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2 	This module is no longer maintained, use arsd.ttf instead.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