-
Notifications
You must be signed in to change notification settings - Fork 3
/
imstb_truetype.h
4903 lines (4340 loc) · 188 KB
/
imstb_truetype.h
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
// [DEAR IMGUI]
// This is a slightly modified version of stb_truetype.h 1.20.
// Mostly fixing for compiler and static analyzer warnings.
// Grep for [DEAR IMGUI] to find the changes.
// stb_truetype.h - v1.20 - public domain
// authored from 2009-2016 by Sean Barrett / RAD Game Tools
//
// This library processes TrueType files:
// parse files
// extract glyph metrics
// extract glyph shapes
// render glyphs to one-channel bitmaps with antialiasing (box filter)
// render glyphs to one-channel SDF bitmaps (signed-distance field/function)
//
// Todo:
// non-MS cmaps
// crashproof on bad data
// hinting? (no longer patented)
// cleartype-style AA?
// optimize: use simple memory allocator for intermediates
// optimize: build edge-list directly from curves
// optimize: rasterize directly from curves?
//
// ADDITIONAL CONTRIBUTORS
//
// Mikko Mononen: compound shape support, more cmap formats
// Tor Andersson: kerning, subpixel rendering
// Dougall Johnson: OpenType / Type 2 font handling
// Daniel Ribeiro Maciel: basic GPOS-based kerning
//
// Misc other:
// Ryan Gordon
// Simon Glass
// github:IntellectualKitty
// Imanol Celaya
// Daniel Ribeiro Maciel
//
// Bug/warning reports/fixes:
// "Zer" on mollyrocket Fabian "ryg" Giesen
// Cass Everitt Martins Mozeiko
// stoiko (Haemimont Games) Cap Petschulat
// Brian Hook Omar Cornut
// Walter van Niftrik github:aloucks
// David Gow Peter LaValle
// David Given Sergey Popov
// Ivan-Assen Ivanov Giumo X. Clanjor
// Anthony Pesch Higor Euripedes
// Johan Duparc Thomas Fields
// Hou Qiming Derek Vinyard
// Rob Loach Cort Stratton
// Kenney Phillis Jr. github:oyvindjam
// Brian Costabile github:vassvik
//
// VERSION HISTORY
//
// 1.20 (2019-02-07) PackFontRange skips missing codepoints; GetScaleFontVMetrics()
// 1.19 (2018-02-11) GPOS kerning, STBTT_fmod
// 1.18 (2018-01-29) add missing function
// 1.17 (2017-07-23) make more arguments const; doc fix
// 1.16 (2017-07-12) SDF support
// 1.15 (2017-03-03) make more arguments const
// 1.14 (2017-01-16) num-fonts-in-TTC function
// 1.13 (2017-01-02) support OpenType fonts, certain Apple fonts
// 1.12 (2016-10-25) suppress warnings about casting away const with -Wcast-qual
// 1.11 (2016-04-02) fix unused-variable warning
// 1.10 (2016-04-02) user-defined fabs(); rare memory leak; remove duplicate typedef
// 1.09 (2016-01-16) warning fix; avoid crash on outofmem; use allocation userdata properly
// 1.08 (2015-09-13) document stbtt_Rasterize(); fixes for vertical & horizontal edges
// 1.07 (2015-08-01) allow PackFontRanges to accept arrays of sparse codepoints;
// variant PackFontRanges to pack and render in separate phases;
// fix stbtt_GetFontOFfsetForIndex (never worked for non-0 input?);
// fixed an assert() bug in the new rasterizer
// replace assert() with STBTT_assert() in new rasterizer
//
// Full history can be found at the end of this file.
//
// LICENSE
//
// See end of file for license information.
//
// USAGE
//
// Include this file in whatever places need to refer to it. In ONE C/C++
// file, write:
// #define STB_TRUETYPE_IMPLEMENTATION
// before the #include of this file. This expands out the actual
// implementation into that C/C++ file.
//
// To make the implementation private to the file that generates the implementation,
// #define STBTT_STATIC
//
// Simple 3D API (don't ship this, but it's fine for tools and quick start)
// stbtt_BakeFontBitmap() -- bake a font to a bitmap for use as texture
// stbtt_GetBakedQuad() -- compute quad to draw for a given char
//
// Improved 3D API (more shippable):
// #include "stb_rect_pack.h" -- optional, but you really want it
// stbtt_PackBegin()
// stbtt_PackSetOversampling() -- for improved quality on small fonts
// stbtt_PackFontRanges() -- pack and renders
// stbtt_PackEnd()
// stbtt_GetPackedQuad()
//
// "Load" a font file from a memory buffer (you have to keep the buffer loaded)
// stbtt_InitFont()
// stbtt_GetFontOffsetForIndex() -- indexing for TTC font collections
// stbtt_GetNumberOfFonts() -- number of fonts for TTC font collections
//
// Render a unicode codepoint to a bitmap
// stbtt_GetCodepointBitmap() -- allocates and returns a bitmap
// stbtt_MakeCodepointBitmap() -- renders into bitmap you provide
// stbtt_GetCodepointBitmapBox() -- how big the bitmap must be
//
// Character advance/positioning
// stbtt_GetCodepointHMetrics()
// stbtt_GetFontVMetrics()
// stbtt_GetFontVMetricsOS2()
// stbtt_GetCodepointKernAdvance()
//
// Starting with version 1.06, the rasterizer was replaced with a new,
// faster and generally-more-precise rasterizer. The new rasterizer more
// accurately measures pixel coverage for anti-aliasing, except in the case
// where multiple shapes overlap, in which case it overestimates the AA pixel
// coverage. Thus, anti-aliasing of intersecting shapes may look wrong. If
// this turns out to be a problem, you can re-enable the old rasterizer with
// #define STBTT_RASTERIZER_VERSION 1
// which will incur about a 15% speed hit.
//
// ADDITIONAL DOCUMENTATION
//
// Immediately after this block comment are a series of sample programs.
//
// After the sample programs is the "header file" section. This section
// includes documentation for each API function.
//
// Some important concepts to understand to use this library:
//
// Codepoint
// Characters are defined by unicode codepoints, e.g. 65 is
// uppercase A, 231 is lowercase c with a cedilla, 0x7e30 is
// the hiragana for "ma".
//
// Glyph
// A visual character shape (every codepoint is rendered as
// some glyph)
//
// Glyph index
// A font-specific integer ID representing a glyph
//
// Baseline
// Glyph shapes are defined relative to a baseline, which is the
// bottom of uppercase characters. Characters extend both above
// and below the baseline.
//
// Current Point
// As you draw text to the screen, you keep track of a "current point"
// which is the origin of each character. The current point's vertical
// position is the baseline. Even "baked fonts" use this model.
//
// Vertical Font Metrics
// The vertical qualities of the font, used to vertically position
// and space the characters. See docs for stbtt_GetFontVMetrics.
//
// Font Size in Pixels or Points
// The preferred interface for specifying font sizes in stb_truetype
// is to specify how tall the font's vertical extent should be in pixels.
// If that sounds good enough, skip the next paragraph.
//
// Most font APIs instead use "points", which are a common typographic
// measurement for describing font size, defined as 72 points per inch.
// stb_truetype provides a point API for compatibility. However, true
// "per inch" conventions don't make much sense on computer displays
// since different monitors have different number of pixels per
// inch. For example, Windows traditionally uses a convention that
// there are 96 pixels per inch, thus making 'inch' measurements have
// nothing to do with inches, and thus effectively defining a point to
// be 1.333 pixels. Additionally, the TrueType font data provides
// an explicit scale factor to scale a given font's glyphs to points,
// but the author has observed that this scale factor is often wrong
// for non-commercial fonts, thus making fonts scaled in points
// according to the TrueType spec incoherently sized in practice.
//
// DETAILED USAGE:
//
// Scale:
// Select how high you want the font to be, in points or pixels.
// Call ScaleForPixelHeight or ScaleForMappingEmToPixels to compute
// a scale factor SF that will be used by all other functions.
//
// Baseline:
// You need to select a y-coordinate that is the baseline of where
// your text will appear. Call GetFontBoundingBox to get the baseline-relative
// bounding box for all characters. SF*-y0 will be the distance in pixels
// that the worst-case character could extend above the baseline, so if
// you want the top edge of characters to appear at the top of the
// screen where y=0, then you would set the baseline to SF*-y0.
//
// Current point:
// Set the current point where the first character will appear. The
// first character could extend left of the current point; this is font
// dependent. You can either choose a current point that is the leftmost
// point and hope, or add some padding, or check the bounding box or
// left-side-bearing of the first character to be displayed and set
// the current point based on that.
//
// Displaying a character:
// Compute the bounding box of the character. It will contain signed values
// relative to <current_point, baseline>. I.e. if it returns x0,y0,x1,y1,
// then the character should be displayed in the rectangle from
// <current_point+SF*x0, baseline+SF*y0> to <current_point+SF*x1,baseline+SF*y1).
//
// Advancing for the next character:
// Call GlyphHMetrics, and compute 'current_point += SF * advance'.
//
//
// ADVANCED USAGE
//
// Quality:
//
// - Use the functions with Subpixel at the end to allow your characters
// to have subpixel positioning. Since the font is anti-aliased, not
// hinted, this is very import for quality. (This is not possible with
// baked fonts.)
//
// - Kerning is now supported, and if you're supporting subpixel rendering
// then kerning is worth using to give your text a polished look.
//
// Performance:
//
// - Convert Unicode codepoints to glyph indexes and operate on the glyphs;
// if you don't do this, stb_truetype is forced to do the conversion on
// every call.
//
// - There are a lot of memory allocations. We should modify it to take
// a temp buffer and allocate from the temp buffer (without freeing),
// should help performance a lot.
//
// NOTES
//
// The system uses the raw data found in the .ttf file without changing it
// and without building auxiliary data structures. This is a bit inefficient
// on little-endian systems (the data is big-endian), but assuming you're
// caching the bitmaps or glyph shapes this shouldn't be a big deal.
//
// It appears to be very hard to programmatically determine what font a
// given file is in a general way. I provide an API for this, but I don't
// recommend it.
//
//
// SOURCE STATISTICS (based on v0.6c, 2050 LOC)
//
// Documentation & header file 520 LOC \___ 660 LOC documentation
// Sample code 140 LOC /
// Truetype parsing 620 LOC ---- 620 LOC TrueType
// Software rasterization 240 LOC \.
// Curve tessellation 120 LOC \__ 550 LOC Bitmap creation
// Bitmap management 100 LOC /
// Baked bitmap interface 70 LOC /
// Font name matching & access 150 LOC ---- 150
// C runtime library abstraction 60 LOC ---- 60
//
//
// PERFORMANCE MEASUREMENTS FOR 1.06:
//
// 32-bit 64-bit
// Previous release: 8.83 s 7.68 s
// Pool allocations: 7.72 s 6.34 s
// Inline sort : 6.54 s 5.65 s
// New rasterizer : 5.63 s 5.00 s
//////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////
////
//// SAMPLE PROGRAMS
////
//
// Incomplete text-in-3d-api example, which draws quads properly aligned to be lossless
//
#if 0
#define STB_TRUETYPE_IMPLEMENTATION // force following include to generate implementation
#include "stb_truetype.h"
unsigned char ttf_buffer[1<<20];
unsigned char temp_bitmap[512*512];
stbtt_bakedchar cdata[96]; // ASCII 32..126 is 95 glyphs
GLuint ftex;
void my_stbtt_initfont(void)
{
fread(ttf_buffer, 1, 1<<20, fopen("c:/windows/fonts/times.ttf", "rb"));
stbtt_BakeFontBitmap(ttf_buffer,0, 32.0, temp_bitmap,512,512, 32,96, cdata); // no guarantee this fits!
// can free ttf_buffer at this point
glGenTextures(1, &ftex);
glBindTexture(GL_TEXTURE_2D, ftex);
glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, 512,512, 0, GL_ALPHA, GL_UNSIGNED_BYTE, temp_bitmap);
// can free temp_bitmap at this point
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
}
void my_stbtt_print(float x, float y, char *text)
{
// assume orthographic projection with units = screen pixels, origin at top left
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, ftex);
glBegin(GL_QUADS);
while (*text) {
if (*text >= 32 && *text < 128) {
stbtt_aligned_quad q;
stbtt_GetBakedQuad(cdata, 512,512, *text-32, &x,&y,&q,1);//1=opengl & d3d10+,0=d3d9
glTexCoord2f(q.s0,q.t1); glVertex2f(q.x0,q.y0);
glTexCoord2f(q.s1,q.t1); glVertex2f(q.x1,q.y0);
glTexCoord2f(q.s1,q.t0); glVertex2f(q.x1,q.y1);
glTexCoord2f(q.s0,q.t0); glVertex2f(q.x0,q.y1);
}
++text;
}
glEnd();
}
#endif
//
//
//////////////////////////////////////////////////////////////////////////////
//
// Complete program (this compiles): get a single bitmap, print as ASCII art
//
#if 0
#include <stdio.h>
#define STB_TRUETYPE_IMPLEMENTATION // force following include to generate implementation
#include "stb_truetype.h"
char ttf_buffer[1<<25];
int main(int argc, char **argv)
{
stbtt_fontinfo font;
unsigned char *bitmap;
int w,h,i,j,c = (argc > 1 ? atoi(argv[1]) : 'a'), s = (argc > 2 ? atoi(argv[2]) : 20);
fread(ttf_buffer, 1, 1<<25, fopen(argc > 3 ? argv[3] : "c:/windows/fonts/arialbd.ttf", "rb"));
stbtt_InitFont(&font, ttf_buffer, stbtt_GetFontOffsetForIndex(ttf_buffer,0));
bitmap = stbtt_GetCodepointBitmap(&font, 0,stbtt_ScaleForPixelHeight(&font, s), c, &w, &h, 0,0);
for (j=0; j < h; ++j) {
for (i=0; i < w; ++i)
putchar(" .:ioVM@"[bitmap[j*w+i]>>5]);
putchar('\n');
}
return 0;
}
#endif
//
// Output:
//
// .ii.
// @@@@@@.
// V@Mio@@o
// :i. V@V
// :oM@@M
// :@@@MM@M
// @@o o@M
// :@@. M@M
// @@@o@@@@
// :M@@V:@@.
//
//////////////////////////////////////////////////////////////////////////////
//
// Complete program: print "Hello World!" banner, with bugs
//
#if 0
char buffer[24<<20];
unsigned char screen[20][79];
int main(int arg, char **argv)
{
stbtt_fontinfo font;
int i,j,ascent,baseline,ch=0;
float scale, xpos=2; // leave a little padding in case the character extends left
char *text = "Heljo World!"; // intentionally misspelled to show 'lj' brokenness
fread(buffer, 1, 1000000, fopen("c:/windows/fonts/arialbd.ttf", "rb"));
stbtt_InitFont(&font, buffer, 0);
scale = stbtt_ScaleForPixelHeight(&font, 15);
stbtt_GetFontVMetrics(&font, &ascent,0,0);
baseline = (int) (ascent*scale);
while (text[ch]) {
int advance,lsb,x0,y0,x1,y1;
float x_shift = xpos - (float) floor(xpos);
stbtt_GetCodepointHMetrics(&font, text[ch], &advance, &lsb);
stbtt_GetCodepointBitmapBoxSubpixel(&font, text[ch], scale,scale,x_shift,0, &x0,&y0,&x1,&y1);
stbtt_MakeCodepointBitmapSubpixel(&font, &screen[baseline + y0][(int) xpos + x0], x1-x0,y1-y0, 79, scale,scale,x_shift,0, text[ch]);
// note that this stomps the old data, so where character boxes overlap (e.g. 'lj') it's wrong
// because this API is really for baking character bitmaps into textures. if you want to render
// a sequence of characters, you really need to render each bitmap to a temp buffer, then
// "alpha blend" that into the working buffer
xpos += (advance * scale);
if (text[ch+1])
xpos += scale*stbtt_GetCodepointKernAdvance(&font, text[ch],text[ch+1]);
++ch;
}
for (j=0; j < 20; ++j) {
for (i=0; i < 78; ++i)
putchar(" .:ioVM@"[screen[j][i]>>5]);
putchar('\n');
}
return 0;
}
#endif
//////////////////////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////////////////////
////
//// INTEGRATION WITH YOUR CODEBASE
////
//// The following sections allow you to supply alternate definitions
//// of C library functions used by stb_truetype, e.g. if you don't
//// link with the C runtime library.
#ifdef STB_TRUETYPE_IMPLEMENTATION
// #define your own (u)stbtt_int8/16/32 before including to override this
#ifndef stbtt_uint8
typedef unsigned char stbtt_uint8;
typedef signed char stbtt_int8;
typedef unsigned short stbtt_uint16;
typedef signed short stbtt_int16;
typedef unsigned int stbtt_uint32;
typedef signed int stbtt_int32;
#endif
typedef char stbtt__check_size32[sizeof(stbtt_int32)==4 ? 1 : -1];
typedef char stbtt__check_size16[sizeof(stbtt_int16)==2 ? 1 : -1];
// e.g. #define your own STBTT_ifloor/STBTT_iceil() to avoid math.h
#ifndef STBTT_ifloor
#include <math.h>
#define STBTT_ifloor(x) ((int) floor(x))
#define STBTT_iceil(x) ((int) ceil(x))
#endif
#ifndef STBTT_sqrt
#include <math.h>
#define STBTT_sqrt(x) sqrt(x)
#define STBTT_pow(x,y) pow(x,y)
#endif
#ifndef STBTT_fmod
#include <math.h>
#define STBTT_fmod(x,y) fmod(x,y)
#endif
#ifndef STBTT_cos
#include <math.h>
#define STBTT_cos(x) cos(x)
#define STBTT_acos(x) acos(x)
#endif
#ifndef STBTT_fabs
#include <math.h>
#define STBTT_fabs(x) fabs(x)
#endif
// #define your own functions "STBTT_malloc" / "STBTT_free" to avoid malloc.h
#ifndef STBTT_malloc
#include <stdlib.h>
#define STBTT_malloc(x,u) ((void)(u),malloc(x))
#define STBTT_free(x,u) ((void)(u),free(x))
#endif
#ifndef STBTT_assert
#include <assert.h>
#define STBTT_assert(x) assert(x)
#endif
#ifndef STBTT_strlen
#include <string.h>
#define STBTT_strlen(x) strlen(x)
#endif
#ifndef STBTT_memcpy
#include <string.h>
#define STBTT_memcpy memcpy
#define STBTT_memset memset
#endif
#endif
///////////////////////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////////////////////
////
//// INTERFACE
////
////
#ifndef __STB_INCLUDE_STB_TRUETYPE_H__
#define __STB_INCLUDE_STB_TRUETYPE_H__
#ifdef STBTT_STATIC
#define STBTT_DEF static
#else
#define STBTT_DEF extern
#endif
#ifdef __cplusplus
extern "C" {
#endif
// private structure
typedef struct
{
unsigned char *data;
int cursor;
int size;
} stbtt__buf;
//////////////////////////////////////////////////////////////////////////////
//
// TEXTURE BAKING API
//
// If you use this API, you only have to call two functions ever.
//
typedef struct
{
unsigned short x0,y0,x1,y1; // coordinates of bbox in bitmap
float xoff,yoff,xadvance;
} stbtt_bakedchar;
STBTT_DEF int stbtt_BakeFontBitmap(const unsigned char *data, int offset, // font location (use offset=0 for plain .ttf)
float pixel_height, // height of font in pixels
unsigned char *pixels, int pw, int ph, // bitmap to be filled in
int first_char, int num_chars, // characters to bake
stbtt_bakedchar *chardata); // you allocate this, it's num_chars long
// if return is positive, the first unused row of the bitmap
// if return is negative, returns the negative of the number of characters that fit
// if return is 0, no characters fit and no rows were used
// This uses a very crappy packing.
typedef struct
{
float x0,y0,s0,t0; // top-left
float x1,y1,s1,t1; // bottom-right
} stbtt_aligned_quad;
STBTT_DEF void stbtt_GetBakedQuad(const stbtt_bakedchar *chardata, int pw, int ph, // same data as above
int char_index, // character to display
float *xpos, float *ypos, // pointers to current position in screen pixel space
stbtt_aligned_quad *q, // output: quad to draw
int opengl_fillrule); // true if opengl fill rule; false if DX9 or earlier
// Call GetBakedQuad with char_index = 'character - first_char', and it
// creates the quad you need to draw and advances the current position.
//
// The coordinate system used assumes y increases downwards.
//
// Characters will extend both above and below the current position;
// see discussion of "BASELINE" above.
//
// It's inefficient; you might want to c&p it and optimize it.
STBTT_DEF void stbtt_GetScaledFontVMetrics(const unsigned char *fontdata, int index, float size, float *ascent, float *descent, float *lineGap);
// Query the font vertical metrics without having to create a font first.
//////////////////////////////////////////////////////////////////////////////
//
// NEW TEXTURE BAKING API
//
// This provides options for packing multiple fonts into one atlas, not
// perfectly but better than nothing.
typedef struct
{
unsigned short x0,y0,x1,y1; // coordinates of bbox in bitmap
float xoff,yoff,xadvance;
float xoff2,yoff2;
} stbtt_packedchar;
typedef struct stbtt_pack_context stbtt_pack_context;
typedef struct stbtt_fontinfo stbtt_fontinfo;
#ifndef STB_RECT_PACK_VERSION
typedef struct stbrp_rect stbrp_rect;
#endif
STBTT_DEF int stbtt_PackBegin(stbtt_pack_context *spc, unsigned char *pixels, int width, int height, int stride_in_bytes, int padding, void *alloc_context);
// Initializes a packing context stored in the passed-in stbtt_pack_context.
// Future calls using this context will pack characters into the bitmap passed
// in here: a 1-channel bitmap that is width * height. stride_in_bytes is
// the distance from one row to the next (or 0 to mean they are packed tightly
// together). "padding" is the amount of padding to leave between each
// character (normally you want '1' for bitmaps you'll use as textures with
// bilinear filtering).
//
// Returns 0 on failure, 1 on success.
STBTT_DEF void stbtt_PackEnd (stbtt_pack_context *spc);
// Cleans up the packing context and frees all memory.
#define STBTT_POINT_SIZE(x) (-(x))
STBTT_DEF int stbtt_PackFontRange(stbtt_pack_context *spc, const unsigned char *fontdata, int font_index, float font_size,
int first_unicode_char_in_range, int num_chars_in_range, stbtt_packedchar *chardata_for_range);
// Creates character bitmaps from the font_index'th font found in fontdata (use
// font_index=0 if you don't know what that is). It creates num_chars_in_range
// bitmaps for characters with unicode values starting at first_unicode_char_in_range
// and increasing. Data for how to render them is stored in chardata_for_range;
// pass these to stbtt_GetPackedQuad to get back renderable quads.
//
// font_size is the full height of the character from ascender to descender,
// as computed by stbtt_ScaleForPixelHeight. To use a point size as computed
// by stbtt_ScaleForMappingEmToPixels, wrap the point size in STBTT_POINT_SIZE()
// and pass that result as 'font_size':
// ..., 20 , ... // font max minus min y is 20 pixels tall
// ..., STBTT_POINT_SIZE(20), ... // 'M' is 20 pixels tall
typedef struct
{
float font_size;
int first_unicode_codepoint_in_range; // if non-zero, then the chars are continuous, and this is the first codepoint
int *array_of_unicode_codepoints; // if non-zero, then this is an array of unicode codepoints
int num_chars;
stbtt_packedchar *chardata_for_range; // output
unsigned char h_oversample, v_oversample; // don't set these, they're used internally
} stbtt_pack_range;
STBTT_DEF int stbtt_PackFontRanges(stbtt_pack_context *spc, const unsigned char *fontdata, int font_index, stbtt_pack_range *ranges, int num_ranges);
// Creates character bitmaps from multiple ranges of characters stored in
// ranges. This will usually create a better-packed bitmap than multiple
// calls to stbtt_PackFontRange. Note that you can call this multiple
// times within a single PackBegin/PackEnd.
STBTT_DEF void stbtt_PackSetOversampling(stbtt_pack_context *spc, unsigned int h_oversample, unsigned int v_oversample);
// Oversampling a font increases the quality by allowing higher-quality subpixel
// positioning, and is especially valuable at smaller text sizes.
//
// This function sets the amount of oversampling for all following calls to
// stbtt_PackFontRange(s) or stbtt_PackFontRangesGatherRects for a given
// pack context. The default (no oversampling) is achieved by h_oversample=1
// and v_oversample=1. The total number of pixels required is
// h_oversample*v_oversample larger than the default; for example, 2x2
// oversampling requires 4x the storage of 1x1. For best results, render
// oversampled textures with bilinear filtering. Look at the readme in
// stb/tests/oversample for information about oversampled fonts
//
// To use with PackFontRangesGather etc., you must set it before calls
// call to PackFontRangesGatherRects.
STBTT_DEF void stbtt_PackSetSkipMissingCodepoints(stbtt_pack_context *spc, int skip);
// If skip != 0, this tells stb_truetype to skip any codepoints for which
// there is no corresponding glyph. If skip=0, which is the default, then
// codepoints without a glyph recived the font's "missing character" glyph,
// typically an empty box by convention.
STBTT_DEF void stbtt_GetPackedQuad(const stbtt_packedchar *chardata, int pw, int ph, // same data as above
int char_index, // character to display
float *xpos, float *ypos, // pointers to current position in screen pixel space
stbtt_aligned_quad *q, // output: quad to draw
int align_to_integer);
STBTT_DEF int stbtt_PackFontRangesGatherRects(stbtt_pack_context *spc, const stbtt_fontinfo *info, stbtt_pack_range *ranges, int num_ranges, stbrp_rect *rects);
STBTT_DEF void stbtt_PackFontRangesPackRects(stbtt_pack_context *spc, stbrp_rect *rects, int num_rects);
STBTT_DEF int stbtt_PackFontRangesRenderIntoRects(stbtt_pack_context *spc, const stbtt_fontinfo *info, stbtt_pack_range *ranges, int num_ranges, stbrp_rect *rects);
// Calling these functions in sequence is roughly equivalent to calling
// stbtt_PackFontRanges(). If you more control over the packing of multiple
// fonts, or if you want to pack custom data into a font texture, take a look
// at the source to of stbtt_PackFontRanges() and create a custom version
// using these functions, e.g. call GatherRects multiple times,
// building up a single array of rects, then call PackRects once,
// then call RenderIntoRects repeatedly. This may result in a
// better packing than calling PackFontRanges multiple times
// (or it may not).
// this is an opaque structure that you shouldn't mess with which holds
// all the context needed from PackBegin to PackEnd.
struct stbtt_pack_context {
void *user_allocator_context;
void *pack_info;
int width;
int height;
int stride_in_bytes;
int padding;
int skip_missing;
unsigned int h_oversample, v_oversample;
unsigned char *pixels;
void *nodes;
};
//////////////////////////////////////////////////////////////////////////////
//
// FONT LOADING
//
//
STBTT_DEF int stbtt_GetNumberOfFonts(const unsigned char *data);
// This function will determine the number of fonts in a font file. TrueType
// collection (.ttc) files may contain multiple fonts, while TrueType font
// (.ttf) files only contain one font. The number of fonts can be used for
// indexing with the previous function where the index is between zero and one
// less than the total fonts. If an error occurs, -1 is returned.
STBTT_DEF int stbtt_GetFontOffsetForIndex(const unsigned char *data, int index);
// Each .ttf/.ttc file may have more than one font. Each font has a sequential
// index number starting from 0. Call this function to get the font offset for
// a given index; it returns -1 if the index is out of range. A regular .ttf
// file will only define one font and it always be at offset 0, so it will
// return '0' for index 0, and -1 for all other indices.
// The following structure is defined publicly so you can declare one on
// the stack or as a global or etc, but you should treat it as opaque.
struct stbtt_fontinfo
{
void * userdata;
unsigned char * data; // pointer to .ttf file
int fontstart; // offset of start of font
int numGlyphs; // number of glyphs, needed for range checking
int loca,head,glyf,hhea,hmtx,kern,gpos; // table locations as offset from start of .ttf
int index_map; // a cmap mapping for our chosen character encoding
int indexToLocFormat; // format needed to map from glyph index to glyph
stbtt__buf cff; // cff font data
stbtt__buf charstrings; // the charstring index
stbtt__buf gsubrs; // global charstring subroutines index
stbtt__buf subrs; // private charstring subroutines index
stbtt__buf fontdicts; // array of font dicts
stbtt__buf fdselect; // map from glyph to fontdict
};
STBTT_DEF int stbtt_InitFont(stbtt_fontinfo *info, const unsigned char *data, int offset);
// Given an offset into the file that defines a font, this function builds
// the necessary cached info for the rest of the system. You must allocate
// the stbtt_fontinfo yourself, and stbtt_InitFont will fill it out. You don't
// need to do anything special to free it, because the contents are pure
// value data with no additional data structures. Returns 0 on failure.
//////////////////////////////////////////////////////////////////////////////
//
// CHARACTER TO GLYPH-INDEX CONVERSIOn
STBTT_DEF int stbtt_FindGlyphIndex(const stbtt_fontinfo *info, int unicode_codepoint);
// If you're going to perform multiple operations on the same character
// and you want a speed-up, call this function with the character you're
// going to process, then use glyph-based functions instead of the
// codepoint-based functions.
// Returns 0 if the character codepoint is not defined in the font.
//////////////////////////////////////////////////////////////////////////////
//
// CHARACTER PROPERTIES
//
STBTT_DEF float stbtt_ScaleForPixelHeight(const stbtt_fontinfo *info, float pixels);
// computes a scale factor to produce a font whose "height" is 'pixels' tall.
// Height is measured as the distance from the highest ascender to the lowest
// descender; in other words, it's equivalent to calling stbtt_GetFontVMetrics
// and computing:
// scale = pixels / (ascent - descent)
// so if you prefer to measure height by the ascent only, use a similar calculation.
STBTT_DEF float stbtt_ScaleForMappingEmToPixels(const stbtt_fontinfo *info, float pixels);
// computes a scale factor to produce a font whose EM size is mapped to
// 'pixels' tall. This is probably what traditional APIs compute, but
// I'm not positive.
STBTT_DEF void stbtt_GetFontVMetrics(const stbtt_fontinfo *info, int *ascent, int *descent, int *lineGap);
// ascent is the coordinate above the baseline the font extends; descent
// is the coordinate below the baseline the font extends (i.e. it is typically negative)
// lineGap is the spacing between one row's descent and the next row's ascent...
// so you should advance the vertical position by "*ascent - *descent + *lineGap"
// these are expressed in unscaled coordinates, so you must multiply by
// the scale factor for a given size
STBTT_DEF int stbtt_GetFontVMetricsOS2(const stbtt_fontinfo *info, int *typoAscent, int *typoDescent, int *typoLineGap);
// analogous to GetFontVMetrics, but returns the "typographic" values from the OS/2
// table (specific to MS/Windows TTF files).
//
// Returns 1 on success (table present), 0 on failure.
STBTT_DEF void stbtt_GetFontBoundingBox(const stbtt_fontinfo *info, int *x0, int *y0, int *x1, int *y1);
// the bounding box around all possible characters
STBTT_DEF void stbtt_GetCodepointHMetrics(const stbtt_fontinfo *info, int codepoint, int *advanceWidth, int *leftSideBearing);
// leftSideBearing is the offset from the current horizontal position to the left edge of the character
// advanceWidth is the offset from the current horizontal position to the next horizontal position
// these are expressed in unscaled coordinates
STBTT_DEF int stbtt_GetCodepointKernAdvance(const stbtt_fontinfo *info, int ch1, int ch2);
// an additional amount to add to the 'advance' value between ch1 and ch2
STBTT_DEF int stbtt_GetCodepointBox(const stbtt_fontinfo *info, int codepoint, int *x0, int *y0, int *x1, int *y1);
// Gets the bounding box of the visible part of the glyph, in unscaled coordinates
STBTT_DEF void stbtt_GetGlyphHMetrics(const stbtt_fontinfo *info, int glyph_index, int *advanceWidth, int *leftSideBearing);
STBTT_DEF int stbtt_GetGlyphKernAdvance(const stbtt_fontinfo *info, int glyph1, int glyph2);
STBTT_DEF int stbtt_GetGlyphBox(const stbtt_fontinfo *info, int glyph_index, int *x0, int *y0, int *x1, int *y1);
// as above, but takes one or more glyph indices for greater efficiency
//////////////////////////////////////////////////////////////////////////////
//
// GLYPH SHAPES (you probably don't need these, but they have to go before
// the bitmaps for C declaration-order reasons)
//
#ifndef STBTT_vmove // you can predefine these to use different values (but why?)
enum {
STBTT_vmove=1,
STBTT_vline,
STBTT_vcurve,
STBTT_vcubic
};
#endif
#ifndef stbtt_vertex // you can predefine this to use different values
// (we share this with other code at RAD)
#define stbtt_vertex_type short // can't use stbtt_int16 because that's not visible in the header file
typedef struct
{
stbtt_vertex_type x,y,cx,cy,cx1,cy1;
unsigned char type,padding;
} stbtt_vertex;
#endif
STBTT_DEF int stbtt_IsGlyphEmpty(const stbtt_fontinfo *info, int glyph_index);
// returns non-zero if nothing is drawn for this glyph
STBTT_DEF int stbtt_GetCodepointShape(const stbtt_fontinfo *info, int unicode_codepoint, stbtt_vertex **vertices);
STBTT_DEF int stbtt_GetGlyphShape(const stbtt_fontinfo *info, int glyph_index, stbtt_vertex **vertices);
// returns # of vertices and fills *vertices with the pointer to them
// these are expressed in "unscaled" coordinates
//
// The shape is a series of contours. Each one starts with
// a STBTT_moveto, then consists of a series of mixed
// STBTT_lineto and STBTT_curveto segments. A lineto
// draws a line from previous endpoint to its x,y; a curveto
// draws a quadratic bezier from previous endpoint to
// its x,y, using cx,cy as the bezier control point.
STBTT_DEF void stbtt_FreeShape(const stbtt_fontinfo *info, stbtt_vertex *vertices);
// frees the data allocated above
//////////////////////////////////////////////////////////////////////////////
//
// BITMAP RENDERING
//
STBTT_DEF void stbtt_FreeBitmap(unsigned char *bitmap, void *userdata);
// frees the bitmap allocated below
STBTT_DEF unsigned char *stbtt_GetCodepointBitmap(const stbtt_fontinfo *info, float scale_x, float scale_y, int codepoint, int *width, int *height, int *xoff, int *yoff);
// allocates a large-enough single-channel 8bpp bitmap and renders the
// specified character/glyph at the specified scale into it, with
// antialiasing. 0 is no coverage (transparent), 255 is fully covered (opaque).
// *width & *height are filled out with the width & height of the bitmap,
// which is stored left-to-right, top-to-bottom.
//
// xoff/yoff are the offset it pixel space from the glyph origin to the top-left of the bitmap
STBTT_DEF unsigned char *stbtt_GetCodepointBitmapSubpixel(const stbtt_fontinfo *info, float scale_x, float scale_y, float shift_x, float shift_y, int codepoint, int *width, int *height, int *xoff, int *yoff);
// the same as stbtt_GetCodepoitnBitmap, but you can specify a subpixel
// shift for the character
STBTT_DEF void stbtt_MakeCodepointBitmap(const stbtt_fontinfo *info, unsigned char *output, int out_w, int out_h, int out_stride, float scale_x, float scale_y, int codepoint);
// the same as stbtt_GetCodepointBitmap, but you pass in storage for the bitmap
// in the form of 'output', with row spacing of 'out_stride' bytes. the bitmap
// is clipped to out_w/out_h bytes. Call stbtt_GetCodepointBitmapBox to get the
// width and height and positioning info for it first.
STBTT_DEF void stbtt_MakeCodepointBitmapSubpixel(const stbtt_fontinfo *info, unsigned char *output, int out_w, int out_h, int out_stride, float scale_x, float scale_y, float shift_x, float shift_y, int codepoint);
// same as stbtt_MakeCodepointBitmap, but you can specify a subpixel
// shift for the character
STBTT_DEF void stbtt_MakeCodepointBitmapSubpixelPrefilter(const stbtt_fontinfo *info, unsigned char *output, int out_w, int out_h, int out_stride, float scale_x, float scale_y, float shift_x, float shift_y, int oversample_x, int oversample_y, float *sub_x, float *sub_y, int codepoint);
// same as stbtt_MakeCodepointBitmapSubpixel, but prefiltering
// is performed (see stbtt_PackSetOversampling)
STBTT_DEF void stbtt_GetCodepointBitmapBox(const stbtt_fontinfo *font, int codepoint, float scale_x, float scale_y, int *ix0, int *iy0, int *ix1, int *iy1);
// get the bbox of the bitmap centered around the glyph origin; so the
// bitmap width is ix1-ix0, height is iy1-iy0, and location to place
// the bitmap top left is (leftSideBearing*scale,iy0).
// (Note that the bitmap uses y-increases-down, but the shape uses
// y-increases-up, so CodepointBitmapBox and CodepointBox are inverted.)
STBTT_DEF void stbtt_GetCodepointBitmapBoxSubpixel(const stbtt_fontinfo *font, int codepoint, float scale_x, float scale_y, float shift_x, float shift_y, int *ix0, int *iy0, int *ix1, int *iy1);
// same as stbtt_GetCodepointBitmapBox, but you can specify a subpixel
// shift for the character
// the following functions are equivalent to the above functions, but operate
// on glyph indices instead of Unicode codepoints (for efficiency)
STBTT_DEF unsigned char *stbtt_GetGlyphBitmap(const stbtt_fontinfo *info, float scale_x, float scale_y, int glyph, int *width, int *height, int *xoff, int *yoff);
STBTT_DEF unsigned char *stbtt_GetGlyphBitmapSubpixel(const stbtt_fontinfo *info, float scale_x, float scale_y, float shift_x, float shift_y, int glyph, int *width, int *height, int *xoff, int *yoff);
STBTT_DEF void stbtt_MakeGlyphBitmap(const stbtt_fontinfo *info, unsigned char *output, int out_w, int out_h, int out_stride, float scale_x, float scale_y, int glyph);
STBTT_DEF void stbtt_MakeGlyphBitmapSubpixel(const stbtt_fontinfo *info, unsigned char *output, int out_w, int out_h, int out_stride, float scale_x, float scale_y, float shift_x, float shift_y, int glyph);
STBTT_DEF void stbtt_MakeGlyphBitmapSubpixelPrefilter(const stbtt_fontinfo *info, unsigned char *output, int out_w, int out_h, int out_stride, float scale_x, float scale_y, float shift_x, float shift_y, int oversample_x, int oversample_y, float *sub_x, float *sub_y, int glyph);
STBTT_DEF void stbtt_GetGlyphBitmapBox(const stbtt_fontinfo *font, int glyph, float scale_x, float scale_y, int *ix0, int *iy0, int *ix1, int *iy1);
STBTT_DEF void stbtt_GetGlyphBitmapBoxSubpixel(const stbtt_fontinfo *font, int glyph, float scale_x, float scale_y,float shift_x, float shift_y, int *ix0, int *iy0, int *ix1, int *iy1);
// @TODO: don't expose this structure
typedef struct
{
int w,h,stride;
unsigned char *pixels;
} stbtt__bitmap;
// rasterize a shape with quadratic beziers into a bitmap
STBTT_DEF void stbtt_Rasterize(stbtt__bitmap *result, // 1-channel bitmap to draw into
float flatness_in_pixels, // allowable error of curve in pixels
stbtt_vertex *vertices, // array of vertices defining shape
int num_verts, // number of vertices in above array
float scale_x, float scale_y, // scale applied to input vertices
float shift_x, float shift_y, // translation applied to input vertices
int x_off, int y_off, // another translation applied to input
int invert, // if non-zero, vertically flip shape
void *userdata); // context for to STBTT_MALLOC
//////////////////////////////////////////////////////////////////////////////
//
// Signed Distance Function (or Field) rendering
STBTT_DEF void stbtt_FreeSDF(unsigned char *bitmap, void *userdata);
// frees the SDF bitmap allocated below
STBTT_DEF unsigned char * stbtt_GetGlyphSDF(const stbtt_fontinfo *info, float scale, int glyph, int padding, unsigned char onedge_value, float pixel_dist_scale, int *width, int *height, int *xoff, int *yoff);
STBTT_DEF unsigned char * stbtt_GetCodepointSDF(const stbtt_fontinfo *info, float scale, int codepoint, int padding, unsigned char onedge_value, float pixel_dist_scale, int *width, int *height, int *xoff, int *yoff);
// These functions compute a discretized SDF field for a single character, suitable for storing
// in a single-channel texture, sampling with bilinear filtering, and testing against
// larger than some threshold to produce scalable fonts.
// info -- the font
// scale -- controls the size of the resulting SDF bitmap, same as it would be creating a regular bitmap
// glyph/codepoint -- the character to generate the SDF for
// padding -- extra "pixels" around the character which are filled with the distance to the character (not 0),
// which allows effects like bit outlines
// onedge_value -- value 0-255 to test the SDF against to reconstruct the character (i.e. the isocontour of the character)
// pixel_dist_scale -- what value the SDF should increase by when moving one SDF "pixel" away from the edge (on the 0..255 scale)
// if positive, > onedge_value is inside; if negative, < onedge_value is inside
// width,height -- output height & width of the SDF bitmap (including padding)
// xoff,yoff -- output origin of the character
// return value -- a 2D array of bytes 0..255, width*height in size
//
// pixel_dist_scale & onedge_value are a scale & bias that allows you to make
// optimal use of the limited 0..255 for your application, trading off precision
// and special effects. SDF values outside the range 0..255 are clamped to 0..255.
//
// Example:
// scale = stbtt_ScaleForPixelHeight(22)
// padding = 5
// onedge_value = 180
// pixel_dist_scale = 180/5.0 = 36.0
//
// This will create an SDF bitmap in which the character is about 22 pixels
// high but the whole bitmap is about 22+5+5=32 pixels high. To produce a filled
// shape, sample the SDF at each pixel and fill the pixel if the SDF value
// is greater than or equal to 180/255. (You'll actually want to antialias,
// which is beyond the scope of this example.) Additionally, you can compute
// offset outlines (e.g. to stroke the character border inside & outside,
// or only outside). For example, to fill outside the character up to 3 SDF
// pixels, you would compare against (180-36.0*3)/255 = 72/255. The above
// choice of variables maps a range from 5 pixels outside the shape to
// 2 pixels inside the shape to 0..255; this is intended primarily for apply
// outside effects only (the interior range is needed to allow proper
// antialiasing of the font at *smaller* sizes)
//
// The function computes the SDF analytically at each SDF pixel, not by e.g.
// building a higher-res bitmap and approximating it. In theory the quality
// should be as high as possible for an SDF of this size & representation, but
// unclear if this is true in practice (perhaps building a higher-res bitmap
// and computing from that can allow drop-out prevention).
//
// The algorithm has not been optimized at all, so expect it to be slow
// if computing lots of characters or very large sizes.
//////////////////////////////////////////////////////////////////////////////
//
// Finding the right font...
//
// You should really just solve this offline, keep your own tables
// of what font is what, and don't try to get it out of the .ttf file.
// That's because getting it out of the .ttf file is really hard, because
// the names in the file can appear in many possible encodings, in many
// possible languages, and e.g. if you need a case-insensitive comparison,
// the details of that depend on the encoding & language in a complex way
// (actually underspecified in truetype, but also gigantic).
//
// But you can use the provided functions in two possible ways:
// stbtt_FindMatchingFont() will use *case-sensitive* comparisons on
// unicode-encoded names to try to find the font you want;
// you can run this before calling stbtt_InitFont()
//
// stbtt_GetFontNameString() lets you get any of the various strings
// from the file yourself and do your own comparisons on them.