[i + 5]);
      break;
 
    case 0x18: // rcurveline
      if (sp < 8)
        return STBTT__CSERR("rcurveline stack");
      for (; i + 5 < sp - 2; i += 6)
        stbtt__csctx_rccurve_to(c, s[i], s[i + 1], s[i + 2], s[i + 3], s[i + 4], s[i + 5]);
      if (i + 1 >= sp)
        return STBTT__CSERR("rcurveline stack");
      stbtt__csctx_rline_to(c, s[i], s[i + 1]);
      break;
 
    case 0x19: // rlinecurve
      if (sp < 8)
        return STBTT__CSERR("rlinecurve stack");
      for (; i + 1 < sp - 6; i += 2)
        stbtt__csctx_rline_to(c, s[i], s[i + 1]);
      if (i + 5 >= sp)
        return STBTT__CSERR("rlinecurve stack");
      stbtt__csctx_rccurve_to(c, s[i], s[i + 1], s[i + 2], s[i + 3], s[i + 4], s[i + 5]);
      break;
 
    case 0x1A: // vvcurveto
    case 0x1B: // hhcurveto
      if (sp < 4)
        return STBTT__CSERR("(vv|hh)curveto stack");
      f = 0.0;
      if (sp & 1) {
        f = s[i];
        i++;
      }
      for (; i + 3 < sp; i += 4) {
        if (b0 == 0x1B)
          stbtt__csctx_rccurve_to(c, s[i], f, s[i + 1], s[i + 2], s[i + 3], 0.0);
        else
          stbtt__csctx_rccurve_to(c, f, s[i], s[i + 1], s[i + 2], 0.0, s[i + 3]);
        f = 0.0;
      }
      break;
 
    case 0x0A: // callsubr
      if (!has_subrs) {
        if (info->fdselect.size)
          subrs = stbtt__cid_get_glyph_subrs(info, glyph_index);
        has_subrs = 1;
      }
      // FALLTHROUGH
    case 0x1D: // callgsubr
      if (sp < 1)
        return STBTT__CSERR("call(g|)subr stack");
      v = (int)s[--sp];
      if (subr_stack_height >= 10)
        return STBTT__CSERR("recursion limit");
      subr_stack[subr_stack_height++] = b;
      b = stbtt__get_subr(b0 == 0x0A ? subrs : info->gsubrs, v);
      if (b.size == 0)
        return STBTT__CSERR("subr not found");
      b.cursor = 0;
      clear_stack = 0;
      break;
 
    case 0x0B: // return
      if (subr_stack_height <= 0)
        return STBTT__CSERR("return outside subr");
      b = subr_stack[--subr_stack_height];
      clear_stack = 0;
      break;
 
    case 0x0E: // endchar
      stbtt__csctx_close_shape(c);
      return 1;
 
    case 0x0C: { // two-byte escape
      float dx1, dx2, dx3, dx4, dx5, dx6, dy1, dy2, dy3, dy4, dy5, dy6;
      float dx, dy;
      int b1 = stbtt__buf_get8(&b);
      switch (b1) {
      // @TODO These "flex" implementations ignore the flex-depth and resolution,
      // and always draw beziers.
      case 0x22: // hflex
        if (sp < 7)
          return STBTT__CSERR("hflex stack");
        dx1 = s[0];
        dx2 = s[1];
        dy2 = s[2];
        dx3 = s[3];
        dx4 = s[4];
        dx5 = s[5];
        dx6 = s[6];
        stbtt__csctx_rccurve_to(c, dx1, 0, dx2, dy2, dx3, 0);
        stbtt__csctx_rccurve_to(c, dx4, 0, dx5, -dy2, dx6, 0);
        break;
 
      case 0x23: // flex
        if (sp < 13)
          return STBTT__CSERR("flex stack");
        dx1 = s[0];
        dy1 = s[1];
        dx2 = s[2];
        dy2 = s[3];
        dx3 = s[4];
        dy3 = s[5];
        dx4 = s[6];
        dy4 = s[7];
        dx5 = s[8];
        dy5 = s[9];
        dx6 = s[10];
        dy6 = s[11];
        // fd is s[12]
        stbtt__csctx_rccurve_to(c, dx1, dy1, dx2, dy2, dx3, dy3);
        stbtt__csctx_rccurve_to(c, dx4, dy4, dx5, dy5, dx6, dy6);
        break;
 
      case 0x24: // hflex1
        if (sp < 9)
          return STBTT__CSERR("hflex1 stack");
        dx1 = s[0];
        dy1 = s[1];
        dx2 = s[2];
        dy2 = s[3];
        dx3 = s[4];
        dx4 = s[5];
        dx5 = s[6];
        dy5 = s[7];
        dx6 = s[8];
        stbtt__csctx_rccurve_to(c, dx1, dy1, dx2, dy2, dx3, 0);
        stbtt__csctx_rccurve_to(c, dx4, 0, dx5, dy5, dx6, -(dy1 + dy2 + dy5));
        break;
 
      case 0x25: // flex1
        if (sp < 11)
          return STBTT__CSERR("flex1 stack");
        dx1 = s[0];
        dy1 = s[1];
        dx2 = s[2];
        dy2 = s[3];
        dx3 = s[4];
        dy3 = s[5];
        dx4 = s[6];
        dy4 = s[7];
        dx5 = s[8];
        dy5 = s[9];
        dx6 = dy6 = s[10];
        dx = dx1 + dx2 + dx3 + dx4 + dx5;
        dy = dy1 + dy2 + dy3 + dy4 + dy5;
        if (STBTT_fabs(dx) > STBTT_fabs(dy))
          dy6 = -dy;
        else
          dx6 = -dx;
        stbtt__csctx_rccurve_to(c, dx1, dy1, dx2, dy2, dx3, dy3);
        stbtt__csctx_rccurve_to(c, dx4, dy4, dx5, dy5, dx6, dy6);
        break;
 
      default:
        return STBTT__CSERR("unimplemented");
      }
    } break;
 
    default:
      if (b0 != 255 && b0 != 28 && b0 < 32)
        return STBTT__CSERR("reserved operator");
 
      // push immediate
      if (b0 == 255) {
        f = (float)(stbtt_int32)stbtt__buf_get32(&b) / 0x10000;
      }
      else {
        stbtt__buf_skip(&b, -1);
        f = (float)(stbtt_int16)stbtt__cff_int(&b);
      }
      if (sp >= 48)
        return STBTT__CSERR("push stack overflow");
      s[sp++] = f;
      clear_stack = 0;
      break;
    }
    if (clear_stack)
      sp = 0;
  }
  return STBTT__CSERR("no endchar");
 
#undef STBTT__CSERR
}
 
static int stbtt__GetGlyphShapeT2(const stbtt_fontinfo *info, int glyph_index, stbtt_vertex **pvertices)
{
  // runs the charstring twice, once to count and once to output (to avoid realloc)
  stbtt__csctx count_ctx = STBTT__CSCTX_INIT(1);
  stbtt__csctx output_ctx = STBTT__CSCTX_INIT(0);
  if (stbtt__run_charstring(info, glyph_index, &count_ctx)) {
    *pvertices = (stbtt_vertex *)STBTT_malloc(count_ctx.num_vertices * sizeof(stbtt_vertex), info->userdata);
    output_ctx.pvertices = *pvertices;
    if (stbtt__run_charstring(info, glyph_index, &output_ctx)) {
      STBTT_assert(output_ctx.num_vertices == count_ctx.num_vertices);
      return output_ctx.num_vertices;
    }
  }
  *pvertices = nullptr;
  return 0;
}
 
static int stbtt__GetGlyphInfoT2(const stbtt_fontinfo *info, int glyph_index, int *x0, int *y0, int *x1, int *y1)
{
  stbtt__csctx c = STBTT__CSCTX_INIT(1);
  int r = stbtt__run_charstring(info, glyph_index, &c);
  if (x0)
    *x0 = r ? c.min_x : 0;
  if (y0)
    *y0 = r ? c.min_y : 0;
  if (x1)
    *x1 = r ? c.max_x : 0;
  if (y1)
    *y1 = r ? c.max_y : 0;
  return r ? c.num_vertices : 0;
}
 
STBTT_DEF int stbtt_GetGlyphShape(const stbtt_fontinfo *info, int glyph_index, stbtt_vertex **pvertices)
{
  if (!info->cff.size)
    return stbtt__GetGlyphShapeTT(info, glyph_index, pvertices);
  else
    return stbtt__GetGlyphShapeT2(info, glyph_index, pvertices);
}
 
STBTT_DEF void stbtt_GetGlyphHMetrics(const stbtt_fontinfo *info, int glyph_index, int *advanceWidth,
                                      int *leftSideBearing)
{
  stbtt_uint16 numOfLongHorMetrics = ttUSHORT(info->data + info->hhea + 34);
  if (glyph_index < numOfLongHorMetrics) {
    if (advanceWidth)
      *advanceWidth = ttSHORT(info->data + info->hmtx + 4 * glyph_index);
    if (leftSideBearing)
      *leftSideBearing = ttSHORT(info->data + info->hmtx + 4 * glyph_index + 2);
  }
  else {
    if (advanceWidth)
      *advanceWidth = ttSHORT(info->data + info->hmtx + 4 * (numOfLongHorMetrics - 1));
    if (leftSideBearing)
      *leftSideBearing =
      ttSHORT(info->data + info->hmtx + 4 * numOfLongHorMetrics + 2 * (glyph_index - numOfLongHorMetrics));
  }
}
 
STBTT_DEF int stbtt_GetKerningTableLength(const stbtt_fontinfo *info)
{
  stbtt_uint8 *data = info->data + info->kern;
 
  // we only look at the first table. it must be 'horizontal' and format 0.
  if (!info->kern)
    return 0;
  if (ttUSHORT(data + 2) < 1) // number of tables, need at least 1
    return 0;
  if (ttUSHORT(data + 8) != 1) // horizontal flag must be set in format
    return 0;
 
  return ttUSHORT(data + 10);
}
 
STBTT_DEF int stbtt_GetKerningTable(const stbtt_fontinfo *info, stbtt_kerningentry *table, int table_length)
{
  stbtt_uint8 *data = info->data + info->kern;
  int k, length;
 
  // we only look at the first table. it must be 'horizontal' and format 0.
  if (!info->kern)
    return 0;
  if (ttUSHORT(data + 2) < 1) // number of tables, need at least 1
    return 0;
  if (ttUSHORT(data + 8) != 1) // horizontal flag must be set in format
    return 0;
 
  length = ttUSHORT(data + 10);
  if (table_length < length)
    length = table_length;
 
  for (k = 0; k < length; k++) {
    table[k].glyph1 = ttUSHORT(data + 18 + (k * 6));
    table[k].glyph2 = ttUSHORT(data + 20 + (k * 6));
    table[k].advance = ttSHORT(data + 22 + (k * 6));
  }
 
  return length;
}
 
static int stbtt__GetGlyphKernInfoAdvance(const stbtt_fontinfo *info, int glyph1, int glyph2)
{
  stbtt_uint8 *data = info->data + info->kern;
  stbtt_uint32 needle, straw;
  int l, r, m;
 
  // we only look at the first table. it must be 'horizontal' and format 0.
  if (!info->kern)
    return 0;
  if (ttUSHORT(data + 2) < 1) // number of tables, need at least 1
    return 0;
  if (ttUSHORT(data + 8) != 1) // horizontal flag must be set in format
    return 0;
 
  l = 0;
  r = ttUSHORT(data + 10) - 1;
  needle = glyph1 << 16 | glyph2;
  while (l <= r) {
    m = (l + r) >> 1;
    straw = ttULONG(data + 18 + (m * 6)); // note: unaligned read
    if (needle < straw)
      r = m - 1;
    else if (needle > straw)
      l = m + 1;
    else
      return ttSHORT(data + 22 + (m * 6));
  }
  return 0;
}
 
static stbtt_int32 stbtt__GetCoverageIndex(stbtt_uint8 *coverageTable, int glyph)
{
  stbtt_uint16 coverageFormat = ttUSHORT(coverageTable);
  switch (coverageFormat) {
  case 1: {
    stbtt_uint16 glyphCount = ttUSHORT(coverageTable + 2);
 
    // Binary search.
    stbtt_int32 l = 0, r = glyphCount - 1, m;
    int straw, needle = glyph;
    while (l <= r) {
      stbtt_uint8 *glyphArray = coverageTable + 4;
      stbtt_uint16 glyphID;
      m = (l + r) >> 1;
      glyphID = ttUSHORT(glyphArray + 2 * m);
      straw = glyphID;
      if (needle < straw)
        r = m - 1;
      else if (needle > straw)
        l = m + 1;
      else {
        return m;
      }
    }
    break;
  }
 
  case 2: {
    stbtt_uint16 rangeCount = ttUSHORT(coverageTable + 2);
    stbtt_uint8 *rangeArray = coverageTable + 4;
 
    // Binary search.
    stbtt_int32 l = 0, r = rangeCount - 1, m;
    int strawStart, strawEnd, needle = glyph;
    while (l <= r) {
      stbtt_uint8 *rangeRecord;
      m = (l + r) >> 1;
      rangeRecord = rangeArray + 6 * m;
      strawStart = ttUSHORT(rangeRecord);
      strawEnd = ttUSHORT(rangeRecord + 2);
      if (needle < strawStart)
        r = m - 1;
      else if (needle > strawEnd)
        l = m + 1;
      else {
        stbtt_uint16 startCoverageIndex = ttUSHORT(rangeRecord + 4);
        return startCoverageIndex + glyph - strawStart;
      }
    }
    break;
  }
 
  default:
    return -1; // unsupported
  }
 
  return -1;
}
 
static stbtt_int32 stbtt__GetGlyphClass(stbtt_uint8 *classDefTable, int glyph)
{
  stbtt_uint16 classDefFormat = ttUSHORT(classDefTable);
  switch (classDefFormat) {
  case 1: {
    stbtt_uint16 startGlyphID = ttUSHORT(classDefTable + 2);
    stbtt_uint16 glyphCount = ttUSHORT(classDefTable + 4);
    stbtt_uint8 *classDef1ValueArray = classDefTable + 6;
 
    if (glyph >= startGlyphID && glyph < startGlyphID + glyphCount)
      return (stbtt_int32)ttUSHORT(classDef1ValueArray + 2 * (glyph - startGlyphID));
    break;
  }
 
  case 2: {
    stbtt_uint16 classRangeCount = ttUSHORT(classDefTable + 2);
    stbtt_uint8 *classRangeRecords = classDefTable + 4;
 
    // Binary search.
    stbtt_int32 l = 0, r = classRangeCount - 1, m;
    int strawStart, strawEnd, needle = glyph;
    while (l <= r) {
      stbtt_uint8 *classRangeRecord;
      m = (l + r) >> 1;
      classRangeRecord = classRangeRecords + 6 * m;
      strawStart = ttUSHORT(classRangeRecord);
      strawEnd = ttUSHORT(classRangeRecord + 2);
      if (needle < strawStart)
        r = m - 1;
      else if (needle > strawEnd)
        l = m + 1;
      else
        return (stbtt_int32)ttUSHORT(classRangeRecord + 4);
    }
    break;
  }
 
  default:
    return -1; // Unsupported definition type, return an error.
  }
 
  // "All glyphs not assigned to a class fall into class 0". (OpenType spec)
  return 0;
}
 
// Define to STBTT_assert(x) if you want to break on unimplemented formats.
#define STBTT_GPOS_TODO_assert(x)
 
static stbtt_int32 stbtt__GetGlyphGPOSInfoAdvance(const stbtt_fontinfo *info, int glyph1, int glyph2)
{
  stbtt_uint16 lookupListOffset;
  stbtt_uint8 *lookupList;
  stbtt_uint16 lookupCount;
  stbtt_uint8 *data;
  stbtt_int32 i, sti;
 
  if (!info->gpos)
    return 0;
 
  data = info->data + info->gpos;
 
  if (ttUSHORT(data + 0) != 1)
    return 0; // Major version 1
  if (ttUSHORT(data + 2) != 0)
    return 0; // Minor version 0
 
  lookupListOffset = ttUSHORT(data + 8);
  lookupList = data + lookupListOffset;
  lookupCount = ttUSHORT(lookupList);
 
  for (i = 0; i < lookupCount; ++i) {
    stbtt_uint16 lookupOffset = ttUSHORT(lookupList + 2 + 2 * i);
    stbtt_uint8 *lookupTable = lookupList + lookupOffset;
 
    stbtt_uint16 lookupType = ttUSHORT(lookupTable);
    stbtt_uint16 subTableCount = ttUSHORT(lookupTable + 4);
    stbtt_uint8 *subTableOffsets = lookupTable + 6;
    if (lookupType != 2) // Pair Adjustment Positioning Subtable
      continue;
 
    for (sti = 0; sti < subTableCount; sti++) {
      stbtt_uint16 subtableOffset = ttUSHORT(subTableOffsets + 2 * sti);
      stbtt_uint8 *table = lookupTable + subtableOffset;
      stbtt_uint16 posFormat = ttUSHORT(table);
      stbtt_uint16 coverageOffset = ttUSHORT(table + 2);
      stbtt_int32 coverageIndex = stbtt__GetCoverageIndex(table + coverageOffset, glyph1);
      if (coverageIndex == -1)
        continue;
 
      switch (posFormat) {
      case 1: {
        stbtt_int32 l, r, m;
        int straw, needle;
        stbtt_uint16 valueFormat1 = ttUSHORT(table + 4);
        stbtt_uint16 valueFormat2 = ttUSHORT(table + 6);
        if (valueFormat1 == 4 && valueFormat2 == 0) { // Support more formats?
          stbtt_int32 valueRecordPairSizeInBytes = 2;
          stbtt_uint16 pairSetCount = ttUSHORT(table + 8);
          stbtt_uint16 pairPosOffset = ttUSHORT(table + 10 + 2 * coverageIndex);
          stbtt_uint8 *pairValueTable = table + pairPosOffset;
          stbtt_uint16 pairValueCount = ttUSHORT(pairValueTable);
          stbtt_uint8 *pairValueArray = pairValueTable + 2;
 
          if (coverageIndex >= pairSetCount)
            return 0;
 
          needle = glyph2;
          r = pairValueCount - 1;
          l = 0;
 
          // Binary search.
          while (l <= r) {
            stbtt_uint16 secondGlyph;
            stbtt_uint8 *pairValue;
            m = (l + r) >> 1;
            pairValue = pairValueArray + (2 + valueRecordPairSizeInBytes) * m;
            secondGlyph = ttUSHORT(pairValue);
            straw = secondGlyph;
            if (needle < straw)
              r = m - 1;
            else if (needle > straw)
              l = m + 1;
            else {
              stbtt_int16 xAdvance = ttSHORT(pairValue + 2);
              return xAdvance;
            }
          }
        }
        else
          return 0;
        break;
      }
 
      case 2: {
        stbtt_uint16 valueFormat1 = ttUSHORT(table + 4);
        stbtt_uint16 valueFormat2 = ttUSHORT(table + 6);
        if (valueFormat1 == 4 && valueFormat2 == 0) { // Support more formats?
          stbtt_uint16 classDef1Offset = ttUSHORT(table + 8);
          stbtt_uint16 classDef2Offset = ttUSHORT(table + 10);
          int glyph1class = stbtt__GetGlyphClass(table + classDef1Offset, glyph1);
          int glyph2class = stbtt__GetGlyphClass(table + classDef2Offset, glyph2);
 
          stbtt_uint16 class1Count = ttUSHORT(table + 12);
          stbtt_uint16 class2Count = ttUSHORT(table + 14);
          stbtt_uint8 *class1Records, *class2Records;
          stbtt_int16 xAdvance;
 
          if (glyph1class < 0 || glyph1class >= class1Count)
            return 0; // malformed
          if (glyph2class < 0 || glyph2class >= class2Count)
            return 0; // malformed
 
          class1Records = table + 16;
          class2Records = class1Records + 2 * (glyph1class * class2Count);
          xAdvance = ttSHORT(class2Records + 2 * glyph2class);
          return xAdvance;
        }
        else
          return 0;
        break;
      }
 
      default:
        return 0; // Unsupported position format
      }
    }
  }
 
  return 0;
}
 
STBTT_DEF int stbtt_GetGlyphKernAdvance(const stbtt_fontinfo *info, int g1, int g2)
{
  int xAdvance = 0;
 
  if (info->gpos)
    xAdvance += stbtt__GetGlyphGPOSInfoAdvance(info, g1, g2);
  else if (info->kern)
    xAdvance += stbtt__GetGlyphKernInfoAdvance(info, g1, g2);
 
  return xAdvance;
}
 
STBTT_DEF int stbtt_GetCodepointKernAdvance(const stbtt_fontinfo *info, int ch1, int ch2)
{
  if (!info->kern && !info->gpos) // if no kerning table, don't waste time looking up both codepoint->glyphs
    return 0;
  return stbtt_GetGlyphKernAdvance(info, stbtt_FindGlyphIndex(info, ch1), stbtt_FindGlyphIndex(info, ch2));
}
 
STBTT_DEF void stbtt_GetCodepointHMetrics(const stbtt_fontinfo *info, int codepoint, int *advanceWidth,
                                          int *leftSideBearing)
{
  stbtt_GetGlyphHMetrics(info, stbtt_FindGlyphIndex(info, codepoint), advanceWidth, leftSideBearing);
}
 
STBTT_DEF void stbtt_GetFontVMetrics(const stbtt_fontinfo *info, int *ascent, int *descent, int *lineGap)
{
  if (ascent)
    *ascent = ttSHORT(info->data + info->hhea + 4);
  if (descent)
    *descent = ttSHORT(info->data + info->hhea + 6);
  if (lineGap)
    *lineGap = ttSHORT(info->data + info->hhea + 8);
}
 
STBTT_DEF int stbtt_GetFontVMetricsOS2(const stbtt_fontinfo *info, int *typoAscent, int *typoDescent, int *typoLineGap)
{
  int tab = stbtt__find_table(info->data, info->fontstart, "OS/2");
  if (!tab)
    return 0;
  if (typoAscent)
    *typoAscent = ttSHORT(info->data + tab + 68);
  if (typoDescent)
    *typoDescent = ttSHORT(info->data + tab + 70);
  if (typoLineGap)
    *typoLineGap = ttSHORT(info->data + tab + 72);
  return 1;
}
 
STBTT_DEF void stbtt_GetFontBoundingBox(const stbtt_fontinfo *info, int *x0, int *y0, int *x1, int *y1)
{
  *x0 = ttSHORT(info->data + info->head + 36);
  *y0 = ttSHORT(info->data + info->head + 38);
  *x1 = ttSHORT(info->data + info->head + 40);
  *y1 = ttSHORT(info->data + info->head + 42);
}
 
STBTT_DEF float stbtt_ScaleForPixelHeight(const stbtt_fontinfo *info, float height)
{
  int fheight = ttSHORT(info->data + info->hhea + 4) - ttSHORT(info->data + info->hhea + 6);
  return (float)height / fheight;
}
 
STBTT_DEF float stbtt_ScaleForMappingEmToPixels(const stbtt_fontinfo *info, float pixels)
{
  int unitsPerEm = ttUSHORT(info->data + info->head + 18);
  return pixels / unitsPerEm;
}
 
STBTT_DEF void stbtt_FreeShape(const stbtt_fontinfo *info, stbtt_vertex *v) { STBTT_free(v, info->userdata); }
 
STBTT_DEF stbtt_uint8 *stbtt_FindSVGDoc(const stbtt_fontinfo *info, int gl)
{
  int i;
  stbtt_uint8 *data = info->data;
  stbtt_uint8 *svg_doc_list = data + stbtt__get_svg((stbtt_fontinfo *)info);
 
  int numEntries = ttUSHORT(svg_doc_list);
  stbtt_uint8 *svg_docs = svg_doc_list + 2;
 
  for (i = 0; i < numEntries; i++) {
    stbtt_uint8 *svg_doc = svg_docs + (12 * i);
    if ((gl >= ttUSHORT(svg_doc)) && (gl <= ttUSHORT(svg_doc + 2)))
      return svg_doc;
  }
  return 0;
}
 
STBTT_DEF int stbtt_GetGlyphSVG(const stbtt_fontinfo *info, int gl, const char **svg)
{
  stbtt_uint8 *data = info->data;
  stbtt_uint8 *svg_doc;
 
  if (info->svg == 0)
    return 0;
 
  svg_doc = stbtt_FindSVGDoc(info, gl);
  if (svg_doc != nullptr) {
    *svg = (char *)data + info->svg + ttULONG(svg_doc + 4);
    return ttULONG(svg_doc + 8);
  }
  else {
    return 0;
  }
}
 
STBTT_DEF int stbtt_GetCodepointSVG(const stbtt_fontinfo *info, int unicode_codepoint, const char **svg)
{
  return stbtt_GetGlyphSVG(info, stbtt_FindGlyphIndex(info, unicode_codepoint), svg);
}

//
// antialiasing software rasterizer
//
 
STBTT_DEF void stbtt_GetGlyphBitmapBoxSubpixel(const stbtt_fontinfo *font, int glyph, float scale_x, float scale_y,
                                               float shift_x, float shift_y, int *ix0, int *iy0, int *ix1, int *iy1)
{
  int x0 = 0, y0 = 0, x1, y1; // =0 suppresses compiler warning
  if (!stbtt_GetGlyphBox(font, glyph, &x0, &y0, &x1, &y1)) {
    // e.g. space character
    if (ix0)
      *ix0 = 0;
    if (iy0)
      *iy0 = 0;
    if (ix1)
      *ix1 = 0;
    if (iy1)
      *iy1 = 0;
  }
  else {
 // move to integral bboxes (treating pixels as little squares, what pixels get touched)?
    if (ix0)
      *ix0 = STBTT_ifloor(x0 * scale_x + shift_x);
    if (iy0)
      *iy0 = STBTT_ifloor(-y1 * scale_y + shift_y);
    if (ix1)
      *ix1 = STBTT_iceil(x1 * scale_x + shift_x);
    if (iy1)
      *iy1 = STBTT_iceil(-y0 * scale_y + shift_y);
  }
}
 
STBTT_DEF void stbtt_GetGlyphBitmapBox(const stbtt_fontinfo *font, int glyph, float scale_x, float scale_y, int *ix0,
                                       int *iy0, int *ix1, int *iy1)
{
  stbtt_GetGlyphBitmapBoxSubpixel(font, glyph, scale_x, scale_y, 0.0f, 0.0f, ix0, iy0, ix1, iy1);
}
 
STBTT_DEF void stbtt_GetCodepointBitmapBoxSubpixel(const stbtt_fontinfo *font, int codepoint, float scale_x,
                                                   float scale_y, float shift_x, float shift_y, int *ix0, int *iy0,
                                                   int *ix1, int *iy1)
{
  stbtt_GetGlyphBitmapBoxSubpixel(font, stbtt_FindGlyphIndex(font, codepoint), scale_x, scale_y, shift_x, shift_y, ix0,
                                  iy0, ix1, iy1);
}
 
STBTT_DEF void stbtt_GetCodepointBitmapBox(const stbtt_fontinfo *font, int codepoint, float scale_x, float scale_y,
                                           int *ix0, int *iy0, int *ix1, int *iy1)
{
  stbtt_GetCodepointBitmapBoxSubpixel(font, codepoint, scale_x, scale_y, 0.0f, 0.0f, ix0, iy0, ix1, iy1);
}

//
//  Rasterizer
 
typedef struct stbtt__hheap_chunk
{
  struct stbtt__hheap_chunk *next;
} stbtt__hheap_chunk;
 
typedef struct stbtt__hheap
{
  struct stbtt__hheap_chunk *head;
  void *first_free;
  int num_remaining_in_head_chunk;
} stbtt__hheap;
 
static void *stbtt__hheap_alloc(stbtt__hheap *hh, size_t size, void *userdata)
{
  if (hh->first_free) {
    void *p = hh->first_free;
    hh->first_free = *(void **)p;
    return p;
  }
  else {
    if (hh->num_remaining_in_head_chunk == 0) {
      int count = (size < 32 ? 2000 : size < 128 ? 800 : 100);
      stbtt__hheap_chunk *c = (stbtt__hheap_chunk *)STBTT_malloc(sizeof(stbtt__hheap_chunk) + size * count, userdata);
      if (c == nullptr)
        return nullptr;
      c->next = hh->head;
      hh->head = c;
      hh->num_remaining_in_head_chunk = count;
    }
    --hh->num_remaining_in_head_chunk;
    return (char *)(hh->head) + sizeof(stbtt__hheap_chunk) + size * hh->num_remaining_in_head_chunk;
  }
}
 
static void stbtt__hheap_free(stbtt__hheap *hh, void *p)
{
  *(void **)p = hh->first_free;
  hh->first_free = p;
}
 
static void stbtt__hheap_cleanup(stbtt__hheap *hh, void *userdata)
{
  stbtt__hheap_chunk *c = hh->head;
  while (c) {
    stbtt__hheap_chunk *n = c->next;
    STBTT_free(c, userdata);
    c = n;
  }
}
 
typedef struct stbtt__edge
{
  float x0, y0, x1, y1;
  int invert;
} stbtt__edge;
 
typedef struct stbtt__active_edge
{
  struct stbtt__active_edge *next;
#if STBTT_RASTERIZER_VERSION == 1
  int x, dx;
  float ey;
  int direction;
#elif STBTT_RASTERIZER_VERSION == 2
  float fx, fdx, fdy;
  float direction;
  float sy;
  float ey;
#else
#error "Unrecognized value of STBTT_RASTERIZER_VERSION"
#endif
} stbtt__active_edge;
 
#if STBTT_RASTERIZER_VERSION == 1
#define STBTT_FIXSHIFT 10
#define STBTT_FIX (1 << STBTT_FIXSHIFT)
#define STBTT_FIXMASK (STBTT_FIX - 1)
 
static stbtt__active_edge *stbtt__new_active(stbtt__hheap *hh, stbtt__edge *e, int off_x, float start_point,
                                             void *userdata)
{
  stbtt__active_edge *z = (stbtt__active_edge *)stbtt__hheap_alloc(hh, sizeof(*z), userdata);
  float dxdy = (e->x1 - e->x0) / (e->y1 - e->y0);
  STBTT_assert(z != nullptr);
  if (!z)
    return z;
 
  // round dx down to avoid overshooting
  if (dxdy < 0)
    z->dx = -STBTT_ifloor(STBTT_FIX * -dxdy);
  else
    z->dx = STBTT_ifloor(STBTT_FIX * dxdy);
 
  z->x = STBTT_ifloor(STBTT_FIX * e->x0 +
                      z->dx * (start_point - e->y0)); // use z->dx so when we offset later it's by the same amount
  z->x -= off_x * STBTT_FIX;
 
  z->ey = e->y1;
  z->next = 0;
  z->direction = e->invert ? 1 : -1;
  return z;
}
#elif STBTT_RASTERIZER_VERSION == 2
static stbtt__active_edge *stbtt__new_active(stbtt__hheap *hh, stbtt__edge *e, int off_x, float start_point,
                                             void *userdata)
{
  stbtt__active_edge *z = (stbtt__active_edge *)stbtt__hheap_alloc(hh, sizeof(*z), userdata);
  float dxdy = (e->x1 - e->x0) / (e->y1 - e->y0);
  STBTT_assert(z != nullptr);
  // STBTT_assert(e->y0 <= start_point);
  if (!z)
    return z;
  z->fdx = dxdy;
  z->fdy = dxdy != 0.0f ? (1.0f / dxdy) : 0.0f;
  z->fx = e->x0 + dxdy * (start_point - e->y0);
  z->fx -= off_x;
  z->direction = e->invert ? 1.0f : -1.0f;
  z->sy = e->y0;
  z->ey = e->y1;
  z->next = 0;
  return z;
}
#else
#error "Unrecognized value of STBTT_RASTERIZER_VERSION"
#endif
 
#if STBTT_RASTERIZER_VERSION == 1
// note: this routine clips fills that extend off the edges... ideally this
// wouldn't happen, but it could happen if the truetype glyph bounding boxes
// are wrong, or if the user supplies a too-small bitmap
static void stbtt__fill_active_edges(unsigned char *scanline, int len, stbtt__active_edge *e, int max_weight)
{
  // non-zero winding fill
  int x0 = 0, w = 0;
 
  while (e) {
    if (w == 0) {
      // if we're currently at zero, we need to record the edge start point
      x0 = e->x;
      w += e->direction;
    }
    else {
      int x1 = e->x;
      w += e->direction;
      // if we went to zero, we need to draw
      if (w == 0) {
        int i = x0 >> STBTT_FIXSHIFT;
        int j = x1 >> STBTT_FIXSHIFT;
 
        if (i < len && j >= 0) {
          if (i == j) {
            // x0,x1 are the same pixel, so compute combined coverage
            scanline[i] = scanline[i] + (stbtt_uint8)((x1 - x0) * max_weight >> STBTT_FIXSHIFT);
          }
          else {
            if (i >= 0) // add antialiasing for x0
              scanline[i] =
              scanline[i] + (stbtt_uint8)(((STBTT_FIX - (x0 & STBTT_FIXMASK)) * max_weight) >> STBTT_FIXSHIFT);
            else
              i = -1; // clip
 
            if (j < len) // add antialiasing for x1
              scanline[j] = scanline[j] + (stbtt_uint8)(((x1 & STBTT_FIXMASK) * max_weight) >> STBTT_FIXSHIFT);
            else
              j = len; // clip
 
            for (++i; i < j; ++i) // fill pixels between x0 and x1
              scanline[i] = scanline[i] + (stbtt_uint8)max_weight;
          }
        }
      }
    }
 
    e = e->next;
  }
}
 
static void stbtt__rasterize_sorted_edges(stbtt__bitmap *result, stbtt__edge *e, int n, int vsubsample, int off_x,
                                          int off_y, void *userdata)
{
  stbtt__hheap hh = { 0, 0, 0 };
  stbtt__active_edge *active = nullptr;
  int y, j = 0;
  int max_weight = (255 / vsubsample); // weight per vertical scanline
  int s;                               // vertical subsample index
  unsigned char scanline_data[512], *scanline;
 
  if (result->w > 512)
    scanline = (unsigned char *)STBTT_malloc(result->w, userdata);
  else
    scanline = scanline_data;
 
  y = off_y * vsubsample;
  e[n].y0 = (off_y + result->h) * (float)vsubsample + 1;
 
  while (j < result->h) {
    STBTT_memset(scanline, 0, result->w);
    for (s = 0; s < vsubsample; ++s) {
      // find center of pixel for this scanline
      float scan_y = y + 0.5f;
      stbtt__active_edge **step = &active;
 
      // update all active edges;
      // remove all active edges that terminate before the center of this scanline
      while (*step) {
        stbtt__active_edge *z = *step;
        if (z->ey <= scan_y) {
          *step = z->next; // delete from list
          STBTT_assert(z->direction);
          z->direction = 0;
          stbtt__hheap_free(&hh, z);
        }
        else {
          z->x += z->dx;           // advance to position for current scanline
          step = &((*step)->next); // advance through list
        }
      }
 
      // resort the list if needed
      for (;;) {
        int changed = 0;
        step = &active;
        while (*step && (*step)->next) {
          if ((*step)->x > (*step)->next->x) {
            stbtt__active_edge *t = *step;
            stbtt__active_edge *q = t->next;
 
            t->next = q->next;
            q->next = t;
            *step = q;
            changed = 1;
          }
          step = &(*step)->next;
        }
        if (!changed)
          break;
      }
 
      // insert all edges that start before the center of this scanline -- omit ones that also end on this scanline
      while (e->y0 <= scan_y) {
        if (e->y1 > scan_y) {
          stbtt__active_edge *z = stbtt__new_active(&hh, e, off_x, scan_y, userdata);
          if (z != nullptr) {
            // find insertion point
            if (active == nullptr)
              active = z;
            else if (z->x < active->x) {
              // insert at front
              z->next = active;
              active = z;
            }
            else {
           // find thing to insert AFTER
              stbtt__active_edge *p = active;
              while (p->next && p->next->x < z->x)
                p = p->next;
              // at this point, p->next->x is NOT < z->x
              z->next = p->next;
              p->next = z;
            }
          }
        }
        ++e;
      }
 
      // now process all active edges in XOR fashion
      if (active)
        stbtt__fill_active_edges(scanline, result->w, active, max_weight);
 
      ++y;
    }
    STBTT_memcpy(result->pixels + j * result->stride, scanline, result->w);
    ++j;
  }
 
  stbtt__hheap_cleanup(&hh, userdata);
 
  if (scanline != scanline_data)
    STBTT_free(scanline, userdata);
}
 
#elif STBTT_RASTERIZER_VERSION == 2
 
// the edge passed in here does not cross the vertical line at x or the vertical line at x+1
// (i.e. it has already been clipped to those)
static void stbtt__handle_clipped_edge(float *scanline, int x, stbtt__active_edge *e, float x0, float y0, float x1,
                                       float y1)
{
  if (y0 == y1)
    return;
  STBTT_assert(y0 < y1);
  STBTT_assert(e->sy <= e->ey);
  if (y0 > e->ey)
    return;
  if (y1 < e->sy)
    return;
  if (y0 < e->sy) {
    x0 += (x1 - x0) * (e->sy - y0) / (y1 - y0);
    y0 = e->sy;
  }
  if (y1 > e->ey) {
    x1 += (x1 - x0) * (e->ey - y1) / (y1 - y0);
    y1 = e->ey;
  }
 
  if (x0 == x)
    STBTT_assert(x1 <= x + 1);
  else if (x0 == x + 1)
    STBTT_assert(x1 >= x);
  else if (x0 <= x)
    STBTT_assert(x1 <= x);
  else if (x0 >= x + 1)
    STBTT_assert(x1 >= x + 1);
  else
    STBTT_assert(x1 >= x && x1 <= x + 1);
 
  if (x0 <= x && x1 <= x)
    scanline[x] += e->direction * (y1 - y0);
  else if (x0 >= x + 1 && x1 >= x + 1)
    ;
  else {
    STBTT_assert(x0 >= x && x0 <= x + 1 && x1 >= x && x1 <= x + 1);
    scanline[x] += e->direction * (y1 - y0) * (1 - ((x0 - x) + (x1 - x)) / 2); // coverage = 1 - average x position
  }
}
 
static float stbtt__sized_trapezoid_area(float height, float top_width, float bottom_width)
{
  STBTT_assert(top_width >= 0);
  STBTT_assert(bottom_width >= 0);
  return (top_width + bottom_width) / 2.0f * height;
}
 
static float stbtt__position_trapezoid_area(float height, float tx0, float tx1, float bx0, float bx1)
{
  return stbtt__sized_trapezoid_area(height, tx1 - tx0, bx1 - bx0);
}
 
static float stbtt__sized_triangle_area(float height, float width) { return height * width / 2; }
 
static void stbtt__fill_active_edges_new(float *scanline, float *scanline_fill, int len, stbtt__active_edge *e,
                                         float y_top)
{
  float y_bottom = y_top + 1;
 
  while (e) {
    // brute force every pixel
 
    // compute intersection points with top & bottom
    STBTT_assert(e->ey >= y_top);
 
    if (e->fdx == 0) {
      float x0 = e->fx;
      if (x0 < len) {
        if (x0 >= 0) {
          stbtt__handle_clipped_edge(scanline, (int)x0, e, x0, y_top, x0, y_bottom);
          stbtt__handle_clipped_edge(scanline_fill - 1, (int)x0 + 1, e, x0, y_top, x0, y_bottom);
        }
        else {
          stbtt__handle_clipped_edge(scanline_fill - 1, 0, e, x0, y_top, x0, y_bottom);
        }
      }
    }
    else {
      float x0 = e->fx;
      float dx = e->fdx;
      float xb = x0 + dx;
      float x_top, x_bottom;
      float sy0, sy1;
      float dy = e->fdy;
      STBTT_assert(e->sy <= y_bottom && e->ey >= y_top);
 
      // compute endpoints of line segment clipped to this scanline (if the
      // line segment starts on this scanline. x0 is the intersection of the
      // line with y_top, but that may be off the line segment.
      if (e->sy > y_top) {
        x_top = x0 + dx * (e->sy - y_top);
        sy0 = e->sy;
      }
      else {
        x_top = x0;
        sy0 = y_top;
      }
      if (e->ey < y_bottom) {
        x_bottom = x0 + dx * (e->ey - y_top);
        sy1 = e->ey;
      }
      else {
        x_bottom = xb;
        sy1 = y_bottom;
      }
 
      if (x_top >= 0 && x_bottom >= 0 && x_top < len && x_bottom < len) {
        // from here on, we don't have to range check x values
 
        if ((int)x_top == (int)x_bottom) {
          float height;
          // simple case, only spans one pixel
          int x = (int)x_top;
          height = (sy1 - sy0) * e->direction;
          STBTT_assert(x >= 0 && x < len);
          scanline[x] += stbtt__position_trapezoid_area(height, x_top, x + 1.0f, x_bottom, x + 1.0f);
          scanline_fill[x] += height; // everything right of this pixel is filled
        }
        else {
          int x, x1, x2;
          float y_crossing, y_final, step, sign, area;
          // covers 2+ pixels
          if (x_top > x_bottom) {
            // flip scanline vertically; signed area is the same
            float t;
            sy0 = y_bottom - (sy0 - y_top);
            sy1 = y_bottom - (sy1 - y_top);
            t = sy0, sy0 = sy1, sy1 = t;
            t = x_bottom, x_bottom = x_top, x_top = t;
            dx = -dx;
            dy = -dy;
            t = x0, x0 = xb, xb = t;
          }
          STBTT_assert(dy >= 0);
          STBTT_assert(dx >= 0);
 
          x1 = (int)x_top;
          x2 = (int)x_bottom;
          // compute intersection with y axis at x1+1
          y_crossing = y_top + dy * (x1 + 1 - x0);
 
          // compute intersection with y axis at x2
          y_final = y_top + dy * (x2 - x0);
 
          //           x1    x_top                            x2    x_bottom
          //     y_top  +------|-----+------------+------------+--------|---+------------+
          //            |            |            |            |            |            |
          //            |            |            |            |            |            |
          //       sy0  |      Txxxxx|............|............|............|............|
          // y_crossing |            *xxxxx.......|............|............|............|
          //            |            |     xxxxx..|............|............|............|
          //            |            |     /-   xx*xxxx........|............|............|
          //            |            | dy <       |    xxxxxx..|............|............|
          //   y_final  |            |     \-     |          xx*xxx.........|............|
          //       sy1  |            |            |            |   xxxxxB...|............|
          //            |            |            |            |            |            |
          //            |            |            |            |            |            |
          //  y_bottom  +------------+------------+------------+------------+------------+
          //
          // goal is to measure the area covered by '.' in each pixel
 
          // if x2 is right at the right edge of x1, y_crossing can blow up, github #1057
          // @TODO: maybe test against sy1 rather than y_bottom?
          if (y_crossing > y_bottom)
            y_crossing = y_bottom;
 
          sign = e->direction;
 
          // area of the rectangle covered from sy0..y_crossing
          area = sign * (y_crossing - sy0);
 
          // area of the triangle (x_top,sy0), (x1+1,sy0), (x1+1,y_crossing)
          scanline[x1] += stbtt__sized_triangle_area(area, x1 + 1 - x_top);
 
          // check if final y_crossing is blown up; no test case for this
          if (y_final > y_bottom) {
            y_final = y_bottom;
            dy = (y_final - y_crossing) / (x2 - (x1 + 1)); // if denom=0, y_final = y_crossing, so y_final <= y_bottom
          }
 
          // in second pixel, area covered by line segment found in first pixel
          // is always a rectangle 1 wide * the height of that line segment; this
          // is exactly what the variable 'area' stores. it also gets a contribution
          // from the line segment within it. the THIRD pixel will get the first
          // pixel's rectangle contribution, the second pixel's rectangle contribution,
          // and its own contribution. the 'own contribution' is the same in every pixel except
          // the leftmost and rightmost, a trapezoid that slides down in each pixel.
          // the second pixel's contribution to the third pixel will be the
          // rectangle 1 wide times the height change in the second pixel, which is dy.
 
          step = sign * dy * 1; // dy is dy/dx, change in y for every 1 change in x,
          // which multiplied by 1-pixel-width is how much pixel area changes for each step in x
          // so the area advances by 'step' every time
 
          for (x = x1 + 1; x < x2; ++x) {
            scanline[x] += area + step / 2; // area of trapezoid is 1*step/2
            area += step;
          }
          STBTT_assert(STBTT_fabs(area) <= 1.01f); // accumulated error from area += step unless we round step down
          STBTT_assert(sy1 > y_final - 0.01f);
 
          // area covered in the last pixel is the rectangle from all the pixels to the left,
          // plus the trapezoid filled by the line segment in this pixel all the way to the right edge
          scanline[x2] +=
            area + sign * stbtt__position_trapezoid_area(sy1 - y_final, (float)x2, x2 + 1.0f, x_bottom, x2 + 1.0f);
 
        // the rest of the line is filled based on the total height of the line segment in this pixel
          scanline_fill[x2] += sign * (sy1 - sy0);
        }
      }
      else {
     // if edge goes outside of box we're drawing, we require
     // clipping logic. since this does not match the intended use
     // of this library, we use a different, very slow brute
     // force implementation
     // note though that this does happen some of the time because
     // x_top and x_bottom can be extrapolated at the top & bottom of
     // the shape and actually lie outside the bounding box
        int x;
        for (x = 0; x < len; ++x) {
          // cases:
          //
          // there can be up to two intersections with the pixel. any intersection
          // with left or right edges can be handled by splitting into two (or three)
          // regions. intersections with top & bottom do not necessitate case-wise logic.
          //
          // the old way of doing this found the intersections with the left & right edges,
          // then used some simple logic to produce up to three segments in sorted order
          // from top-to-bottom. however, this had a problem: if an x edge was epsilon
          // across the x border, then the corresponding y position might not be distinct
          // from the other y segment, and it might ignored as an empty segment. to avoid
          // that, we need to explicitly produce segments based on x positions.
 
          // rename variables to clearly-defined pairs
          float y0 = y_top;
          float x1 = (float)(x);
          float x2 = (float)(x + 1);
          float x3 = xb;
          float y3 = y_bottom;
 
          // x = e->x + e->dx * (y-y_top)
          // (y-y_top) = (x - e->x) / e->dx
          // y = (x - e->x) / e->dx + y_top
          float y1 = (x - x0) / dx + y_top;
          float y2 = (x + 1 - x0) / dx + y_top;
 
          if (x0 < x1 && x3 > x2) { // three segments descending down-right
            stbtt__handle_clipped_edge(scanline, x, e, x0, y0, x1, y1);
            stbtt__handle_clipped_edge(scanline, x, e, x1, y1, x2, y2);
            stbtt__handle_clipped_edge(scanline, x, e, x2, y2, x3, y3);
          }
          else if (x3 < x1 && x0 > x2) { // three segments descending down-left
            stbtt__handle_clipped_edge(scanline, x, e, x0, y0, x2, y2);
            stbtt__handle_clipped_edge(scanline, x, e, x2, y2, x1, y1);
            stbtt__handle_clipped_edge(scanline, x, e, x1, y1, x3, y3);
          }
          else if (x0 < x1 && x3 > x1) { // two segments across x, down-right
            stbtt__handle_clipped_edge(scanline, x, e, x0, y0, x1, y1);
            stbtt__handle_clipped_edge(scanline, x, e, x1, y1, x3, y3);
          }
          else if (x3 < x1 && x0 > x1) { // two segments across x, down-left
            stbtt__handle_clipped_edge(scanline, x, e, x0, y0, x1, y1);
            stbtt__handle_clipped_edge(scanline, x, e, x1, y1, x3, y3);
          }
          else if (x0 < x2 && x3 > x2) { // two segments across x+1, down-right
            stbtt__handle_clipped_edge(scanline, x, e, x0, y0, x2, y2);
            stbtt__handle_clipped_edge(scanline, x, e, x2, y2, x3, y3);
          }
          else if (x3 < x2 && x0 > x2) { // two segments across x+1, down-left
            stbtt__handle_clipped_edge(scanline, x, e, x0, y0, x2, y2);
            stbtt__handle_clipped_edge(scanline, x, e, x2, y2, x3, y3);
          }
          else { // one segment
            stbtt__handle_clipped_edge(scanline, x, e, x0, y0, x3, y3);
          }
        }
      }
    }
    e = e->next;
  }
}
 
// directly AA rasterize edges w/o supersampling
static void stbtt__rasterize_sorted_edges(stbtt__bitmap *result, stbtt__edge *e, int n, int vsubsample, int off_x,
                                          int off_y, void *userdata)
{
  stbtt__hheap hh = { 0, 0, 0 };
  stbtt__active_edge *active = nullptr;
  int y, j = 0, i;
  float scanline_data[129], *scanline, *scanline2;
 
  STBTT__NOTUSED(vsubsample);
 
  if (result->w > 64)
    scanline = (float *)STBTT_malloc((result->w * 2 + 1) * sizeof(float), userdata);
  else
    scanline = scanline_data;
 
  scanline2 = scanline + result->w;
 
  y = off_y;
  e[n].y0 = (float)(off_y + result->h) + 1;
 
  while (j < result->h) {
    // find center of pixel for this scanline
    float scan_y_top = y + 0.0f;
    float scan_y_bottom = y + 1.0f;
    stbtt__active_edge **step = &active;
 
    STBTT_memset(scanline, 0, result->w * sizeof(scanline[0]));
    STBTT_memset(scanline2, 0, (result->w + 1) * sizeof(scanline[0]));
 
    // update all active edges;
    // remove all active edges that terminate before the top of this scanline
    while (*step) {
      stbtt__active_edge *z = *step;
      if (z->ey <= scan_y_top) {
        *step = z->next; // delete from list
        STBTT_assert(z->direction);
        z->direction = 0;
        stbtt__hheap_free(&hh, z);
      }
      else {
        step = &((*step)->next); // advance through list
      }
    }
 
    // insert all edges that start before the bottom of this scanline
    while (e->y0 <= scan_y_bottom) {
      if (e->y0 != e->y1) {
        stbtt__active_edge *z = stbtt__new_active(&hh, e, off_x, scan_y_top, userdata);
        if (z != nullptr) {
          if (j == 0 && off_y != 0) {
            if (z->ey < scan_y_top) {
              // this can happen due to subpixel positioning and some kind of fp rounding error i think
              z->ey = scan_y_top;
            }
          }
          STBTT_assert(z->ey >= scan_y_top); // if we get really unlucky a tiny bit of an edge can be out of bounds
          // insert at front
          z->next = active;
          active = z;
        }
      }
      ++e;
    }
 
    // now process all active edges
    if (active)
      stbtt__fill_active_edges_new(scanline, scanline2 + 1, result->w, active, scan_y_top);
 
    {
      float sum = 0;
      for (i = 0; i < result->w; ++i) {
        float k;
        int m;
        sum += scanline2[i];
        k = scanline[i] + sum;
        k = (float)STBTT_fabs(k) * 255 + 0.5f;
        m = (int)k;
        if (m > 255)
          m = 255;
        result->pixels[j * result->stride + i] = (unsigned char)m;
      }
    }
    // advance all the edges
    step = &active;
    while (*step) {
      stbtt__active_edge *z = *step;
      z->fx += z->fdx;         // advance to position for current scanline
      step = &((*step)->next); // advance through list
    }
 
    ++y;
    ++j;
  }
 
  stbtt__hheap_cleanup(&hh, userdata);
 
  if (scanline != scanline_data)
    STBTT_free(scanline, userdata);
}
#else
#error "Unrecognized value of STBTT_RASTERIZER_VERSION"
#endif
 
#define STBTT__COMPARE(a, b) ((a)->y0 < (b)->y0)
 
static void stbtt__sort_edges_ins_sort(stbtt__edge *p, int n)
{
  int i, j;
  for (i = 1; i < n; ++i) {
    stbtt__edge t = p[i], *a = &t;
    j = i;
    while (j > 0) {
      stbtt__edge *b = &p[j - 1];
      int c = STBTT__COMPARE(a, b);
      if (!c)
        break;
      p[j] = p[j - 1];
      --j;
    }
    if (i != j)
      p[j] = t;
  }
}
 
static void stbtt__sort_edges_quicksort(stbtt__edge *p, int n)
{
  /* threshold for transitioning to insertion sort */
  while (n > 12) {
    stbtt__edge t;
    int c01, c12, c, m, i, j;
 
    /* compute median of three */
    m = n >> 1;
    c01 = STBTT__COMPARE(&p[0], &p[m]);
    c12 = STBTT__COMPARE(&p[m], &p[n - 1]);
    /* if 0 >= mid >= end, or 0 < mid < end, then use mid */
    if (c01 != c12) {
      /* otherwise, we'll need to swap something else to middle */
      int z;
      c = STBTT__COMPARE(&p[0], &p[n - 1]);
      /* 0>mid && mid<n:  0>n => n; 0<n => 0 */
      /* 0<mid && mid>n:  0>n => 0; 0<n => n */
      z = (c == c12) ? 0 : n - 1;
      t = p[z];
      p[z] = p[m];
      p[m] = t;
    }
    /* now p[m] is the median-of-three */
    /* swap it to the beginning so it won't move around */
    t = p[0];
    p[0] = p[m];
    p[m] = t;
 
    /* partition loop */
    i = 1;
    j = n - 1;
    for (;;) {
      /* handling of equality is crucial here */
      /* for sentinels & efficiency with duplicates */
      for (;; ++i) {
        if (!STBTT__COMPARE(&p[i], &p[0]))
          break;
      }
      for (;; --j) {
        if (!STBTT__COMPARE(&p[0], &p[j]))
          break;
      }
      /* make sure we haven't crossed */
      if (i >= j)
        break;
      t = p[i];
      p[i] = p[j];
      p[j] = t;
 
      ++i;
      --j;
    }
    /* recurse on smaller side, iterate on larger */
    if (j < (n - i)) {
      stbtt__sort_edges_quicksort(p, j);
      p = p + i;
      n = n - i;
    }
    else {
      stbtt__sort_edges_quicksort(p + i, n - i);
      n = j;
    }
  }
}
 
static void stbtt__sort_edges(stbtt__edge *p, int n)
{
  stbtt__sort_edges_quicksort(p, n);
  stbtt__sort_edges_ins_sort(p, n);
}
 
typedef struct
{
  float x, y;
} stbtt__point;
 
static void stbtt__rasterize(stbtt__bitmap *result, stbtt__point *pts, int *wcount, int windings, float scale_x,
                             float scale_y, float shift_x, float shift_y, int off_x, int off_y, int invert,
                             void *userdata)
{
  float y_scale_inv = invert ? -scale_y : scale_y;
  stbtt__edge *e;
  int n, i, j, k, m;
#if STBTT_RASTERIZER_VERSION == 1
  int vsubsample = result->h < 8 ? 15 : 5;
#elif STBTT_RASTERIZER_VERSION == 2
  int vsubsample = 1;
#else
#error "Unrecognized value of STBTT_RASTERIZER_VERSION"
#endif
  // vsubsample should divide 255 evenly; otherwise we won't reach full opacity
 
  // now we have to blow out the windings into explicit edge lists
  n = 0;
  for (i = 0; i < windings; ++i)
    n += wcount[i];
 
  e = (stbtt__edge *)STBTT_malloc(sizeof(*e) * (n + 1), userdata); // add an extra one as a sentinel
  if (e == 0)
    return;
  n = 0;
 
  m = 0;
  for (i = 0; i < windings; ++i) {
    stbtt__point *p = pts + m;
    m += wcount[i];
    j = wcount[i] - 1;
    for (k = 0; k < wcount[i]; j = k++) {
      int a = k, b = j;
      // skip the edge if horizontal
      if (p[j].y == p[k].y)
        continue;
      // add edge from j to k to the list
      e[n].invert = 0;
      if (invert ? p[j].y > p[k].y : p[j].y < p[k].y) {
        e[n].invert = 1;
        a = j, b = k;
      }
      e[n].x0 = p[a].x * scale_x + shift_x;
      e[n].y0 = (p[a].y * y_scale_inv + shift_y) * vsubsample;
      e[n].x1 = p[b].x * scale_x + shift_x;
      e[n].y1 = (p[b].y * y_scale_inv + shift_y) * vsubsample;
      ++n;
    }
  }
 
  // now sort the edges by their highest point (should snap to integer, and then by x)
  // STBTT_sort(e, n, sizeof(e[0]), stbtt__edge_compare);
  stbtt__sort_edges(e, n);
 
  // now, traverse the scanlines and find the intersections on each scanline, use xor winding rule
  stbtt__rasterize_sorted_edges(result, e, n, vsubsample, off_x, off_y, userdata);
 
  STBTT_free(e, userdata);
}
 
static void stbtt__add_point(stbtt__point *points, int n, float x, float y)
{
  if (!points)
    return; // during first pass, it's unallocated
  points[n].x = x;
  points[n].y = y;
}
 
// tessellate until threshold p is happy... @TODO warped to compensate for non-linear stretching
static int stbtt__tesselate_curve(stbtt__point *points, int *num_points, float x0, float y0, float x1, float y1,
                                  float x2, float y2, float objspace_flatness_squared, int n)
{
  // midpoint
  float mx = (x0 + 2 * x1 + x2) / 4;
  float my = (y0 + 2 * y1 + y2) / 4;
  // versus directly drawn line
  float dx = (x0 + x2) / 2 - mx;
  float dy = (y0 + y2) / 2 - my;
  if (n > 16) // 65536 segments on one curve better be enough!
    return 1;
  if (dx * dx + dy * dy > objspace_flatness_squared) { // half-pixel error allowed... need to be smaller if AA
    stbtt__tesselate_curve(points, num_points, x0, y0, (x0 + x1) / 2.0f, (y0 + y1) / 2.0f, mx, my,
                           objspace_flatness_squared, n + 1);
    stbtt__tesselate_curve(points, num_points, mx, my, (x1 + x2) / 2.0f, (y1 + y2) / 2.0f, x2, y2,
                           objspace_flatness_squared, n + 1);
  }
  else {
    stbtt__add_point(points, *num_points, x2, y2);
    *num_points = *num_points + 1;
  }
  return 1;
}
 
static void stbtt__tesselate_cubic(stbtt__point *points, int *num_points, float x0, float y0, float x1, float y1,
                                   float x2, float y2, float x3, float y3, float objspace_flatness_squared, int n)
{
  // @TODO this "flatness" calculation is just made-up nonsense that seems to work well enough
  float dx0 = x1 - x0;
  float dy0 = y1 - y0;
  float dx1 = x2 - x1;
  float dy1 = y2 - y1;
  float dx2 = x3 - x2;
  float dy2 = y3 - y2;
  float dx = x3 - x0;
  float dy = y3 - y0;
  float longlen = (float)(STBTT_sqrt(dx0 * dx0 + dy0 * dy0) + STBTT_sqrt(dx1 * dx1 + dy1 * dy1) +
                          STBTT_sqrt(dx2 * dx2 + dy2 * dy2));
  float shortlen = (float)STBTT_sqrt(dx * dx + dy * dy);
  float flatness_squared = longlen * longlen - shortlen * shortlen;
 
  if (n > 16) // 65536 segments on one curve better be enough!
    return;
 
  if (flatness_squared > objspace_flatness_squared) {
    float x01 = (x0 + x1) / 2;
    float y01 = (y0 + y1) / 2;
    float x12 = (x1 + x2) / 2;
    float y12 = (y1 + y2) / 2;
    float x23 = (x2 + x3) / 2;
    float y23 = (y2 + y3) / 2;
 
    float xa = (x01 + x12) / 2;
    float ya = (y01 + y12) / 2;
    float xb = (x12 + x23) / 2;
    float yb = (y12 + y23) / 2;
 
    float mx = (xa + xb) / 2;
    float my = (ya + yb) / 2;
 
    stbtt__tesselate_cubic(points, num_points, x0, y0, x01, y01, xa, ya, mx, my, objspace_flatness_squared, n + 1);
    stbtt__tesselate_cubic(points, num_points, mx, my, xb, yb, x23, y23, x3, y3, objspace_flatness_squared, n + 1);
  }
  else {
    stbtt__add_point(points, *num_points, x3, y3);
    *num_points = *num_points + 1;
  }
}
 
// returns number of contours
static stbtt__point *stbtt_FlattenCurves(stbtt_vertex *vertices, int num_verts, float objspace_flatness,
                                         int **contour_lengths, int *num_contours, void *userdata)
{
  stbtt__point *points = 0;
  int num_points = 0;
 
  float objspace_flatness_squared = objspace_flatness * objspace_flatness;
  int i, n = 0, start = 0, pass;
 
  // count how many "moves" there are to get the contour count
  for (i = 0; i < num_verts; ++i)
    if (vertices[i].type == STBTT_vmove)
      ++n;
 
  *num_contours = n;
  if (n == 0)
    return 0;
 
  *contour_lengths = (int *)STBTT_malloc(sizeof(**contour_lengths) * n, userdata);
 
  if (*contour_lengths == 0) {
    *num_contours = 0;
    return 0;
  }
 
  // make two passes through the points so we don't need to realloc
  for (pass = 0; pass < 2; ++pass) {
    float x = 0, y = 0;
    if (pass == 1) {
      points = (stbtt__point *)STBTT_malloc(num_points * sizeof(points[0]), userdata);
      if (points == nullptr)
        goto error;
    }
    num_points = 0;
    n = -1;
    for (i = 0; i < num_verts; ++i) {
      switch (vertices[i].type) {
      case STBTT_vmove:
        // start the next contour
        if (n >= 0)
          (*contour_lengths)[n] = num_points - start;
        ++n;
        start = num_points;
 
        x = vertices[i].x, y = vertices[i].y;
        stbtt__add_point(points, num_points++, x, y);
        break;
      case STBTT_vline:
        x = vertices[i].x, y = vertices[i].y;
        stbtt__add_point(points, num_points++, x, y);
        break;
      case STBTT_vcurve:
        stbtt__tesselate_curve(points, &num_points, x, y, vertices[i].cx, vertices[i].cy, vertices[i].x, vertices[i].y,
                               objspace_flatness_squared, 0);
        x = vertices[i].x, y = vertices[i].y;
        break;
      case STBTT_vcubic:
        stbtt__tesselate_cubic(points, &num_points, x, y, vertices[i].cx, vertices[i].cy, vertices[i].cx1,
                               vertices[i].cy1, vertices[i].x, vertices[i].y, objspace_flatness_squared, 0);
        x = vertices[i].x, y = vertices[i].y;
        break;
      }
    }
    (*contour_lengths)[n] = num_points - start;
  }
 
  return points;
error:
  STBTT_free(points, userdata);
  STBTT_free(*contour_lengths, userdata);
  *contour_lengths = 0;
  *num_contours = 0;
  return nullptr;
}
 
STBTT_DEF void stbtt_Rasterize(stbtt__bitmap *result, float flatness_in_pixels, stbtt_vertex *vertices, int num_verts,
                               float scale_x, float scale_y, float shift_x, float shift_y, int x_off, int y_off,
                               int invert, void *userdata)
{
  float scale = scale_x > scale_y ? scale_y : scale_x;
  int winding_count = 0;
  int *winding_lengths = nullptr;
  stbtt__point *windings =
    stbtt_FlattenCurves(vertices, num_verts, flatness_in_pixels / scale, &winding_lengths, &winding_count, userdata);
  if (windings) {
    stbtt__rasterize(result, windings, winding_lengths, winding_count, scale_x, scale_y, shift_x, shift_y, x_off, y_off,
                     invert, userdata);
    STBTT_free(winding_lengths, userdata);
    STBTT_free(windings, userdata);
  }
}
 
STBTT_DEF void stbtt_FreeBitmap(unsigned char *bitmap, void *userdata) { STBTT_free(bitmap, userdata); }
 
STBTT_DEF unsigned char *stbtt_GetGlyphBitmapSubpixel(const stbtt_fontinfo *info, float scale_x, float scale_y,
                                                      float shift_x, float shift_y, int glyph, int *width, int *height,
                                                      int *xoff, int *yoff)
{
  int ix0, iy0, ix1, iy1;
  stbtt__bitmap gbm;
  stbtt_vertex *vertices;
  int num_verts = stbtt_GetGlyphShape(info, glyph, &vertices);
 
  if (scale_x == 0)
    scale_x = scale_y;
  if (scale_y == 0) {
    if (scale_x == 0) {
      STBTT_free(vertices, info->userdata);
      return nullptr;
    }
    scale_y = scale_x;
  }
 
  stbtt_GetGlyphBitmapBoxSubpixel(info, glyph, scale_x, scale_y, shift_x, shift_y, &ix0, &iy0, &ix1, &iy1);
 
  // now we get the size
  gbm.w = (ix1 - ix0);
  gbm.h = (iy1 - iy0);
  gbm.pixels = nullptr; // in case we error
 
  if (width)
    *width = gbm.w;
  if (height)
    *height = gbm.h;
  if (xoff)
    *xoff = ix0;
  if (yoff)
    *yoff = iy0;
 
  if (gbm.w && gbm.h) {
    gbm.pixels = (unsigned char *)STBTT_malloc(gbm.w * gbm.h, info->userdata);
    if (gbm.pixels) {
      gbm.stride = gbm.w;
 
      stbtt_Rasterize(&gbm, 0.35f, vertices, num_verts, scale_x, scale_y, shift_x, shift_y, ix0, iy0, 1,
                      info->userdata);
    }
  }
  STBTT_free(vertices, info->userdata);
  return gbm.pixels;
}
 
STBTT_DEF unsigned char *stbtt_GetGlyphBitmap(const stbtt_fontinfo *info, float scale_x, float scale_y, int glyph,
                                              int *width, int *height, int *xoff, int *yoff)
{
  return stbtt_GetGlyphBitmapSubpixel(info, scale_x, scale_y, 0.0f, 0.0f, glyph, width, height, xoff, yoff);
}
 
STBTT_DEF void stbtt_MakeGlyphBitmapSubpixel(const stbtt_fontinfo *info, unsigned char *output, int out_w, int out_h,
                                             int out_stride, float scale_x, float scale_y, float shift_x, float shift_y,
                                             int glyph)
{
  int ix0, iy0;
  stbtt_vertex *vertices;
  int num_verts = stbtt_GetGlyphShape(info, glyph, &vertices);
  stbtt__bitmap gbm;
 
  stbtt_GetGlyphBitmapBoxSubpixel(info, glyph, scale_x, scale_y, shift_x, shift_y, &ix0, &iy0, 0, 0);
  gbm.pixels = output;
  gbm.w = out_w;
  gbm.h = out_h;
  gbm.stride = out_stride;
 
  if (gbm.w && gbm.h)
    stbtt_Rasterize(&gbm, 0.35f, vertices, num_verts, scale_x, scale_y, shift_x, shift_y, ix0, iy0, 1, info->userdata);
 
  STBTT_free(vertices, info->userdata);
}
 
STBTT_DEF void stbtt_MakeGlyphBitmap(const stbtt_fontinfo *info, unsigned char *output, int out_w, int out_h,
                                     int out_stride, float scale_x, float scale_y, int glyph)
{
  stbtt_MakeGlyphBitmapSubpixel(info, output, out_w, out_h, out_stride, scale_x, scale_y, 0.0f, 0.0f, glyph);
}
 
STBTT_DEF unsigned char *stbtt_GetCodepointBitmapSubpixel(const stbtt_fontinfo *info, float scale_x, float scale_y,
                                                          float shift_x, float shift_y, int codepoint, int *width,
                                                          int *height, int *xoff, int *yoff)
{
  return stbtt_GetGlyphBitmapSubpixel(info, scale_x, scale_y, shift_x, shift_y, stbtt_FindGlyphIndex(info, codepoint),
                                      width, height, xoff, yoff);
}
 
STBTT_DEF void stbtt_MakeCodepointBitmapSubpixelPrefilter(const stbtt_fontinfo *info, unsigned char *output, int out_w,
                                                          int out_h, int out_stride, float scale_x, float scale_y,
                                                          float shift_x, float shift_y, int oversample_x,
                                                          int oversample_y, float *sub_x, float *sub_y, int codepoint)
{
  stbtt_MakeGlyphBitmapSubpixelPrefilter(info, output, out_w, out_h, out_stride, scale_x, scale_y, shift_x, shift_y,
                                         oversample_x, oversample_y, sub_x, sub_y,
                                         stbtt_FindGlyphIndex(info, codepoint));
}
 
STBTT_DEF void stbtt_MakeCodepointBitmapSubpixel(const stbtt_fontinfo *info, unsigned char *output, int out_w,
                                                 int out_h, int out_stride, float scale_x, float scale_y, float shift_x,
                                                 float shift_y, int codepoint)
{
  stbtt_MakeGlyphBitmapSubpixel(info, output, out_w, out_h, out_stride, scale_x, scale_y, shift_x, shift_y,
                                stbtt_FindGlyphIndex(info, codepoint));
}
 
STBTT_DEF unsigned char *stbtt_GetCodepointBitmap(const stbtt_fontinfo *info, float scale_x, float scale_y,
                                                  int codepoint, int *width, int *height, int *xoff, int *yoff)
{
  return stbtt_GetCodepointBitmapSubpixel(info, scale_x, scale_y, 0.0f, 0.0f, codepoint, width, height, xoff, yoff);
}
 
STBTT_DEF void stbtt_MakeCodepointBitmap(const stbtt_fontinfo *info, unsigned char *output, int out_w, int out_h,
                                         int out_stride, float scale_x, float scale_y, int codepoint)
{
  stbtt_MakeCodepointBitmapSubpixel(info, output, out_w, out_h, out_stride, scale_x, scale_y, 0.0f, 0.0f, codepoint);
}

//
// bitmap baking
//
// This is SUPER-CRAPPY packing to keep source code small
 
static int stbtt_BakeFontBitmap_internal(unsigned char *data, int offset, // font location (use offset=0 for plain .ttf)
                                         float pixel_height,              // height of font in pixels
                                         unsigned char *pixels, int pw, int ph, // bitmap to be filled in
                                         int first_char, int num_chars,         // characters to bake
                                         stbtt_bakedchar *chardata)
{
  float scale;
  int x, y, bottom_y, i;
  stbtt_fontinfo f;
  f.userdata = nullptr;
  if (!stbtt_InitFont(&f, data, offset))
    return -1;
  STBTT_memset(pixels, 0, pw * ph); // background of 0 around pixels
  x = y = 1;
  bottom_y = 1;
 
  scale = stbtt_ScaleForPixelHeight(&f, pixel_height);
 
  for (i = 0; i < num_chars; ++i) {
    int advance, lsb, x0, y0, x1, y1, gw, gh;
    int g = stbtt_FindGlyphIndex(&f, first_char + i);
    stbtt_GetGlyphHMetrics(&f, g, &advance, &lsb);
    stbtt_GetGlyphBitmapBox(&f, g, scale, scale, &x0, &y0, &x1, &y1);
    gw = x1 - x0;
    gh = y1 - y0;
    if (x + gw + 1 >= pw)
      y = bottom_y, x = 1; // advance to next row
    if (y + gh + 1 >= ph)  // check if it fits vertically AFTER potentially moving to next row
      return -i;
    STBTT_assert(x + gw < pw);
    STBTT_assert(y + gh < ph);
    stbtt_MakeGlyphBitmap(&f, pixels + x + y * pw, gw, gh, pw, scale, scale, g);
    chardata[i].x0 = (stbtt_int16)x;
    chardata[i].y0 = (stbtt_int16)y;
    chardata[i].x1 = (stbtt_int16)(x + gw);
    chardata[i].y1 = (stbtt_int16)(y + gh);
    chardata[i].xadvance = scale * advance;
    chardata[i].xoff = (float)x0;
    chardata[i].yoff = (float)y0;
    x = x + gw + 1;
    if (y + gh + 1 > bottom_y)
      bottom_y = y + gh + 1;
  }
  return bottom_y;
}
 
STBTT_DEF void stbtt_GetBakedQuad(const stbtt_bakedchar *chardata, int pw, int ph, int char_index, float *xpos,
                                  float *ypos, stbtt_aligned_quad *q, int opengl_fillrule)
{
  float d3d_bias = opengl_fillrule ? 0 : -0.5f;
  float ipw = 1.0f / pw, iph = 1.0f / ph;
  const stbtt_bakedchar *b = chardata + char_index;
  int round_x = STBTT_ifloor((*xpos + b->xoff) + 0.5f);
  int round_y = STBTT_ifloor((*ypos + b->yoff) + 0.5f);
 
  q->x0 = round_x + d3d_bias;
  q->y0 = round_y + d3d_bias;
  q->x1 = round_x + b->x1 - b->x0 + d3d_bias;
  q->y1 = round_y + b->y1 - b->y0 + d3d_bias;
 
  q->s0 = b->x0 * ipw;
  q->t0 = b->y0 * iph;
  q->s1 = b->x1 * ipw;
  q->t1 = b->y1 * iph;
 
  *xpos += b->xadvance;
}

//
// rectangle packing replacement routines if you don't have stb_rect_pack.h
//
 
#ifndef STB_RECT_PACK_VERSION
 
typedef int stbrp_coord;

//                                                                                //
//                                                                                //
// COMPILER WARNING ?!?!?                                                         //
//                                                                                //
//                                                                                //
// if you get a compile warning due to these symbols being defined more than      //
// once, move #include "stb_rect_pack.h" before #include "stb_truetype.h"         //
//                                                                                //
 
typedef struct
{
  int width, height;
  int x, y, bottom_y;
} stbrp_context;
 
typedef struct
{
  unsigned char x;
} stbrp_node;
 
struct stbrp_rect
{
  stbrp_coord x, y;
  int id, w, h, was_packed;
};
 
static void stbrp_init_target(stbrp_context *con, int pw, int ph, stbrp_node *nodes, int num_nodes)
{
  con->width = pw;
  con->height = ph;
  con->x = 0;
  con->y = 0;
  con->bottom_y = 0;
  STBTT__NOTUSED(nodes);
  STBTT__NOTUSED(num_nodes);
}
 
static void stbrp_pack_rects(stbrp_context *con, stbrp_rect *rects, int num_rects)
{
  int i;
  for (i = 0; i < num_rects; ++i) {
    if (con->x + rects[i].w > con->width) {
      con->x = 0;
      con->y = con->bottom_y;
    }
    if (con->y + rects[i].h > con->height)
      break;
    rects[i].x = con->x;
    rects[i].y = con->y;
    rects[i].was_packed = 1;
    con->x += rects[i].w;
    if (con->y + rects[i].h > con->bottom_y)
      con->bottom_y = con->y + rects[i].h;
  }
  for (; i < num_rects; ++i)
    rects[i].was_packed = 0;
}
#endif

//
// bitmap baking
//
// This is SUPER-AWESOME (tm Ryan Gordon) packing using stb_rect_pack.h. If
// stb_rect_pack.h isn't available, it uses the BakeFontBitmap strategy.
 
STBTT_DEF int stbtt_PackBegin(stbtt_pack_context *spc, unsigned char *pixels, int pw, int ph, int stride_in_bytes,
                              int padding, void *alloc_context)
{
  stbrp_context *context = (stbrp_context *)STBTT_malloc(sizeof(*context), alloc_context);
  int num_nodes = pw - padding;
  stbrp_node *nodes = (stbrp_node *)STBTT_malloc(sizeof(*nodes) * num_nodes, alloc_context);
 
  if (context == nullptr || nodes == nullptr) {
    if (context != nullptr)
      STBTT_free(context, alloc_context);
    if (nodes != nullptr)
      STBTT_free(nodes, alloc_context);
    return 0;
  }
 
  spc->user_allocator_context = alloc_context;
  spc->width = pw;
  spc->height = ph;
  spc->pixels = pixels;
  spc->pack_info = context;
  spc->nodes = nodes;
  spc->padding = padding;
  spc->stride_in_bytes = stride_in_bytes != 0 ? stride_in_bytes : pw;
  spc->h_oversample = 1;
  spc->v_oversample = 1;
  spc->skip_missing = 0;
 
  stbrp_init_target(context, pw - padding, ph - padding, nodes, num_nodes);
 
  if (pixels)
    STBTT_memset(pixels, 0, pw * ph); // background of 0 around pixels
 
  return 1;
}
 
STBTT_DEF void stbtt_PackEnd(stbtt_pack_context *spc)
{
  STBTT_free(spc->nodes, spc->user_allocator_context);
  STBTT_free(spc->pack_info, spc->user_allocator_context);
}
 
STBTT_DEF void stbtt_PackSetOversampling(stbtt_pack_context *spc, unsigned int h_oversample, unsigned int v_oversample)
{
  STBTT_assert(h_oversample <= STBTT_MAX_OVERSAMPLE);
  STBTT_assert(v_oversample <= STBTT_MAX_OVERSAMPLE);
  if (h_oversample <= STBTT_MAX_OVERSAMPLE)
    spc->h_oversample = h_oversample;
  if (v_oversample <= STBTT_MAX_OVERSAMPLE)
    spc->v_oversample = v_oversample;
}
 
STBTT_DEF void stbtt_PackSetSkipMissingCodepoints(stbtt_pack_context *spc, int skip) { spc->skip_missing = skip; }
 
#define STBTT__OVER_MASK (STBTT_MAX_OVERSAMPLE - 1)
 
static void stbtt__h_prefilter(unsigned char *pixels, int w, int h, int stride_in_bytes, unsigned int kernel_width)
{
  unsigned char buffer[STBTT_MAX_OVERSAMPLE];
  int safe_w = w - kernel_width;
  int j;
  STBTT_memset(buffer, 0, STBTT_MAX_OVERSAMPLE); // suppress bogus warning from VS2013 -analyze
  for (j = 0; j < h; ++j) {
    int i;
    unsigned int total;
    STBTT_memset(buffer, 0, kernel_width);
 
    total = 0;
 
    // make kernel_width a constant in common cases so compiler can optimize out the divide
    switch (kernel_width) {
    case 2:
      for (i = 0; i <= safe_w; ++i) {
        total += pixels[i] - buffer[i & STBTT__OVER_MASK];
        buffer[(i + kernel_width) & STBTT__OVER_MASK] = pixels[i];
        pixels[i] = (unsigned char)(total / 2);
      }
      break;
    case 3:
      for (i = 0; i <= safe_w; ++i) {
        total += pixels[i] - buffer[i & STBTT__OVER_MASK];
        buffer[(i + kernel_width) & STBTT__OVER_MASK] = pixels[i];
        pixels[i] = (unsigned char)(total / 3);
      }
      break;
    case 4:
      for (i = 0; i <= safe_w; ++i) {
        total += pixels[i] - buffer[i & STBTT__OVER_MASK];
        buffer[(i + kernel_width) & STBTT__OVER_MASK] = pixels[i];
        pixels[i] = (unsigned char)(total / 4);
      }
      break;
    case 5:
      for (i = 0; i <= safe_w; ++i) {
        total += pixels[i] - buffer[i & STBTT__OVER_MASK];
        buffer[(i + kernel_width) & STBTT__OVER_MASK] = pixels[i];
        pixels[i] = (unsigned char)(total / 5);
      }
      break;
    default:
      for (i = 0; i <= safe_w; ++i) {
        total += pixels[i] - buffer[i & STBTT__OVER_MASK];
        buffer[(i + kernel_width) & STBTT__OVER_MASK] = pixels[i];
        pixels[i] = (unsigned char)(total / kernel_width);
      }
      break;
    }
 
    for (; i < w; ++i) {
      STBTT_assert(pixels[i] == 0);
      total -= buffer[i & STBTT__OVER_MASK];
      pixels[i] = (unsigned char)(total / kernel_width);
    }
 
    pixels += stride_in_bytes;
  }
}
 
static void stbtt__v_prefilter(unsigned char *pixels, int w, int h, int stride_in_bytes, unsigned int kernel_width)
{
  unsigned char buffer[STBTT_MAX_OVERSAMPLE];
  int safe_h = h - kernel_width;
  int j;
  STBTT_memset(buffer, 0, STBTT_MAX_OVERSAMPLE); // suppress bogus warning from VS2013 -analyze
  for (j = 0; j < w; ++j) {
    int i;
    unsigned int total;
    STBTT_memset(buffer, 0, kernel_width);
 
    total = 0;
 
    // make kernel_width a constant in common cases so compiler can optimize out the divide
    switch (kernel_width) {
    case 2:
      for (i = 0; i <= safe_h; ++i) {
        total += pixels[i * stride_in_bytes] - buffer[i & STBTT__OVER_MASK];
        buffer[(i + kernel_width) & STBTT__OVER_MASK] = pixels[i * stride_in_bytes];
        pixels[i * stride_in_bytes] = (unsigned char)(total / 2);
      }
      break;
    case 3:
      for (i = 0; i <= safe_h; ++i) {
        total += pixels[i * stride_in_bytes] - buffer[i & STBTT__OVER_MASK];
        buffer[(i + kernel_width) & STBTT__OVER_MASK] = pixels[i * stride_in_bytes];
        pixels[i * stride_in_bytes] = (unsigned char)(total / 3);
      }
      break;
    case 4:
      for (i = 0; i <= safe_h; ++i) {
        total += pixels[i * stride_in_bytes] - buffer[i & STBTT__OVER_MASK];
        buffer[(i + kernel_width) & STBTT__OVER_MASK] = pixels[i * stride_in_bytes];
        pixels[i * stride_in_bytes] = (unsigned char)(total / 4);
      }
      break;
    case 5:
      for (i = 0; i <= safe_h; ++i) {
        total += pixels[i * stride_in_bytes] - buffer[i & STBTT__OVER_MASK];
        buffer[(i + kernel_width) & STBTT__OVER_MASK] = pixels[i * stride_in_bytes];
        pixels[i * stride_in_bytes] = (unsigned char)(total / 5);
      }
      break;
    default:
      for (i = 0; i <= safe_h; ++i) {
        total += pixels[i * stride_in_bytes] - buffer[i & STBTT__OVER_MASK];
        buffer[(i + kernel_width) & STBTT__OVER_MASK] = pixels[i * stride_in_bytes];
        pixels[i * stride_in_bytes] = (unsigned char)(total / kernel_width);
      }
      break;
    }
 
    for (; i < h; ++i) {
      STBTT_assert(pixels[i * stride_in_bytes] == 0);
      total -= buffer[i & STBTT__OVER_MASK];
      pixels[i * stride_in_bytes] = (unsigned char)(total / kernel_width);
    }
 
    pixels += 1;
  }
}
 
static float stbtt__oversample_shift(int oversample)
{
  if (!oversample)
    return 0.0f;
 
  // The prefilter is a box filter of width "oversample",
  // which shifts phase by (oversample - 1)/2 pixels in
  // oversampled space. We want to shift in the opposite
  // direction to counter this.
  return (float)-(oversample - 1) / (2.0f * (float)oversample);
}
 
// rects array must be big enough to accommodate all characters in the given ranges
STBTT_DEF int stbtt_PackFontRangesGatherRects(stbtt_pack_context *spc, const stbtt_fontinfo *info,
                                              stbtt_pack_range *ranges, int num_ranges, stbrp_rect *rects)
{
  int i, j, k;
  int missing_glyph_added = 0;
 
  k = 0;
  for (i = 0; i < num_ranges; ++i) {
    float fh = ranges[i].font_size;
    float scale = fh > 0 ? stbtt_ScaleForPixelHeight(info, fh) : stbtt_ScaleForMappingEmToPixels(info, -fh);
    ranges[i].h_oversample = (unsigned char)spc->h_oversample;
    ranges[i].v_oversample = (unsigned char)spc->v_oversample;
    for (j = 0; j < ranges[i].num_chars; ++j) {
      int x0, y0, x1, y1;
      int codepoint = ranges[i].array_of_unicode_codepoints == nullptr ? ranges[i].first_unicode_codepoint_in_range + j
        : ranges[i].array_of_unicode_codepoints[j];
      int glyph = stbtt_FindGlyphIndex(info, codepoint);
      if (glyph == 0 && (spc->skip_missing || missing_glyph_added)) {
        rects[k].w = rects[k].h = 0;
      }
      else {
        stbtt_GetGlyphBitmapBoxSubpixel(info, glyph, scale * spc->h_oversample, scale * spc->v_oversample, 0, 0, &x0,
                                        &y0, &x1, &y1);
        rects[k].w = (stbrp_coord)(x1 - x0 + spc->padding + spc->h_oversample - 1);
        rects[k].h = (stbrp_coord)(y1 - y0 + spc->padding + spc->v_oversample - 1);
        if (glyph == 0)
          missing_glyph_added = 1;
      }
      ++k;
    }
  }
 
  return k;
}
 
STBTT_DEF void stbtt_MakeGlyphBitmapSubpixelPrefilter(const stbtt_fontinfo *info, unsigned char *output, int out_w,
                                                      int out_h, int out_stride, float scale_x, float scale_y,
                                                      float shift_x, float shift_y, int prefilter_x, int prefilter_y,
                                                      float *sub_x, float *sub_y, int glyph)
{
  stbtt_MakeGlyphBitmapSubpixel(info, output, out_w - (prefilter_x - 1), out_h - (prefilter_y - 1), out_stride, scale_x,
                                scale_y, shift_x, shift_y, glyph);
 
  if (prefilter_x > 1)
    stbtt__h_prefilter(output, out_w, out_h, out_stride, prefilter_x);
 
  if (prefilter_y > 1)
    stbtt__v_prefilter(output, out_w, out_h, out_stride, prefilter_y);
 
  *sub_x = stbtt__oversample_shift(prefilter_x);
  *sub_y = stbtt__oversample_shift(prefilter_y);
}
 
// rects array must be big enough to accommodate all characters in the given ranges
STBTT_DEF int stbtt_PackFontRangesRenderIntoRects(stbtt_pack_context *spc, const stbtt_fontinfo *info,
                                                  stbtt_pack_range *ranges, int num_ranges, stbrp_rect *rects)
{
  int i, j, k, missing_glyph = -1, return_value = 1;
 
  // save current values
  int old_h_over = spc->h_oversample;
  int old_v_over = spc->v_oversample;
 
  k = 0;
  for (i = 0; i < num_ranges; ++i) {
    float fh = ranges[i].font_size;
    float scale = fh > 0 ? stbtt_ScaleForPixelHeight(info, fh) : stbtt_ScaleForMappingEmToPixels(info, -fh);
    float recip_h, recip_v, sub_x, sub_y;
    spc->h_oversample = ranges[i].h_oversample;
    spc->v_oversample = ranges[i].v_oversample;
    recip_h = 1.0f / spc->h_oversample;
    recip_v = 1.0f / spc->v_oversample;
    sub_x = stbtt__oversample_shift(spc->h_oversample);
    sub_y = stbtt__oversample_shift(spc->v_oversample);
    for (j = 0; j < ranges[i].num_chars; ++j) {
      stbrp_rect *r = &rects[k];
      if (r->was_packed && r->w != 0 && r->h != 0) {
        stbtt_packedchar *bc = &ranges[i].chardata_for_range[j];
        int advance, lsb, x0, y0, x1, y1;
        int codepoint = ranges[i].array_of_unicode_codepoints == nullptr ? ranges[i].first_unicode_codepoint_in_range + j
          : ranges[i].array_of_unicode_codepoints[j];
        int glyph = stbtt_FindGlyphIndex(info, codepoint);
        stbrp_coord pad = (stbrp_coord)spc->padding;
 
        // pad on left and top
        r->x += pad;
        r->y += pad;
        r->w -= pad;
        r->h -= pad;
        stbtt_GetGlyphHMetrics(info, glyph, &advance, &lsb);
        stbtt_GetGlyphBitmapBox(info, glyph, scale * spc->h_oversample, scale * spc->v_oversample, &x0, &y0, &x1, &y1);
        stbtt_MakeGlyphBitmapSubpixel(info, spc->pixels + r->x + r->y * spc->stride_in_bytes,
                                      r->w - spc->h_oversample + 1, r->h - spc->v_oversample + 1, spc->stride_in_bytes,
                                      scale * spc->h_oversample, scale * spc->v_oversample, 0, 0, glyph);
 
        if (spc->h_oversample > 1)
          stbtt__h_prefilter(spc->pixels + r->x + r->y * spc->stride_in_bytes, r->w, r->h, spc->stride_in_bytes,
                             spc->h_oversample);
 
        if (spc->v_oversample > 1)
          stbtt__v_prefilter(spc->pixels + r->x + r->y * spc->stride_in_bytes, r->w, r->h, spc->stride_in_bytes,
                             spc->v_oversample);
 
        bc->x0 = (stbtt_int16)r->x;
        bc->y0 = (stbtt_int16)r->y;
        bc->x1 = (stbtt_int16)(r->x + r->w);
        bc->y1 = (stbtt_int16)(r->y + r->h);
        bc->xadvance = scale * advance;
        bc->xoff = (float)x0 * recip_h + sub_x;
        bc->yoff = (float)y0 * recip_v + sub_y;
        bc->xoff2 = (x0 + r->w) * recip_h + sub_x;
        bc->yoff2 = (y0 + r->h) * recip_v + sub_y;
 
        if (glyph == 0)
          missing_glyph = j;
      }
      else if (spc->skip_missing) {
        return_value = 0;
      }
      else if (r->was_packed && r->w == 0 && r->h == 0 && missing_glyph >= 0) {
        ranges[i].chardata_for_range[j] = ranges[i].chardata_for_range[missing_glyph];
      }
      else {
        return_value = 0; // if any fail, report failure
      }
 
      ++k;
    }
  }
 
  // restore original values
  spc->h_oversample = old_h_over;
  spc->v_oversample = old_v_over;
 
  return return_value;
}
 
STBTT_DEF void stbtt_PackFontRangesPackRects(stbtt_pack_context *spc, stbrp_rect *rects, int num_rects)
{
  stbrp_pack_rects((stbrp_context *)spc->pack_info, rects, num_rects);
}
 
STBTT_DEF int stbtt_PackFontRanges(stbtt_pack_context *spc, const unsigned char *fontdata, int font_index,
                                   stbtt_pack_range *ranges, int num_ranges)
{
  stbtt_fontinfo info;
  int i, j, n, return_value = 1;
  // stbrp_context *context = (stbrp_context *) spc->pack_info;
  stbrp_rect *rects;
 
  // flag all characters as NOT packed
  for (i = 0; i < num_ranges; ++i)
    for (j = 0; j < ranges[i].num_chars; ++j)
      ranges[i].chardata_for_range[j].x0 = ranges[i].chardata_for_range[j].y0 = ranges[i].chardata_for_range[j].x1 =
      ranges[i].chardata_for_range[j].y1 = 0;
 
  n = 0;
  for (i = 0; i < num_ranges; ++i)
    n += ranges[i].num_chars;
 
  rects = (stbrp_rect *)STBTT_malloc(sizeof(*rects) * n, spc->user_allocator_context);
  if (rects == nullptr)
    return 0;
 
  info.userdata = spc->user_allocator_context;
  stbtt_InitFont(&info, fontdata, stbtt_GetFontOffsetForIndex(fontdata, font_index));
 
  n = stbtt_PackFontRangesGatherRects(spc, &info, ranges, num_ranges, rects);
 
  stbtt_PackFontRangesPackRects(spc, rects, n);
 
  return_value = stbtt_PackFontRangesRenderIntoRects(spc, &info, ranges, num_ranges, rects);
 
  STBTT_free(rects, spc->user_allocator_context);
  return return_value;
}
 
STBTT_DEF int stbtt_PackFontRange(stbtt_pack_context *spc, const unsigned char *fontdata, int font_index,
                                  float font_size, int first_unicode_codepoint_in_range, int num_chars_in_range,
                                  stbtt_packedchar *chardata_for_range)
{
  stbtt_pack_range range;
  range.first_unicode_codepoint_in_range = first_unicode_codepoint_in_range;
  range.array_of_unicode_codepoints = nullptr;
  range.num_chars = num_chars_in_range;
  range.chardata_for_range = chardata_for_range;
  range.font_size = font_size;
  return stbtt_PackFontRanges(spc, fontdata, font_index, &range, 1);
}
 
STBTT_DEF void stbtt_GetScaledFontVMetrics(const unsigned char *fontdata, int index, float size, float *ascent,
                                           float *descent, float *lineGap)
{
  int i_ascent, i_descent, i_lineGap;
  float scale;
  stbtt_fontinfo info;
  stbtt_InitFont(&info, fontdata, stbtt_GetFontOffsetForIndex(fontdata, index));
  scale = size > 0 ? stbtt_ScaleForPixelHeight(&info, size) : stbtt_ScaleForMappingEmToPixels(&info, -size);
  stbtt_GetFontVMetrics(&info, &i_ascent, &i_descent, &i_lineGap);
  *ascent = (float)i_ascent * scale;
  *descent = (float)i_descent * scale;
  *lineGap = (float)i_lineGap * scale;
}
 
STBTT_DEF void stbtt_GetPackedQuad(const stbtt_packedchar *chardata, int pw, int ph, int char_index, float *xpos,
                                   float *ypos, stbtt_aligned_quad *q, int align_to_integer)
{
  float ipw = 1.0f / pw, iph = 1.0f / ph;
  const stbtt_packedchar *b = chardata + char_index;
 
  if (align_to_integer) {
    float x = (float)STBTT_ifloor((*xpos + b->xoff) + 0.5f);
    float y = (float)STBTT_ifloor((*ypos + b->yoff) + 0.5f);
    q->x0 = x;
    q->y0 = y;
    q->x1 = x + b->xoff2 - b->xoff;
    q->y1 = y + b->yoff2 - b->yoff;
  }
  else {
    q->x0 = *xpos + b->xoff;
    q->y0 = *ypos + b->yoff;
    q->x1 = *xpos + b->xoff2;
    q->y1 = *ypos + b->yoff2;
  }
 
  q->s0 = b->x0 * ipw;
  q->t0 = b->y0 * iph;
  q->s1 = b->x1 * ipw;
  q->t1 = b->y1 * iph;
 
  *xpos += b->xadvance;
}

//
// sdf computation
//
 
#define STBTT_min(a, b) ((a) < (b) ? (a) : (b))
#define STBTT_max(a, b) ((a) < (b) ? (b) : (a))
 
static int stbtt__ray_intersect_bezier(float orig[2], float ray[2], float q0[2], float q1[2], float q2[2],
                                       float hits[2][2])
{
  float q0perp = q0[1] * ray[0] - q0[0] * ray[1];
  float q1perp = q1[1] * ray[0] - q1[0] * ray[1];
  float q2perp = q2[1] * ray[0] - q2[0] * ray[1];
  float roperp = orig[1] * ray[0] - orig[0] * ray[1];
 
  float a = q0perp - 2 * q1perp + q2perp;
  float b = q1perp - q0perp;
  float c = q0perp - roperp;
 
  float s0 = 0., s1 = 0.;
  int num_s = 0;
 
  if (a != 0.0) {
    float discr = b * b - a * c;
    if (discr > 0.0) {
      float rcpna = -1 / a;
      float d = (float)STBTT_sqrt(discr);
      s0 = (b + d) * rcpna;
      s1 = (b - d) * rcpna;
      if (s0 >= 0.0 && s0 <= 1.0)
        num_s = 1;
      if (d > 0.0 && s1 >= 0.0 && s1 <= 1.0) {
        if (num_s == 0)
          s0 = s1;
        ++num_s;
      }
    }
  }
  else {
 // 2*b*s + c = 0
 // s = -c / (2*b)
    s0 = c / (-2 * b);
    if (s0 >= 0.0 && s0 <= 1.0)
      num_s = 1;
  }
 
  if (num_s == 0)
    return 0;
  else {
    float rcp_len2 = 1 / (ray[0] * ray[0] + ray[1] * ray[1]);
    float rayn_x = ray[0] * rcp_len2, rayn_y = ray[1] * rcp_len2;
 
    float q0d = q0[0] * rayn_x + q0[1] * rayn_y;
    float q1d = q1[0] * rayn_x + q1[1] * rayn_y;
    float q2d = q2[0] * rayn_x + q2[1] * rayn_y;
    float rod = orig[0] * rayn_x + orig[1] * rayn_y;
 
    float q10d = q1d - q0d;
    float q20d = q2d - q0d;
    float q0rd = q0d - rod;
 
    hits[0][0] = q0rd + s0 * (2.0f - 2.0f * s0) * q10d + s0 * s0 * q20d;
    hits[0][1] = a * s0 + b;
 
    if (num_s > 1) {
      hits[1][0] = q0rd + s1 * (2.0f - 2.0f * s1) * q10d + s1 * s1 * q20d;
      hits[1][1] = a * s1 + b;
      return 2;
    }
    else {
      return 1;
    }
  }
}
 
static int equal(float *a, float *b) { return (a[0] == b[0] && a[1] == b[1]); }
 
static int stbtt__compute_crossings_x(float x, float y, int nverts, stbtt_vertex *verts)
{
  int i;
  float orig[2], ray[2] = { 1, 0 };
  float y_frac;
  int winding = 0;
 
  // make sure y never passes through a vertex of the shape
  y_frac = (float)STBTT_fmod(y, 1.0f);
  if (y_frac < 0.01f)
    y += 0.01f;
  else if (y_frac > 0.99f)
    y -= 0.01f;
 
  orig[0] = x;
  orig[1] = y;
 
  // test a ray from (-infinity,y) to (x,y)
  for (i = 0; i < nverts; ++i) {
    if (verts[i].type == STBTT_vline) {
      int x0 = (int)verts[i - 1].x, y0 = (int)verts[i - 1].y;
      int x1 = (int)verts[i].x, y1 = (int)verts[i].y;
      if (y > STBTT_min(y0, y1) && y < STBTT_max(y0, y1) && x > STBTT_min(x0, x1)) {
        float x_inter = (y - y0) / (y1 - y0) * (x1 - x0) + x0;
        if (x_inter < x)
          winding += (y0 < y1) ? 1 : -1;
      }
    }
    if (verts[i].type == STBTT_vcurve) {
      int x0 = (int)verts[i - 1].x, y0 = (int)verts[i - 1].y;
      int x1 = (int)verts[i].cx, y1 = (int)verts[i].cy;
      int x2 = (int)verts[i].x, y2 = (int)verts[i].y;
      int ax = STBTT_min(x0, STBTT_min(x1, x2)), ay = STBTT_min(y0, STBTT_min(y1, y2));
      int by = STBTT_max(y0, STBTT_max(y1, y2));
      if (y > ay && y < by && x > ax) {
        float q0[2], q1[2], q2[2];
        float hits[2][2];
        q0[0] = (float)x0;
        q0[1] = (float)y0;
        q1[0] = (float)x1;
        q1[1] = (float)y1;
        q2[0] = (float)x2;
        q2[1] = (float)y2;
        if (equal(q0, q1) || equal(q1, q2)) {
          x0 = (int)verts[i - 1].x;
          y0 = (int)verts[i - 1].y;
          x1 = (int)verts[i].x;
          y1 = (int)verts[i].y;
          if (y > STBTT_min(y0, y1) && y < STBTT_max(y0, y1) && x > STBTT_min(x0, x1)) {
            float x_inter = (y - y0) / (y1 - y0) * (x1 - x0) + x0;
            if (x_inter < x)
              winding += (y0 < y1) ? 1 : -1;
          }
        }
        else {
          int num_hits = stbtt__ray_intersect_bezier(orig, ray, q0, q1, q2, hits);
          if (num_hits >= 1)
            if (hits[0][0] < 0)
              winding += (hits[0][1] < 0 ? -1 : 1);
          if (num_hits >= 2)
            if (hits[1][0] < 0)
              winding += (hits[1][1] < 0 ? -1 : 1);
        }
      }
    }
  }
  return winding;
}
 
static float stbtt__cuberoot(float x)
{
  if (x < 0)
    return -(float)STBTT_pow(-x, 1.0f / 3.0f);
  else
    return (float)STBTT_pow(x, 1.0f / 3.0f);
}
 
// x^3 + a*x^2 + b*x + c = 0
static int stbtt__solve_cubic(float a, float b, float c, float *r)
{
  float s = -a / 3;
  float p = b - a * a / 3;
  float q = a * (2 * a * a - 9 * b) / 27 + c;
  float p3 = p * p * p;
  float d = q * q + 4 * p3 / 27;
  if (d >= 0) {
    float z = (float)STBTT_sqrt(d);
    float u = (-q + z) / 2;
    float v = (-q - z) / 2;
    u = stbtt__cuberoot(u);
    v = stbtt__cuberoot(v);
    r[0] = s + u + v;
    return 1;
  }
  else {
    float u = (float)STBTT_sqrt(-p / 3);
    float v = (float)STBTT_acos(-STBTT_sqrt(-27 / p3) * q / 2) / 3; // p3 must be negative, since d is negative
    float m = (float)STBTT_cos(v);
    float n = (float)STBTT_cos(v - 3.141592 / 2) * 1.732050808f;
    r[0] = s + u * 2 * m;
    r[1] = s - u * (m + n);
    r[2] = s - u * (m - n);
 
    // STBTT_assert( STBTT_fabs(((r[0]+a)*r[0]+b)*r[0]+c) < 0.05f);  // these asserts may not be safe at all scales,
    // though they're in bezier t parameter units so maybe? STBTT_assert( STBTT_fabs(((r[1]+a)*r[1]+b)*r[1]+c) < 0.05f);
    // STBTT_assert( STBTT_fabs(((r[2]+a)*r[2]+b)*r[2]+c) < 0.05f);
    return 3;
  }
}
 
STBTT_DEF unsigned char *stbtt_GetGlyphSDF(const stbtt_fontinfo *info, float scale, int glyph, int padding,
                                           unsigned char onedge_value, float pixel_dist_scale, int *width, int *height,
                                           int *xoff, int *yoff)
{
  float scale_x = scale, scale_y = scale;
  int ix0, iy0, ix1, iy1;
  int w, h;
  unsigned char *data;
 
  if (scale == 0)
    return nullptr;
 
  stbtt_GetGlyphBitmapBoxSubpixel(info, glyph, scale, scale, 0.0f, 0.0f, &ix0, &iy0, &ix1, &iy1);
 
  // if empty, return nullptr
  if (ix0 == ix1 || iy0 == iy1)
    return nullptr;
 
  ix0 -= padding;
  iy0 -= padding;
  ix1 += padding;
  iy1 += padding;
 
  w = (ix1 - ix0);
  h = (iy1 - iy0);
 
  if (width)
    *width = w;
  if (height)
    *height = h;
  if (xoff)
    *xoff = ix0;
  if (yoff)
    *yoff = iy0;
 
  // invert for y-downwards bitmaps
  scale_y = -scale_y;
 
  {
    int x, y, i, j;
    float *precompute;
    stbtt_vertex *verts;
    int num_verts = stbtt_GetGlyphShape(info, glyph, &verts);
    data = (unsigned char *)STBTT_malloc(w * h, info->userdata);
    precompute = (float *)STBTT_malloc(num_verts * sizeof(float), info->userdata);
 
    for (i = 0, j = num_verts - 1; i < num_verts; j = i++) {
      if (verts[i].type == STBTT_vline) {
        float x0 = verts[i].x * scale_x, y0 = verts[i].y * scale_y;
        float x1 = verts[j].x * scale_x, y1 = verts[j].y * scale_y;
        float dist = (float)STBTT_sqrt((x1 - x0) * (x1 - x0) + (y1 - y0) * (y1 - y0));
        precompute[i] = (dist == 0) ? 0.0f : 1.0f / dist;
      }
      else if (verts[i].type == STBTT_vcurve) {
        float x2 = verts[j].x * scale_x, y2 = verts[j].y * scale_y;
        float x1 = verts[i].cx * scale_x, y1 = verts[i].cy * scale_y;
        float x0 = verts[i].x * scale_x, y0 = verts[i].y * scale_y;
        float bx = x0 - 2 * x1 + x2, by = y0 - 2 * y1 + y2;
        float len2 = bx * bx + by * by;
        if (len2 != 0.0f)
          precompute[i] = 1.0f / (bx * bx + by * by);
        else
          precompute[i] = 0.0f;
      }
      else
        precompute[i] = 0.0f;
    }
 
    for (y = iy0; y < iy1; ++y) {
      for (x = ix0; x < ix1; ++x) {
        float val;
        float min_dist = 999999.0f;
        float sx = (float)x + 0.5f;
        float sy = (float)y + 0.5f;
        float x_gspace = (sx / scale_x);
        float y_gspace = (sy / scale_y);
 
        int winding = stbtt__compute_crossings_x(x_gspace, y_gspace, num_verts,
                                                 verts); // @OPTIMIZE: this could just be a rasterization, but needs to
                                                         // be line vs. non-tesselated curves so a new path
 
        for (i = 0; i < num_verts; ++i) {
          float x0 = verts[i].x * scale_x, y0 = verts[i].y * scale_y;
 
          if (verts[i].type == STBTT_vline && precompute[i] != 0.0f) {
            float x1 = verts[i - 1].x * scale_x, y1 = verts[i - 1].y * scale_y;
 
            float dist, dist2 = (x0 - sx) * (x0 - sx) + (y0 - sy) * (y0 - sy);
            if (dist2 < min_dist * min_dist)
              min_dist = (float)STBTT_sqrt(dist2);
 
            // coarse culling against bbox
            // if (sx > STBTT_min(x0,x1)-min_dist && sx < STBTT_max(x0,x1)+min_dist &&
            //    sy > STBTT_min(y0,y1)-min_dist && sy < STBTT_max(y0,y1)+min_dist)
            dist = (float)STBTT_fabs((x1 - x0) * (y0 - sy) - (y1 - y0) * (x0 - sx)) * precompute[i];
            STBTT_assert(i != 0);
            if (dist < min_dist) {
              // check position along line
              // x' = x0 + t*(x1-x0), y' = y0 + t*(y1-y0)
              // minimize (x'-sx)*(x'-sx)+(y'-sy)*(y'-sy)
              float dx = x1 - x0, dy = y1 - y0;
              float px = x0 - sx, py = y0 - sy;
              // minimize (px+t*dx)^2 + (py+t*dy)^2 = px*px + 2*px*dx*t + t^2*dx*dx + py*py + 2*py*dy*t + t^2*dy*dy
              // derivative: 2*px*dx + 2*py*dy + (2*dx*dx+2*dy*dy)*t, set to 0 and solve
              float t = -(px * dx + py * dy) / (dx * dx + dy * dy);
              if (t >= 0.0f && t <= 1.0f)
                min_dist = dist;
            }
          }
          else if (verts[i].type == STBTT_vcurve) {
            float x2 = verts[i - 1].x * scale_x, y2 = verts[i - 1].y * scale_y;
            float x1 = verts[i].cx * scale_x, y1 = verts[i].cy * scale_y;
            float box_x0 = STBTT_min(STBTT_min(x0, x1), x2);
            float box_y0 = STBTT_min(STBTT_min(y0, y1), y2);
            float box_x1 = STBTT_max(STBTT_max(x0, x1), x2);
            float box_y1 = STBTT_max(STBTT_max(y0, y1), y2);
            // coarse culling against bbox to avoid computing cubic unnecessarily
            if (sx > box_x0 - min_dist && sx < box_x1 + min_dist && sy > box_y0 - min_dist && sy < box_y1 + min_dist) {
              int num = 0;
              float ax = x1 - x0, ay = y1 - y0;
              float bx = x0 - 2 * x1 + x2, by = y0 - 2 * y1 + y2;
              float mx = x0 - sx, my = y0 - sy;
              float res[3] = { 0.f, 0.f, 0.f };
              float px, py, t, it, dist2;
              float a_inv = precompute[i];
              if (a_inv == 0.0) { // if a_inv is 0, it's 2nd degree so use quadratic formula
                float a = 3 * (ax * bx + ay * by);
                float b = 2 * (ax * ax + ay * ay) + (mx * bx + my * by);
                float c = mx * ax + my * ay;
                if (a == 0.0) { // if a is 0, it's linear
                  if (b != 0.0) {
                    res[num++] = -c / b;
                  }
                }
                else {
                  float discriminant = b * b - 4 * a * c;
                  if (discriminant < 0)
                    num = 0;
                  else {
                    float root = (float)STBTT_sqrt(discriminant);
                    res[0] = (-b - root) / (2 * a);
                    res[1] = (-b + root) / (2 * a);
                    num = 2; // don't bother distinguishing 1-solution case, as code below will still work
                  }
                }
              }
              else {
                float b = 3 * (ax * bx + ay * by) * a_inv; // could precompute this as it doesn't depend on sample point
                float c = (2 * (ax * ax + ay * ay) + (mx * bx + my * by)) * a_inv;
                float d = (mx * ax + my * ay) * a_inv;
                num = stbtt__solve_cubic(b, c, d, res);
              }
              dist2 = (x0 - sx) * (x0 - sx) + (y0 - sy) * (y0 - sy);
              if (dist2 < min_dist * min_dist)
                min_dist = (float)STBTT_sqrt(dist2);
 
              if (num >= 1 && res[0] >= 0.0f && res[0] <= 1.0f) {
                t = res[0], it = 1.0f - t;
                px = it * it * x0 + 2 * t * it * x1 + t * t * x2;
                py = it * it * y0 + 2 * t * it * y1 + t * t * y2;
                dist2 = (px - sx) * (px - sx) + (py - sy) * (py - sy);
                if (dist2 < min_dist * min_dist)
                  min_dist = (float)STBTT_sqrt(dist2);
              }
              if (num >= 2 && res[1] >= 0.0f && res[1] <= 1.0f) {
                t = res[1], it = 1.0f - t;
                px = it * it * x0 + 2 * t * it * x1 + t * t * x2;
                py = it * it * y0 + 2 * t * it * y1 + t * t * y2;
                dist2 = (px - sx) * (px - sx) + (py - sy) * (py - sy);
                if (dist2 < min_dist * min_dist)
                  min_dist = (float)STBTT_sqrt(dist2);
              }
              if (num >= 3 && res[2] >= 0.0f && res[2] <= 1.0f) {
                t = res[2], it = 1.0f - t;
                px = it * it * x0 + 2 * t * it * x1 + t * t * x2;
                py = it * it * y0 + 2 * t * it * y1 + t * t * y2;
                dist2 = (px - sx) * (px - sx) + (py - sy) * (py - sy);
                if (dist2 < min_dist * min_dist)
                  min_dist = (float)STBTT_sqrt(dist2);
              }
            }
          }
        }
        if (winding == 0)
          min_dist = -min_dist; // if outside the shape, value is negative
        val = onedge_value + pixel_dist_scale * min_dist;
        if (val < 0)
          val = 0;
        else if (val > 255)
          val = 255;
        data[(y - iy0) * w + (x - ix0)] = (unsigned char)val;
      }
    }
    STBTT_free(precompute, info->userdata);
    STBTT_free(verts, info->userdata);
  }
  return data;
}
 
STBTT_DEF unsigned char *stbtt_GetCodepointSDF(const stbtt_fontinfo *info, float scale, int codepoint, int padding,
                                               unsigned char onedge_value, float pixel_dist_scale, int *width,
                                               int *height, int *xoff, int *yoff)
{
  return stbtt_GetGlyphSDF(info, scale, stbtt_FindGlyphIndex(info, codepoint), padding, onedge_value, pixel_dist_scale,
                           width, height, xoff, yoff);
}
 
STBTT_DEF void stbtt_FreeSDF(unsigned char *bitmap, void *userdata) { STBTT_free(bitmap, userdata); }

//
// font name matching -- recommended not to use this
//
 
// check if a utf8 string contains a prefix which is the utf16 string; if so return length of matching utf8 string
static stbtt_int32 stbtt__CompareUTF8toUTF16_bigendian_prefix(stbtt_uint8 *s1, stbtt_int32 len1, stbtt_uint8 *s2,
                                                              stbtt_int32 len2)
{
  stbtt_int32 i = 0;
 
  // convert utf16 to utf8 and compare the results while converting
  while (len2) {
    stbtt_uint16 ch = s2[0] * 256 + s2[1];
    if (ch < 0x80) {
      if (i >= len1)
        return -1;
      if (s1[i++] != ch)
        return -1;
    }
    else if (ch < 0x800) {
      if (i + 1 >= len1)
        return -1;
      if (s1[i++] != 0xc0 + (ch >> 6))
        return -1;
      if (s1[i++] != 0x80 + (ch & 0x3f))
        return -1;
    }
    else if (ch >= 0xd800 && ch < 0xdc00) {
      stbtt_uint32 c;
      stbtt_uint16 ch2 = s2[2] * 256 + s2[3];
      if (i + 3 >= len1)
        return -1;
      c = ((ch - 0xd800) << 10) + (ch2 - 0xdc00) + 0x10000;
      if (s1[i++] != 0xf0 + (c >> 18))
        return -1;
      if (s1[i++] != 0x80 + ((c >> 12) & 0x3f))
        return -1;
      if (s1[i++] != 0x80 + ((c >> 6) & 0x3f))
        return -1;
      if (s1[i++] != 0x80 + ((c)&0x3f))
        return -1;
      s2 += 2; // plus another 2 below
      len2 -= 2;
    }
    else if (ch >= 0xdc00 && ch < 0xe000) {
      return -1;
    }
    else {
      if (i + 2 >= len1)
        return -1;
      if (s1[i++] != 0xe0 + (ch >> 12))
        return -1;
      if (s1[i++] != 0x80 + ((ch >> 6) & 0x3f))
        return -1;
      if (s1[i++] != 0x80 + ((ch)&0x3f))
        return -1;
    }
    s2 += 2;
    len2 -= 2;
  }
  return i;
}
 
static int stbtt_CompareUTF8toUTF16_bigendian_internal(char *s1, int len1, char *s2, int len2)
{
  return len1 == stbtt__CompareUTF8toUTF16_bigendian_prefix((stbtt_uint8 *)s1, len1, (stbtt_uint8 *)s2, len2);
}
 
// returns results in whatever encoding you request... but note that 2-byte encodings
// will be BIG-ENDIAN... use stbtt_CompareUTF8toUTF16_bigendian() to compare
STBTT_DEF const char *stbtt_GetFontNameString(const stbtt_fontinfo *font, int *length, int platformID, int encodingID,
                                              int languageID, int nameID)
{
  stbtt_int32 i, count, stringOffset;
  stbtt_uint8 *fc = font->data;
  stbtt_uint32 offset = font->fontstart;
  stbtt_uint32 nm = stbtt__find_table(fc, offset, "name");
  if (!nm)
    return nullptr;
 
  count = ttUSHORT(fc + nm + 2);
  stringOffset = nm + ttUSHORT(fc + nm + 4);
  for (i = 0; i < count; ++i) {
    stbtt_uint32 loc = nm + 6 + 12 * i;
    if (platformID == ttUSHORT(fc + loc + 0) && encodingID == ttUSHORT(fc + loc + 2) &&
        languageID == ttUSHORT(fc + loc + 4) && nameID == ttUSHORT(fc + loc + 6)) {
      *length = ttUSHORT(fc + loc + 8);
      return (const char *)(fc + stringOffset + ttUSHORT(fc + loc + 10));
    }
  }
  return nullptr;
}
 
static int stbtt__matchpair(stbtt_uint8 *fc, stbtt_uint32 nm, stbtt_uint8 *name, stbtt_int32 nlen,
                            stbtt_int32 target_id, stbtt_int32 next_id)
{
  stbtt_int32 i;
  stbtt_int32 count = ttUSHORT(fc + nm + 2);
  stbtt_int32 stringOffset = nm + ttUSHORT(fc + nm + 4);
 
  for (i = 0; i < count; ++i) {
    stbtt_uint32 loc = nm + 6 + 12 * i;
    stbtt_int32 id = ttUSHORT(fc + loc + 6);
    if (id == target_id) {
      // find the encoding
      stbtt_int32 platform = ttUSHORT(fc + loc + 0), encoding = ttUSHORT(fc + loc + 2),
        language = ttUSHORT(fc + loc + 4);
 
// is this a Unicode encoding?
      if (platform == 0 || (platform == 3 && encoding == 1) || (platform == 3 && encoding == 10)) {
        stbtt_int32 slen = ttUSHORT(fc + loc + 8);
        stbtt_int32 off = ttUSHORT(fc + loc + 10);
 
        // check if there's a prefix match
        stbtt_int32 matchlen = stbtt__CompareUTF8toUTF16_bigendian_prefix(name, nlen, fc + stringOffset + off, slen);
        if (matchlen >= 0) {
          // check for target_id+1 immediately following, with same encoding & language
          if (i + 1 < count && ttUSHORT(fc + loc + 12 + 6) == next_id && ttUSHORT(fc + loc + 12) == platform &&
              ttUSHORT(fc + loc + 12 + 2) == encoding && ttUSHORT(fc + loc + 12 + 4) == language) {
            slen = ttUSHORT(fc + loc + 12 + 8);
            off = ttUSHORT(fc + loc + 12 + 10);
            if (slen == 0) {
              if (matchlen == nlen)
                return 1;
            }
            else if (matchlen < nlen && name[matchlen] == ' ') {
              ++matchlen;
              if (stbtt_CompareUTF8toUTF16_bigendian_internal((char *)(name + matchlen), nlen - matchlen,
                                                              (char *)(fc + stringOffset + off), slen))
                return 1;
            }
          }
          else {
         // if nothing immediately following
            if (matchlen == nlen)
              return 1;
          }
        }
      }
 
      // @TODO handle other encodings
    }
  }
  return 0;
}
 
static int stbtt__matches(stbtt_uint8 *fc, stbtt_uint32 offset, stbtt_uint8 *name, stbtt_int32 flags)
{
  stbtt_int32 nlen = (stbtt_int32)STBTT_strlen((char *)name);
  stbtt_uint32 nm, hd;
  if (!stbtt__isfont(fc + offset))
    return 0;
 
  // check italics/bold/underline flags in macStyle...
  if (flags) {
    hd = stbtt__find_table(fc, offset, "head");
    if ((ttUSHORT(fc + hd + 44) & 7) != (flags & 7))
      return 0;
  }
 
  nm = stbtt__find_table(fc, offset, "name");
  if (!nm)
    return 0;
 
  if (flags) {
    // if we checked the macStyle flags, then just check the family and ignore the subfamily
    if (stbtt__matchpair(fc, nm, name, nlen, 16, -1))
      return 1;
    if (stbtt__matchpair(fc, nm, name, nlen, 1, -1))
      return 1;
    if (stbtt__matchpair(fc, nm, name, nlen, 3, -1))
      return 1;
  }
  else {
    if (stbtt__matchpair(fc, nm, name, nlen, 16, 17))
      return 1;
    if (stbtt__matchpair(fc, nm, name, nlen, 1, 2))
      return 1;
    if (stbtt__matchpair(fc, nm, name, nlen, 3, -1))
      return 1;
  }
 
  return 0;
}
 
static int stbtt_FindMatchingFont_internal(unsigned char *font_collection, char *name_utf8, stbtt_int32 flags)
{
  stbtt_int32 i;
  for (i = 0;; ++i) {
    stbtt_int32 off = stbtt_GetFontOffsetForIndex(font_collection, i);
    if (off < 0)
      return off;
    if (stbtt__matches((stbtt_uint8 *)font_collection, off, (stbtt_uint8 *)name_utf8, flags))
      return off;
  }
}
 
#if defined(__GNUC__) || defined(__clang__)
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wcast-qual"
#endif
 
STBTT_DEF int stbtt_BakeFontBitmap(const unsigned char *data, int offset, float pixel_height, unsigned char *pixels,
                                   int pw, int ph, int first_char, int num_chars, stbtt_bakedchar *chardata)
{
  return stbtt_BakeFontBitmap_internal((unsigned char *)data, offset, pixel_height, pixels, pw, ph, first_char,
                                       num_chars, chardata);
}
 
STBTT_DEF int stbtt_GetFontOffsetForIndex(const unsigned char *data, int index)
{
  return stbtt_GetFontOffsetForIndex_internal((unsigned char *)data, index);
}
 
STBTT_DEF int stbtt_GetNumberOfFonts(const unsigned char *data)
{
  return stbtt_GetNumberOfFonts_internal((unsigned char *)data);
}
 
STBTT_DEF int stbtt_InitFont(stbtt_fontinfo *info, const unsigned char *data, int offset)
{
  return stbtt_InitFont_internal(info, (unsigned char *)data, offset);
}
 
STBTT_DEF int stbtt_FindMatchingFont(const unsigned char *fontdata, const char *name, int flags)
{
  return stbtt_FindMatchingFont_internal((unsigned char *)fontdata, (char *)name, flags);
}
 
STBTT_DEF int stbtt_CompareUTF8toUTF16_bigendian(const char *s1, int len1, const char *s2, int len2)
{
  return stbtt_CompareUTF8toUTF16_bigendian_internal((char *)s1, len1, (char *)s2, len2);
}
 
#if defined(__GNUC__) || defined(__clang__)
#pragma GCC diagnostic pop
#endif
 
#endif // DOXYGEN_SHOULD_SKIP_THIS
#endif // STB_TRUETYPE_IMPLEMENTATION
 
// FULL VERSION HISTORY
//
//   1.25 (2021-07-11) many fixes
//   1.24 (2020-02-05) fix warning
//   1.23 (2020-02-02) query SVG data for glyphs; query whole kerning table (but only kern not GPOS)
//   1.22 (2019-08-11) minimize missing-glyph duplication; fix kerning if both 'GPOS' and 'kern' are defined
//   1.21 (2019-02-25) fix warning
//   1.20 (2019-02-07) PackFontRange skips missing codepoints; GetScaleFontVMetrics()
//   1.19 (2018-02-11) OpenType GPOS kerning (horizontal only), STBTT_fmod
//   1.18 (2018-01-29) add missing function
//   1.17 (2017-07-23) make more arguments const; doc fix
//   1.16 (2017-07-12) SDF support
//   1.15 (2017-03-03) make more arguments const
//   1.14 (2017-01-16) num-fonts-in-TTC function
//   1.13 (2017-01-02) support OpenType fonts, certain Apple fonts
//   1.12 (2016-10-25) suppress warnings about casting away const with -Wcast-qual
//   1.11 (2016-04-02) fix unused-variable warning
//   1.10 (2016-04-02) allow user-defined fabs() replacement
//                     fix memory leak if fontsize=0.0
//                     fix warning from duplicate typedef
//   1.09 (2016-01-16) warning fix; avoid crash on outofmem; use alloc userdata for PackFontRanges
//   1.08 (2015-09-13) document stbtt_Rasterize(); fixes for vertical & horizontal edges
//   1.07 (2015-08-01) allow PackFontRanges to accept arrays of sparse codepoints;
//                     allow PackFontRanges to pack and render in separate phases;
//                     fix stbtt_GetFontOFfsetForIndex (never worked for non-0 input?);
//                     fixed an assert() bug in the new rasterizer
//                     replace assert() with STBTT_assert() in new rasterizer
//   1.06 (2015-07-14) performance improvements (~35% faster on x86 and x64 on test machine)
//                     also more precise AA rasterizer, except if shapes overlap
//                     remove need for STBTT_sort
//   1.05 (2015-04-15) fix misplaced definitions for STBTT_STATIC
//   1.04 (2015-04-15) typo in example
//   1.03 (2015-04-12) STBTT_STATIC, fix memory leak in new packing, various fixes
//   1.02 (2014-12-10) fix various warnings & compile issues w/ stb_rect_pack, C++
//   1.01 (2014-12-08) fix subpixel position when oversampling to exactly match
//                        non-oversampled; STBTT_POINT_SIZE for packed case only
//   1.00 (2014-12-06) add new PackBegin etc. API, w/ support for oversampling
//   0.99 (2014-09-18) fix multiple bugs with subpixel rendering (ryg)
//   0.9  (2014-08-07) support certain mac/iOS fonts without an MS platformID
//   0.8b (2014-07-07) fix a warning
//   0.8  (2014-05-25) fix a few more warnings
//   0.7  (2013-09-25) bugfix: subpixel glyph bug fixed in 0.5 had come back
//   0.6c (2012-07-24) improve documentation
//   0.6b (2012-07-20) fix a few more warnings
//   0.6  (2012-07-17) fix warnings; added stbtt_ScaleForMappingEmToPixels,
//                        stbtt_GetFontBoundingBox, stbtt_IsGlyphEmpty
//   0.5  (2011-12-09) bugfixes:
//                        subpixel glyph renderer computed wrong bounding box
//                        first vertex of shape can be off-curve (FreeSans)
//   0.4b (2011-12-03) fixed an error in the font baking example
//   0.4  (2011-12-01) kerning, subpixel rendering (tor)
//                    bugfixes for:
//                        codepoint-to-glyph conversion using table fmt=12
//                        codepoint-to-glyph conversion using table fmt=4
//                        stbtt_GetBakedQuad with non-square texture (Zer)
//                    updated Hello World! sample to use kerning and subpixel
//                    fixed some warnings
//   0.3  (2009-06-24) cmap fmt=12, compound shapes (MM)
//                    userdata, malloc-from-userdata, non-zero fill (stb)
//   0.2  (2009-03-11) Fix unsigned/signed char warnings
//   0.1  (2009-03-09) First public release
//
 
/*
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This software is available under 2 licenses -- choose whichever you prefer.
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ALTERNATIVE A - MIT License
Copyright (c) 2017 Sean Barrett
Permission is hereby granted, free of charge, to any person obtaining a copy of
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SOFTWARE.
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This is free and unencumbered software released into the public domain.
Anyone is free to copy, modify, publish, use, compile, sell, or distribute this
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this software under copyright law.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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*/