1 /****************************************************************************
2 *
3 * ttsubpix.c
4 *
5 * TrueType Subpixel Hinting.
6 *
7 * Copyright (C) 2010-2019 by
8 * David Turner, Robert Wilhelm, and Werner Lemberg.
9 *
10 * This file is part of the FreeType project, and may only be used,
11 * modified, and distributed under the terms of the FreeType project
12 * license, LICENSE.TXT. By continuing to use, modify, or distribute
13 * this file you indicate that you have read the license and
14 * understand and accept it fully.
15 *
16 */
17
18 #include <ft2build.h>
19 #include FT_INTERNAL_DEBUG_H
20 #include FT_INTERNAL_CALC_H
21 #include FT_INTERNAL_STREAM_H
22 #include FT_INTERNAL_SFNT_H
23 #include FT_TRUETYPE_TAGS_H
24 #include FT_OUTLINE_H
25 #include FT_DRIVER_H
26
27 #include "ttsubpix.h"
28
29
30 #if defined( TT_USE_BYTECODE_INTERPRETER ) && \
31 defined( TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY )
32
33 /**************************************************************************
34 *
35 * These rules affect how the TT Interpreter does hinting, with the
36 * goal of doing subpixel hinting by (in general) ignoring x moves.
37 * Some of these rules are fixes that go above and beyond the
38 * stated techniques in the MS whitepaper on Cleartype, due to
39 * artifacts in many glyphs. So, these rules make some glyphs render
40 * better than they do in the MS rasterizer.
41 *
42 * "" string or 0 int/char indicates to apply to all glyphs.
43 * "-" used as dummy placeholders, but any non-matching string works.
44 *
45 * Some of this could arguably be implemented in fontconfig, however:
46 *
47 * - Fontconfig can't set things on a glyph-by-glyph basis.
48 * - The tweaks that happen here are very low-level, from an average
49 * user's point of view and are best implemented in the hinter.
50 *
51 * The goal is to make the subpixel hinting techniques as generalized
52 * as possible across all fonts to prevent the need for extra rules such
53 * as these.
54 *
55 * The rule structure is designed so that entirely new rules can easily
56 * be added when a new compatibility feature is discovered.
57 *
58 * The rule structures could also use some enhancement to handle ranges.
59 *
60 * ****************** WORK IN PROGRESS *******************
61 */
62
63 /* These are `classes' of fonts that can be grouped together and used in */
64 /* rules below. A blank entry "" is required at the end of these! */
65 #define FAMILY_CLASS_RULES_SIZE 7
66
67 static const SPH_Font_Class FAMILY_CLASS_Rules
68 [FAMILY_CLASS_RULES_SIZE] =
69 {
70 { "MS Legacy Fonts",
71 { "Aharoni",
72 "Andale Mono",
73 "Andalus",
74 "Angsana New",
75 "AngsanaUPC",
76 "Arabic Transparent",
77 "Arial Black",
78 "Arial Narrow",
79 "Arial Unicode MS",
80 "Arial",
81 "Batang",
82 "Browallia New",
83 "BrowalliaUPC",
84 "Comic Sans MS",
85 "Cordia New",
86 "CordiaUPC",
87 "Courier New",
88 "DFKai-SB",
89 "David Transparent",
90 "David",
91 "DilleniaUPC",
92 "Estrangelo Edessa",
93 "EucrosiaUPC",
94 "FangSong_GB2312",
95 "Fixed Miriam Transparent",
96 "FrankRuehl",
97 "Franklin Gothic Medium",
98 "FreesiaUPC",
99 "Garamond",
100 "Gautami",
101 "Georgia",
102 "Gulim",
103 "Impact",
104 "IrisUPC",
105 "JasmineUPC",
106 "KaiTi_GB2312",
107 "KodchiangUPC",
108 "Latha",
109 "Levenim MT",
110 "LilyUPC",
111 "Lucida Console",
112 "Lucida Sans Unicode",
113 "MS Gothic",
114 "MS Mincho",
115 "MV Boli",
116 "Mangal",
117 "Marlett",
118 "Microsoft Sans Serif",
119 "Mingliu",
120 "Miriam Fixed",
121 "Miriam Transparent",
122 "Miriam",
123 "Narkisim",
124 "Palatino Linotype",
125 "Raavi",
126 "Rod Transparent",
127 "Rod",
128 "Shruti",
129 "SimHei",
130 "Simplified Arabic Fixed",
131 "Simplified Arabic",
132 "Simsun",
133 "Sylfaen",
134 "Symbol",
135 "Tahoma",
136 "Times New Roman",
137 "Traditional Arabic",
138 "Trebuchet MS",
139 "Tunga",
140 "Verdana",
141 "Webdings",
142 "Wingdings",
143 "",
144 },
145 },
146 { "Core MS Legacy Fonts",
147 { "Arial Black",
148 "Arial Narrow",
149 "Arial Unicode MS",
150 "Arial",
151 "Comic Sans MS",
152 "Courier New",
153 "Garamond",
154 "Georgia",
155 "Impact",
156 "Lucida Console",
157 "Lucida Sans Unicode",
158 "Microsoft Sans Serif",
159 "Palatino Linotype",
160 "Tahoma",
161 "Times New Roman",
162 "Trebuchet MS",
163 "Verdana",
164 "",
165 },
166 },
167 { "Apple Legacy Fonts",
168 { "Geneva",
169 "Times",
170 "Monaco",
171 "Century",
172 "Chalkboard",
173 "Lobster",
174 "Century Gothic",
175 "Optima",
176 "Lucida Grande",
177 "Gill Sans",
178 "Baskerville",
179 "Helvetica",
180 "Helvetica Neue",
181 "",
182 },
183 },
184 { "Legacy Sans Fonts",
185 { "Andale Mono",
186 "Arial Unicode MS",
187 "Arial",
188 "Century Gothic",
189 "Comic Sans MS",
190 "Franklin Gothic Medium",
191 "Geneva",
192 "Lucida Console",
193 "Lucida Grande",
194 "Lucida Sans Unicode",
195 "Lucida Sans Typewriter",
196 "Microsoft Sans Serif",
197 "Monaco",
198 "Tahoma",
199 "Trebuchet MS",
200 "Verdana",
201 "",
202 },
203 },
204
205 { "Misc Legacy Fonts",
206 { "Dark Courier", "", }, },
207 { "Verdana Clones",
208 { "DejaVu Sans",
209 "Bitstream Vera Sans", "", }, },
210 { "Verdana and Clones",
211 { "DejaVu Sans",
212 "Bitstream Vera Sans",
213 "Verdana", "", }, },
214 };
215
216
217 /* Define this to force natural (i.e. not bitmap-compatible) widths. */
218 /* The default leans strongly towards natural widths except for a few */
219 /* legacy fonts where a selective combination produces nicer results. */
220 /* #define FORCE_NATURAL_WIDTHS */
221
222
223 /* Define `classes' of styles that can be grouped together and used in */
224 /* rules below. A blank entry "" is required at the end of these! */
225 #define STYLE_CLASS_RULES_SIZE 5
226
227 static const SPH_Font_Class STYLE_CLASS_Rules
228 [STYLE_CLASS_RULES_SIZE] =
229 {
230 { "Regular Class",
231 { "Regular",
232 "Book",
233 "Medium",
234 "Roman",
235 "Normal",
236 "",
237 },
238 },
239 { "Regular/Italic Class",
240 { "Regular",
241 "Book",
242 "Medium",
243 "Italic",
244 "Oblique",
245 "Roman",
246 "Normal",
247 "",
248 },
249 },
250 { "Bold/BoldItalic Class",
251 { "Bold",
252 "Bold Italic",
253 "Black",
254 "",
255 },
256 },
257 { "Bold/Italic/BoldItalic Class",
258 { "Bold",
259 "Bold Italic",
260 "Black",
261 "Italic",
262 "Oblique",
263 "",
264 },
265 },
266 { "Regular/Bold Class",
267 { "Regular",
268 "Book",
269 "Medium",
270 "Normal",
271 "Roman",
272 "Bold",
273 "Black",
274 "",
275 },
276 },
277 };
278
279
280 /* Force special legacy fixes for fonts. */
281 #define COMPATIBILITY_MODE_RULES_SIZE 1
282
283 static const SPH_TweakRule COMPATIBILITY_MODE_Rules
284 [COMPATIBILITY_MODE_RULES_SIZE] =
285 {
286 { "Verdana Clones", 0, "", 0 },
287 };
288
289
290 /* Don't do subpixel (ignore_x_mode) hinting; do normal hinting. */
291 #define PIXEL_HINTING_RULES_SIZE 2
292
293 static const SPH_TweakRule PIXEL_HINTING_Rules
294 [PIXEL_HINTING_RULES_SIZE] =
295 {
296 /* these characters are almost always safe */
297 { "Courier New", 12, "Italic", 'z' },
298 { "Courier New", 11, "Italic", 'z' },
299 };
300
301
302 /* Subpixel hinting ignores SHPIX rules on X. Force SHPIX for these. */
303 #define DO_SHPIX_RULES_SIZE 1
304
305 static const SPH_TweakRule DO_SHPIX_Rules
306 [DO_SHPIX_RULES_SIZE] =
307 {
308 { "-", 0, "", 0 },
309 };
310
311
312 /* Skip Y moves that start with a point that is not on a Y pixel */
313 /* boundary and don't move that point to a Y pixel boundary. */
314 #define SKIP_NONPIXEL_Y_MOVES_RULES_SIZE 4
315
316 static const SPH_TweakRule SKIP_NONPIXEL_Y_MOVES_Rules
317 [SKIP_NONPIXEL_Y_MOVES_RULES_SIZE] =
318 {
319 /* fix vwxyz thinness*/
320 { "Consolas", 0, "", 0 },
321 /* Fix thin middle stems */
322 { "Core MS Legacy Fonts", 0, "Regular", 0 },
323 /* Cyrillic small letter I */
324 { "Legacy Sans Fonts", 0, "", 0 },
325 /* Fix artifacts with some Regular & Bold */
326 { "Verdana Clones", 0, "", 0 },
327 };
328
329
330 #define SKIP_NONPIXEL_Y_MOVES_RULES_EXCEPTIONS_SIZE 1
331
332 static const SPH_TweakRule SKIP_NONPIXEL_Y_MOVES_Rules_Exceptions
333 [SKIP_NONPIXEL_Y_MOVES_RULES_EXCEPTIONS_SIZE] =
334 {
335 /* Fixes < and > */
336 { "Courier New", 0, "Regular", 0 },
337 };
338
339
340 /* Skip Y moves that start with a point that is not on a Y pixel */
341 /* boundary and don't move that point to a Y pixel boundary. */
342 #define SKIP_NONPIXEL_Y_MOVES_DELTAP_RULES_SIZE 2
343
344 static const SPH_TweakRule SKIP_NONPIXEL_Y_MOVES_DELTAP_Rules
345 [SKIP_NONPIXEL_Y_MOVES_DELTAP_RULES_SIZE] =
346 {
347 /* Maintain thickness of diagonal in 'N' */
348 { "Times New Roman", 0, "Regular/Bold Class", 'N' },
349 { "Georgia", 0, "Regular/Bold Class", 'N' },
350 };
351
352
353 /* Skip Y moves that move a point off a Y pixel boundary. */
354 #define SKIP_OFFPIXEL_Y_MOVES_RULES_SIZE 1
355
356 static const SPH_TweakRule SKIP_OFFPIXEL_Y_MOVES_Rules
357 [SKIP_OFFPIXEL_Y_MOVES_RULES_SIZE] =
358 {
359 { "-", 0, "", 0 },
360 };
361
362
363 #define SKIP_OFFPIXEL_Y_MOVES_RULES_EXCEPTIONS_SIZE 1
364
365 static const SPH_TweakRule SKIP_OFFPIXEL_Y_MOVES_Rules_Exceptions
366 [SKIP_OFFPIXEL_Y_MOVES_RULES_EXCEPTIONS_SIZE] =
367 {
368 { "-", 0, "", 0 },
369 };
370
371
372 /* Round moves that don't move a point to a Y pixel boundary. */
373 #define ROUND_NONPIXEL_Y_MOVES_RULES_SIZE 2
374
375 static const SPH_TweakRule ROUND_NONPIXEL_Y_MOVES_Rules
376 [ROUND_NONPIXEL_Y_MOVES_RULES_SIZE] =
377 {
378 /* Droid font instructions don't snap Y to pixels */
379 { "Droid Sans", 0, "Regular/Italic Class", 0 },
380 { "Droid Sans Mono", 0, "", 0 },
381 };
382
383
384 #define ROUND_NONPIXEL_Y_MOVES_RULES_EXCEPTIONS_SIZE 1
385
386 static const SPH_TweakRule ROUND_NONPIXEL_Y_MOVES_Rules_Exceptions
387 [ROUND_NONPIXEL_Y_MOVES_RULES_EXCEPTIONS_SIZE] =
388 {
389 { "-", 0, "", 0 },
390 };
391
392
393 /* Allow a Direct_Move along X freedom vector if matched. */
394 #define ALLOW_X_DMOVE_RULES_SIZE 1
395
396 static const SPH_TweakRule ALLOW_X_DMOVE_Rules
397 [ALLOW_X_DMOVE_RULES_SIZE] =
398 {
399 /* Fixes vanishing diagonal in 4 */
400 { "Verdana", 0, "Regular", '4' },
401 };
402
403
404 /* Return MS rasterizer version 35 if matched. */
405 #define RASTERIZER_35_RULES_SIZE 8
406
407 static const SPH_TweakRule RASTERIZER_35_Rules
408 [RASTERIZER_35_RULES_SIZE] =
409 {
410 /* This seems to be the only way to make these look good */
411 { "Times New Roman", 0, "Regular", 'i' },
412 { "Times New Roman", 0, "Regular", 'j' },
413 { "Times New Roman", 0, "Regular", 'm' },
414 { "Times New Roman", 0, "Regular", 'r' },
415 { "Times New Roman", 0, "Regular", 'a' },
416 { "Times New Roman", 0, "Regular", 'n' },
417 { "Times New Roman", 0, "Regular", 'p' },
418 { "Times", 0, "", 0 },
419 };
420
421
422 /* Don't round to the subpixel grid. Round to pixel grid. */
423 #define NORMAL_ROUND_RULES_SIZE 1
424
425 static const SPH_TweakRule NORMAL_ROUND_Rules
426 [NORMAL_ROUND_RULES_SIZE] =
427 {
428 /* Fix serif thickness for certain ppems */
429 /* Can probably be generalized somehow */
430 { "Courier New", 0, "", 0 },
431 };
432
433
434 /* Skip IUP instructions if matched. */
435 #define SKIP_IUP_RULES_SIZE 1
436
437 static const SPH_TweakRule SKIP_IUP_Rules
438 [SKIP_IUP_RULES_SIZE] =
439 {
440 { "Arial", 13, "Regular", 'a' },
441 };
442
443
444 /* Skip MIAP Twilight hack if matched. */
445 #define MIAP_HACK_RULES_SIZE 1
446
447 static const SPH_TweakRule MIAP_HACK_Rules
448 [MIAP_HACK_RULES_SIZE] =
449 {
450 { "Geneva", 12, "", 0 },
451 };
452
453
454 /* Skip DELTAP instructions if matched. */
455 #define ALWAYS_SKIP_DELTAP_RULES_SIZE 23
456
457 static const SPH_TweakRule ALWAYS_SKIP_DELTAP_Rules
458 [ALWAYS_SKIP_DELTAP_RULES_SIZE] =
459 {
460 { "Georgia", 0, "Regular", 'k' },
461 /* fix various problems with e in different versions */
462 { "Trebuchet MS", 14, "Regular", 'e' },
463 { "Trebuchet MS", 13, "Regular", 'e' },
464 { "Trebuchet MS", 15, "Regular", 'e' },
465 { "Trebuchet MS", 0, "Italic", 'v' },
466 { "Trebuchet MS", 0, "Italic", 'w' },
467 { "Trebuchet MS", 0, "Regular", 'Y' },
468 { "Arial", 11, "Regular", 's' },
469 /* prevent problems with '3' and others */
470 { "Verdana", 10, "Regular", 0 },
471 { "Verdana", 9, "Regular", 0 },
472 /* Cyrillic small letter short I */
473 { "Legacy Sans Fonts", 0, "", 0x438 },
474 { "Legacy Sans Fonts", 0, "", 0x439 },
475 { "Arial", 10, "Regular", '6' },
476 { "Arial", 0, "Bold/BoldItalic Class", 'a' },
477 /* Make horizontal stems consistent with the rest */
478 { "Arial", 24, "Bold", 'a' },
479 { "Arial", 25, "Bold", 'a' },
480 { "Arial", 24, "Bold", 's' },
481 { "Arial", 25, "Bold", 's' },
482 { "Arial", 34, "Bold", 's' },
483 { "Arial", 35, "Bold", 's' },
484 { "Arial", 36, "Bold", 's' },
485 { "Arial", 25, "Regular", 's' },
486 { "Arial", 26, "Regular", 's' },
487 };
488
489
490 /* Always do DELTAP instructions if matched. */
491 #define ALWAYS_DO_DELTAP_RULES_SIZE 1
492
493 static const SPH_TweakRule ALWAYS_DO_DELTAP_Rules
494 [ALWAYS_DO_DELTAP_RULES_SIZE] =
495 {
496 { "-", 0, "", 0 },
497 };
498
499
500 /* Don't allow ALIGNRP after IUP. */
501 #define NO_ALIGNRP_AFTER_IUP_RULES_SIZE 1
502
503 static const SPH_TweakRule NO_ALIGNRP_AFTER_IUP_Rules
504 [NO_ALIGNRP_AFTER_IUP_RULES_SIZE] =
505 {
506 /* Prevent creation of dents in outline */
507 { "-", 0, "", 0 },
508 };
509
510
511 /* Don't allow DELTAP after IUP. */
512 #define NO_DELTAP_AFTER_IUP_RULES_SIZE 1
513
514 static const SPH_TweakRule NO_DELTAP_AFTER_IUP_Rules
515 [NO_DELTAP_AFTER_IUP_RULES_SIZE] =
516 {
517 { "-", 0, "", 0 },
518 };
519
520
521 /* Don't allow CALL after IUP. */
522 #define NO_CALL_AFTER_IUP_RULES_SIZE 1
523
524 static const SPH_TweakRule NO_CALL_AFTER_IUP_Rules
525 [NO_CALL_AFTER_IUP_RULES_SIZE] =
526 {
527 /* Prevent creation of dents in outline */
528 { "-", 0, "", 0 },
529 };
530
531
532 /* De-embolden these glyphs slightly. */
533 #define DEEMBOLDEN_RULES_SIZE 9
534
535 static const SPH_TweakRule DEEMBOLDEN_Rules
536 [DEEMBOLDEN_RULES_SIZE] =
537 {
538 { "Courier New", 0, "Bold", 'A' },
539 { "Courier New", 0, "Bold", 'W' },
540 { "Courier New", 0, "Bold", 'w' },
541 { "Courier New", 0, "Bold", 'M' },
542 { "Courier New", 0, "Bold", 'X' },
543 { "Courier New", 0, "Bold", 'K' },
544 { "Courier New", 0, "Bold", 'x' },
545 { "Courier New", 0, "Bold", 'z' },
546 { "Courier New", 0, "Bold", 'v' },
547 };
548
549
550 /* Embolden these glyphs slightly. */
551 #define EMBOLDEN_RULES_SIZE 2
552
553 static const SPH_TweakRule EMBOLDEN_Rules
554 [EMBOLDEN_RULES_SIZE] =
555 {
556 { "Courier New", 0, "Regular", 0 },
557 { "Courier New", 0, "Italic", 0 },
558 };
559
560
561 /* This is a CVT hack that makes thick horizontal stems on 2, 5, 7 */
562 /* similar to Windows XP. */
563 #define TIMES_NEW_ROMAN_HACK_RULES_SIZE 12
564
565 static const SPH_TweakRule TIMES_NEW_ROMAN_HACK_Rules
566 [TIMES_NEW_ROMAN_HACK_RULES_SIZE] =
567 {
568 { "Times New Roman", 16, "Italic", '2' },
569 { "Times New Roman", 16, "Italic", '5' },
570 { "Times New Roman", 16, "Italic", '7' },
571 { "Times New Roman", 16, "Regular", '2' },
572 { "Times New Roman", 16, "Regular", '5' },
573 { "Times New Roman", 16, "Regular", '7' },
574 { "Times New Roman", 17, "Italic", '2' },
575 { "Times New Roman", 17, "Italic", '5' },
576 { "Times New Roman", 17, "Italic", '7' },
577 { "Times New Roman", 17, "Regular", '2' },
578 { "Times New Roman", 17, "Regular", '5' },
579 { "Times New Roman", 17, "Regular", '7' },
580 };
581
582
583 /* This fudges distance on 2 to get rid of the vanishing stem issue. */
584 /* A real solution to this is certainly welcome. */
585 #define COURIER_NEW_2_HACK_RULES_SIZE 15
586
587 static const SPH_TweakRule COURIER_NEW_2_HACK_Rules
588 [COURIER_NEW_2_HACK_RULES_SIZE] =
589 {
590 { "Courier New", 10, "Regular", '2' },
591 { "Courier New", 11, "Regular", '2' },
592 { "Courier New", 12, "Regular", '2' },
593 { "Courier New", 13, "Regular", '2' },
594 { "Courier New", 14, "Regular", '2' },
595 { "Courier New", 15, "Regular", '2' },
596 { "Courier New", 16, "Regular", '2' },
597 { "Courier New", 17, "Regular", '2' },
598 { "Courier New", 18, "Regular", '2' },
599 { "Courier New", 19, "Regular", '2' },
600 { "Courier New", 20, "Regular", '2' },
601 { "Courier New", 21, "Regular", '2' },
602 { "Courier New", 22, "Regular", '2' },
603 { "Courier New", 23, "Regular", '2' },
604 { "Courier New", 24, "Regular", '2' },
605 };
606
607
608 #ifndef FORCE_NATURAL_WIDTHS
609
610 /* Use compatible widths with these glyphs. Compatible widths is always */
611 /* on when doing B/W TrueType instructing, but is used selectively here, */
612 /* typically on glyphs with 3 or more vertical stems. */
613 #define COMPATIBLE_WIDTHS_RULES_SIZE 38
614
615 static const SPH_TweakRule COMPATIBLE_WIDTHS_Rules
616 [COMPATIBLE_WIDTHS_RULES_SIZE] =
617 {
618 { "Arial Unicode MS", 12, "Regular Class", 'm' },
619 { "Arial Unicode MS", 14, "Regular Class", 'm' },
620 /* Cyrillic small letter sha */
621 { "Arial", 10, "Regular Class", 0x448 },
622 { "Arial", 11, "Regular Class", 'm' },
623 { "Arial", 12, "Regular Class", 'm' },
624 /* Cyrillic small letter sha */
625 { "Arial", 12, "Regular Class", 0x448 },
626 { "Arial", 13, "Regular Class", 0x448 },
627 { "Arial", 14, "Regular Class", 'm' },
628 /* Cyrillic small letter sha */
629 { "Arial", 14, "Regular Class", 0x448 },
630 { "Arial", 15, "Regular Class", 0x448 },
631 { "Arial", 17, "Regular Class", 'm' },
632 { "DejaVu Sans", 15, "Regular Class", 0 },
633 { "Microsoft Sans Serif", 11, "Regular Class", 0 },
634 { "Microsoft Sans Serif", 12, "Regular Class", 0 },
635 { "Segoe UI", 11, "Regular Class", 0 },
636 { "Monaco", 0, "Regular Class", 0 },
637 { "Segoe UI", 12, "Regular Class", 'm' },
638 { "Segoe UI", 14, "Regular Class", 'm' },
639 { "Tahoma", 11, "Regular Class", 0 },
640 { "Times New Roman", 16, "Regular Class", 'c' },
641 { "Times New Roman", 16, "Regular Class", 'm' },
642 { "Times New Roman", 16, "Regular Class", 'o' },
643 { "Times New Roman", 16, "Regular Class", 'w' },
644 { "Trebuchet MS", 11, "Regular Class", 0 },
645 { "Trebuchet MS", 12, "Regular Class", 0 },
646 { "Trebuchet MS", 14, "Regular Class", 0 },
647 { "Trebuchet MS", 15, "Regular Class", 0 },
648 { "Ubuntu", 12, "Regular Class", 'm' },
649 /* Cyrillic small letter sha */
650 { "Verdana", 10, "Regular Class", 0x448 },
651 { "Verdana", 11, "Regular Class", 0x448 },
652 { "Verdana and Clones", 12, "Regular Class", 'i' },
653 { "Verdana and Clones", 12, "Regular Class", 'j' },
654 { "Verdana and Clones", 12, "Regular Class", 'l' },
655 { "Verdana and Clones", 12, "Regular Class", 'm' },
656 { "Verdana and Clones", 13, "Regular Class", 'i' },
657 { "Verdana and Clones", 13, "Regular Class", 'j' },
658 { "Verdana and Clones", 13, "Regular Class", 'l' },
659 { "Verdana and Clones", 14, "Regular Class", 'm' },
660 };
661
662
663 /* Scaling slightly in the x-direction prior to hinting results in */
664 /* more visually pleasing glyphs in certain cases. */
665 /* This sometimes needs to be coordinated with compatible width rules. */
666 /* A value of 1000 corresponds to a scaled value of 1.0. */
667
668 #define X_SCALING_RULES_SIZE 50
669
670 static const SPH_ScaleRule X_SCALING_Rules[X_SCALING_RULES_SIZE] =
671 {
672 { "DejaVu Sans", 12, "Regular Class", 'm', 950 },
673 { "Verdana and Clones", 12, "Regular Class", 'a', 1100 },
674 { "Verdana and Clones", 13, "Regular Class", 'a', 1050 },
675 { "Arial", 11, "Regular Class", 'm', 975 },
676 { "Arial", 12, "Regular Class", 'm', 1050 },
677 /* Cyrillic small letter el */
678 { "Arial", 13, "Regular Class", 0x43B, 950 },
679 { "Arial", 13, "Regular Class", 'o', 950 },
680 { "Arial", 13, "Regular Class", 'e', 950 },
681 { "Arial", 14, "Regular Class", 'm', 950 },
682 /* Cyrillic small letter el */
683 { "Arial", 15, "Regular Class", 0x43B, 925 },
684 { "Bitstream Vera Sans", 10, "Regular/Italic Class", 0, 1100 },
685 { "Bitstream Vera Sans", 12, "Regular/Italic Class", 0, 1050 },
686 { "Bitstream Vera Sans", 16, "Regular Class", 0, 1050 },
687 { "Bitstream Vera Sans", 9, "Regular/Italic Class", 0, 1050 },
688 { "DejaVu Sans", 12, "Regular Class", 'l', 975 },
689 { "DejaVu Sans", 12, "Regular Class", 'i', 975 },
690 { "DejaVu Sans", 12, "Regular Class", 'j', 975 },
691 { "DejaVu Sans", 13, "Regular Class", 'l', 950 },
692 { "DejaVu Sans", 13, "Regular Class", 'i', 950 },
693 { "DejaVu Sans", 13, "Regular Class", 'j', 950 },
694 { "DejaVu Sans", 10, "Regular/Italic Class", 0, 1100 },
695 { "DejaVu Sans", 12, "Regular/Italic Class", 0, 1050 },
696 { "Georgia", 10, "", 0, 1050 },
697 { "Georgia", 11, "", 0, 1100 },
698 { "Georgia", 12, "", 0, 1025 },
699 { "Georgia", 13, "", 0, 1050 },
700 { "Georgia", 16, "", 0, 1050 },
701 { "Georgia", 17, "", 0, 1030 },
702 { "Liberation Sans", 12, "Regular Class", 'm', 1100 },
703 { "Lucida Grande", 11, "Regular Class", 'm', 1100 },
704 { "Microsoft Sans Serif", 11, "Regular Class", 'm', 950 },
705 { "Microsoft Sans Serif", 12, "Regular Class", 'm', 1050 },
706 { "Segoe UI", 12, "Regular Class", 'H', 1050 },
707 { "Segoe UI", 12, "Regular Class", 'm', 1050 },
708 { "Segoe UI", 14, "Regular Class", 'm', 1050 },
709 { "Tahoma", 11, "Regular Class", 'i', 975 },
710 { "Tahoma", 11, "Regular Class", 'l', 975 },
711 { "Tahoma", 11, "Regular Class", 'j', 900 },
712 { "Tahoma", 11, "Regular Class", 'm', 918 },
713 { "Verdana", 10, "Regular/Italic Class", 0, 1100 },
714 { "Verdana", 12, "Regular Class", 'm', 975 },
715 { "Verdana", 12, "Regular/Italic Class", 0, 1050 },
716 { "Verdana", 13, "Regular/Italic Class", 'i', 950 },
717 { "Verdana", 13, "Regular/Italic Class", 'j', 950 },
718 { "Verdana", 13, "Regular/Italic Class", 'l', 950 },
719 { "Verdana", 16, "Regular Class", 0, 1050 },
720 { "Verdana", 9, "Regular/Italic Class", 0, 1050 },
721 { "Times New Roman", 16, "Regular Class", 'm', 918 },
722 { "Trebuchet MS", 11, "Regular Class", 'm', 800 },
723 { "Trebuchet MS", 12, "Regular Class", 'm', 800 },
724 };
725
726 #else
727
728 #define COMPATIBLE_WIDTHS_RULES_SIZE 1
729
730 static const SPH_TweakRule COMPATIBLE_WIDTHS_Rules
731 [COMPATIBLE_WIDTHS_RULES_SIZE] =
732 {
733 { "-", 0, "", 0 },
734 };
735
736
737 #define X_SCALING_RULES_SIZE 1
738
739 static const SPH_ScaleRule X_SCALING_Rules
740 [X_SCALING_RULES_SIZE] =
741 {
742 { "-", 0, "", 0, 1000 },
743 };
744
745 #endif /* FORCE_NATURAL_WIDTHS */
746
747
748 static FT_Bool
749 is_member_of_family_class( const FT_String* detected_font_name,
750 const FT_String* rule_font_name )
751 {
752 FT_UInt i, j;
753
754
755 /* Does font name match rule family? */
756 if ( ft_strcmp( detected_font_name, rule_font_name ) == 0 )
757 return TRUE;
758
759 /* Is font name a wildcard ""? */
760 if ( ft_strcmp( rule_font_name, "" ) == 0 )
761 return TRUE;
762
763 /* Is font name contained in a class list? */
764 for ( i = 0; i < FAMILY_CLASS_RULES_SIZE; i++ )
765 {
766 if ( ft_strcmp( FAMILY_CLASS_Rules[i].name, rule_font_name ) == 0 )
767 {
768 for ( j = 0; j < SPH_MAX_CLASS_MEMBERS; j++ )
769 {
770 if ( ft_strcmp( FAMILY_CLASS_Rules[i].member[j], "" ) == 0 )
771 continue;
772 if ( ft_strcmp( FAMILY_CLASS_Rules[i].member[j],
773 detected_font_name ) == 0 )
774 return TRUE;
775 }
776 }
777 }
778
779 return FALSE;
780 }
781
782
783 static FT_Bool
784 is_member_of_style_class( const FT_String* detected_font_style,
785 const FT_String* rule_font_style )
786 {
787 FT_UInt i, j;
788
789
790 /* Does font style match rule style? */
791 if ( ft_strcmp( detected_font_style, rule_font_style ) == 0 )
792 return TRUE;
793
794 /* Is font style a wildcard ""? */
795 if ( ft_strcmp( rule_font_style, "" ) == 0 )
796 return TRUE;
797
798 /* Is font style contained in a class list? */
799 for ( i = 0; i < STYLE_CLASS_RULES_SIZE; i++ )
800 {
801 if ( ft_strcmp( STYLE_CLASS_Rules[i].name, rule_font_style ) == 0 )
802 {
803 for ( j = 0; j < SPH_MAX_CLASS_MEMBERS; j++ )
804 {
805 if ( ft_strcmp( STYLE_CLASS_Rules[i].member[j], "" ) == 0 )
806 continue;
807 if ( ft_strcmp( STYLE_CLASS_Rules[i].member[j],
808 detected_font_style ) == 0 )
809 return TRUE;
810 }
811 }
812 }
813
814 return FALSE;
815 }
816
817
818 FT_LOCAL_DEF( FT_Bool )
819 sph_test_tweak( TT_Face face,
820 const FT_String* family,
821 FT_UInt ppem,
822 const FT_String* style,
823 FT_UInt glyph_index,
824 const SPH_TweakRule* rule,
825 FT_UInt num_rules )
826 {
827 FT_UInt i;
828
829
830 /* rule checks may be able to be optimized further */
831 for ( i = 0; i < num_rules; i++ )
832 {
833 if ( family &&
834 ( is_member_of_family_class ( family, rule[i].family ) ) )
835 if ( rule[i].ppem == 0 ||
836 rule[i].ppem == ppem )
837 if ( style &&
838 is_member_of_style_class ( style, rule[i].style ) )
839 if ( rule[i].glyph == 0 ||
840 FT_Get_Char_Index( (FT_Face)face,
841 rule[i].glyph ) == glyph_index )
842 return TRUE;
843 }
844
845 return FALSE;
846 }
847
848
849 static FT_UInt
850 scale_test_tweak( TT_Face face,
851 const FT_String* family,
852 FT_UInt ppem,
853 const FT_String* style,
854 FT_UInt glyph_index,
855 const SPH_ScaleRule* rule,
856 FT_UInt num_rules )
857 {
858 FT_UInt i;
859
860
861 /* rule checks may be able to be optimized further */
862 for ( i = 0; i < num_rules; i++ )
863 {
864 if ( family &&
865 ( is_member_of_family_class ( family, rule[i].family ) ) )
866 if ( rule[i].ppem == 0 ||
867 rule[i].ppem == ppem )
868 if ( style &&
869 is_member_of_style_class( style, rule[i].style ) )
870 if ( rule[i].glyph == 0 ||
871 FT_Get_Char_Index( (FT_Face)face,
872 rule[i].glyph ) == glyph_index )
873 return rule[i].scale;
874 }
875
876 return 1000;
877 }
878
879
880 FT_LOCAL_DEF( FT_UInt )
881 sph_test_tweak_x_scaling( TT_Face face,
882 const FT_String* family,
883 FT_UInt ppem,
884 const FT_String* style,
885 FT_UInt glyph_index )
886 {
887 return scale_test_tweak( face, family, ppem, style, glyph_index,
888 X_SCALING_Rules, X_SCALING_RULES_SIZE );
889 }
890
891
892 #define TWEAK_RULES( x ) \
893 if ( sph_test_tweak( face, family, ppem, style, glyph_index, \
894 x##_Rules, x##_RULES_SIZE ) ) \
895 loader->exec->sph_tweak_flags |= SPH_TWEAK_##x;
896
897 #define TWEAK_RULES_EXCEPTIONS( x ) \
898 if ( sph_test_tweak( face, family, ppem, style, glyph_index, \
899 x##_Rules_Exceptions, x##_RULES_EXCEPTIONS_SIZE ) ) \
900 loader->exec->sph_tweak_flags &= ~SPH_TWEAK_##x;
901
902
903 FT_LOCAL_DEF( void )
904 sph_set_tweaks( TT_Loader loader,
905 FT_UInt glyph_index )
906 {
907 TT_Face face = loader->face;
908 FT_String* family = face->root.family_name;
909 FT_UInt ppem = loader->size->metrics->x_ppem;
910 FT_String* style = face->root.style_name;
911
912
913 /* don't apply rules if style isn't set */
914 if ( !face->root.style_name )
915 return;
916
917 #ifdef SPH_DEBUG_MORE_VERBOSE
918 printf( "%s,%d,%s,%c=%d ",
919 family, ppem, style, glyph_index, glyph_index );
920 #endif
921
922 TWEAK_RULES( PIXEL_HINTING );
923
924 if ( loader->exec->sph_tweak_flags & SPH_TWEAK_PIXEL_HINTING )
925 {
926 loader->exec->ignore_x_mode = FALSE;
927 return;
928 }
929
930 TWEAK_RULES( ALLOW_X_DMOVE );
931 TWEAK_RULES( ALWAYS_DO_DELTAP );
932 TWEAK_RULES( ALWAYS_SKIP_DELTAP );
933 TWEAK_RULES( DEEMBOLDEN );
934 TWEAK_RULES( DO_SHPIX );
935 TWEAK_RULES( EMBOLDEN );
936 TWEAK_RULES( MIAP_HACK );
937 TWEAK_RULES( NORMAL_ROUND );
938 TWEAK_RULES( NO_ALIGNRP_AFTER_IUP );
939 TWEAK_RULES( NO_CALL_AFTER_IUP );
940 TWEAK_RULES( NO_DELTAP_AFTER_IUP );
941 TWEAK_RULES( RASTERIZER_35 );
942 TWEAK_RULES( SKIP_IUP );
943
944 TWEAK_RULES( SKIP_OFFPIXEL_Y_MOVES );
945 TWEAK_RULES_EXCEPTIONS( SKIP_OFFPIXEL_Y_MOVES );
946
947 TWEAK_RULES( SKIP_NONPIXEL_Y_MOVES_DELTAP );
948
949 TWEAK_RULES( SKIP_NONPIXEL_Y_MOVES );
950 TWEAK_RULES_EXCEPTIONS( SKIP_NONPIXEL_Y_MOVES );
951
952 TWEAK_RULES( ROUND_NONPIXEL_Y_MOVES );
953 TWEAK_RULES_EXCEPTIONS( ROUND_NONPIXEL_Y_MOVES );
954
955 if ( loader->exec->sph_tweak_flags & SPH_TWEAK_RASTERIZER_35 )
956 {
957 if ( loader->exec->rasterizer_version != TT_INTERPRETER_VERSION_35 )
958 {
959 loader->exec->rasterizer_version = TT_INTERPRETER_VERSION_35;
960 loader->exec->size->cvt_ready = -1;
961
962 tt_size_ready_bytecode(
963 loader->exec->size,
964 FT_BOOL( loader->load_flags & FT_LOAD_PEDANTIC ) );
965 }
966 else
967 loader->exec->rasterizer_version = TT_INTERPRETER_VERSION_35;
968 }
969 else
970 {
971 if ( loader->exec->rasterizer_version !=
972 SPH_OPTION_SET_RASTERIZER_VERSION )
973 {
974 loader->exec->rasterizer_version = SPH_OPTION_SET_RASTERIZER_VERSION;
975 loader->exec->size->cvt_ready = -1;
976
977 tt_size_ready_bytecode(
978 loader->exec->size,
979 FT_BOOL( loader->load_flags & FT_LOAD_PEDANTIC ) );
980 }
981 else
982 loader->exec->rasterizer_version = SPH_OPTION_SET_RASTERIZER_VERSION;
983 }
984
985 if ( IS_HINTED( loader->load_flags ) )
986 {
987 TWEAK_RULES( TIMES_NEW_ROMAN_HACK );
988 TWEAK_RULES( COURIER_NEW_2_HACK );
989 }
990
991 if ( sph_test_tweak( face, family, ppem, style, glyph_index,
992 COMPATIBILITY_MODE_Rules, COMPATIBILITY_MODE_RULES_SIZE ) )
993 loader->exec->face->sph_compatibility_mode = TRUE;
994
995
996 if ( IS_HINTED( loader->load_flags ) )
997 {
998 if ( sph_test_tweak( face, family, ppem, style, glyph_index,
999 COMPATIBLE_WIDTHS_Rules, COMPATIBLE_WIDTHS_RULES_SIZE ) )
1000 loader->exec->compatible_widths |= TRUE;
1001 }
1002 }
1003
1004 #else /* !(TT_USE_BYTECODE_INTERPRETER && */
1005 /* TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY) */
1006
1007 /* ANSI C doesn't like empty source files */
1008 typedef int _tt_subpix_dummy;
1009
1010 #endif /* !(TT_USE_BYTECODE_INTERPRETER && */
1011 /* TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY) */
1012
1013
1014 /* END */