1 /* ***********************
2 	This module is no longer maintained, use arsd.ttf instead.
3 *************************/
4 
5 
6 // stb_truetype.h - v0.6c - public domain
7 // authored from 2009-2012 by Sean Barrett / RAD Game Tools
8 //
9 // http://nothings.org/stb/stb_truetype.h
10 //
11 // port to D by adam d. ruppe. see the link above for more info about the lib and real author.
12 
13 // here's some D convenience functions
14 module stb_truetype;
15 
16 @system:
17 
18 struct TtfFont {
19 	stbtt_fontinfo font;
20 	this(in ubyte[] data) {
21 		load(data);
22 	}
23 
24 	void load(in ubyte[] data) {
25    		if(stbtt_InitFont(&font, data.ptr, stbtt_GetFontOffsetForIndex(data.ptr, 0)) == 0)
26 			throw new Exception("load font problem");
27 	}
28 
29 	ubyte[] renderCharacter(dchar c, int size, out int width, out int height, float shift_x = 0.0, float shift_y = 0.0) {
30    		auto ptr = stbtt_GetCodepointBitmapSubpixel(&font, 0.0,stbtt_ScaleForPixelHeight(&font, size),
31 			shift_x, shift_y, c, &width, &height, null,null);
32 		return ptr[0 .. width * height];
33 	}
34 
35 	void getStringSize(in char[] s, int size, out int width, out int height) {
36 		float xpos=0;
37 
38 		auto scale = stbtt_ScaleForPixelHeight(&font, size);
39 		int ascent, descent, line_gap;
40 		stbtt_GetFontVMetrics(&font, &ascent,&descent,&line_gap);
41 		auto baseline = cast(int) (ascent*scale);
42 
43 		import std.math;
44 
45 		int maxWidth;
46 
47 		foreach(i, dchar ch; s) {
48 			int advance,lsb;
49 			auto x_shift = xpos - floor(xpos);
50 			stbtt_GetCodepointHMetrics(&font, ch, &advance, &lsb);
51 
52 			int x0, y0, x1, y1;
53 			stbtt_GetCodepointBitmapBoxSubpixel(&font, ch, scale,scale,x_shift,0, &x0,&y0,&x1,&y1);
54 
55 			maxWidth = cast(int)(xpos + x1);
56 
57 			xpos += (advance * scale);
58 			if (i + 1 < s.length)
59 				xpos += scale*stbtt_GetCodepointKernAdvance(&font, ch,s[i+1]);
60 		}
61 
62    		width = maxWidth;
63 		height = size;
64 	}
65 
66 	ubyte[] renderString(in char[] s, int size, out int width, out int height) {
67 		float xpos=0;
68 
69 		auto scale = stbtt_ScaleForPixelHeight(&font, size);
70 		int ascent, descent, line_gap;
71 		stbtt_GetFontVMetrics(&font, &ascent,&descent,&line_gap);
72 		auto baseline = cast(int) (ascent*scale);
73 
74 		import std.math;
75 
76 		int swidth;
77 		int sheight;
78 		getStringSize(s, size, swidth, sheight);
79 		auto screen = new ubyte[](swidth * sheight);
80 
81 		foreach(i, dchar ch; s) {
82 			int advance,lsb;
83 			auto x_shift = xpos - floor(xpos);
84 			stbtt_GetCodepointHMetrics(&font, ch, &advance, &lsb);
85 			int cw, cheight;
86 			auto c = renderCharacter(ch, size, cw, cheight, x_shift, 0.0);
87 
88 			int x0, y0, x1, y1;
89 			stbtt_GetCodepointBitmapBoxSubpixel(&font, ch, scale,scale,x_shift,0, &x0,&y0,&x1,&y1);
90 
91 			int x = cast(int) xpos + x0;
92 			int y = baseline + y0;
93 			int cx = 0;
94 			foreach(index, pixel; c) {
95 				if(cx == cw) {
96 					cx = 0;
97 					y++;
98 					x = cast(int) xpos + x0;
99 				}
100 				auto offset = swidth * y + x;
101 				if(offset >= screen.length)
102 					break;
103 				int val = (cast(int) pixel * (255 - screen[offset]) / 255);
104 				if(val > 255)
105 					val = 255;
106 				screen[offset] += cast(ubyte)(val);
107 				x++;
108 				cx++;
109 			}
110 
111 			//stbtt_MakeCodepointBitmapSubpixel(&font, &screen[(baseline + y0) * swidth + cast(int) xpos + x0], x1-x0,y1-y0, 79, scale,scale,      x_shift,0, ch);
112 			// note that this stomps the old data, so where character boxes overlap (e.g. 'lj') it's wrong
113 			// because this API is really for baking character bitmaps into textures. if you want to render
114 			// a sequence of characters, you really need to render each bitmap to a temp buffer, then
115 			// "alpha blend" that into the working buffer
116 			xpos += (advance * scale);
117 			if (i + 1 < s.length)
118 				xpos += scale*stbtt_GetCodepointKernAdvance(&font, ch,s[i+1]);
119 		}
120 
121    		width = swidth;
122 		height = sheight;
123 
124 		return screen;
125 	}
126 
127 	// ~this() {}
128 }
129 
130 
131 // test program
132 /+
133 int main(string[] args)
134 {
135 import std.conv;
136 import arsd.simpledisplay;
137    int c = (args.length > 1 ? to!int(args[1]) : 'a'), s = (args.length > 2 ? to!int(args[2]) : 20);
138 import std.file;
139 
140    auto font = TtfFont(cast(ubyte[]) /*import("sans-serif.ttf"));//*/std.file.read(args.length > 3 ? args[3] : "sans-serif.ttf"));
141 
142    int w, h;
143    auto bitmap = font.renderString("Hejlqo, world!qMpj", s, w, h);
144 	auto img = new Image(w, h);
145 
146    for (int j=0; j < h; ++j) {
147       for (int i=0; i < w; ++i)
148       	img.putPixel(i, j, Color(0, (bitmap[j*w+i] > 128) ? 255 : 0, 0));
149    }
150    img.displayImage();
151    return 0;
152 }
153 +/
154 
155 
156 
157 
158 // STB_IMAGE FOLLOWS
159 
160 
161    alias ubyte  stbtt_uint8;
162    alias byte   stbtt_int8;
163    alias ushort stbtt_uint16;
164    alias short  stbtt_int16;
165    alias uint   stbtt_uint32;
166    alias int    stbtt_int32;
167 
168    alias char[(stbtt_int32.sizeof)==4 ? 1 : -1] stbtt__check_size32;
169    alias char[(stbtt_int16.sizeof)==2 ? 1 : -1] stbtt__check_size16;
170 
171    static import core.stdc.stdlib;
172    alias STBTT_sort = core.stdc.stdlib.qsort;
173 
174    static import std.math;
175    int STBTT_ifloor(float x) { return cast(int) std.math.floor(x); }
176    int STBTT_iceil(float x) { return cast(int) std.math.ceil(x); }
177 
178    void* STBTT_malloc(size_t x, in void* u) { import core.memory; return GC.malloc(x); /*return core.stdc.stdlib.malloc(x);*/ }
179    void STBTT_free(void* x,in void* u) { /*return core.stdc.stdlib.free(x);*/ }
180 
181    static import core.stdc.string;
182    alias STBTT_strlen = core.stdc..string.strlen;
183 
184    alias STBTT_memcpy = core.stdc..string.memcpy;
185    alias STBTT_memset = core.stdc..string.memset;
186 
187 // ////////////////////////////////////////////////////////////////////////////
188 //
189 // TEXTURE BAKING API
190 //
191 // If you use this API, you only have to call two functions ever.
192 //
193 
194 struct stbtt_bakedchar
195 {
196    ushort x0,y0,x1,y1; // coordinates of bbox in bitmap
197    float xoff,yoff,xadvance;   
198 }
199 
200 // if return is positive, the first unused row of the bitmap
201 // if return is negative, returns the negative of the number of characters that fit
202 // if return is 0, no characters fit and no rows were used
203 // This uses a very crappy packing.
204 
205 struct stbtt_aligned_quad
206 {
207    float x0,y0,s0,t0; // top-left
208    float x1,y1,s1,t1; // bottom-right
209 }
210 
211 // Call GetBakedQuad with char_index = 'character - first_char', and it
212 // creates the quad you need to draw and advances the current position.
213 //
214 // The coordinate system used assumes y increases downwards.
215 //
216 // Characters will extend both above and below the current position;
217 // see discussion of "BASELINE" above.
218 //
219 // It's inefficient; you might want to c&p it and optimize it.
220 
221 
222 // ////////////////////////////////////////////////////////////////////////////
223 //
224 // FONT LOADING
225 //
226 //
227 
228 // Each .ttf/.ttc file may have more than one font. Each font has a sequential
229 // index number starting from 0. Call this function to get the font offset for
230 // a given index; it returns -1 if the index is out of range. A regular .ttf
231 // file will only define one font and it always be at offset 0, so it will
232 // return '0' for index 0, and -1 for all other indices. You can just skip
233 // this step if you know it's that kind of font.
234 
235 
236 // The following structure is defined publically so you can declare one on
237 // the stack or as a global or etc, but you should treat it as opaque.
238 struct stbtt_fontinfo
239 {
240    void           * userdata;
241    ubyte  * data;              // pointer to .ttf file
242    int              fontstart;         // offset of start of font
243 
244    int numGlyphs;                     // number of glyphs, needed for range checking
245 
246    int loca,head,glyf,hhea,hmtx,kern; // table locations as offset from start of .ttf
247    int index_map;                     // a cmap mapping for our chosen character encoding
248    int indexToLocFormat;              // format needed to map from glyph index to glyph
249 }
250 
251 // Given an offset into the file that defines a font, this function builds
252 // the necessary cached info for the rest of the system. You must allocate
253 // the stbtt_fontinfo yourself, and stbtt_InitFont will fill it out. You don't
254 // need to do anything special to free it, because the contents are pure
255 // value data with no additional data structures. Returns 0 on failure.
256 
257 
258 // ////////////////////////////////////////////////////////////////////////////
259 //
260 // GLYPH SHAPES (you probably don't need these, but they have to go before
261 // the bitmaps for C declaration-order reasons)
262 //
263 
264    enum {
265       STBTT_vmove=1,
266       STBTT_vline,
267       STBTT_vcurve
268    }
269 
270    alias short stbtt_vertex_type;
271    struct stbtt_vertex
272    {
273       stbtt_vertex_type x,y,cx,cy;
274       ubyte type,padding;
275    }
276 
277 // @TODO: don't expose this structure
278 struct stbtt__bitmap
279 {
280    int w,h,stride;
281    ubyte *pixels;
282 }
283 
284 // ////////////////////////////////////////////////////////////////////////////
285 //
286 // Finding the right font...
287 //
288 // You should really just solve this offline, keep your own tables
289 // of what font is what, and don't try to get it out of the .ttf file.
290 // That's because getting it out of the .ttf file is really hard, because
291 // the names in the file can appear in many possible encodings, in many
292 // possible languages, and e.g. if you need a case-insensitive comparison,
293 // the details of that depend on the encoding & language in a complex way
294 // (actually underspecified in truetype, but also gigantic).
295 //
296 // But you can use the provided functions in two possible ways:
297 //     stbtt_FindMatchingFont() will use *case-sensitive* comparisons on
298 //             unicode-encoded names to try to find the font you want;
299 //             you can run this before calling stbtt_InitFont()
300 //
301 //     stbtt_GetFontNameString() lets you get any of the various strings
302 //             from the file yourself and do your own comparisons on them.
303 //             You have to have called stbtt_InitFont() first.
304 
305 
306 enum STBTT_MACSTYLE_DONTCARE   = 0;
307 enum STBTT_MACSTYLE_BOLD       = 1;
308 enum STBTT_MACSTYLE_ITALIC     = 2;
309 enum STBTT_MACSTYLE_UNDERSCORE = 4;
310 enum STBTT_MACSTYLE_NONE       = 8;   // <= not same as 0, this makes us check the bitfield is 0
311 
312 // returns the string (which may be big-endian double byte, e.g. for unicode)
313 // and puts the length in bytes in *length.
314 //
315 // some of the values for the IDs are below; for more see the truetype spec:
316 //     http://developer.apple.com/textfonts/TTRefMan/RM06/Chap6name.html
317 //     http://www.microsoft.com/typography/otspec/name.htm
318 
319 enum { // platformID
320    STBTT_PLATFORM_ID_UNICODE   =0,
321    STBTT_PLATFORM_ID_MAC       =1,
322    STBTT_PLATFORM_ID_ISO       =2,
323    STBTT_PLATFORM_ID_MICROSOFT =3
324 };
325 
326 enum { // encodingID for STBTT_PLATFORM_ID_UNICODE
327    STBTT_UNICODE_EID_UNICODE_1_0    =0,
328    STBTT_UNICODE_EID_UNICODE_1_1    =1,
329    STBTT_UNICODE_EID_ISO_10646      =2,
330    STBTT_UNICODE_EID_UNICODE_2_0_BMP=3,
331    STBTT_UNICODE_EID_UNICODE_2_0_FULL=4
332 };
333 
334 enum { // encodingID for STBTT_PLATFORM_ID_MICROSOFT
335    STBTT_MS_EID_SYMBOL        =0,
336    STBTT_MS_EID_UNICODE_BMP   =1,
337    STBTT_MS_EID_SHIFTJIS      =2,
338    STBTT_MS_EID_UNICODE_FULL  =10
339 };
340 
341 enum { // encodingID for STBTT_PLATFORM_ID_MAC; same as Script Manager codes
342    STBTT_MAC_EID_ROMAN        =0,   STBTT_MAC_EID_ARABIC       =4,
343    STBTT_MAC_EID_JAPANESE     =1,   STBTT_MAC_EID_HEBREW       =5,
344    STBTT_MAC_EID_CHINESE_TRAD =2,   STBTT_MAC_EID_GREEK        =6,
345    STBTT_MAC_EID_KOREAN       =3,   STBTT_MAC_EID_RUSSIAN      =7
346 };
347 
348 enum { // languageID for STBTT_PLATFORM_ID_MICROSOFT; same as LCID...
349        // problematic because there are e.g. 16 english LCIDs and 16 arabic LCIDs
350    STBTT_MS_LANG_ENGLISH     =0x0409,   STBTT_MS_LANG_ITALIAN     =0x0410,
351    STBTT_MS_LANG_CHINESE     =0x0804,   STBTT_MS_LANG_JAPANESE    =0x0411,
352    STBTT_MS_LANG_DUTCH       =0x0413,   STBTT_MS_LANG_KOREAN      =0x0412,
353    STBTT_MS_LANG_FRENCH      =0x040c,   STBTT_MS_LANG_RUSSIAN     =0x0419,
354    STBTT_MS_LANG_GERMAN      =0x0407,   STBTT_MS_LANG_SPANISH     =0x0409,
355    STBTT_MS_LANG_HEBREW      =0x040d,   STBTT_MS_LANG_SWEDISH     =0x041D
356 };
357 
358 enum { // languageID for STBTT_PLATFORM_ID_MAC
359    STBTT_MAC_LANG_ENGLISH      =0 ,   STBTT_MAC_LANG_JAPANESE     =11,
360    STBTT_MAC_LANG_ARABIC       =12,   STBTT_MAC_LANG_KOREAN       =23,
361    STBTT_MAC_LANG_DUTCH        =4 ,   STBTT_MAC_LANG_RUSSIAN      =32,
362    STBTT_MAC_LANG_FRENCH       =1 ,   STBTT_MAC_LANG_SPANISH      =6 ,
363    STBTT_MAC_LANG_GERMAN       =2 ,   STBTT_MAC_LANG_SWEDISH      =5 ,
364    STBTT_MAC_LANG_HEBREW       =10,   STBTT_MAC_LANG_CHINESE_SIMPLIFIED =33,
365    STBTT_MAC_LANG_ITALIAN      =3 ,   STBTT_MAC_LANG_CHINESE_TRAD =19
366 };
367 
368 // /////////////////////////////////////////////////////////////////////////////
369 // /////////////////////////////////////////////////////////////////////////////
370 // //
371 // //   IMPLEMENTATION
372 // //
373 // //
374 
375 // ////////////////////////////////////////////////////////////////////////
376 //
377 // accessors to parse data from file
378 //
379 
380 // on platforms that don't allow misaligned reads, if we want to allow
381 // truetype fonts that aren't padded to alignment, define ALLOW_UNALIGNED_TRUETYPE
382 
383 stbtt_uint8 ttBYTE(in stbtt_uint8* p) { return * cast(stbtt_uint8 *) (p); }
384 stbtt_int8 ttCHAR(in stbtt_uint8* p)     { return * cast(stbtt_int8 *) (p); }
385 stbtt_int32 ttFixed(in stbtt_uint8* p) { return ttLONG(p); }
386 
387 version(BigEndian) {
388    stbtt_uint16 ttUSHORT(in stbtt_uint8* p)   { return * cast(stbtt_uint16 *) (p); }
389    stbtt_int16 ttSHORT(in stbtt_uint8* p)    { return * cast(stbtt_int16 *) (p); }
390    stbtt_uint32 ttULONG(in stbtt_uint8* p)    { return * cast(stbtt_uint32 *) (p); }
391    stbtt_int32 ttLONG(in stbtt_uint8* p)     { return * cast(stbtt_int32 *) (p); }
392 } else {
393    stbtt_uint16 ttUSHORT(const stbtt_uint8 *p) { return p[0]*256 + p[1]; }
394    stbtt_int16 ttSHORT(const stbtt_uint8 *p)   { return cast(short)(p[0]*256 + p[1]); }
395    stbtt_uint32 ttULONG(const stbtt_uint8 *p)  { return (p[0]<<24) + (p[1]<<16) + (p[2]<<8) + p[3]; }
396    stbtt_int32 ttLONG(const stbtt_uint8 *p)    { return (p[0]<<24) + (p[1]<<16) + (p[2]<<8) + p[3]; }
397 }
398 
399 
400 bool stbtt_tag4(in stbtt_uint8* p,int c0, int c1, int c2, int c3) { return ((p)[0] == (c0) && (p)[1] == (c1) && (p)[2] == (c2) && (p)[3] == (c3)); }
401 bool stbtt_tag(in stbtt_uint8* p, in char* str) { return stbtt_tag4(p,str[0],str[1],str[2],str[3]); }
402 
403 static int stbtt__isfont(const stbtt_uint8 *font)
404 {
405    // check the version number
406    if (stbtt_tag4(font, '1',0,0,0))  return 1; // TrueType 1
407    if (stbtt_tag(font, "typ1".ptr))   return 1; // TrueType with type 1 font -- we don't support this!
408    if (stbtt_tag(font, "OTTO".ptr))   return 1; // OpenType with CFF
409    if (stbtt_tag4(font, 0,1,0,0)) return 1; // OpenType 1.0
410    return 0;
411 }
412 
413 // @OPTIMIZE: binary search
414 static stbtt_uint32 stbtt__find_table(const(stbtt_uint8) *data, stbtt_uint32 fontstart, const char *tag)
415 {
416    stbtt_int32 num_tables = ttUSHORT(data+fontstart+4);
417    stbtt_uint32 tabledir = fontstart + 12;
418    stbtt_int32 i;
419    for (i=0; i < num_tables; ++i) {
420       stbtt_uint32 loc = tabledir + 16*i;
421       if (stbtt_tag(data+loc+0, tag))
422          return ttULONG(data+loc+8);
423    }
424    return 0;
425 }
426 
427 int stbtt_GetFontOffsetForIndex(const ubyte *font_collection, int index)
428 {
429    // if it's just a font, there's only one valid index
430    if (stbtt__isfont(font_collection))
431       return index == 0 ? 0 : -1;
432 
433    // check if it's a TTC
434    if (stbtt_tag(font_collection, "ttcf")) {
435       // version 1?
436       if (ttULONG(font_collection+4) == 0x00010000 || ttULONG(font_collection+4) == 0x00020000) {
437          stbtt_int32 n = ttLONG(font_collection+8);
438          if (index >= n)
439             return -1;
440          return ttULONG(font_collection+12+index*14);
441       }
442    }
443    return -1;
444 }
445 
446 int stbtt_InitFont(stbtt_fontinfo *info, const ubyte *data2, int fontstart)
447 {
448    stbtt_uint8 *data = cast(stbtt_uint8 *) data2;
449    stbtt_uint32 cmap, t;
450    stbtt_int32 i,numTables;
451 
452    info.data = data;
453    info.fontstart = fontstart;
454 
455    cmap = stbtt__find_table(data, fontstart, "cmap");       // required
456    info.loca = stbtt__find_table(data, fontstart, "loca"); // required
457    info.head = stbtt__find_table(data, fontstart, "head"); // required
458    info.glyf = stbtt__find_table(data, fontstart, "glyf"); // required
459    info.hhea = stbtt__find_table(data, fontstart, "hhea"); // required
460    info.hmtx = stbtt__find_table(data, fontstart, "hmtx"); // required
461    info.kern = stbtt__find_table(data, fontstart, "kern"); // not required
462    if (!cmap || !info.loca || !info.head || !info.glyf || !info.hhea || !info.hmtx)
463       return 0;
464 
465    t = stbtt__find_table(data, fontstart, "maxp");
466    if (t)
467       info.numGlyphs = ttUSHORT(data+t+4);
468    else
469       info.numGlyphs = 0xffff;
470 
471    // find a cmap encoding table we understand *now* to avoid searching
472    // later. (todo: could make this installable)
473    // the same regardless of glyph.
474    numTables = ttUSHORT(data + cmap + 2);
475    info.index_map = 0;
476    for (i=0; i < numTables; ++i) {
477       stbtt_uint32 encoding_record = cmap + 4 + 8 * i;
478       // find an encoding we understand:
479       switch(ttUSHORT(data+encoding_record)) {
480       	default: break;//assert(0);
481          case STBTT_PLATFORM_ID_MICROSOFT:
482             switch (ttUSHORT(data+encoding_record+2)) {
483 	       default: assert(0);
484                case STBTT_MS_EID_UNICODE_BMP:
485                case STBTT_MS_EID_UNICODE_FULL:
486                   // MS/Unicode
487                   info.index_map = cmap + ttULONG(data+encoding_record+4);
488                   break;
489             }
490             break;
491       }
492    }
493    if (info.index_map == 0)
494       return 0;
495 
496    info.indexToLocFormat = ttUSHORT(data+info.head + 50);
497    return 1;
498 }
499 
500 int stbtt_FindGlyphIndex(const stbtt_fontinfo *info, int unicode_codepoint)
501 {
502    const(stbtt_uint8) *data = info.data;
503    stbtt_uint32 index_map = info.index_map;
504 
505    stbtt_uint16 format = ttUSHORT(data + index_map + 0);
506    if (format == 0) { // apple byte encoding
507       stbtt_int32 bytes = ttUSHORT(data + index_map + 2);
508       if (unicode_codepoint < bytes-6)
509          return ttBYTE(data + index_map + 6 + unicode_codepoint);
510       return 0;
511    } else if (format == 6) {
512       stbtt_uint32 first = ttUSHORT(data + index_map + 6);
513       stbtt_uint32 count = ttUSHORT(data + index_map + 8);
514       if (cast(stbtt_uint32) unicode_codepoint >= first && cast(stbtt_uint32) unicode_codepoint < first+count)
515          return ttUSHORT(data + index_map + 10 + (unicode_codepoint - first)*2);
516       return 0;
517    } else if (format == 2) {
518       assert(0); // @TODO: high-byte mapping for japanese/chinese/korean
519       //return 0;
520    } else if (format == 4) { // standard mapping for windows fonts: binary search collection of ranges
521       stbtt_uint16 segcount = ttUSHORT(data+index_map+6) >> 1;
522       stbtt_uint16 searchRange = ttUSHORT(data+index_map+8) >> 1;
523       stbtt_uint16 entrySelector = ttUSHORT(data+index_map+10);
524       stbtt_uint16 rangeShift = ttUSHORT(data+index_map+12) >> 1;
525       stbtt_uint16 item, offset, start, end;
526 
527       // do a binary search of the segments
528       stbtt_uint32 endCount = index_map + 14;
529       stbtt_uint32 search = endCount;
530 
531       if (unicode_codepoint > 0xffff)
532          return 0;
533 
534       // they lie from endCount .. endCount + segCount
535       // but searchRange is the nearest power of two, so...
536       if (unicode_codepoint >= ttUSHORT(data + search + rangeShift*2))
537          search += rangeShift*2;
538 
539       // now decrement to bias correctly to find smallest
540       search -= 2;
541       while (entrySelector) {
542          stbtt_uint16 start2, end2;
543          searchRange >>= 1;
544          start2 = ttUSHORT(data + search + 2 + segcount*2 + 2);
545          end2 = ttUSHORT(data + search + 2);
546          start2 = ttUSHORT(data + search + searchRange*2 + segcount*2 + 2);
547          end2 = ttUSHORT(data + search + searchRange*2);
548          if (unicode_codepoint > end2)
549             search += searchRange*2;
550          --entrySelector;
551       }
552       search += 2;
553 
554       item = cast(stbtt_uint16) ((search - endCount) >> 1);
555 
556       assert(unicode_codepoint <= ttUSHORT(data + endCount + 2*item));
557       start = ttUSHORT(data + index_map + 14 + segcount*2 + 2 + 2*item);
558       end = ttUSHORT(data + index_map + 14 + 2 + 2*item);
559       if (unicode_codepoint < start)
560          return 0;
561 
562       offset = ttUSHORT(data + index_map + 14 + segcount*6 + 2 + 2*item);
563       if (offset == 0)
564          return cast(stbtt_uint16) (unicode_codepoint + ttSHORT(data + index_map + 14 + segcount*4 + 2 + 2*item));
565 
566       return ttUSHORT(data + offset + (unicode_codepoint-start)*2 + index_map + 14 + segcount*6 + 2 + 2*item);
567    } else if (format == 12 || format == 13) {
568       stbtt_uint32 ngroups = ttULONG(data+index_map+12);
569       stbtt_int32 low,high;
570       low = 0; high = cast(stbtt_int32)ngroups;
571       // Binary search the right group.
572       while (low < high) {
573          stbtt_int32 mid = low + ((high-low) >> 1); // rounds down, so low <= mid < high
574          stbtt_uint32 start_char = ttULONG(data+index_map+16+mid*12);
575          stbtt_uint32 end_char = ttULONG(data+index_map+16+mid*12+4);
576          if (cast(stbtt_uint32) unicode_codepoint < start_char)
577             high = mid;
578          else if (cast(stbtt_uint32) unicode_codepoint > end_char)
579             low = mid+1;
580          else {
581             stbtt_uint32 start_glyph = ttULONG(data+index_map+16+mid*12+8);
582             if (format == 12)
583                return start_glyph + unicode_codepoint-start_char;
584             else // format == 13
585                return start_glyph;
586          }
587       }
588       return 0; // not found
589    }
590    // @TODO
591    assert(0);
592    // return 0;
593 }
594 
595 int stbtt_GetCodepointShape(const stbtt_fontinfo *info, int unicode_codepoint, stbtt_vertex **vertices)
596 {
597    return stbtt_GetGlyphShape(info, stbtt_FindGlyphIndex(info, unicode_codepoint), vertices);
598 }
599 
600 static void stbtt_setvertex(stbtt_vertex *v, stbtt_uint8 type, stbtt_int32 x, stbtt_int32 y, stbtt_int32 cx, stbtt_int32 cy)
601 {
602    v.type = type;
603    v.x = cast(stbtt_int16) x;
604    v.y = cast(stbtt_int16) y;
605    v.cx = cast(stbtt_int16) cx;
606    v.cy = cast(stbtt_int16) cy;
607 }
608 
609 static int stbtt__GetGlyfOffset(const stbtt_fontinfo *info, int glyph_index)
610 {
611    int g1,g2;
612 
613    if (glyph_index >= info.numGlyphs) return -1; // glyph index out of range
614    if (info.indexToLocFormat >= 2)    return -1; // unknown index.glyph map format
615 
616    if (info.indexToLocFormat == 0) {
617       g1 = info.glyf + ttUSHORT(info.data + info.loca + glyph_index * 2) * 2;
618       g2 = info.glyf + ttUSHORT(info.data + info.loca + glyph_index * 2 + 2) * 2;
619    } else {
620       g1 = info.glyf + ttULONG (info.data + info.loca + glyph_index * 4);
621       g2 = info.glyf + ttULONG (info.data + info.loca + glyph_index * 4 + 4);
622    }
623 
624    return g1==g2 ? -1 : g1; // if length is 0, return -1
625 }
626 
627 int stbtt_GetGlyphBox(const stbtt_fontinfo *info, int glyph_index, int *x0, int *y0, int *x1, int *y1)
628 {
629    int g = stbtt__GetGlyfOffset(info, glyph_index);
630    if (g < 0) return 0;
631 
632    if (x0) *x0 = ttSHORT(info.data + g + 2);
633    if (y0) *y0 = ttSHORT(info.data + g + 4);
634    if (x1) *x1 = ttSHORT(info.data + g + 6);
635    if (y1) *y1 = ttSHORT(info.data + g + 8);
636    return 1;
637 }
638 
639 int stbtt_GetCodepointBox(const stbtt_fontinfo *info, int codepoint, int *x0, int *y0, int *x1, int *y1)
640 {
641    return stbtt_GetGlyphBox(info, stbtt_FindGlyphIndex(info,codepoint), x0,y0,x1,y1);
642 }
643 
644 int stbtt_IsGlyphEmpty(const stbtt_fontinfo *info, int glyph_index)
645 {
646    stbtt_int16 numberOfContours;
647    int g = stbtt__GetGlyfOffset(info, glyph_index);
648    if (g < 0) return 1;
649    numberOfContours = ttSHORT(info.data + g);
650    return numberOfContours == 0;
651 }
652 
653 static int stbtt__close_shape(stbtt_vertex *vertices, int num_vertices, int was_off, int start_off,
654     stbtt_int32 sx, stbtt_int32 sy, stbtt_int32 scx, stbtt_int32 scy, stbtt_int32 cx, stbtt_int32 cy)
655 {
656    if (start_off) {
657       if (was_off)
658          stbtt_setvertex(&vertices[num_vertices++], STBTT_vcurve, (cx+scx)>>1, (cy+scy)>>1, cx,cy);
659       stbtt_setvertex(&vertices[num_vertices++], STBTT_vcurve, sx,sy,scx,scy);
660    } else {
661       if (was_off)
662          stbtt_setvertex(&vertices[num_vertices++], STBTT_vcurve,sx,sy,cx,cy);
663       else
664          stbtt_setvertex(&vertices[num_vertices++], STBTT_vline,sx,sy,0,0);
665    }
666    return num_vertices;
667 }
668 
669 int stbtt_GetGlyphShape(const stbtt_fontinfo *info, int glyph_index, stbtt_vertex **pvertices)
670 {
671    stbtt_int16 numberOfContours;
672    const(stbtt_uint8) *endPtsOfContours;
673    const(stbtt_uint8) *data = info.data;
674    stbtt_vertex *vertices=null;
675    int num_vertices=0;
676    int g = stbtt__GetGlyfOffset(info, glyph_index);
677 
678    *pvertices = null;
679 
680    if (g < 0) return 0;
681 
682    numberOfContours = ttSHORT(data + g);
683 
684    if (numberOfContours > 0) {
685       stbtt_uint8 flags=0,flagcount;
686       stbtt_int32 ins, i,j=0,m,n, next_move, was_off=0, off, start_off=0;
687       stbtt_int32 x,y,cx,cy,sx,sy, scx,scy;
688       const(stbtt_uint8) *points;
689       endPtsOfContours = (data + g + 10);
690       ins = ttUSHORT(data + g + 10 + numberOfContours * 2);
691       points = data + g + 10 + numberOfContours * 2 + 2 + ins;
692 
693       n = 1+ttUSHORT(endPtsOfContours + numberOfContours*2-2);
694 
695       m = n + 2*numberOfContours;  // a loose bound on how many vertices we might need
696       vertices = cast(stbtt_vertex *) STBTT_malloc(m * vertices[0].sizeof, info.userdata);
697       if (vertices is null)
698          return 0;
699 
700       next_move = 0;
701       flagcount=0;
702 
703       // in first pass, we load uninterpreted data into the allocated array
704       // above, shifted to the end of the array so we won't overwrite it when
705       // we create our final data starting from the front
706 
707       off = m - n; // starting offset for uninterpreted data, regardless of how m ends up being calculated
708 
709       // first load flags
710 
711       for (i=0; i < n; ++i) {
712          if (flagcount == 0) {
713             flags = *points++;
714             if (flags & 8)
715                flagcount = *points++;
716          } else
717             --flagcount;
718          vertices[off+i].type = flags;
719       }
720 
721       // now load x coordinates
722       x=0;
723       for (i=0; i < n; ++i) {
724          flags = vertices[off+i].type;
725          if (flags & 2) {
726             stbtt_int16 dx = *points++;
727             x += (flags & 16) ? dx : -cast(int)dx; // ???
728          } else {
729             if (!(flags & 16)) {
730                x = x + cast(stbtt_int16) (points[0]*256 + points[1]);
731                points += 2;
732             }
733          }
734          vertices[off+i].x = cast(stbtt_int16) x;
735       }
736 
737       // now load y coordinates
738       y=0;
739       for (i=0; i < n; ++i) {
740          flags = vertices[off+i].type;
741          if (flags & 4) {
742             stbtt_int16 dy = *points++;
743             y += (flags & 32) ? dy : -cast(int)dy; // ???
744          } else {
745             if (!(flags & 32)) {
746                y = y + cast(stbtt_int16) (points[0]*256 + points[1]);
747                points += 2;
748             }
749          }
750          vertices[off+i].y = cast(stbtt_int16) y;
751       }
752 
753       // now convert them to our format
754       num_vertices=0;
755       sx = sy = cx = cy = scx = scy = 0;
756       for (i=0; i < n; ++i) {
757          flags = vertices[off+i].type;
758          x     = cast(stbtt_int16) vertices[off+i].x;
759          y     = cast(stbtt_int16) vertices[off+i].y;
760 
761          if (next_move == i) {
762             if (i != 0)
763                num_vertices = stbtt__close_shape(vertices, num_vertices, was_off, start_off, sx,sy,scx,scy,cx,cy);
764 
765             // now start the new one               
766             start_off = !(flags & 1);
767             if (start_off) {
768                // if we start off with an off-curve point, then when we need to find a point on the curve
769                // where we can start, and we need to save some state for when we wraparound.
770                scx = x;
771                scy = y;
772                if (!(vertices[off+i+1].type & 1)) {
773                   // next point is also a curve point, so interpolate an on-point curve
774                   sx = (x + cast(stbtt_int32) vertices[off+i+1].x) >> 1;
775                   sy = (y + cast(stbtt_int32) vertices[off+i+1].y) >> 1;
776                } else {
777                   // otherwise just use the next point as our start point
778                   sx = cast(stbtt_int32) vertices[off+i+1].x;
779                   sy = cast(stbtt_int32) vertices[off+i+1].y;
780                   ++i; // we're using point i+1 as the starting point, so skip it
781                }
782             } else {
783                sx = x;
784                sy = y;
785             }
786             stbtt_setvertex(&vertices[num_vertices++], STBTT_vmove,sx,sy,0,0);
787             was_off = 0;
788             next_move = 1 + ttUSHORT(endPtsOfContours+j*2);
789             ++j;
790          } else {
791             if (!(flags & 1)) { // if it's a curve
792                if (was_off) // two off-curve control points in a row means interpolate an on-curve midpoint
793                   stbtt_setvertex(&vertices[num_vertices++], STBTT_vcurve, (cx+x)>>1, (cy+y)>>1, cx, cy);
794                cx = x;
795                cy = y;
796                was_off = 1;
797             } else {
798                if (was_off)
799                   stbtt_setvertex(&vertices[num_vertices++], STBTT_vcurve, x,y, cx, cy);
800                else
801                   stbtt_setvertex(&vertices[num_vertices++], STBTT_vline, x,y,0,0);
802                was_off = 0;
803             }
804          }
805       }
806       num_vertices = stbtt__close_shape(vertices, num_vertices, was_off, start_off, sx,sy,scx,scy,cx,cy);
807    } else if (numberOfContours == -1) {
808       // Compound shapes.
809       int more = 1;
810       const(stbtt_uint8) *comp = data + g + 10;
811       num_vertices = 0;
812       vertices = null;
813       while (more) {
814          stbtt_uint16 flags, gidx;
815          int comp_num_verts = 0, i;
816          stbtt_vertex* comp_verts = null, tmp = null;
817          float[6] mtx = [1,0,0,1,0,0];
818 	 float m, n;
819          
820          flags = ttSHORT(comp); comp+=2;
821          gidx = ttSHORT(comp); comp+=2;
822 
823          if (flags & 2) { // XY values
824             if (flags & 1) { // shorts
825                mtx[4] = ttSHORT(comp); comp+=2;
826                mtx[5] = ttSHORT(comp); comp+=2;
827             } else {
828                mtx[4] = ttCHAR(comp); comp+=1;
829                mtx[5] = ttCHAR(comp); comp+=1;
830             }
831          }
832          else {
833             // @TODO handle matching point
834             assert(0);
835          }
836          if (flags & (1<<3)) { // WE_HAVE_A_SCALE
837             mtx[0] = mtx[3] = ttSHORT(comp)/16384.0f; comp+=2;
838             mtx[1] = mtx[2] = 0;
839          } else if (flags & (1<<6)) { // WE_HAVE_AN_X_AND_YSCALE
840             mtx[0] = ttSHORT(comp)/16384.0f; comp+=2;
841             mtx[1] = mtx[2] = 0;
842             mtx[3] = ttSHORT(comp)/16384.0f; comp+=2;
843          } else if (flags & (1<<7)) { // WE_HAVE_A_TWO_BY_TWO
844             mtx[0] = ttSHORT(comp)/16384.0f; comp+=2;
845             mtx[1] = ttSHORT(comp)/16384.0f; comp+=2;
846             mtx[2] = ttSHORT(comp)/16384.0f; comp+=2;
847             mtx[3] = ttSHORT(comp)/16384.0f; comp+=2;
848          }
849          
850          // Find transformation scales.
851          m = cast(float) std.math.sqrt(mtx[0]*mtx[0] + mtx[1]*mtx[1]);
852          n = cast(float) std.math.sqrt(mtx[2]*mtx[2] + mtx[3]*mtx[3]);
853 
854          // Get indexed glyph.
855          comp_num_verts = stbtt_GetGlyphShape(info, gidx, &comp_verts);
856          if (comp_num_verts > 0) {
857             // Transform vertices.
858             for (i = 0; i < comp_num_verts; ++i) {
859                stbtt_vertex* v = &comp_verts[i];
860                stbtt_vertex_type x,y;
861                x=v.x; y=v.y;
862                v.x = cast(stbtt_vertex_type)(m * (mtx[0]*x + mtx[2]*y + mtx[4]));
863                v.y = cast(stbtt_vertex_type)(n * (mtx[1]*x + mtx[3]*y + mtx[5]));
864                x=v.cx; y=v.cy;
865                v.cx = cast(stbtt_vertex_type)(m * (mtx[0]*x + mtx[2]*y + mtx[4]));
866                v.cy = cast(stbtt_vertex_type)(n * (mtx[1]*x + mtx[3]*y + mtx[5]));
867             }
868             // Append vertices.
869             tmp = cast(stbtt_vertex*)STBTT_malloc((num_vertices+comp_num_verts)*stbtt_vertex.sizeof, info.userdata);
870             if (!tmp) {
871                if (vertices) STBTT_free(vertices, info.userdata);
872                if (comp_verts) STBTT_free(comp_verts, info.userdata);
873                return 0;
874             }
875             if (num_vertices > 0) core.stdc..string.memcpy(tmp, vertices, num_vertices*stbtt_vertex.sizeof);
876             core.stdc..string.memcpy(tmp+num_vertices, comp_verts, comp_num_verts*stbtt_vertex.sizeof);
877             if (vertices) STBTT_free(vertices, info.userdata);
878             vertices = tmp;
879             STBTT_free(comp_verts, info.userdata);
880             num_vertices += comp_num_verts;
881          }
882          // More components ?
883          more = flags & (1<<5);
884       }
885    } else if (numberOfContours < 0) {
886       // @TODO other compound variations?
887       assert(0);
888    } else {
889       // numberOfCounters == 0, do nothing
890    }
891 
892    *pvertices = vertices;
893    return num_vertices;
894 }
895 
896 void stbtt_GetGlyphHMetrics(const stbtt_fontinfo *info, int glyph_index, int *advanceWidth, int *leftSideBearing)
897 {
898    stbtt_uint16 numOfLongHorMetrics = ttUSHORT(info.data+info.hhea + 34);
899    if (glyph_index < numOfLongHorMetrics) {
900       if (advanceWidth)     *advanceWidth    = ttSHORT(info.data + info.hmtx + 4*glyph_index);
901       if (leftSideBearing)  *leftSideBearing = ttSHORT(info.data + info.hmtx + 4*glyph_index + 2);
902    } else {
903       if (advanceWidth)     *advanceWidth    = ttSHORT(info.data + info.hmtx + 4*(numOfLongHorMetrics-1));
904       if (leftSideBearing)  *leftSideBearing = ttSHORT(info.data + info.hmtx + 4*numOfLongHorMetrics + 2*(glyph_index - numOfLongHorMetrics));
905    }
906 }
907 
908 int  stbtt_GetGlyphKernAdvance(const stbtt_fontinfo *info, int glyph1, int glyph2)
909 {
910    const(stbtt_uint8) *data = info.data + info.kern;
911    stbtt_uint32 needle, straw;
912    int l, r, m;
913 
914    // we only look at the first table. it must be 'horizontal' and format 0.
915    if (!info.kern)
916       return 0;
917    if (ttUSHORT(data+2) < 1) // number of tables, need at least 1
918       return 0;
919    if (ttUSHORT(data+8) != 1) // horizontal flag must be set in format
920       return 0;
921 
922    l = 0;
923    r = ttUSHORT(data+10) - 1;
924    needle = glyph1 << 16 | glyph2;
925    while (l <= r) {
926       m = (l + r) >> 1;
927       straw = ttULONG(data+18+(m*6)); // note: unaligned read
928       if (needle < straw)
929          r = m - 1;
930       else if (needle > straw)
931          l = m + 1;
932       else
933          return ttSHORT(data+22+(m*6));
934    }
935    return 0;
936 }
937 
938 int  stbtt_GetCodepointKernAdvance(const stbtt_fontinfo *info, int ch1, int ch2)
939 {
940    if (!info.kern) // if no kerning table, don't waste time looking up both codepoint.glyphs
941       return 0;
942    return stbtt_GetGlyphKernAdvance(info, stbtt_FindGlyphIndex(info,ch1), stbtt_FindGlyphIndex(info,ch2));
943 }
944 
945 void stbtt_GetCodepointHMetrics(const stbtt_fontinfo *info, int codepoint, int *advanceWidth, int *leftSideBearing)
946 {
947    stbtt_GetGlyphHMetrics(info, stbtt_FindGlyphIndex(info,codepoint), advanceWidth, leftSideBearing);
948 }
949 
950 void stbtt_GetFontVMetrics(const stbtt_fontinfo *info, int *ascent, int *descent, int *lineGap)
951 {
952    if (ascent ) *ascent  = ttSHORT(info.data+info.hhea + 4);
953    if (descent) *descent = ttSHORT(info.data+info.hhea + 6);
954    if (lineGap) *lineGap = ttSHORT(info.data+info.hhea + 8);
955 }
956 
957 void stbtt_GetFontBoundingBox(const stbtt_fontinfo *info, int *x0, int *y0, int *x1, int *y1)
958 {
959    *x0 = ttSHORT(info.data + info.head + 36);
960    *y0 = ttSHORT(info.data + info.head + 38);
961    *x1 = ttSHORT(info.data + info.head + 40);
962    *y1 = ttSHORT(info.data + info.head + 42);
963 }
964 
965 float stbtt_ScaleForPixelHeight(const stbtt_fontinfo *info, float height)
966 {
967    int fheight = ttSHORT(info.data + info.hhea + 4) - ttSHORT(info.data + info.hhea + 6);
968    return cast(float) height / fheight;
969 }
970 
971 float stbtt_ScaleForMappingEmToPixels(const stbtt_fontinfo *info, float pixels)
972 {
973    int unitsPerEm = ttUSHORT(info.data + info.head + 18);
974    return pixels / unitsPerEm;
975 }
976 
977 void stbtt_FreeShape(const stbtt_fontinfo *info, stbtt_vertex *v)
978 {
979    STBTT_free(v, info.userdata);
980 }
981 
982 // ////////////////////////////////////////////////////////////////////////////
983 //
984 // antialiasing software rasterizer
985 //
986 
987 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)
988 {
989    int x0,y0,x1,y1;
990    if (!stbtt_GetGlyphBox(font, glyph, &x0,&y0,&x1,&y1))
991       x0=y0=x1=y1=0; // e.g. space character
992    // now move to integral bboxes (treating pixels as little squares, what pixels get touched)?
993    if (ix0) *ix0 =  STBTT_ifloor(x0 * scale_x + shift_x);
994    if (iy0) *iy0 = -STBTT_iceil (y1 * scale_y + shift_y);
995    if (ix1) *ix1 =  STBTT_iceil (x1 * scale_x + shift_x);
996    if (iy1) *iy1 = -STBTT_ifloor(y0 * scale_y + shift_y);
997 }
998 void stbtt_GetGlyphBitmapBox(const stbtt_fontinfo *font, int glyph, float scale_x, float scale_y, int *ix0, int *iy0, int *ix1, int *iy1)
999 {
1000    stbtt_GetGlyphBitmapBoxSubpixel(font, glyph, scale_x, scale_y,0.0f,0.0f, ix0, iy0, ix1, iy1);
1001 }
1002 
1003 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)
1004 {
1005    stbtt_GetGlyphBitmapBoxSubpixel(font, stbtt_FindGlyphIndex(font,codepoint), scale_x, scale_y,shift_x,shift_y, ix0,iy0,ix1,iy1);
1006 }
1007 
1008 void stbtt_GetCodepointBitmapBox(const stbtt_fontinfo *font, int codepoint, float scale_x, float scale_y, int *ix0, int *iy0, int *ix1, int *iy1)
1009 {
1010    stbtt_GetCodepointBitmapBoxSubpixel(font, codepoint, scale_x, scale_y,0.0f,0.0f, ix0,iy0,ix1,iy1);
1011 }
1012 
1013 struct stbtt__edge {
1014    float x0,y0, x1,y1;
1015    int invert;
1016 }
1017 
1018 struct stbtt__active_edge
1019 {
1020    int x,dx;
1021    float ey;
1022    stbtt__active_edge *next;
1023    int valid;
1024 }
1025 
1026 enum FIXSHIFT =  10;
1027 enum FIX      =  (1 << FIXSHIFT);
1028 enum FIXMASK  =  (FIX-1);
1029 
1030 static stbtt__active_edge *new_active(stbtt__edge *e, int off_x, float start_point, in void *userdata)
1031 {
1032    stbtt__active_edge *z = cast(stbtt__active_edge *) STBTT_malloc((stbtt__active_edge).sizeof, userdata); // @TODO: make a pool of these!!!
1033    float dxdy = (e.x1 - e.x0) / (e.y1 - e.y0);
1034    assert(e.y0 <= start_point);
1035    if (!z) return z;
1036    // round dx down to avoid going too far
1037    if (dxdy < 0)
1038       z.dx = -STBTT_ifloor(FIX * -dxdy);
1039    else
1040       z.dx = STBTT_ifloor(FIX * dxdy);
1041    z.x = STBTT_ifloor(FIX * (e.x0 + dxdy * (start_point - e.y0)));
1042    z.x -= off_x * FIX;
1043    z.ey = e.y1;
1044    z.next = null;
1045    z.valid = e.invert ? 1 : -1;
1046    return z;
1047 }
1048 
1049 // note: this routine clips fills that extend off the edges... ideally this
1050 // wouldn't happen, but it could happen if the truetype glyph bounding boxes
1051 // are wrong, or if the user supplies a too-small bitmap
1052 static void stbtt__fill_active_edges(ubyte *scanline, int len, stbtt__active_edge *e, int max_weight)
1053 {
1054    // non-zero winding fill
1055    int x0=0, w=0;
1056 
1057    while (e) {
1058       if (w == 0) {
1059          // if we're currently at zero, we need to record the edge start point
1060          x0 = e.x; w += e.valid;
1061       } else {
1062          int x1 = e.x; w += e.valid;
1063          // if we went to zero, we need to draw
1064          if (w == 0) {
1065             int i = x0 >> FIXSHIFT;
1066             int j = x1 >> FIXSHIFT;
1067 
1068             if (i < len && j >= 0) {
1069                if (i == j) {
1070                   // x0,x1 are the same pixel, so compute combined coverage
1071                   scanline[i] = cast(ubyte)(scanline[i] + cast(stbtt_uint8) ((x1 - x0) * max_weight >> FIXSHIFT));
1072                } else {
1073                   if (i >= 0) // add antialiasing for x0
1074                      scanline[i] = cast(ubyte)( scanline[i] + cast(stbtt_uint8) (((FIX - (x0 & FIXMASK)) * max_weight) >> FIXSHIFT));
1075                   else
1076                      i = -1; // clip
1077 
1078                   if (j < len) // add antialiasing for x1
1079                      scanline[j] =  cast(ubyte)(scanline[j] + cast(stbtt_uint8) (((x1 & FIXMASK) * max_weight) >> FIXSHIFT));
1080                   else
1081                      j = len; // clip
1082 
1083                   for (++i; i < j; ++i) // fill pixels between x0 and x1
1084                      scanline[i] =  cast(ubyte)(scanline[i] + cast(stbtt_uint8) max_weight);
1085                }
1086             }
1087          }
1088       }
1089       
1090       e = e.next;
1091    }
1092 }
1093 
1094 static void stbtt__rasterize_sorted_edges(stbtt__bitmap *result, stbtt__edge *e, int n, int vsubsample, int off_x, int off_y, in void *userdata)
1095 {
1096    stbtt__active_edge *active = null;
1097    int y,j=0;
1098    int max_weight = (255 / vsubsample);  // weight per vertical scanline
1099    int s; // vertical subsample index
1100    ubyte[512] scanline_data;
1101    ubyte *scanline;
1102 
1103    if (result.w > 512)
1104       scanline = cast(ubyte *) STBTT_malloc(result.w, userdata);
1105    else
1106       scanline = scanline_data.ptr;
1107 
1108    y = off_y * vsubsample;
1109    e[n].y0 = (off_y + result.h) * cast(float) vsubsample + 1;
1110 
1111    while (j < result.h) {
1112       STBTT_memset(scanline, 0, result.w);
1113       for (s=0; s < vsubsample; ++s) {
1114          // find center of pixel for this scanline
1115          float scan_y = y + 0.5f;
1116          stbtt__active_edge **step = &active;
1117 
1118          // update all active edges;
1119          // remove all active edges that terminate before the center of this scanline
1120          while (*step) {
1121             stbtt__active_edge * z = *step;
1122             if (z.ey <= scan_y) {
1123                *step = z.next; // delete from list
1124                assert(z.valid);
1125                z.valid = 0;
1126                STBTT_free(z, userdata);
1127             } else {
1128                z.x += z.dx; // advance to position for current scanline
1129                step = &((*step).next); // advance through list
1130             }
1131          }
1132 
1133          // resort the list if needed
1134          for(;;) {
1135             int changed=0;
1136             step = &active;
1137             while (*step && (*step).next) {
1138                if ((*step).x > (*step).next.x) {
1139                   stbtt__active_edge *t = *step;
1140                   stbtt__active_edge *q = t.next;
1141 
1142                   t.next = q.next;
1143                   q.next = t;
1144                   *step = q;
1145                   changed = 1;
1146                }
1147                step = &(*step).next;
1148             }
1149             if (!changed) break;
1150          }
1151 
1152          // insert all edges that start before the center of this scanline -- omit ones that also end on this scanline
1153          while (e.y0 <= scan_y) {
1154             if (e.y1 > scan_y) {
1155                stbtt__active_edge *z = new_active(e, off_x, scan_y, userdata);
1156                // find insertion point
1157                if (active == null)
1158                   active = z;
1159                else if (z.x < active.x) {
1160                   // insert at front
1161                   z.next = active;
1162                   active = z;
1163                } else {
1164                   // find thing to insert AFTER
1165                   stbtt__active_edge *p = active;
1166                   while (p.next && p.next.x < z.x)
1167                      p = p.next;
1168                   // at this point, p.next.x is NOT < z.x
1169                   z.next = p.next;
1170                   p.next = z;
1171                }
1172             }
1173             ++e;
1174          }
1175 
1176          // now process all active edges in XOR fashion
1177          if (active)
1178             stbtt__fill_active_edges(scanline, result.w, active, max_weight);
1179 
1180          ++y;
1181       }
1182       STBTT_memcpy(result.pixels + j * result.stride, scanline, result.w);
1183       ++j;
1184    }
1185 
1186    while (active) {
1187       stbtt__active_edge *z = active;
1188       active = active.next;
1189       STBTT_free(z, userdata);
1190    }
1191 
1192    if (scanline != scanline_data.ptr)
1193       STBTT_free(scanline, userdata);
1194 }
1195 
1196 extern(C) int stbtt__edge_compare(const void *p, const void *q)
1197 {
1198    stbtt__edge *a = cast(stbtt__edge *) p;
1199    stbtt__edge *b = cast(stbtt__edge *) q;
1200 
1201    if (a.y0 < b.y0) return -1;
1202    if (a.y0 > b.y0) return  1;
1203    return 0;
1204 }
1205 
1206 struct stbtt__point
1207 {
1208    float x,y;
1209 }
1210 
1211 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, in void *userdata)
1212 {
1213    float y_scale_inv = invert ? -scale_y : scale_y;
1214    stbtt__edge *e;
1215    int n,i,j,k,m;
1216    int vsubsample = result.h < 8 ? 15 : 5;
1217    // vsubsample should divide 255 evenly; otherwise we won't reach full opacity
1218 
1219    // now we have to blow out the windings into explicit edge lists
1220    n = 0;
1221    for (i=0; i < windings; ++i)
1222       n += wcount[i];
1223 
1224    e = cast(stbtt__edge *) STBTT_malloc((*e).sizeof * (n+1), userdata); // add an extra one as a sentinel
1225    if (e is null) return;
1226    n = 0;
1227 
1228    m=0;
1229    for (i=0; i < windings; ++i) {
1230       stbtt__point *p = pts + m;
1231       m += wcount[i];
1232       j = wcount[i]-1;
1233       for (k=0; k < wcount[i]; j=k++) {
1234          int a=k,b=j;
1235          // skip the edge if horizontal
1236          if (p[j].y == p[k].y)
1237             continue;
1238          // add edge from j to k to the list
1239          e[n].invert = 0;
1240          if (invert ? p[j].y > p[k].y : p[j].y < p[k].y) {
1241             e[n].invert = 1;
1242             a=j;b=k;
1243          }
1244          e[n].x0 = p[a].x * scale_x + shift_x;
1245          e[n].y0 = p[a].y * y_scale_inv * vsubsample + shift_y;
1246          e[n].x1 = p[b].x * scale_x + shift_x;
1247          e[n].y1 = p[b].y * y_scale_inv * vsubsample + shift_y;
1248          ++n;
1249       }
1250    }
1251 
1252    // now sort the edges by their highest point (should snap to integer, and then by x)
1253    STBTT_sort(cast(void*) e, n, (e[0]).sizeof, &stbtt__edge_compare);
1254 
1255    // now, traverse the scanlines and find the intersections on each scanline, use xor winding rule
1256    stbtt__rasterize_sorted_edges(result, e, n, vsubsample, off_x, off_y, userdata);
1257 
1258    STBTT_free(e, userdata);
1259 }
1260 
1261 static void stbtt__add_point(stbtt__point *points, int n, float x, float y)
1262 {
1263    if (!points) return; // during first pass, it's unallocated
1264    points[n].x = x;
1265    points[n].y = y;
1266 }
1267 
1268 // tesselate until threshhold p is happy... @TODO warped to compensate for non-linear stretching
1269 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)
1270 {
1271    // midpoint
1272    float mx = (x0 + 2*x1 + x2)/4;
1273    float my = (y0 + 2*y1 + y2)/4;
1274    // versus directly drawn line
1275    float dx = (x0+x2)/2 - mx;
1276    float dy = (y0+y2)/2 - my;
1277    if (n > 16) // 65536 segments on one curve better be enough!
1278       return 1;
1279    if (dx*dx+dy*dy > objspace_flatness_squared) { // half-pixel error allowed... need to be smaller if AA
1280       stbtt__tesselate_curve(points, num_points, x0,y0, (x0+x1)/2.0f,(y0+y1)/2.0f, mx,my, objspace_flatness_squared,n+1);
1281       stbtt__tesselate_curve(points, num_points, mx,my, (x1+x2)/2.0f,(y1+y2)/2.0f, x2,y2, objspace_flatness_squared,n+1);
1282    } else {
1283       stbtt__add_point(points, *num_points,x2,y2);
1284       *num_points = *num_points+1;
1285    }
1286    return 1;
1287 }
1288 
1289 // returns number of contours
1290 stbtt__point *stbtt_FlattenCurves(stbtt_vertex *vertices, int num_verts, float objspace_flatness, int **contour_lengths, int *num_contours, in void *userdata)
1291 {
1292    stbtt__point *points=null;
1293    int num_points=0;
1294 
1295    float objspace_flatness_squared = objspace_flatness * objspace_flatness;
1296    int i,n=0,start=0, pass;
1297 
1298    // count how many "moves" there are to get the contour count
1299    for (i=0; i < num_verts; ++i)
1300       if (vertices[i].type == STBTT_vmove)
1301          ++n;
1302 
1303    *num_contours = n;
1304    if (n == 0) return null;
1305 
1306    *contour_lengths = cast(int *) STBTT_malloc((**contour_lengths).sizeof * n, userdata);
1307 
1308    if (*contour_lengths is null) {
1309       *num_contours = 0;
1310       return null;
1311    }
1312 
1313    // make two passes through the points so we don't need to realloc
1314    for (pass=0; pass < 2; ++pass) {
1315       float x=0,y=0;
1316       if (pass == 1) {
1317          points = cast(stbtt__point *) STBTT_malloc(num_points * (points[0]).sizeof, userdata);
1318          if (points == null) goto error;
1319       }
1320       num_points = 0;
1321       n= -1;
1322       for (i=0; i < num_verts; ++i) {
1323          switch (vertices[i].type) {
1324 	 default: assert(0);
1325             case STBTT_vmove:
1326                // start the next contour
1327                if (n >= 0)
1328                   (*contour_lengths)[n] = num_points - start;
1329                ++n;
1330                start = num_points;
1331 
1332                x = vertices[i].x; y = vertices[i].y;
1333                stbtt__add_point(points, num_points++, x,y);
1334                break;
1335             case STBTT_vline:
1336                x = vertices[i].x, y = vertices[i].y;
1337                stbtt__add_point(points, num_points++, x, y);
1338                break;
1339             case STBTT_vcurve:
1340                stbtt__tesselate_curve(points, &num_points, x,y,
1341                                         vertices[i].cx, vertices[i].cy,
1342                                         vertices[i].x,  vertices[i].y,
1343                                         objspace_flatness_squared, 0);
1344                x = vertices[i].x; y = vertices[i].y;
1345                break;
1346          }
1347       }
1348       (*contour_lengths)[n] = num_points - start;
1349    }
1350 
1351    return points;
1352 error:
1353    STBTT_free(points, userdata);
1354    STBTT_free(*contour_lengths, userdata);
1355    *contour_lengths = null;
1356    *num_contours = 0;
1357    return null;
1358 }
1359 
1360 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, in void *userdata)
1361 {
1362    float scale = scale_x > scale_y ? scale_y : scale_x;
1363    int winding_count;
1364    int *winding_lengths;
1365    stbtt__point *windings = stbtt_FlattenCurves(vertices, num_verts, flatness_in_pixels / scale, &winding_lengths, &winding_count, userdata);
1366    if (windings) {
1367       stbtt__rasterize(result, windings, winding_lengths, winding_count, scale_x, scale_y, shift_x, shift_y, x_off, y_off, invert, userdata);
1368       STBTT_free(winding_lengths, userdata);
1369       STBTT_free(windings, userdata);
1370    }
1371 }
1372 
1373 void stbtt_FreeBitmap(ubyte *bitmap, void *userdata)
1374 {
1375    STBTT_free(bitmap, userdata);
1376 }
1377 
1378 ubyte *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)
1379 {
1380    int ix0,iy0,ix1,iy1;
1381    stbtt__bitmap gbm;
1382    stbtt_vertex *vertices;   
1383    int num_verts = stbtt_GetGlyphShape(info, glyph, &vertices);
1384 
1385    if (scale_x == 0) scale_x = scale_y;
1386    if (scale_y == 0) {
1387       if (scale_x == 0) return null;
1388       scale_y = scale_x;
1389    }
1390 
1391    stbtt_GetGlyphBitmapBox(info, glyph, scale_x, scale_y, &ix0,&iy0,&ix1,&iy1);
1392 
1393    // now we get the size
1394    gbm.w = (ix1 - ix0);
1395    gbm.h = (iy1 - iy0);
1396    gbm.pixels = null; // in case we error
1397 
1398    if (width ) *width  = gbm.w;
1399    if (height) *height = gbm.h;
1400    if (xoff  ) *xoff   = ix0;
1401    if (yoff  ) *yoff   = iy0;
1402    
1403    if (gbm.w && gbm.h) {
1404       gbm.pixels = cast(ubyte *) STBTT_malloc(gbm.w * gbm.h, info.userdata);
1405       if (gbm.pixels) {
1406          gbm.stride = gbm.w;
1407 
1408          stbtt_Rasterize(&gbm, 0.35f, vertices, num_verts, scale_x, scale_y, shift_x, shift_y, ix0, iy0, 1, info.userdata);
1409       }
1410    }
1411    STBTT_free(vertices, info.userdata);
1412    return gbm.pixels;
1413 }   
1414 
1415 ubyte *stbtt_GetGlyphBitmap(const stbtt_fontinfo *info, float scale_x, float scale_y, int glyph, int *width, int *height, int *xoff, int *yoff)
1416 {
1417    return stbtt_GetGlyphBitmapSubpixel(info, scale_x, scale_y, 0.0f, 0.0f, glyph, width, height, xoff, yoff);
1418 }
1419 
1420 void stbtt_MakeGlyphBitmapSubpixel(const stbtt_fontinfo *info, ubyte *output, int out_w, int out_h, int out_stride, float scale_x, float scale_y, float shift_x, float shift_y, int glyph)
1421 {
1422    int ix0,iy0;
1423    stbtt_vertex *vertices;
1424    int num_verts = stbtt_GetGlyphShape(info, glyph, &vertices);
1425    stbtt__bitmap gbm;   
1426 
1427    stbtt_GetGlyphBitmapBoxSubpixel(info, glyph, scale_x, scale_y, shift_x, shift_y, &ix0,&iy0,null,null);
1428    gbm.pixels = output;
1429    gbm.w = out_w;
1430    gbm.h = out_h;
1431    gbm.stride = out_stride;
1432 
1433    if (gbm.w && gbm.h)
1434       stbtt_Rasterize(&gbm, 0.35f, vertices, num_verts, scale_x, scale_y, shift_x, shift_y, ix0,iy0, 1, info.userdata);
1435 
1436    STBTT_free(vertices, info.userdata);
1437 }
1438 
1439 void stbtt_MakeGlyphBitmap(const stbtt_fontinfo *info, ubyte *output, int out_w, int out_h, int out_stride, float scale_x, float scale_y, int glyph)
1440 {
1441    stbtt_MakeGlyphBitmapSubpixel(info, output, out_w, out_h, out_stride, scale_x, scale_y, 0.0f,0.0f, glyph);
1442 }
1443 
1444 ubyte *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)
1445 {
1446    return stbtt_GetGlyphBitmapSubpixel(info, scale_x, scale_y,shift_x,shift_y, stbtt_FindGlyphIndex(info,codepoint), width,height,xoff,yoff);
1447 }   
1448 
1449 void stbtt_MakeCodepointBitmapSubpixel(const stbtt_fontinfo *info, ubyte *output, int out_w, int out_h, int out_stride, float scale_x, float scale_y, float shift_x, float shift_y, int codepoint)
1450 {
1451    stbtt_MakeGlyphBitmapSubpixel(info, output, out_w, out_h, out_stride, scale_x, scale_y, shift_x, shift_y, stbtt_FindGlyphIndex(info,codepoint));
1452 }
1453 
1454 ubyte *stbtt_GetCodepointBitmap(const stbtt_fontinfo *info, float scale_x, float scale_y, int codepoint, int *width, int *height, int *xoff, int *yoff)
1455 {
1456    return stbtt_GetCodepointBitmapSubpixel(info, scale_x, scale_y, 0.0f,0.0f, codepoint, width,height,xoff,yoff);
1457 }   
1458 
1459 void stbtt_MakeCodepointBitmap(const stbtt_fontinfo *info, ubyte *output, int out_w, int out_h, int out_stride, float scale_x, float scale_y, int codepoint)
1460 {
1461    stbtt_MakeCodepointBitmapSubpixel(info, output, out_w, out_h, out_stride, scale_x, scale_y, 0.0f,0.0f, codepoint);
1462 }
1463 
1464 // ////////////////////////////////////////////////////////////////////////////
1465 //
1466 // bitmap baking
1467 //
1468 // This is SUPER-CRAPPY packing to keep source code small
1469 
1470 extern int stbtt_BakeFontBitmap(const ubyte *data, int offset,  // font location (use offset=0 for plain .ttf)
1471                                 float pixel_height,                     // height of font in pixels
1472                                 ubyte *pixels, int pw, int ph,  // bitmap to be filled in
1473                                 int first_char, int num_chars,          // characters to bake
1474                                 stbtt_bakedchar *chardata)
1475 {
1476    float scale;
1477    int x,y,bottom_y, i;
1478    stbtt_fontinfo f;
1479    stbtt_InitFont(&f, data, offset);
1480    STBTT_memset(pixels, 0, pw*ph); // background of 0 around pixels
1481    x=y=1;
1482    bottom_y = 1;
1483 
1484    scale = stbtt_ScaleForPixelHeight(&f, pixel_height);
1485 
1486    for (i=0; i < num_chars; ++i) {
1487       int advance, lsb, x0,y0,x1,y1,gw,gh;
1488       int g = stbtt_FindGlyphIndex(&f, first_char + i);
1489       stbtt_GetGlyphHMetrics(&f, g, &advance, &lsb);
1490       stbtt_GetGlyphBitmapBox(&f, g, scale,scale, &x0,&y0,&x1,&y1);
1491       gw = x1-x0;
1492       gh = y1-y0;
1493       if (x + gw + 1 >= pw)
1494          { y = bottom_y; x = 1; } // advance to next row
1495       if (y + gh + 1 >= ph) // check if it fits vertically AFTER potentially moving to next row
1496          return -i;
1497       assert(x+gw < pw);
1498       assert(y+gh < ph);
1499       stbtt_MakeGlyphBitmap(&f, pixels+x+y*pw, gw,gh,pw, scale,scale, g);
1500       chardata[i].x0 = cast(stbtt_int16) x;
1501       chardata[i].y0 = cast(stbtt_int16) y;
1502       chardata[i].x1 = cast(stbtt_int16) (x + gw);
1503       chardata[i].y1 = cast(stbtt_int16) (y + gh);
1504       chardata[i].xadvance = scale * advance;
1505       chardata[i].xoff     = cast(float) x0;
1506       chardata[i].yoff     = cast(float) y0;
1507       x = x + gw + 2;
1508       if (y+gh+2 > bottom_y)
1509          bottom_y = y+gh+2;
1510    }
1511    return bottom_y;
1512 }
1513 
1514 void stbtt_GetBakedQuad(stbtt_bakedchar *chardata, int pw, int ph, int char_index, float *xpos, float *ypos, stbtt_aligned_quad *q, int opengl_fillrule)
1515 {
1516    float d3d_bias = opengl_fillrule ? 0 : -0.5f;
1517    float ipw = 1.0f / pw, iph = 1.0f / ph;
1518    stbtt_bakedchar *b = chardata + char_index;
1519    int round_x = STBTT_ifloor((*xpos + b.xoff) + 0.5);
1520    int round_y = STBTT_ifloor((*ypos + b.yoff) + 0.5);
1521 
1522    q.x0 = round_x + d3d_bias;
1523    q.y0 = round_y + d3d_bias;
1524    q.x1 = round_x + b.x1 - b.x0 + d3d_bias;
1525    q.y1 = round_y + b.y1 - b.y0 + d3d_bias;
1526 
1527    q.s0 = b.x0 * ipw;
1528    q.t0 = b.y0 * iph;
1529    q.s1 = b.x1 * ipw;
1530    q.t1 = b.y1 * iph;
1531 
1532    *xpos += b.xadvance;
1533 }
1534 
1535 // ////////////////////////////////////////////////////////////////////////////
1536 //
1537 // font name matching -- recommended not to use this
1538 //
1539 
1540 // check if a utf8 string contains a prefix which is the utf16 string; if so return length of matching utf8 string
1541 static stbtt_int32 stbtt__CompareUTF8toUTF16_bigendian_prefix(const stbtt_uint8 *s1, stbtt_int32 len1, const(stbtt_uint8) *s2, stbtt_int32 len2) 
1542 {
1543    stbtt_int32 i=0;
1544 
1545    // convert utf16 to utf8 and compare the results while converting
1546    while (len2) {
1547       stbtt_uint16 ch = s2[0]*256 + s2[1];
1548       if (ch < 0x80) {
1549          if (i >= len1) return -1;
1550          if (s1[i++] != ch) return -1;
1551       } else if (ch < 0x800) {
1552          if (i+1 >= len1) return -1;
1553          if (s1[i++] != 0xc0 + (ch >> 6)) return -1;
1554          if (s1[i++] != 0x80 + (ch & 0x3f)) return -1;
1555       } else if (ch >= 0xd800 && ch < 0xdc00) {
1556          stbtt_uint32 c;
1557          stbtt_uint16 ch2 = s2[2]*256 + s2[3];
1558          if (i+3 >= len1) return -1;
1559          c = ((ch - 0xd800) << 10) + (ch2 - 0xdc00) + 0x10000;
1560          if (s1[i++] != 0xf0 + (c >> 18)) return -1;
1561          if (s1[i++] != 0x80 + ((c >> 12) & 0x3f)) return -1;
1562          if (s1[i++] != 0x80 + ((c >>  6) & 0x3f)) return -1;
1563          if (s1[i++] != 0x80 + ((c      ) & 0x3f)) return -1;
1564          s2 += 2; // plus another 2 below
1565          len2 -= 2;
1566       } else if (ch >= 0xdc00 && ch < 0xe000) {
1567          return -1;
1568       } else {
1569          if (i+2 >= len1) return -1;
1570          if (s1[i++] != 0xe0 + (ch >> 12)) return -1;
1571          if (s1[i++] != 0x80 + ((ch >> 6) & 0x3f)) return -1;
1572          if (s1[i++] != 0x80 + ((ch     ) & 0x3f)) return -1;
1573       }
1574       s2 += 2;
1575       len2 -= 2;
1576    }
1577    return i;
1578 }
1579 
1580 int stbtt_CompareUTF8toUTF16_bigendian(const char *s1, int len1, const char *s2, int len2) 
1581 {
1582    return len1 == stbtt__CompareUTF8toUTF16_bigendian_prefix(cast(const stbtt_uint8*) s1, len1,cast (const stbtt_uint8*) s2, len2);
1583 }
1584 
1585 // returns results in whatever encoding you request... but note that 2-byte encodings
1586 // will be BIG-ENDIAN... use stbtt_CompareUTF8toUTF16_bigendian() to compare
1587 const(char) *stbtt_GetFontNameString(const stbtt_fontinfo *font, int *length, int platformID, int encodingID, int languageID, int nameID)
1588 {
1589    stbtt_int32 i,count,stringOffset;
1590    const(stbtt_uint8) *fc = font.data;
1591    stbtt_uint32 offset = font.fontstart;
1592    stbtt_uint32 nm = stbtt__find_table(fc, offset, "name".ptr);
1593    if (!nm) return null;
1594 
1595    count = ttUSHORT(fc+nm+2);
1596    stringOffset = nm + ttUSHORT(fc+nm+4);
1597    for (i=0; i < count; ++i) {
1598       stbtt_uint32 loc = nm + 6 + 12 * i;
1599       if (platformID == ttUSHORT(fc+loc+0) && encodingID == ttUSHORT(fc+loc+2)
1600           && languageID == ttUSHORT(fc+loc+4) && nameID == ttUSHORT(fc+loc+6)) {
1601          *length = ttUSHORT(fc+loc+8);
1602          return cast(const(char) *) (fc+stringOffset+ttUSHORT(fc+loc+10));
1603       }
1604    }
1605    return null;
1606 }
1607 
1608 static int stbtt__matchpair(stbtt_uint8 *fc, stbtt_uint32 nm, stbtt_uint8 *name, stbtt_int32 nlen, stbtt_int32 target_id, stbtt_int32 next_id)
1609 {
1610    stbtt_int32 i;
1611    stbtt_int32 count = ttUSHORT(fc+nm+2);
1612    stbtt_int32 stringOffset = nm + ttUSHORT(fc+nm+4);
1613 
1614    for (i=0; i < count; ++i) {
1615       stbtt_uint32 loc = nm + 6 + 12 * i;
1616       stbtt_int32 id = ttUSHORT(fc+loc+6);
1617       if (id == target_id) {
1618          // find the encoding
1619          stbtt_int32 platform = ttUSHORT(fc+loc+0), encoding = ttUSHORT(fc+loc+2), language = ttUSHORT(fc+loc+4);
1620 
1621          // is this a Unicode encoding?
1622          if (platform == 0 || (platform == 3 && encoding == 1) || (platform == 3 && encoding == 10)) {
1623             stbtt_int32 slen = ttUSHORT(fc+loc+8), off = ttUSHORT(fc+loc+10);
1624 
1625             // check if there's a prefix match
1626             stbtt_int32 matchlen = stbtt__CompareUTF8toUTF16_bigendian_prefix(name, nlen, fc+stringOffset+off,slen);
1627             if (matchlen >= 0) {
1628                // check for target_id+1 immediately following, with same encoding & language
1629                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) {
1630                   stbtt_int32 slen2 = ttUSHORT(fc+loc+12+8), off2 = ttUSHORT(fc+loc+12+10);
1631                   if (slen2 == 0) {
1632                      if (matchlen == nlen)
1633                         return 1;
1634                   } else if (matchlen < nlen && name[matchlen] == ' ') {
1635                      ++matchlen;
1636                      if (stbtt_CompareUTF8toUTF16_bigendian(cast(char*) (name+matchlen), nlen-matchlen, cast(char*)(fc+stringOffset+off2),slen2))
1637                         return 1;
1638                   }
1639                } else {
1640                   // if nothing immediately following
1641                   if (matchlen == nlen)
1642                      return 1;
1643                }
1644             }
1645          }
1646 
1647          // @TODO handle other encodings
1648       }
1649    }
1650    return 0;
1651 }
1652 
1653 static int stbtt__matches(stbtt_uint8 *fc, stbtt_uint32 offset, stbtt_uint8 *name, stbtt_int32 flags)
1654 {
1655    stbtt_int32 nlen = cast(stbtt_int32) STBTT_strlen(cast(char *) name);
1656    stbtt_uint32 nm,hd;
1657    if (!stbtt__isfont(fc+offset)) return 0;
1658 
1659    // check italics/bold/underline flags in macStyle...
1660    if (flags) {
1661       hd = stbtt__find_table(fc, offset, "head");
1662       if ((ttUSHORT(fc+hd+44) & 7) != (flags & 7)) return 0;
1663    }
1664 
1665    nm = stbtt__find_table(fc, offset, "name");
1666    if (!nm) return 0;
1667 
1668    if (flags) {
1669       // if we checked the macStyle flags, then just check the family and ignore the subfamily
1670       if (stbtt__matchpair(fc, nm, name, nlen, 16, -1))  return 1;
1671       if (stbtt__matchpair(fc, nm, name, nlen,  1, -1))  return 1;
1672       if (stbtt__matchpair(fc, nm, name, nlen,  3, -1))  return 1;
1673    } else {
1674       if (stbtt__matchpair(fc, nm, name, nlen, 16, 17))  return 1;
1675       if (stbtt__matchpair(fc, nm, name, nlen,  1,  2))  return 1;
1676       if (stbtt__matchpair(fc, nm, name, nlen,  3, -1))  return 1;
1677    }
1678 
1679    return 0;
1680 }
1681 
1682 int stbtt_FindMatchingFont(const ubyte *font_collection, const char *name_utf8, stbtt_int32 flags)
1683 {
1684    stbtt_int32 i;
1685    for (i=0;;++i) {
1686       stbtt_int32 off = stbtt_GetFontOffsetForIndex(font_collection, i);
1687       if (off < 0) return off;
1688       if (stbtt__matches(cast(stbtt_uint8 *) font_collection, off, cast(stbtt_uint8*) name_utf8, flags))
1689          return off;
1690    }
1691 }