stb_truetype.h

// stb_truetype.h - v0.7 - public domain
// authored from 2009-2013 by Sean Barrett / RAD Game Tools
//
//   This library processes TrueType files:
//        parse files
//        extract glyph metrics
//        extract glyph shapes
//        render glyphs to one-channel bitmaps with antialiasing (box filter)
//
//   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
//
//   Bug/warning reports:
//       "Zer" on mollyrocket (with fix)
//       Cass Everitt
//       stoiko (Haemimont Games)
//       Brian Hook 
//       Walter van Niftrik
//
// VERSION HISTORY
//
//   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
//
// LICENSE
//
//   This software is in the public domain. Where that dedication is not
//   recognized, you are granted a perpetual, irrevokable license to copy
//   and modify this file as you see fit.
//
// USAGE
//
//   Include this file in whatever places neeed 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.
//
//   Simple 3D API (don't ship this, but it's fine for tools and quick start,
//                  and you can cut and paste from it to move to more advanced)
//           stbtt_BakeFontBitmap()               -- bake a font to a bitmap for use as texture
//           stbtt_GetBakedQuad()                 -- compute quad to draw for a given char
//
//   "Load" a font file from a memory buffer (you have to keep the buffer loaded)
//           stbtt_InitFont()
//           stbtt_GetFontOffsetForIndex()        -- use 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_GetCodepointKernAdvance()
//
// 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 they 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.
//
// 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.
//
//
// SOURCE STATISTICS (based on v0.6c, 2050 LOC)
//
//   Documentation & header file        520 LOC  \___ 660 LOC documentation
//   Sample code                        140 LOC  /
//   Truetype parsing                   620 LOC  ---- 620 LOC TrueType
//   Software rasterization             240 LOC  \                           .
//   Curve tesselation                  120 LOC   \__ 550 LOC Bitmap creation
//   Bitmap management                  100 LOC   /
//   Baked bitmap interface              70 LOC  /
//   Font name matching & access        150 LOC  ---- 150 
//   C runtime library abstraction       60 LOC  ----  60


//////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////
////
////  SAMPLE PROGRAMS
////
//
//  Incomplete text-in-3d-api example, which draws quads properly aligned to be lossless
//
#if 0
#define STB_TRUETYPE_IMPLEMENTATION  // force following include to generate implementation
#include "stb_truetype.h"

char ttf_buffer[1<<20];
unsigned char temp_bitmap[512*512];

stbtt_bakedchar cdata[96]; // ASCII 32..126 is 95 glyphs
GLstbtt_uint ftex;

void my_stbtt_initfont(void)
{
   fread(ttf_buffer, 1, 1<<20, fopen("c:/windows/fonts/times.ttf", "rb"));
   stbtt_BakeFontBitmap(data,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
   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,0=old d3d
         glTexCoord2f(q.s0,q.t1); glVertex2f(q.x0,q.y0);
         glTexCoord2f(q.s1,q.t1); glVertex2f(q.x1,q.y0);
         glTexCoord2f(q.s1,q.t0); glVertex2f(q.x1,q.y1);
         glTexCoord2f(q.s0,q.t0); 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=0;
   char *text = "Heljo World!";

   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 = (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][(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


//////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////
////
////   INTEGRATION WITH YOUR CODEBASE
////
////   The following sections allow you to supply alternate definitions
////   of C library functions used by stb_truetype.

#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];

   // #define your own STBTT_sort() to override this to avoid qsort
   #ifndef STBTT_sort
   #include <stdlib.h>
   #define STBTT_sort(data,num_items,item_size,compare_func)   qsort(data,num_items,item_size,compare_func)
   #endif

   // #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

   // #define your own functions "STBTT_malloc" / "STBTT_free" to avoid malloc.h
   #ifndef STBTT_malloc
   #include <malloc.h>
   #define STBTT_malloc(x,u)  malloc(x)
   #define STBTT_free(x,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 <memory.h>
   #define STBTT_memcpy       memcpy
   #define STBTT_memset       memset
   #endif
#endif

///////////////////////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////////////////////
////
////   INTERFACE
////
////

#ifndef __STB_INCLUDE_STB_TRUETYPE_H__
#define __STB_INCLUDE_STB_TRUETYPE_H__

#ifdef __cplusplus
extern "C" {
#endif

//////////////////////////////////////////////////////////////////////////////
//
// 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;

extern 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;

extern void stbtt_GetBakedQuad(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.


//////////////////////////////////////////////////////////////////////////////
//
// FONT LOADING
//
//

extern 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. You can just skip
// this step if you know it's that kind of font.


// The following structure is defined publically so you can declare one on
// the stack or as a global or etc, but you should treat it as opaque.
typedef 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; // 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_fontinfo;

extern 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

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.


//////////////////////////////////////////////////////////////////////////////
//
// CHARACTER PROPERTIES
//

extern 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.

extern 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.

extern 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

extern void stbtt_GetFontBoundingBox(const stbtt_fontinfo *info, int *x0, int *y0, int *x1, int *y1);
// the bounding box around all possible characters

extern 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

extern int  stbtt_GetCodepointKernAdvance(const stbtt_fontinfo *info, int ch1, int ch2);
// an additional amount to add to the 'advance' value between ch1 and ch2
// @TODO; for now always returns 0!

extern 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

extern void stbtt_GetGlyphHMetrics(const stbtt_fontinfo *info, int glyph_index, int *advanceWidth, int *leftSideBearing);
extern int  stbtt_GetGlyphKernAdvance(const stbtt_fontinfo *info, int glyph1, int glyph2);
extern 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


//////////////////////////////////////////////////////////////////////////////
//
// 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
   };
#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;
      unsigned char type,padding;
   } stbtt_vertex;
#endif

extern int stbtt_IsGlyphEmpty(const stbtt_fontinfo *info, int glyph_index);
// returns non-zero if nothing is drawn for this glyph

extern int stbtt_GetCodepointShape(const stbtt_fontinfo *info, int unicode_codepoint, stbtt_vertex **vertices);
extern 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

extern void stbtt_FreeShape(const stbtt_fontinfo *info, stbtt_vertex *vertices);
// frees the data allocated above

//////////////////////////////////////////////////////////////////////////////
//
// BITMAP RENDERING
//

extern void stbtt_FreeBitmap(unsigned char *bitmap, void *userdata);
// frees the bitmap allocated below

extern 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

extern 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

extern 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.

extern 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

extern 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.)

extern 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)
extern unsigned char *stbtt_GetGlyphBitmap(const stbtt_fontinfo *info, float scale_x, float scale_y, int glyph, int *width, int *height, int *xoff, int *yoff);
extern 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);
extern 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);
extern 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);
extern void stbtt_GetGlyphBitmapBox(const stbtt_fontinfo *font, int glyph, float scale_x, float scale_y, int *ix0, int *iy0, int *ix1, int *iy1);
extern 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;

extern 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);

//////////////////////////////////////////////////////////////////////////////
//
// 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.


extern 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

extern 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

extern 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__

///////////////////////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////////////////////
////
////   IMPLEMENTATION
////
////

#ifdef STB_TRUETYPE_IMPLEMENTATION

//////////////////////////////////////////////////////////////////////////
//
// 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)

#if defined(STB_TRUETYPE_BIGENDIAN) && !defined(ALLOW_UNALIGNED_TRUETYPE)

   #define ttUSHORT(p)   (* (stbtt_uint16 *) (p))
   #define ttSHORT(p)    (* (stbtt_int16 *) (p))
   #define ttULONG(p)    (* (stbtt_uint32 *) (p))
   #define ttLONG(p)     (* (stbtt_int32 *) (p))

#else

   stbtt_uint16 ttUSHORT(const stbtt_uint8 *p) { return p[0]*256 + p[1]; }
   stbtt_int16 ttSHORT(const stbtt_uint8 *p)   { return p[0]*256 + p[1]; }
   stbtt_uint32 ttULONG(const stbtt_uint8 *p)  { return (p[0]<<24) + (p[1]<<16) + (p[2]<<8) + p[3]; }
   stbtt_int32 ttLONG(const stbtt_uint8 *p)    { return (p[0]<<24) + (p[1]<<16) + (p[2]<<8) + p[3]; }

#endif

#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(const 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
   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;
}

int stbtt_GetFontOffsetForIndex(const 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*14);
      }
   }
   return -1;
}

int stbtt_InitFont(stbtt_fontinfo *info, const unsigned char *data2, int fontstart)
{
   stbtt_uint8 *data = (stbtt_uint8 *) data2;
   stbtt_uint32 cmap, t;
   stbtt_int32 i,numTables;

   info->data = data;
   info->fontstart = fontstart;

   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
   if (!cmap || !info->loca || !info->head || !info->glyf || !info->hhea || !info->hmtx)
      return 0;

   t = stbtt__find_table(data, fontstart, "maxp");
   if (t)
      info->numGlyphs = ttUSHORT(data+t+4);
   else
      info->numGlyphs = 0xffff;

   // 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;
      }
   }
   if (info->index_map == 0)
      return 0;

   info->indexToLocFormat = ttUSHORT(data+info->head + 50);
   return 1;
}

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;
      stbtt_uint16 item, offset, start, end;

      // 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 start, end;
         searchRange >>= 1;
         start = ttUSHORT(data + search + 2 + segcount*2 + 2);
         end = ttUSHORT(data + search + 2);
         start = ttUSHORT(data + search + searchRange*2 + segcount*2 + 2);
         end = ttUSHORT(data + search + searchRange*2);
         if (unicode_codepoint > end)
            search += searchRange*2;
         --entrySelector;
      }
      search += 2;

      item = (stbtt_uint16) ((search - endCount) >> 1);

      STBTT_assert(unicode_codepoint <= ttUSHORT(data + endCount + 2*item));
      start = ttUSHORT(data + index_map + 14 + segcount*2 + 2 + 2*item);
      end = ttUSHORT(data + index_map + 14 + 2 + 2*item);
      if (unicode_codepoint < start)
         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;
}

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;

   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);
   }