From 55f0abbe991c9b1c6eed2cbb714cb3164519ca25 Mon Sep 17 00:00:00 2001 From: raysan5 Date: Sat, 2 Jan 2016 10:44:03 +0100 Subject: [PATCH] Updated to latest version --- src/stb_truetype.h | 871 ++++++++++++++++++++++++++++++++++++++------- 1 file changed, 737 insertions(+), 134 deletions(-) diff --git a/src/stb_truetype.h b/src/stb_truetype.h index ae60212e0..00d22eb6d 100644 --- a/src/stb_truetype.h +++ b/src/stb_truetype.h @@ -1,5 +1,5 @@ -// stb_truetype.h - v1.05 - public domain -// authored from 2009-2014 by Sean Barrett / RAD Game Tools +// stb_truetype.h - v1.08 - public domain +// authored from 2009-2015 by Sean Barrett / RAD Game Tools // // This library processes TrueType files: // parse files @@ -39,49 +39,35 @@ // Omar Cornut // github:aloucks // Peter LaValle +// Sergey Popov +// Giumo X. Clanjor +// Higor Euripedes // // Misc other: // Ryan Gordon // // VERSION HISTORY // +// 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 +// 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 +// +// Full history can be found at the end of this file. // // 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. +// recognized, you are granted a perpetual, irrevocable license to copy, +// distribute, and modify this file as you see fit. // // USAGE // @@ -102,7 +88,7 @@ // #include "stb_rect_pack.h" -- optional, but you really want it // stbtt_PackBegin() // stbtt_PackSetOversample() -- for improved quality on small fonts -// stbtt_PackFontRanges() +// stbtt_PackFontRanges() -- pack and renders // stbtt_PackEnd() // stbtt_GetPackedQuad() // @@ -120,6 +106,15 @@ // stbtt_GetFontVMetrics() // 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. @@ -219,7 +214,15 @@ // Baked bitmap interface 70 LOC / // Font name matching & access 150 LOC ---- 150 // C runtime library abstraction 60 LOC ---- 60 - +// +// +// 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 ////////////////////////////////////////////////////////////////////////////// ////////////////////////////////////////////////////////////////////////////// @@ -330,7 +333,7 @@ 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!"; + 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); @@ -388,12 +391,6 @@ int main(int arg, char **argv) 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 - #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 @@ -511,13 +508,17 @@ typedef struct } 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 weight x 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 +// 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). // @@ -546,28 +547,34 @@ STBTT_DEF int stbtt_PackFontRange(stbtt_pack_context *spc, unsigned char *fontd typedef struct { float font_size; - int first_unicode_char_in_range; - int num_chars_in_range; + 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, 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. - +// 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). The default (no oversampling) is achieved by -// h_oversample=1, v_oversample=1. The total number of pixels required is +// 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_GetPackedQuad(stbtt_packedchar *chardata, int pw, int ph, // same data as above int char_index, // character to display @@ -575,6 +582,19 @@ STBTT_DEF void stbtt_GetPackedQuad(stbtt_packedchar *chardata, int pw, int ph, stbtt_aligned_quad *q, // output: quad to draw int align_to_integer); +STBTT_DEF int stbtt_PackFontRangesGatherRects(stbtt_pack_context *spc, 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, 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 { @@ -785,7 +805,16 @@ typedef struct unsigned char *pixels; } stbtt__bitmap; -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); +// 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 ////////////////////////////////////////////////////////////////////////////// // @@ -900,8 +929,16 @@ enum { // languageID for STBTT_PLATFORM_ID_MAC #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 + ////////////////////////////////////////////////////////////////////////// // // accessors to parse data from file @@ -970,7 +1007,7 @@ STBTT_DEF int stbtt_GetFontOffsetForIndex(const unsigned char *font_collection, stbtt_int32 n = ttLONG(font_collection+8); if (index >= n) return -1; - return ttULONG(font_collection+12+index*14); + return ttULONG(font_collection+12+index*4); } } return -1; @@ -1550,42 +1587,129 @@ STBTT_DEF void stbtt_GetCodepointBitmapBox(const stbtt_fontinfo *font, int codep 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 == NULL) + return NULL; + c->next = hh->head; + hh->head = c; + hh->num_remaining_in_head_chunk = count; + } + --hh->num_remaining_in_head_chunk; + return (char *) (hh->head) + 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; - struct stbtt__active_edge *next; - int valid; + 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; -#define FIXSHIFT 10 -#define FIX (1 << FIXSHIFT) -#define FIXMASK (FIX-1) +#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 *new_active(stbtt__edge *e, int off_x, float start_point, void *userdata) +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_malloc(sizeof(*z), userdata); // @TODO: make a pool of these!!! + 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(e->y0 <= start_point); if (!z) return z; - // round dx down to avoid going too far + + // round dx down to avoid overshooting if (dxdy < 0) - z->dx = -STBTT_ifloor(FIX * -dxdy); + z->dx = -STBTT_ifloor(STBTT_FIX * -dxdy); else - z->dx = STBTT_ifloor(FIX * dxdy); - z->x = STBTT_ifloor(FIX * (e->x0 + dxdy * (start_point - e->y0))); - z->x -= off_x * FIX; + 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->valid = e->invert ? 1 : -1; + 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(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 @@ -1597,26 +1721,26 @@ static void stbtt__fill_active_edges(unsigned char *scanline, int len, stbtt__ac while (e) { if (w == 0) { // if we're currently at zero, we need to record the edge start point - x0 = e->x; w += e->valid; + x0 = e->x; w += e->direction; } else { - int x1 = e->x; w += e->valid; + int x1 = e->x; w += e->direction; // if we went to zero, we need to draw if (w == 0) { - int i = x0 >> FIXSHIFT; - int j = x1 >> FIXSHIFT; + 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 >> FIXSHIFT); + 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) (((FIX - (x0 & FIXMASK)) * max_weight) >> FIXSHIFT); + 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 & FIXMASK) * max_weight) >> FIXSHIFT); + scanline[j] = scanline[j] + (stbtt_uint8) (((x1 & STBTT_FIXMASK) * max_weight) >> STBTT_FIXSHIFT); else j = len; // clip @@ -1633,6 +1757,7 @@ static void stbtt__fill_active_edges(unsigned char *scanline, int len, stbtt__ac 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 = NULL; int y,j=0; int max_weight = (255 / vsubsample); // weight per vertical scanline @@ -1660,9 +1785,9 @@ static void stbtt__rasterize_sorted_edges(stbtt__bitmap *result, stbtt__edge *e, stbtt__active_edge * z = *step; if (z->ey <= scan_y) { *step = z->next; // delete from list - STBTT_assert(z->valid); - z->valid = 0; - STBTT_free(z, userdata); + 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 @@ -1691,7 +1816,7 @@ static void stbtt__rasterize_sorted_edges(stbtt__bitmap *result, stbtt__edge *e, // 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 = new_active(e, off_x, scan_y, userdata); + stbtt__active_edge *z = stbtt__new_active(&hh, e, off_x, scan_y, userdata); // find insertion point if (active == NULL) active = z; @@ -1722,24 +1847,392 @@ static void stbtt__rasterize_sorted_edges(stbtt__bitmap *result, stbtt__edge *e, ++j; } - while (active) { - stbtt__active_edge *z = active; - active = active->next; - STBTT_free(z, userdata); - } + stbtt__hheap_cleanup(&hh, userdata); if (scanline != scanline_data) STBTT_free(scanline, userdata); } -static int stbtt__edge_compare(const void *p, const void *q) -{ - stbtt__edge *a = (stbtt__edge *) p; - stbtt__edge *b = (stbtt__edge *) q; +#elif STBTT_RASTERIZER_VERSION == 2 - if (a->y0 < b->y0) return -1; - if (a->y0 > b->y0) return 1; - return 0; +// 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 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; + STBTT_assert(x >= 0 && x < len); + scanline[x] += e->direction * (1-((x_top - x) + (x_bottom-x))/2) * height; + scanline_fill[x] += e->direction * height; // everything right of this pixel is filled + } else { + int x,x1,x2; + float y_crossing, 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; + } + + x1 = (int) x_top; + x2 = (int) x_bottom; + // compute intersection with y axis at x1+1 + y_crossing = (x1+1 - x0) * dy + y_top; + + sign = e->direction; + // area of the rectangle covered from y0..y_crossing + area = sign * (y_crossing-sy0); + // area of the triangle (x_top,y0), (x+1,y0), (x+1,y_crossing) + scanline[x1] += area * (1-((x_top - x1)+(x1+1-x1))/2); + + step = sign * dy; + for (x = x1+1; x < x2; ++x) { + scanline[x] += area + step/2; + area += step; + } + y_crossing += dy * (x2 - (x1+1)); + + STBTT_assert(fabs(area) <= 1.01f); + + scanline[x2] += area + sign * (1-((x2-x2)+(x_bottom-x2))/2) * (sy1-y_crossing); + + 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 + 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 clear pairs + float y0 = y_top; + float x1 = (float) (x); + float x2 = (float) (x+1); + float x3 = xb; + float y3 = y_bottom; + float y1,y2; + + // x = e->x + e->dx * (y-y_top) + // (y-y_top) = (x - e->x) / e->dx + // y = (x - e->x) / e->dx + y_top + y1 = (x - x0) / dx + y_top; + 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 = NULL; + int y,j=0, i; + float scanline_data[129], *scanline, *scanline2; + + 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); + STBTT_assert(z->ey >= scan_y_top); + // 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) 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) +{ + /* threshhold 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 && midn => n; 0 0 */ + /* 0n: 0>n => 0; 0 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 @@ -1752,7 +2245,13 @@ static void stbtt__rasterize(stbtt__bitmap *result, stbtt__point *pts, int *wcou 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 @@ -1789,7 +2288,8 @@ static void stbtt__rasterize(stbtt__bitmap *result, stbtt__point *pts, int *wcou } // 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(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); @@ -2106,11 +2606,11 @@ typedef struct unsigned char x; } stbrp_node; -typedef struct +struct stbrp_rect { stbrp_coord x,y; int id,w,h,was_packed; -} stbrp_rect; +}; static void stbrp_init_target(stbrp_context *con, int pw, int ph, stbrp_node *nodes, int num_nodes) { @@ -2177,7 +2677,8 @@ STBTT_DEF int stbtt_PackBegin(stbtt_pack_context *spc, unsigned char *pixels, in stbrp_init_target(context, pw-padding, ph-padding, nodes, num_nodes); - STBTT_memset(pixels, 0, pw*ph); // background of 0 around pixels + if (pixels) + STBTT_memset(pixels, 0, pw*ph); // background of 0 around pixels return 1; } @@ -2235,6 +2736,13 @@ static void stbtt__h_prefilter(unsigned char *pixels, int w, int h, int stride_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]; @@ -2289,6 +2797,13 @@ static void stbtt__v_prefilter(unsigned char *pixels, int w, int h, int stride_i 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]; @@ -2320,63 +2835,62 @@ static float stbtt__oversample_shift(int oversample) return (float)-(oversample - 1) / (2.0f * (float)oversample); } -STBTT_DEF int stbtt_PackFontRanges(stbtt_pack_context *spc, unsigned char *fontdata, int font_index, stbtt_pack_range *ranges, int num_ranges) +// rects array must be big enough to accommodate all characters in the given ranges +STBTT_DEF int stbtt_PackFontRangesGatherRects(stbtt_pack_context *spc, stbtt_fontinfo *info, stbtt_pack_range *ranges, int num_ranges, stbrp_rect *rects) { - stbtt_fontinfo info; - float recip_h = 1.0f / spc->h_oversample; - float recip_v = 1.0f / spc->v_oversample; - float sub_x = stbtt__oversample_shift(spc->h_oversample); - float sub_y = stbtt__oversample_shift(spc->v_oversample); - int i,j,k,n, return_value = 1; - stbrp_context *context = (stbrp_context *) spc->pack_info; - stbrp_rect *rects; + int i,j,k; - // flag all characters as NOT packed - for (i=0; i < num_ranges; ++i) - for (j=0; j < ranges[i].num_chars_in_range; ++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_in_range; - - rects = (stbrp_rect *) STBTT_malloc(sizeof(*rects) * n, spc->user_allocator_context); - if (rects == NULL) - return 0; - - stbtt_InitFont(&info, fontdata, stbtt_GetFontOffsetForIndex(fontdata,font_index)); 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); - for (j=0; j < ranges[i].num_chars_in_range; ++j) { + 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; - stbtt_GetCodepointBitmapBoxSubpixel(&info, ranges[i].first_unicode_char_in_range + j, - scale * spc->h_oversample, - scale * spc->v_oversample, - 0,0, - &x0,&y0,&x1,&y1); + int codepoint = ranges[i].array_of_unicode_codepoints == NULL ? ranges[i].first_unicode_codepoint_in_range + j : ranges[i].array_of_unicode_codepoints[j]; + int glyph = stbtt_FindGlyphIndex(info, codepoint); + 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); ++k; } } - stbrp_pack_rects(context, rects, k); + return k; +} + +// rects array must be big enough to accommodate all characters in the given ranges +STBTT_DEF int stbtt_PackFontRangesRenderIntoRects(stbtt_pack_context *spc, stbtt_fontinfo *info, stbtt_pack_range *ranges, int num_ranges, stbrp_rect *rects) +{ + int i,j,k, 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); - for (j=0; j < ranges[i].num_chars_in_range; ++j) { + 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) { stbtt_packedchar *bc = &ranges[i].chardata_for_range[j]; int advance, lsb, x0,y0,x1,y1; - int glyph = stbtt_FindGlyphIndex(&info, ranges[i].first_unicode_char_in_range + j); + int codepoint = ranges[i].array_of_unicode_codepoints == NULL ? 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 @@ -2384,12 +2898,12 @@ STBTT_DEF int stbtt_PackFontRanges(stbtt_pack_context *spc, unsigned char *fontd r->y += pad; r->w -= pad; r->h -= pad; - stbtt_GetGlyphHMetrics(&info, glyph, &advance, &lsb); - stbtt_GetGlyphBitmapBox(&info, glyph, + 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, + 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, @@ -2426,16 +2940,60 @@ STBTT_DEF int stbtt_PackFontRanges(stbtt_pack_context *spc, unsigned char *fontd } } + // 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, 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 == NULL) + return 0; + + 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, 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) + int first_unicode_codepoint_in_range, int num_chars_in_range, stbtt_packedchar *chardata_for_range) { stbtt_pack_range range; - range.first_unicode_char_in_range = first_unicode_char_in_range; - range.num_chars_in_range = num_chars_in_range; + range.first_unicode_codepoint_in_range = first_unicode_codepoint_in_range; + range.array_of_unicode_codepoints = NULL; + 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); @@ -2630,3 +3188,48 @@ STBTT_DEF int stbtt_FindMatchingFont(const unsigned char *font_collection, const } #endif // STB_TRUETYPE_IMPLEMENTATION + + +// FULL VERSION HISTORY +// +// 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 +//