1 | /* ATTENTION: This file doesn't compile. It is only here as a reference */ |
2 | /* of an alternative latin hinting algorithm that was always */ |
3 | /* marked as experimental. */ |
4 | |
5 | |
6 | /***************************************************************************/ |
7 | /* */ |
8 | /* aflatin2.c */ |
9 | /* */ |
10 | /* Auto-fitter hinting routines for latin writing system (body). */ |
11 | /* */ |
12 | /* Copyright 2003-2018 by */ |
13 | /* David Turner, Robert Wilhelm, and Werner Lemberg. */ |
14 | /* */ |
15 | /* This file is part of the FreeType project, and may only be used, */ |
16 | /* modified, and distributed under the terms of the FreeType project */ |
17 | /* license, LICENSE.TXT. By continuing to use, modify, or distribute */ |
18 | /* this file you indicate that you have read the license and */ |
19 | /* understand and accept it fully. */ |
20 | /* */ |
21 | /***************************************************************************/ |
22 | |
23 | |
24 | #include FT_ADVANCES_H |
25 | |
26 | |
27 | #ifdef FT_OPTION_AUTOFIT2 |
28 | |
29 | #include "afglobal.h" |
30 | #include "aflatin.h" |
31 | #include "aflatin2.h" |
32 | #include "aferrors.h" |
33 | |
34 | |
35 | #ifdef AF_CONFIG_OPTION_USE_WARPER |
36 | #include "afwarp.h" |
37 | #endif |
38 | |
39 | |
40 | /*************************************************************************/ |
41 | /* */ |
42 | /* The macro FT_COMPONENT is used in trace mode. It is an implicit */ |
43 | /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log */ |
44 | /* messages during execution. */ |
45 | /* */ |
46 | #undef FT_COMPONENT |
47 | #define FT_COMPONENT trace_aflatin2 |
48 | |
49 | |
50 | FT_LOCAL_DEF( FT_Error ) |
51 | af_latin2_hints_compute_segments( AF_GlyphHints hints, |
52 | AF_Dimension dim ); |
53 | |
54 | FT_LOCAL_DEF( void ) |
55 | af_latin2_hints_link_segments( AF_GlyphHints hints, |
56 | AF_Dimension dim ); |
57 | |
58 | /*************************************************************************/ |
59 | /*************************************************************************/ |
60 | /***** *****/ |
61 | /***** L A T I N G L O B A L M E T R I C S *****/ |
62 | /***** *****/ |
63 | /*************************************************************************/ |
64 | /*************************************************************************/ |
65 | |
66 | FT_LOCAL_DEF( void ) |
67 | af_latin2_metrics_init_widths( AF_LatinMetrics metrics, |
68 | FT_Face face ) |
69 | { |
70 | /* scan the array of segments in each direction */ |
71 | AF_GlyphHintsRec hints[1]; |
72 | |
73 | |
74 | af_glyph_hints_init( hints, face->memory ); |
75 | |
76 | metrics->axis[AF_DIMENSION_HORZ].width_count = 0; |
77 | metrics->axis[AF_DIMENSION_VERT].width_count = 0; |
78 | |
79 | { |
80 | FT_Error error; |
81 | FT_UInt glyph_index; |
82 | int dim; |
83 | AF_LatinMetricsRec dummy[1]; |
84 | AF_Scaler scaler = &dummy->root.scaler; |
85 | |
86 | |
87 | glyph_index = FT_Get_Char_Index( |
88 | face, |
89 | metrics->root.style_class->standard_char ); |
90 | if ( glyph_index == 0 ) |
91 | goto Exit; |
92 | |
93 | error = FT_Load_Glyph( face, glyph_index, FT_LOAD_NO_SCALE ); |
94 | if ( error || face->glyph->outline.n_points <= 0 ) |
95 | goto Exit; |
96 | |
97 | FT_ZERO( dummy ); |
98 | |
99 | dummy->units_per_em = metrics->units_per_em; |
100 | scaler->x_scale = scaler->y_scale = 0x10000L; |
101 | scaler->x_delta = scaler->y_delta = 0; |
102 | scaler->face = face; |
103 | scaler->render_mode = FT_RENDER_MODE_NORMAL; |
104 | scaler->flags = 0; |
105 | |
106 | af_glyph_hints_rescale( hints, (AF_StyleMetrics)dummy ); |
107 | |
108 | error = af_glyph_hints_reload( hints, &face->glyph->outline ); |
109 | if ( error ) |
110 | goto Exit; |
111 | |
112 | for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ ) |
113 | { |
114 | AF_LatinAxis axis = &metrics->axis[dim]; |
115 | AF_AxisHints axhints = &hints->axis[dim]; |
116 | AF_Segment seg, limit, link; |
117 | FT_UInt num_widths = 0; |
118 | |
119 | |
120 | error = af_latin2_hints_compute_segments( hints, |
121 | (AF_Dimension)dim ); |
122 | if ( error ) |
123 | goto Exit; |
124 | |
125 | af_latin2_hints_link_segments( hints, |
126 | (AF_Dimension)dim ); |
127 | |
128 | seg = axhints->segments; |
129 | limit = seg + axhints->num_segments; |
130 | |
131 | for ( ; seg < limit; seg++ ) |
132 | { |
133 | link = seg->link; |
134 | |
135 | /* we only consider stem segments there! */ |
136 | if ( link && link->link == seg && link > seg ) |
137 | { |
138 | FT_Pos dist; |
139 | |
140 | |
141 | dist = seg->pos - link->pos; |
142 | if ( dist < 0 ) |
143 | dist = -dist; |
144 | |
145 | if ( num_widths < AF_LATIN_MAX_WIDTHS ) |
146 | axis->widths[num_widths++].org = dist; |
147 | } |
148 | } |
149 | |
150 | af_sort_widths( num_widths, axis->widths ); |
151 | axis->width_count = num_widths; |
152 | } |
153 | |
154 | Exit: |
155 | for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ ) |
156 | { |
157 | AF_LatinAxis axis = &metrics->axis[dim]; |
158 | FT_Pos stdw; |
159 | |
160 | |
161 | stdw = ( axis->width_count > 0 ) |
162 | ? axis->widths[0].org |
163 | : AF_LATIN_CONSTANT( metrics, 50 ); |
164 | |
165 | /* let's try 20% of the smallest width */ |
166 | axis->edge_distance_threshold = stdw / 5; |
167 | axis->standard_width = stdw; |
168 | axis->extra_light = 0; |
169 | } |
170 | } |
171 | |
172 | af_glyph_hints_done( hints ); |
173 | } |
174 | |
175 | |
176 | |
177 | #define AF_LATIN_MAX_TEST_CHARACTERS 12 |
178 | |
179 | |
180 | static const char af_latin2_blue_chars[AF_LATIN_MAX_BLUES] |
181 | [AF_LATIN_MAX_TEST_CHARACTERS+1] = |
182 | { |
183 | "THEZOCQS" , |
184 | "HEZLOCUS" , |
185 | "fijkdbh" , |
186 | "xzroesc" , |
187 | "xzroesc" , |
188 | "pqgjy" |
189 | }; |
190 | |
191 | |
192 | static void |
193 | af_latin2_metrics_init_blues( AF_LatinMetrics metrics, |
194 | FT_Face face ) |
195 | { |
196 | FT_Pos flats [AF_LATIN_MAX_TEST_CHARACTERS]; |
197 | FT_Pos rounds[AF_LATIN_MAX_TEST_CHARACTERS]; |
198 | FT_Int num_flats; |
199 | FT_Int num_rounds; |
200 | FT_Int bb; |
201 | AF_LatinBlue blue; |
202 | FT_Error error; |
203 | AF_LatinAxis axis = &metrics->axis[AF_DIMENSION_VERT]; |
204 | FT_GlyphSlot glyph = face->glyph; |
205 | |
206 | |
207 | /* we compute the blues simply by loading each character from the */ |
208 | /* 'af_latin2_blue_chars[blues]' string, then compute its top-most or */ |
209 | /* bottom-most points (depending on `AF_IS_TOP_BLUE') */ |
210 | |
211 | FT_TRACE5(( "blue zones computation\n" |
212 | "======================\n\n" )); |
213 | |
214 | for ( bb = 0; bb < AF_LATIN_BLUE_MAX; bb++ ) |
215 | { |
216 | const char* p = af_latin2_blue_chars[bb]; |
217 | const char* limit = p + AF_LATIN_MAX_TEST_CHARACTERS; |
218 | FT_Pos* blue_ref; |
219 | FT_Pos* blue_shoot; |
220 | |
221 | |
222 | FT_TRACE5(( "blue zone %d:\n" , bb )); |
223 | |
224 | num_flats = 0; |
225 | num_rounds = 0; |
226 | |
227 | for ( ; p < limit && *p; p++ ) |
228 | { |
229 | FT_UInt glyph_index; |
230 | FT_Int best_point, best_y, best_first, best_last; |
231 | FT_Vector* points; |
232 | FT_Bool round; |
233 | |
234 | |
235 | /* load the character in the face -- skip unknown or empty ones */ |
236 | glyph_index = FT_Get_Char_Index( face, (FT_UInt)*p ); |
237 | if ( glyph_index == 0 ) |
238 | continue; |
239 | |
240 | error = FT_Load_Glyph( face, glyph_index, FT_LOAD_NO_SCALE ); |
241 | if ( error || glyph->outline.n_points <= 0 ) |
242 | continue; |
243 | |
244 | /* now compute min or max point indices and coordinates */ |
245 | points = glyph->outline.points; |
246 | best_point = -1; |
247 | best_y = 0; /* make compiler happy */ |
248 | best_first = 0; /* ditto */ |
249 | best_last = 0; /* ditto */ |
250 | |
251 | { |
252 | FT_Int nn; |
253 | FT_Int first = 0; |
254 | FT_Int last = -1; |
255 | |
256 | |
257 | for ( nn = 0; nn < glyph->outline.n_contours; first = last+1, nn++ ) |
258 | { |
259 | FT_Int old_best_point = best_point; |
260 | FT_Int pp; |
261 | |
262 | |
263 | last = glyph->outline.contours[nn]; |
264 | |
265 | /* Avoid single-point contours since they are never rasterized. */ |
266 | /* In some fonts, they correspond to mark attachment points */ |
267 | /* which are way outside of the glyph's real outline. */ |
268 | if ( last == first ) |
269 | continue; |
270 | |
271 | if ( AF_LATIN_IS_TOP_BLUE( bb ) ) |
272 | { |
273 | for ( pp = first; pp <= last; pp++ ) |
274 | if ( best_point < 0 || points[pp].y > best_y ) |
275 | { |
276 | best_point = pp; |
277 | best_y = points[pp].y; |
278 | } |
279 | } |
280 | else |
281 | { |
282 | for ( pp = first; pp <= last; pp++ ) |
283 | if ( best_point < 0 || points[pp].y < best_y ) |
284 | { |
285 | best_point = pp; |
286 | best_y = points[pp].y; |
287 | } |
288 | } |
289 | |
290 | if ( best_point != old_best_point ) |
291 | { |
292 | best_first = first; |
293 | best_last = last; |
294 | } |
295 | } |
296 | FT_TRACE5(( " %c %d" , *p, best_y )); |
297 | } |
298 | |
299 | /* now check whether the point belongs to a straight or round */ |
300 | /* segment; we first need to find in which contour the extremum */ |
301 | /* lies, then inspect its previous and next points */ |
302 | { |
303 | FT_Pos best_x = points[best_point].x; |
304 | FT_Int start, end, prev, next; |
305 | FT_Pos dist; |
306 | |
307 | |
308 | /* now look for the previous and next points that are not on the */ |
309 | /* same Y coordinate. Threshold the `closeness'... */ |
310 | start = end = best_point; |
311 | |
312 | do |
313 | { |
314 | prev = start - 1; |
315 | if ( prev < best_first ) |
316 | prev = best_last; |
317 | |
318 | dist = FT_ABS( points[prev].y - best_y ); |
319 | /* accept a small distance or a small angle (both values are */ |
320 | /* heuristic; value 20 corresponds to approx. 2.9 degrees) */ |
321 | if ( dist > 5 ) |
322 | if ( FT_ABS( points[prev].x - best_x ) <= 20 * dist ) |
323 | break; |
324 | |
325 | start = prev; |
326 | |
327 | } while ( start != best_point ); |
328 | |
329 | do |
330 | { |
331 | next = end + 1; |
332 | if ( next > best_last ) |
333 | next = best_first; |
334 | |
335 | dist = FT_ABS( points[next].y - best_y ); |
336 | if ( dist > 5 ) |
337 | if ( FT_ABS( points[next].x - best_x ) <= 20 * dist ) |
338 | break; |
339 | |
340 | end = next; |
341 | |
342 | } while ( end != best_point ); |
343 | |
344 | /* now, set the `round' flag depending on the segment's kind */ |
345 | round = FT_BOOL( |
346 | FT_CURVE_TAG( glyph->outline.tags[start] ) != FT_CURVE_TAG_ON || |
347 | FT_CURVE_TAG( glyph->outline.tags[ end ] ) != FT_CURVE_TAG_ON ); |
348 | |
349 | FT_TRACE5(( " (%s)\n" , round ? "round" : "flat" )); |
350 | } |
351 | |
352 | if ( round ) |
353 | rounds[num_rounds++] = best_y; |
354 | else |
355 | flats[num_flats++] = best_y; |
356 | } |
357 | |
358 | if ( num_flats == 0 && num_rounds == 0 ) |
359 | { |
360 | /* |
361 | * we couldn't find a single glyph to compute this blue zone, |
362 | * we will simply ignore it then |
363 | */ |
364 | FT_TRACE5(( " empty\n" )); |
365 | continue; |
366 | } |
367 | |
368 | /* we have computed the contents of the `rounds' and `flats' tables, */ |
369 | /* now determine the reference and overshoot position of the blue -- */ |
370 | /* we simply take the median value after a simple sort */ |
371 | af_sort_pos( num_rounds, rounds ); |
372 | af_sort_pos( num_flats, flats ); |
373 | |
374 | blue = & axis->blues[axis->blue_count]; |
375 | blue_ref = & blue->ref.org; |
376 | blue_shoot = & blue->shoot.org; |
377 | |
378 | axis->blue_count++; |
379 | |
380 | if ( num_flats == 0 ) |
381 | { |
382 | *blue_ref = |
383 | *blue_shoot = rounds[num_rounds / 2]; |
384 | } |
385 | else if ( num_rounds == 0 ) |
386 | { |
387 | *blue_ref = |
388 | *blue_shoot = flats[num_flats / 2]; |
389 | } |
390 | else |
391 | { |
392 | *blue_ref = flats[num_flats / 2]; |
393 | *blue_shoot = rounds[num_rounds / 2]; |
394 | } |
395 | |
396 | /* there are sometimes problems: if the overshoot position of top */ |
397 | /* zones is under its reference position, or the opposite for bottom */ |
398 | /* zones. We must thus check everything there and correct the errors */ |
399 | if ( *blue_shoot != *blue_ref ) |
400 | { |
401 | FT_Pos ref = *blue_ref; |
402 | FT_Pos shoot = *blue_shoot; |
403 | FT_Bool over_ref = FT_BOOL( shoot > ref ); |
404 | |
405 | |
406 | if ( AF_LATIN_IS_TOP_BLUE( bb ) ^ over_ref ) |
407 | { |
408 | *blue_ref = |
409 | *blue_shoot = ( shoot + ref ) / 2; |
410 | |
411 | FT_TRACE5(( " [overshoot smaller than reference," |
412 | " taking mean value]\n" )); |
413 | } |
414 | } |
415 | |
416 | blue->flags = 0; |
417 | if ( AF_LATIN_IS_TOP_BLUE( bb ) ) |
418 | blue->flags |= AF_LATIN_BLUE_TOP; |
419 | |
420 | /* |
421 | * The following flag is used later to adjust the y and x scales |
422 | * in order to optimize the pixel grid alignment of the top of small |
423 | * letters. |
424 | */ |
425 | if ( AF_LATIN_IS_X_HEIGHT_BLUE( bb ) ) |
426 | blue->flags |= AF_LATIN_BLUE_ADJUSTMENT; |
427 | |
428 | FT_TRACE5(( " -> reference = %ld\n" |
429 | " overshoot = %ld\n" , |
430 | *blue_ref, *blue_shoot )); |
431 | } |
432 | |
433 | return; |
434 | } |
435 | |
436 | |
437 | FT_LOCAL_DEF( void ) |
438 | af_latin2_metrics_check_digits( AF_LatinMetrics metrics, |
439 | FT_Face face ) |
440 | { |
441 | FT_UInt i; |
442 | FT_Bool started = 0, same_width = 1; |
443 | FT_Fixed advance, old_advance = 0; |
444 | |
445 | |
446 | /* check whether all ASCII digits have the same advance width; */ |
447 | /* digit `0' is 0x30 in all supported charmaps */ |
448 | for ( i = 0x30; i <= 0x39; i++ ) |
449 | { |
450 | FT_UInt glyph_index; |
451 | |
452 | |
453 | glyph_index = FT_Get_Char_Index( face, i ); |
454 | if ( glyph_index == 0 ) |
455 | continue; |
456 | |
457 | if ( FT_Get_Advance( face, glyph_index, |
458 | FT_LOAD_NO_SCALE | |
459 | FT_LOAD_NO_HINTING | |
460 | FT_LOAD_IGNORE_TRANSFORM, |
461 | &advance ) ) |
462 | continue; |
463 | |
464 | if ( started ) |
465 | { |
466 | if ( advance != old_advance ) |
467 | { |
468 | same_width = 0; |
469 | break; |
470 | } |
471 | } |
472 | else |
473 | { |
474 | old_advance = advance; |
475 | started = 1; |
476 | } |
477 | } |
478 | |
479 | metrics->root.digits_have_same_width = same_width; |
480 | } |
481 | |
482 | |
483 | FT_LOCAL_DEF( FT_Error ) |
484 | af_latin2_metrics_init( AF_LatinMetrics metrics, |
485 | FT_Face face ) |
486 | { |
487 | FT_Error error = FT_Err_Ok; |
488 | FT_CharMap oldmap = face->charmap; |
489 | FT_UInt ee; |
490 | |
491 | static const FT_Encoding latin_encodings[] = |
492 | { |
493 | FT_ENCODING_UNICODE, |
494 | FT_ENCODING_APPLE_ROMAN, |
495 | FT_ENCODING_ADOBE_STANDARD, |
496 | FT_ENCODING_ADOBE_LATIN_1, |
497 | FT_ENCODING_NONE /* end of list */ |
498 | }; |
499 | |
500 | |
501 | metrics->units_per_em = face->units_per_EM; |
502 | |
503 | /* do we have a latin charmap in there? */ |
504 | for ( ee = 0; latin_encodings[ee] != FT_ENCODING_NONE; ee++ ) |
505 | { |
506 | error = FT_Select_Charmap( face, latin_encodings[ee] ); |
507 | if ( !error ) |
508 | break; |
509 | } |
510 | |
511 | if ( !error ) |
512 | { |
513 | af_latin2_metrics_init_widths( metrics, face ); |
514 | af_latin2_metrics_init_blues( metrics, face ); |
515 | af_latin2_metrics_check_digits( metrics, face ); |
516 | } |
517 | |
518 | FT_Set_Charmap( face, oldmap ); |
519 | return FT_Err_Ok; |
520 | } |
521 | |
522 | |
523 | static void |
524 | af_latin2_metrics_scale_dim( AF_LatinMetrics metrics, |
525 | AF_Scaler scaler, |
526 | AF_Dimension dim ) |
527 | { |
528 | FT_Fixed scale; |
529 | FT_Pos delta; |
530 | AF_LatinAxis axis; |
531 | FT_UInt nn; |
532 | |
533 | |
534 | if ( dim == AF_DIMENSION_HORZ ) |
535 | { |
536 | scale = scaler->x_scale; |
537 | delta = scaler->x_delta; |
538 | } |
539 | else |
540 | { |
541 | scale = scaler->y_scale; |
542 | delta = scaler->y_delta; |
543 | } |
544 | |
545 | axis = &metrics->axis[dim]; |
546 | |
547 | if ( axis->org_scale == scale && axis->org_delta == delta ) |
548 | return; |
549 | |
550 | axis->org_scale = scale; |
551 | axis->org_delta = delta; |
552 | |
553 | /* |
554 | * correct Y scale to optimize the alignment of the top of small |
555 | * letters to the pixel grid |
556 | */ |
557 | if ( dim == AF_DIMENSION_VERT ) |
558 | { |
559 | AF_LatinAxis vaxis = &metrics->axis[AF_DIMENSION_VERT]; |
560 | AF_LatinBlue blue = NULL; |
561 | |
562 | |
563 | for ( nn = 0; nn < vaxis->blue_count; nn++ ) |
564 | { |
565 | if ( vaxis->blues[nn].flags & AF_LATIN_BLUE_ADJUSTMENT ) |
566 | { |
567 | blue = &vaxis->blues[nn]; |
568 | break; |
569 | } |
570 | } |
571 | |
572 | if ( blue ) |
573 | { |
574 | FT_Pos scaled; |
575 | FT_Pos threshold; |
576 | FT_Pos fitted; |
577 | FT_UInt limit; |
578 | FT_UInt ppem; |
579 | |
580 | |
581 | scaled = FT_MulFix( blue->shoot.org, scaler->y_scale ); |
582 | ppem = metrics->root.scaler.face->size->metrics.x_ppem; |
583 | limit = metrics->root.globals->increase_x_height; |
584 | threshold = 40; |
585 | |
586 | /* if the `increase-x-height' property is active, */ |
587 | /* we round up much more often */ |
588 | if ( limit && |
589 | ppem <= limit && |
590 | ppem >= AF_PROP_INCREASE_X_HEIGHT_MIN ) |
591 | threshold = 52; |
592 | |
593 | fitted = ( scaled + threshold ) & ~63; |
594 | |
595 | #if 1 |
596 | if ( scaled != fitted ) |
597 | { |
598 | scale = FT_MulDiv( scale, fitted, scaled ); |
599 | FT_TRACE5(( "== scaled x-top = %.2g" |
600 | " fitted = %.2g, scaling = %.4g\n" , |
601 | scaled / 64.0, fitted / 64.0, |
602 | ( fitted * 1.0 ) / scaled )); |
603 | } |
604 | #endif |
605 | } |
606 | } |
607 | |
608 | axis->scale = scale; |
609 | axis->delta = delta; |
610 | |
611 | if ( dim == AF_DIMENSION_HORZ ) |
612 | { |
613 | metrics->root.scaler.x_scale = scale; |
614 | metrics->root.scaler.x_delta = delta; |
615 | } |
616 | else |
617 | { |
618 | metrics->root.scaler.y_scale = scale; |
619 | metrics->root.scaler.y_delta = delta; |
620 | } |
621 | |
622 | /* scale the standard widths */ |
623 | for ( nn = 0; nn < axis->width_count; nn++ ) |
624 | { |
625 | AF_Width width = axis->widths + nn; |
626 | |
627 | |
628 | width->cur = FT_MulFix( width->org, scale ); |
629 | width->fit = width->cur; |
630 | } |
631 | |
632 | /* an extra-light axis corresponds to a standard width that is */ |
633 | /* smaller than 5/8 pixels */ |
634 | axis->extra_light = |
635 | (FT_Bool)( FT_MulFix( axis->standard_width, scale ) < 32 + 8 ); |
636 | |
637 | if ( dim == AF_DIMENSION_VERT ) |
638 | { |
639 | /* scale the blue zones */ |
640 | for ( nn = 0; nn < axis->blue_count; nn++ ) |
641 | { |
642 | AF_LatinBlue blue = &axis->blues[nn]; |
643 | FT_Pos dist; |
644 | |
645 | |
646 | blue->ref.cur = FT_MulFix( blue->ref.org, scale ) + delta; |
647 | blue->ref.fit = blue->ref.cur; |
648 | blue->shoot.cur = FT_MulFix( blue->shoot.org, scale ) + delta; |
649 | blue->shoot.fit = blue->shoot.cur; |
650 | blue->flags &= ~AF_LATIN_BLUE_ACTIVE; |
651 | |
652 | /* a blue zone is only active if it is less than 3/4 pixels tall */ |
653 | dist = FT_MulFix( blue->ref.org - blue->shoot.org, scale ); |
654 | if ( dist <= 48 && dist >= -48 ) |
655 | { |
656 | FT_Pos delta1, delta2; |
657 | |
658 | delta1 = blue->shoot.org - blue->ref.org; |
659 | delta2 = delta1; |
660 | if ( delta1 < 0 ) |
661 | delta2 = -delta2; |
662 | |
663 | delta2 = FT_MulFix( delta2, scale ); |
664 | |
665 | if ( delta2 < 32 ) |
666 | delta2 = 0; |
667 | else if ( delta2 < 64 ) |
668 | delta2 = 32 + ( ( ( delta2 - 32 ) + 16 ) & ~31 ); |
669 | else |
670 | delta2 = FT_PIX_ROUND( delta2 ); |
671 | |
672 | if ( delta1 < 0 ) |
673 | delta2 = -delta2; |
674 | |
675 | blue->ref.fit = FT_PIX_ROUND( blue->ref.cur ); |
676 | blue->shoot.fit = blue->ref.fit + delta2; |
677 | |
678 | FT_TRACE5(( ">> activating blue zone %d:" |
679 | " ref.cur=%.2g ref.fit=%.2g" |
680 | " shoot.cur=%.2g shoot.fit=%.2g\n" , |
681 | nn, blue->ref.cur / 64.0, blue->ref.fit / 64.0, |
682 | blue->shoot.cur / 64.0, blue->shoot.fit / 64.0 )); |
683 | |
684 | blue->flags |= AF_LATIN_BLUE_ACTIVE; |
685 | } |
686 | } |
687 | } |
688 | } |
689 | |
690 | |
691 | FT_LOCAL_DEF( void ) |
692 | af_latin2_metrics_scale( AF_LatinMetrics metrics, |
693 | AF_Scaler scaler ) |
694 | { |
695 | metrics->root.scaler.render_mode = scaler->render_mode; |
696 | metrics->root.scaler.face = scaler->face; |
697 | metrics->root.scaler.flags = scaler->flags; |
698 | |
699 | af_latin2_metrics_scale_dim( metrics, scaler, AF_DIMENSION_HORZ ); |
700 | af_latin2_metrics_scale_dim( metrics, scaler, AF_DIMENSION_VERT ); |
701 | } |
702 | |
703 | |
704 | /* Extract standard_width from writing system/script specific */ |
705 | /* metrics class. */ |
706 | |
707 | FT_LOCAL_DEF( void ) |
708 | af_latin2_get_standard_widths( AF_LatinMetrics metrics, |
709 | FT_Pos* stdHW, |
710 | FT_Pos* stdVW ) |
711 | { |
712 | if ( stdHW ) |
713 | *stdHW = metrics->axis[AF_DIMENSION_VERT].standard_width; |
714 | |
715 | if ( stdVW ) |
716 | *stdVW = metrics->axis[AF_DIMENSION_HORZ].standard_width; |
717 | } |
718 | |
719 | |
720 | /*************************************************************************/ |
721 | /*************************************************************************/ |
722 | /***** *****/ |
723 | /***** L A T I N G L Y P H A N A L Y S I S *****/ |
724 | /***** *****/ |
725 | /*************************************************************************/ |
726 | /*************************************************************************/ |
727 | |
728 | #define SORT_SEGMENTS |
729 | |
730 | FT_LOCAL_DEF( FT_Error ) |
731 | af_latin2_hints_compute_segments( AF_GlyphHints hints, |
732 | AF_Dimension dim ) |
733 | { |
734 | AF_AxisHints axis = &hints->axis[dim]; |
735 | FT_Memory memory = hints->memory; |
736 | FT_Error error = FT_Err_Ok; |
737 | AF_Segment segment = NULL; |
738 | AF_SegmentRec seg0; |
739 | AF_Point* contour = hints->contours; |
740 | AF_Point* contour_limit = contour + hints->num_contours; |
741 | AF_Direction major_dir, segment_dir; |
742 | |
743 | |
744 | FT_ZERO( &seg0 ); |
745 | seg0.score = 32000; |
746 | seg0.flags = AF_EDGE_NORMAL; |
747 | |
748 | major_dir = (AF_Direction)FT_ABS( axis->major_dir ); |
749 | segment_dir = major_dir; |
750 | |
751 | axis->num_segments = 0; |
752 | |
753 | /* set up (u,v) in each point */ |
754 | if ( dim == AF_DIMENSION_HORZ ) |
755 | { |
756 | AF_Point point = hints->points; |
757 | AF_Point limit = point + hints->num_points; |
758 | |
759 | |
760 | for ( ; point < limit; point++ ) |
761 | { |
762 | point->u = point->fx; |
763 | point->v = point->fy; |
764 | } |
765 | } |
766 | else |
767 | { |
768 | AF_Point point = hints->points; |
769 | AF_Point limit = point + hints->num_points; |
770 | |
771 | |
772 | for ( ; point < limit; point++ ) |
773 | { |
774 | point->u = point->fy; |
775 | point->v = point->fx; |
776 | } |
777 | } |
778 | |
779 | /* do each contour separately */ |
780 | for ( ; contour < contour_limit; contour++ ) |
781 | { |
782 | AF_Point point = contour[0]; |
783 | AF_Point start = point; |
784 | AF_Point last = point->prev; |
785 | |
786 | |
787 | if ( point == last ) /* skip singletons -- just in case */ |
788 | continue; |
789 | |
790 | /* already on an edge ?, backtrack to find its start */ |
791 | if ( FT_ABS( point->in_dir ) == major_dir ) |
792 | { |
793 | point = point->prev; |
794 | |
795 | while ( point->in_dir == start->in_dir ) |
796 | point = point->prev; |
797 | } |
798 | else /* otherwise, find first segment start, if any */ |
799 | { |
800 | while ( FT_ABS( point->out_dir ) != major_dir ) |
801 | { |
802 | point = point->next; |
803 | |
804 | if ( point == start ) |
805 | goto NextContour; |
806 | } |
807 | } |
808 | |
809 | start = point; |
810 | |
811 | for (;;) |
812 | { |
813 | AF_Point first; |
814 | FT_Pos min_u, min_v, max_u, max_v; |
815 | |
816 | /* we're at the start of a new segment */ |
817 | FT_ASSERT( FT_ABS( point->out_dir ) == major_dir && |
818 | point->in_dir != point->out_dir ); |
819 | first = point; |
820 | |
821 | min_u = max_u = point->u; |
822 | min_v = max_v = point->v; |
823 | |
824 | point = point->next; |
825 | |
826 | while ( point->out_dir == first->out_dir ) |
827 | { |
828 | point = point->next; |
829 | |
830 | if ( point->u < min_u ) |
831 | min_u = point->u; |
832 | |
833 | if ( point->u > max_u ) |
834 | max_u = point->u; |
835 | } |
836 | |
837 | if ( point->v < min_v ) |
838 | min_v = point->v; |
839 | |
840 | if ( point->v > max_v ) |
841 | max_v = point->v; |
842 | |
843 | /* record new segment */ |
844 | error = af_axis_hints_new_segment( axis, memory, &segment ); |
845 | if ( error ) |
846 | goto Exit; |
847 | |
848 | segment[0] = seg0; |
849 | segment->dir = first->out_dir; |
850 | segment->first = first; |
851 | segment->last = point; |
852 | segment->pos = (FT_Short)( ( min_u + max_u ) >> 1 ); |
853 | segment->min_coord = (FT_Short) min_v; |
854 | segment->max_coord = (FT_Short) max_v; |
855 | segment->height = (FT_Short)( max_v - min_v ); |
856 | |
857 | /* a segment is round if it doesn't have successive */ |
858 | /* on-curve points. */ |
859 | { |
860 | AF_Point pt = first; |
861 | AF_Point last = point; |
862 | FT_UInt f0 = pt->flags & AF_FLAG_CONTROL; |
863 | FT_UInt f1; |
864 | |
865 | |
866 | segment->flags &= ~AF_EDGE_ROUND; |
867 | |
868 | for ( ; pt != last; f0 = f1 ) |
869 | { |
870 | pt = pt->next; |
871 | f1 = pt->flags & AF_FLAG_CONTROL; |
872 | |
873 | if ( !f0 && !f1 ) |
874 | break; |
875 | |
876 | if ( pt == last ) |
877 | segment->flags |= AF_EDGE_ROUND; |
878 | } |
879 | } |
880 | |
881 | /* this can happen in the case of a degenerate contour |
882 | * e.g. a 2-point vertical contour |
883 | */ |
884 | if ( point == start ) |
885 | break; |
886 | |
887 | /* jump to the start of the next segment, if any */ |
888 | while ( FT_ABS( point->out_dir ) != major_dir ) |
889 | { |
890 | point = point->next; |
891 | |
892 | if ( point == start ) |
893 | goto NextContour; |
894 | } |
895 | } |
896 | |
897 | NextContour: |
898 | ; |
899 | } /* contours */ |
900 | |
901 | /* now slightly increase the height of segments when this makes */ |
902 | /* sense -- this is used to better detect and ignore serifs */ |
903 | { |
904 | AF_Segment segments = axis->segments; |
905 | AF_Segment segments_end = segments + axis->num_segments; |
906 | |
907 | |
908 | for ( segment = segments; segment < segments_end; segment++ ) |
909 | { |
910 | AF_Point first = segment->first; |
911 | AF_Point last = segment->last; |
912 | AF_Point p; |
913 | FT_Pos first_v = first->v; |
914 | FT_Pos last_v = last->v; |
915 | |
916 | |
917 | if ( first_v < last_v ) |
918 | { |
919 | p = first->prev; |
920 | if ( p->v < first_v ) |
921 | segment->height = (FT_Short)( segment->height + |
922 | ( ( first_v - p->v ) >> 1 ) ); |
923 | |
924 | p = last->next; |
925 | if ( p->v > last_v ) |
926 | segment->height = (FT_Short)( segment->height + |
927 | ( ( p->v - last_v ) >> 1 ) ); |
928 | } |
929 | else |
930 | { |
931 | p = first->prev; |
932 | if ( p->v > first_v ) |
933 | segment->height = (FT_Short)( segment->height + |
934 | ( ( p->v - first_v ) >> 1 ) ); |
935 | |
936 | p = last->next; |
937 | if ( p->v < last_v ) |
938 | segment->height = (FT_Short)( segment->height + |
939 | ( ( last_v - p->v ) >> 1 ) ); |
940 | } |
941 | } |
942 | } |
943 | |
944 | #ifdef AF_SORT_SEGMENTS |
945 | /* place all segments with a negative direction to the start |
946 | * of the array, used to speed up segment linking later... |
947 | */ |
948 | { |
949 | AF_Segment segments = axis->segments; |
950 | FT_UInt count = axis->num_segments; |
951 | FT_UInt ii, jj; |
952 | |
953 | for ( ii = 0; ii < count; ii++ ) |
954 | { |
955 | if ( segments[ii].dir > 0 ) |
956 | { |
957 | for ( jj = ii + 1; jj < count; jj++ ) |
958 | { |
959 | if ( segments[jj].dir < 0 ) |
960 | { |
961 | AF_SegmentRec tmp; |
962 | |
963 | |
964 | tmp = segments[ii]; |
965 | segments[ii] = segments[jj]; |
966 | segments[jj] = tmp; |
967 | |
968 | break; |
969 | } |
970 | } |
971 | |
972 | if ( jj == count ) |
973 | break; |
974 | } |
975 | } |
976 | axis->mid_segments = ii; |
977 | } |
978 | #endif |
979 | |
980 | Exit: |
981 | return error; |
982 | } |
983 | |
984 | |
985 | FT_LOCAL_DEF( void ) |
986 | af_latin2_hints_link_segments( AF_GlyphHints hints, |
987 | AF_Dimension dim ) |
988 | { |
989 | AF_AxisHints axis = &hints->axis[dim]; |
990 | AF_Segment segments = axis->segments; |
991 | AF_Segment segment_limit = segments + axis->num_segments; |
992 | #ifdef AF_SORT_SEGMENTS |
993 | AF_Segment segment_mid = segments + axis->mid_segments; |
994 | #endif |
995 | FT_Pos len_threshold, len_score; |
996 | AF_Segment seg1, seg2; |
997 | |
998 | |
999 | len_threshold = AF_LATIN_CONSTANT( hints->metrics, 8 ); |
1000 | if ( len_threshold == 0 ) |
1001 | len_threshold = 1; |
1002 | |
1003 | len_score = AF_LATIN_CONSTANT( hints->metrics, 6000 ); |
1004 | |
1005 | #ifdef AF_SORT_SEGMENTS |
1006 | for ( seg1 = segments; seg1 < segment_mid; seg1++ ) |
1007 | { |
1008 | if ( seg1->dir != axis->major_dir ) |
1009 | continue; |
1010 | |
1011 | for ( seg2 = segment_mid; seg2 < segment_limit; seg2++ ) |
1012 | #else |
1013 | /* now compare each segment to the others */ |
1014 | for ( seg1 = segments; seg1 < segment_limit; seg1++ ) |
1015 | { |
1016 | if ( seg1->dir != axis->major_dir ) |
1017 | continue; |
1018 | |
1019 | for ( seg2 = segments; seg2 < segment_limit; seg2++ ) |
1020 | if ( seg1->dir + seg2->dir == 0 && seg2->pos > seg1->pos ) |
1021 | #endif |
1022 | { |
1023 | FT_Pos pos1 = seg1->pos; |
1024 | FT_Pos pos2 = seg2->pos; |
1025 | FT_Pos dist = pos2 - pos1; |
1026 | |
1027 | |
1028 | if ( dist < 0 ) |
1029 | continue; |
1030 | |
1031 | { |
1032 | FT_Pos min = seg1->min_coord; |
1033 | FT_Pos max = seg1->max_coord; |
1034 | FT_Pos len, score; |
1035 | |
1036 | |
1037 | if ( min < seg2->min_coord ) |
1038 | min = seg2->min_coord; |
1039 | |
1040 | if ( max > seg2->max_coord ) |
1041 | max = seg2->max_coord; |
1042 | |
1043 | len = max - min; |
1044 | if ( len >= len_threshold ) |
1045 | { |
1046 | score = dist + len_score / len; |
1047 | if ( score < seg1->score ) |
1048 | { |
1049 | seg1->score = score; |
1050 | seg1->link = seg2; |
1051 | } |
1052 | |
1053 | if ( score < seg2->score ) |
1054 | { |
1055 | seg2->score = score; |
1056 | seg2->link = seg1; |
1057 | } |
1058 | } |
1059 | } |
1060 | } |
1061 | } |
1062 | #if 0 |
1063 | } |
1064 | #endif |
1065 | |
1066 | /* now, compute the `serif' segments */ |
1067 | for ( seg1 = segments; seg1 < segment_limit; seg1++ ) |
1068 | { |
1069 | seg2 = seg1->link; |
1070 | |
1071 | if ( seg2 ) |
1072 | { |
1073 | if ( seg2->link != seg1 ) |
1074 | { |
1075 | seg1->link = NULL; |
1076 | seg1->serif = seg2->link; |
1077 | } |
1078 | } |
1079 | } |
1080 | } |
1081 | |
1082 | |
1083 | FT_LOCAL_DEF( FT_Error ) |
1084 | af_latin2_hints_compute_edges( AF_GlyphHints hints, |
1085 | AF_Dimension dim ) |
1086 | { |
1087 | AF_AxisHints axis = &hints->axis[dim]; |
1088 | FT_Error error = FT_Err_Ok; |
1089 | FT_Memory memory = hints->memory; |
1090 | AF_LatinAxis laxis = &((AF_LatinMetrics)hints->metrics)->axis[dim]; |
1091 | |
1092 | AF_Segment segments = axis->segments; |
1093 | AF_Segment segment_limit = segments + axis->num_segments; |
1094 | AF_Segment seg; |
1095 | |
1096 | AF_Direction up_dir; |
1097 | FT_Fixed scale; |
1098 | FT_Pos edge_distance_threshold; |
1099 | FT_Pos segment_length_threshold; |
1100 | |
1101 | |
1102 | axis->num_edges = 0; |
1103 | |
1104 | scale = ( dim == AF_DIMENSION_HORZ ) ? hints->x_scale |
1105 | : hints->y_scale; |
1106 | |
1107 | up_dir = ( dim == AF_DIMENSION_HORZ ) ? AF_DIR_UP |
1108 | : AF_DIR_RIGHT; |
1109 | |
1110 | /* |
1111 | * We want to ignore very small (mostly serif) segments, we do that |
1112 | * by ignoring those that whose length is less than a given fraction |
1113 | * of the standard width. If there is no standard width, we ignore |
1114 | * those that are less than a given size in pixels |
1115 | * |
1116 | * also, unlink serif segments that are linked to segments farther |
1117 | * than 50% of the standard width |
1118 | */ |
1119 | if ( dim == AF_DIMENSION_HORZ ) |
1120 | { |
1121 | if ( laxis->width_count > 0 ) |
1122 | segment_length_threshold = ( laxis->standard_width * 10 ) >> 4; |
1123 | else |
1124 | segment_length_threshold = FT_DivFix( 64, hints->y_scale ); |
1125 | } |
1126 | else |
1127 | segment_length_threshold = 0; |
1128 | |
1129 | /*********************************************************************/ |
1130 | /* */ |
1131 | /* We will begin by generating a sorted table of edges for the */ |
1132 | /* current direction. To do so, we simply scan each segment and try */ |
1133 | /* to find an edge in our table that corresponds to its position. */ |
1134 | /* */ |
1135 | /* If no edge is found, we create and insert a new edge in the */ |
1136 | /* sorted table. Otherwise, we simply add the segment to the edge's */ |
1137 | /* list which will be processed in the second step to compute the */ |
1138 | /* edge's properties. */ |
1139 | /* */ |
1140 | /* Note that the edges table is sorted along the segment/edge */ |
1141 | /* position. */ |
1142 | /* */ |
1143 | /*********************************************************************/ |
1144 | |
1145 | edge_distance_threshold = FT_MulFix( laxis->edge_distance_threshold, |
1146 | scale ); |
1147 | if ( edge_distance_threshold > 64 / 4 ) |
1148 | edge_distance_threshold = 64 / 4; |
1149 | |
1150 | edge_distance_threshold = FT_DivFix( edge_distance_threshold, |
1151 | scale ); |
1152 | |
1153 | for ( seg = segments; seg < segment_limit; seg++ ) |
1154 | { |
1155 | AF_Edge found = NULL; |
1156 | FT_Int ee; |
1157 | |
1158 | |
1159 | if ( seg->height < segment_length_threshold ) |
1160 | continue; |
1161 | |
1162 | /* A special case for serif edges: If they are smaller than */ |
1163 | /* 1.5 pixels we ignore them. */ |
1164 | if ( seg->serif ) |
1165 | { |
1166 | FT_Pos dist = seg->serif->pos - seg->pos; |
1167 | |
1168 | |
1169 | if ( dist < 0 ) |
1170 | dist = -dist; |
1171 | |
1172 | if ( dist >= laxis->standard_width >> 1 ) |
1173 | { |
1174 | /* unlink this serif, it is too distant from its reference stem */ |
1175 | seg->serif = NULL; |
1176 | } |
1177 | else if ( 2*seg->height < 3 * segment_length_threshold ) |
1178 | continue; |
1179 | } |
1180 | |
1181 | /* look for an edge corresponding to the segment */ |
1182 | for ( ee = 0; ee < axis->num_edges; ee++ ) |
1183 | { |
1184 | AF_Edge edge = axis->edges + ee; |
1185 | FT_Pos dist; |
1186 | |
1187 | |
1188 | dist = seg->pos - edge->fpos; |
1189 | if ( dist < 0 ) |
1190 | dist = -dist; |
1191 | |
1192 | if ( dist < edge_distance_threshold && edge->dir == seg->dir ) |
1193 | { |
1194 | found = edge; |
1195 | break; |
1196 | } |
1197 | } |
1198 | |
1199 | if ( !found ) |
1200 | { |
1201 | AF_Edge edge; |
1202 | |
1203 | |
1204 | /* insert a new edge in the list and */ |
1205 | /* sort according to the position */ |
1206 | error = af_axis_hints_new_edge( axis, seg->pos, seg->dir, 0, |
1207 | memory, &edge ); |
1208 | if ( error ) |
1209 | goto Exit; |
1210 | |
1211 | /* add the segment to the new edge's list */ |
1212 | FT_ZERO( edge ); |
1213 | |
1214 | edge->first = seg; |
1215 | edge->last = seg; |
1216 | edge->dir = seg->dir; |
1217 | edge->fpos = seg->pos; |
1218 | edge->opos = FT_MulFix( seg->pos, scale ); |
1219 | edge->pos = edge->opos; |
1220 | seg->edge_next = seg; |
1221 | } |
1222 | else |
1223 | { |
1224 | /* if an edge was found, simply add the segment to the edge's */ |
1225 | /* list */ |
1226 | seg->edge_next = found->first; |
1227 | found->last->edge_next = seg; |
1228 | found->last = seg; |
1229 | } |
1230 | } |
1231 | |
1232 | |
1233 | /*********************************************************************/ |
1234 | /* */ |
1235 | /* Good, we will now compute each edge's properties according to */ |
1236 | /* segments found on its position. Basically, these are: */ |
1237 | /* */ |
1238 | /* - edge's main direction */ |
1239 | /* - stem edge, serif edge or both (which defaults to stem then) */ |
1240 | /* - rounded edge, straight or both (which defaults to straight) */ |
1241 | /* - link for edge */ |
1242 | /* */ |
1243 | /*********************************************************************/ |
1244 | |
1245 | /* first of all, set the `edge' field in each segment -- this is */ |
1246 | /* required in order to compute edge links */ |
1247 | |
1248 | /* |
1249 | * Note that removing this loop and setting the `edge' field of each |
1250 | * segment directly in the code above slows down execution speed for |
1251 | * some reasons on platforms like the Sun. |
1252 | */ |
1253 | { |
1254 | AF_Edge edges = axis->edges; |
1255 | AF_Edge edge_limit = edges + axis->num_edges; |
1256 | AF_Edge edge; |
1257 | |
1258 | |
1259 | for ( edge = edges; edge < edge_limit; edge++ ) |
1260 | { |
1261 | seg = edge->first; |
1262 | if ( seg ) |
1263 | do |
1264 | { |
1265 | seg->edge = edge; |
1266 | seg = seg->edge_next; |
1267 | |
1268 | } while ( seg != edge->first ); |
1269 | } |
1270 | |
1271 | /* now, compute each edge properties */ |
1272 | for ( edge = edges; edge < edge_limit; edge++ ) |
1273 | { |
1274 | FT_Int is_round = 0; /* does it contain round segments? */ |
1275 | FT_Int is_straight = 0; /* does it contain straight segments? */ |
1276 | #if 0 |
1277 | FT_Pos ups = 0; /* number of upwards segments */ |
1278 | FT_Pos downs = 0; /* number of downwards segments */ |
1279 | #endif |
1280 | |
1281 | |
1282 | seg = edge->first; |
1283 | |
1284 | do |
1285 | { |
1286 | FT_Bool is_serif; |
1287 | |
1288 | |
1289 | /* check for roundness of segment */ |
1290 | if ( seg->flags & AF_EDGE_ROUND ) |
1291 | is_round++; |
1292 | else |
1293 | is_straight++; |
1294 | |
1295 | #if 0 |
1296 | /* check for segment direction */ |
1297 | if ( seg->dir == up_dir ) |
1298 | ups += seg->max_coord-seg->min_coord; |
1299 | else |
1300 | downs += seg->max_coord-seg->min_coord; |
1301 | #endif |
1302 | |
1303 | /* check for links -- if seg->serif is set, then seg->link must */ |
1304 | /* be ignored */ |
1305 | is_serif = (FT_Bool)( seg->serif && |
1306 | seg->serif->edge && |
1307 | seg->serif->edge != edge ); |
1308 | |
1309 | if ( ( seg->link && seg->link->edge ) || is_serif ) |
1310 | { |
1311 | AF_Edge edge2; |
1312 | AF_Segment seg2; |
1313 | |
1314 | |
1315 | edge2 = edge->link; |
1316 | seg2 = seg->link; |
1317 | |
1318 | if ( is_serif ) |
1319 | { |
1320 | seg2 = seg->serif; |
1321 | edge2 = edge->serif; |
1322 | } |
1323 | |
1324 | if ( edge2 ) |
1325 | { |
1326 | FT_Pos edge_delta; |
1327 | FT_Pos seg_delta; |
1328 | |
1329 | |
1330 | edge_delta = edge->fpos - edge2->fpos; |
1331 | if ( edge_delta < 0 ) |
1332 | edge_delta = -edge_delta; |
1333 | |
1334 | seg_delta = seg->pos - seg2->pos; |
1335 | if ( seg_delta < 0 ) |
1336 | seg_delta = -seg_delta; |
1337 | |
1338 | if ( seg_delta < edge_delta ) |
1339 | edge2 = seg2->edge; |
1340 | } |
1341 | else |
1342 | edge2 = seg2->edge; |
1343 | |
1344 | if ( is_serif ) |
1345 | { |
1346 | edge->serif = edge2; |
1347 | edge2->flags |= AF_EDGE_SERIF; |
1348 | } |
1349 | else |
1350 | edge->link = edge2; |
1351 | } |
1352 | |
1353 | seg = seg->edge_next; |
1354 | |
1355 | } while ( seg != edge->first ); |
1356 | |
1357 | /* set the round/straight flags */ |
1358 | edge->flags = AF_EDGE_NORMAL; |
1359 | |
1360 | if ( is_round > 0 && is_round >= is_straight ) |
1361 | edge->flags |= AF_EDGE_ROUND; |
1362 | |
1363 | #if 0 |
1364 | /* set the edge's main direction */ |
1365 | edge->dir = AF_DIR_NONE; |
1366 | |
1367 | if ( ups > downs ) |
1368 | edge->dir = (FT_Char)up_dir; |
1369 | |
1370 | else if ( ups < downs ) |
1371 | edge->dir = (FT_Char)-up_dir; |
1372 | |
1373 | else if ( ups == downs ) |
1374 | edge->dir = 0; /* both up and down! */ |
1375 | #endif |
1376 | |
1377 | /* gets rid of serifs if link is set */ |
1378 | /* XXX: This gets rid of many unpleasant artefacts! */ |
1379 | /* Example: the `c' in cour.pfa at size 13 */ |
1380 | |
1381 | if ( edge->serif && edge->link ) |
1382 | edge->serif = NULL; |
1383 | } |
1384 | } |
1385 | |
1386 | Exit: |
1387 | return error; |
1388 | } |
1389 | |
1390 | |
1391 | FT_LOCAL_DEF( FT_Error ) |
1392 | af_latin2_hints_detect_features( AF_GlyphHints hints, |
1393 | AF_Dimension dim ) |
1394 | { |
1395 | FT_Error error; |
1396 | |
1397 | |
1398 | error = af_latin2_hints_compute_segments( hints, dim ); |
1399 | if ( !error ) |
1400 | { |
1401 | af_latin2_hints_link_segments( hints, dim ); |
1402 | |
1403 | error = af_latin2_hints_compute_edges( hints, dim ); |
1404 | } |
1405 | return error; |
1406 | } |
1407 | |
1408 | |
1409 | static void |
1410 | af_latin2_hints_compute_blue_edges( AF_GlyphHints hints, |
1411 | AF_LatinMetrics metrics ) |
1412 | { |
1413 | AF_AxisHints axis = &hints->axis[AF_DIMENSION_VERT]; |
1414 | AF_Edge edge = axis->edges; |
1415 | AF_Edge edge_limit = edge + axis->num_edges; |
1416 | AF_LatinAxis latin = &metrics->axis[AF_DIMENSION_VERT]; |
1417 | FT_Fixed scale = latin->scale; |
1418 | FT_Pos best_dist0; /* initial threshold */ |
1419 | |
1420 | |
1421 | /* compute the initial threshold as a fraction of the EM size */ |
1422 | best_dist0 = FT_MulFix( metrics->units_per_em / 40, scale ); |
1423 | |
1424 | if ( best_dist0 > 64 / 2 ) |
1425 | best_dist0 = 64 / 2; |
1426 | |
1427 | /* compute which blue zones are active, i.e. have their scaled */ |
1428 | /* size < 3/4 pixels */ |
1429 | |
1430 | /* for each horizontal edge search the blue zone which is closest */ |
1431 | for ( ; edge < edge_limit; edge++ ) |
1432 | { |
1433 | FT_Int bb; |
1434 | AF_Width best_blue = NULL; |
1435 | FT_Pos best_dist = best_dist0; |
1436 | |
1437 | for ( bb = 0; bb < AF_LATIN_BLUE_MAX; bb++ ) |
1438 | { |
1439 | AF_LatinBlue blue = latin->blues + bb; |
1440 | FT_Bool is_top_blue, is_major_dir; |
1441 | |
1442 | |
1443 | /* skip inactive blue zones (i.e., those that are too small) */ |
1444 | if ( !( blue->flags & AF_LATIN_BLUE_ACTIVE ) ) |
1445 | continue; |
1446 | |
1447 | /* if it is a top zone, check for right edges -- if it is a bottom */ |
1448 | /* zone, check for left edges */ |
1449 | /* */ |
1450 | /* of course, that's for TrueType */ |
1451 | is_top_blue = (FT_Byte)( ( blue->flags & AF_LATIN_BLUE_TOP ) != 0 ); |
1452 | is_major_dir = FT_BOOL( edge->dir == axis->major_dir ); |
1453 | |
1454 | /* if it is a top zone, the edge must be against the major */ |
1455 | /* direction; if it is a bottom zone, it must be in the major */ |
1456 | /* direction */ |
1457 | if ( is_top_blue ^ is_major_dir ) |
1458 | { |
1459 | FT_Pos dist; |
1460 | AF_Width compare; |
1461 | |
1462 | |
1463 | /* if it's a rounded edge, compare it to the overshoot position */ |
1464 | /* if it's a flat edge, compare it to the reference position */ |
1465 | if ( edge->flags & AF_EDGE_ROUND ) |
1466 | compare = &blue->shoot; |
1467 | else |
1468 | compare = &blue->ref; |
1469 | |
1470 | dist = edge->fpos - compare->org; |
1471 | if ( dist < 0 ) |
1472 | dist = -dist; |
1473 | |
1474 | dist = FT_MulFix( dist, scale ); |
1475 | if ( dist < best_dist ) |
1476 | { |
1477 | best_dist = dist; |
1478 | best_blue = compare; |
1479 | } |
1480 | |
1481 | #if 0 |
1482 | /* now, compare it to the overshoot position if the edge is */ |
1483 | /* rounded, and if the edge is over the reference position of a */ |
1484 | /* top zone, or under the reference position of a bottom zone */ |
1485 | if ( edge->flags & AF_EDGE_ROUND && dist != 0 ) |
1486 | { |
1487 | FT_Bool is_under_ref = FT_BOOL( edge->fpos < blue->ref.org ); |
1488 | |
1489 | |
1490 | if ( is_top_blue ^ is_under_ref ) |
1491 | { |
1492 | blue = latin->blues + bb; |
1493 | dist = edge->fpos - blue->shoot.org; |
1494 | if ( dist < 0 ) |
1495 | dist = -dist; |
1496 | |
1497 | dist = FT_MulFix( dist, scale ); |
1498 | if ( dist < best_dist ) |
1499 | { |
1500 | best_dist = dist; |
1501 | best_blue = & blue->shoot; |
1502 | } |
1503 | } |
1504 | } |
1505 | #endif |
1506 | } |
1507 | } |
1508 | |
1509 | if ( best_blue ) |
1510 | edge->blue_edge = best_blue; |
1511 | } |
1512 | } |
1513 | |
1514 | |
1515 | static FT_Error |
1516 | af_latin2_hints_init( AF_GlyphHints hints, |
1517 | AF_LatinMetrics metrics ) |
1518 | { |
1519 | FT_Render_Mode mode; |
1520 | FT_UInt32 scaler_flags, other_flags; |
1521 | FT_Face face = metrics->root.scaler.face; |
1522 | |
1523 | |
1524 | af_glyph_hints_rescale( hints, (AF_StyleMetrics)metrics ); |
1525 | |
1526 | /* |
1527 | * correct x_scale and y_scale if needed, since they may have |
1528 | * been modified `af_latin2_metrics_scale_dim' above |
1529 | */ |
1530 | hints->x_scale = metrics->axis[AF_DIMENSION_HORZ].scale; |
1531 | hints->x_delta = metrics->axis[AF_DIMENSION_HORZ].delta; |
1532 | hints->y_scale = metrics->axis[AF_DIMENSION_VERT].scale; |
1533 | hints->y_delta = metrics->axis[AF_DIMENSION_VERT].delta; |
1534 | |
1535 | /* compute flags depending on render mode, etc. */ |
1536 | mode = metrics->root.scaler.render_mode; |
1537 | |
1538 | #if 0 /* #ifdef AF_CONFIG_OPTION_USE_WARPER */ |
1539 | if ( mode == FT_RENDER_MODE_LCD || mode == FT_RENDER_MODE_LCD_V ) |
1540 | metrics->root.scaler.render_mode = mode = FT_RENDER_MODE_NORMAL; |
1541 | #endif |
1542 | |
1543 | scaler_flags = hints->scaler_flags; |
1544 | other_flags = 0; |
1545 | |
1546 | /* |
1547 | * We snap the width of vertical stems for the monochrome and |
1548 | * horizontal LCD rendering targets only. |
1549 | */ |
1550 | if ( mode == FT_RENDER_MODE_MONO || mode == FT_RENDER_MODE_LCD ) |
1551 | other_flags |= AF_LATIN_HINTS_HORZ_SNAP; |
1552 | |
1553 | /* |
1554 | * We snap the width of horizontal stems for the monochrome and |
1555 | * vertical LCD rendering targets only. |
1556 | */ |
1557 | if ( mode == FT_RENDER_MODE_MONO || mode == FT_RENDER_MODE_LCD_V ) |
1558 | other_flags |= AF_LATIN_HINTS_VERT_SNAP; |
1559 | |
1560 | /* |
1561 | * We adjust stems to full pixels unless in `light' or `lcd' mode. |
1562 | */ |
1563 | if ( mode != FT_RENDER_MODE_LIGHT && mode != FT_RENDER_MODE_LCD ) |
1564 | other_flags |= AF_LATIN_HINTS_STEM_ADJUST; |
1565 | |
1566 | if ( mode == FT_RENDER_MODE_MONO ) |
1567 | other_flags |= AF_LATIN_HINTS_MONO; |
1568 | |
1569 | /* |
1570 | * In `light' or `lcd' mode we disable horizontal hinting completely. |
1571 | * We also do it if the face is italic. |
1572 | */ |
1573 | if ( mode == FT_RENDER_MODE_LIGHT || mode == FT_RENDER_MODE_LCD || |
1574 | ( face->style_flags & FT_STYLE_FLAG_ITALIC ) != 0 ) |
1575 | scaler_flags |= AF_SCALER_FLAG_NO_HORIZONTAL; |
1576 | |
1577 | #ifdef AF_CONFIG_OPTION_USE_WARPER |
1578 | /* get (global) warper flag */ |
1579 | if ( !metrics->root.globals->module->warping ) |
1580 | scaler_flags |= AF_SCALER_FLAG_NO_WARPER; |
1581 | #endif |
1582 | |
1583 | hints->scaler_flags = scaler_flags; |
1584 | hints->other_flags = other_flags; |
1585 | |
1586 | return 0; |
1587 | } |
1588 | |
1589 | |
1590 | /*************************************************************************/ |
1591 | /*************************************************************************/ |
1592 | /***** *****/ |
1593 | /***** L A T I N G L Y P H G R I D - F I T T I N G *****/ |
1594 | /***** *****/ |
1595 | /*************************************************************************/ |
1596 | /*************************************************************************/ |
1597 | |
1598 | /* snap a given width in scaled coordinates to one of the */ |
1599 | /* current standard widths */ |
1600 | |
1601 | static FT_Pos |
1602 | af_latin2_snap_width( AF_Width widths, |
1603 | FT_UInt count, |
1604 | FT_Pos width ) |
1605 | { |
1606 | FT_UInt n; |
1607 | FT_Pos best = 64 + 32 + 2; |
1608 | FT_Pos reference = width; |
1609 | FT_Pos scaled; |
1610 | |
1611 | |
1612 | for ( n = 0; n < count; n++ ) |
1613 | { |
1614 | FT_Pos w; |
1615 | FT_Pos dist; |
1616 | |
1617 | |
1618 | w = widths[n].cur; |
1619 | dist = width - w; |
1620 | if ( dist < 0 ) |
1621 | dist = -dist; |
1622 | if ( dist < best ) |
1623 | { |
1624 | best = dist; |
1625 | reference = w; |
1626 | } |
1627 | } |
1628 | |
1629 | scaled = FT_PIX_ROUND( reference ); |
1630 | |
1631 | if ( width >= reference ) |
1632 | { |
1633 | if ( width < scaled + 48 ) |
1634 | width = reference; |
1635 | } |
1636 | else |
1637 | { |
1638 | if ( width > scaled - 48 ) |
1639 | width = reference; |
1640 | } |
1641 | |
1642 | return width; |
1643 | } |
1644 | |
1645 | |
1646 | /* compute the snapped width of a given stem */ |
1647 | |
1648 | static FT_Pos |
1649 | af_latin2_compute_stem_width( AF_GlyphHints hints, |
1650 | AF_Dimension dim, |
1651 | FT_Pos width, |
1652 | FT_UInt base_flags, |
1653 | FT_UInt stem_flags ) |
1654 | { |
1655 | AF_LatinMetrics metrics = (AF_LatinMetrics) hints->metrics; |
1656 | AF_LatinAxis axis = & metrics->axis[dim]; |
1657 | FT_Pos dist = width; |
1658 | FT_Int sign = 0; |
1659 | FT_Int vertical = ( dim == AF_DIMENSION_VERT ); |
1660 | |
1661 | FT_UNUSED( base_flags ); |
1662 | |
1663 | |
1664 | if ( !AF_LATIN_HINTS_DO_STEM_ADJUST( hints ) || |
1665 | axis->extra_light ) |
1666 | return width; |
1667 | |
1668 | if ( dist < 0 ) |
1669 | { |
1670 | dist = -width; |
1671 | sign = 1; |
1672 | } |
1673 | |
1674 | if ( ( vertical && !AF_LATIN_HINTS_DO_VERT_SNAP( hints ) ) || |
1675 | ( !vertical && !AF_LATIN_HINTS_DO_HORZ_SNAP( hints ) ) ) |
1676 | { |
1677 | /* smooth hinting process: very lightly quantize the stem width */ |
1678 | |
1679 | /* leave the widths of serifs alone */ |
1680 | |
1681 | if ( ( stem_flags & AF_EDGE_SERIF ) && vertical && ( dist < 3 * 64 ) ) |
1682 | goto Done_Width; |
1683 | |
1684 | #if 0 |
1685 | else if ( ( base_flags & AF_EDGE_ROUND ) ) |
1686 | { |
1687 | if ( dist < 80 ) |
1688 | dist = 64; |
1689 | } |
1690 | else if ( dist < 56 ) |
1691 | dist = 56; |
1692 | #endif |
1693 | if ( axis->width_count > 0 ) |
1694 | { |
1695 | FT_Pos delta; |
1696 | |
1697 | |
1698 | /* compare to standard width */ |
1699 | if ( axis->width_count > 0 ) |
1700 | { |
1701 | delta = dist - axis->widths[0].cur; |
1702 | |
1703 | if ( delta < 0 ) |
1704 | delta = -delta; |
1705 | |
1706 | if ( delta < 40 ) |
1707 | { |
1708 | dist = axis->widths[0].cur; |
1709 | if ( dist < 48 ) |
1710 | dist = 48; |
1711 | |
1712 | goto Done_Width; |
1713 | } |
1714 | } |
1715 | |
1716 | if ( dist < 3 * 64 ) |
1717 | { |
1718 | delta = dist & 63; |
1719 | dist &= -64; |
1720 | |
1721 | if ( delta < 10 ) |
1722 | dist += delta; |
1723 | |
1724 | else if ( delta < 32 ) |
1725 | dist += 10; |
1726 | |
1727 | else if ( delta < 54 ) |
1728 | dist += 54; |
1729 | |
1730 | else |
1731 | dist += delta; |
1732 | } |
1733 | else |
1734 | dist = ( dist + 32 ) & ~63; |
1735 | } |
1736 | } |
1737 | else |
1738 | { |
1739 | /* strong hinting process: snap the stem width to integer pixels */ |
1740 | FT_Pos org_dist = dist; |
1741 | |
1742 | |
1743 | dist = af_latin2_snap_width( axis->widths, axis->width_count, dist ); |
1744 | |
1745 | if ( vertical ) |
1746 | { |
1747 | /* in the case of vertical hinting, always round */ |
1748 | /* the stem heights to integer pixels */ |
1749 | |
1750 | if ( dist >= 64 ) |
1751 | dist = ( dist + 16 ) & ~63; |
1752 | else |
1753 | dist = 64; |
1754 | } |
1755 | else |
1756 | { |
1757 | if ( AF_LATIN_HINTS_DO_MONO( hints ) ) |
1758 | { |
1759 | /* monochrome horizontal hinting: snap widths to integer pixels */ |
1760 | /* with a different threshold */ |
1761 | |
1762 | if ( dist < 64 ) |
1763 | dist = 64; |
1764 | else |
1765 | dist = ( dist + 32 ) & ~63; |
1766 | } |
1767 | else |
1768 | { |
1769 | /* for horizontal anti-aliased hinting, we adopt a more subtle */ |
1770 | /* approach: we strengthen small stems, round stems whose size */ |
1771 | /* is between 1 and 2 pixels to an integer, otherwise nothing */ |
1772 | |
1773 | if ( dist < 48 ) |
1774 | dist = ( dist + 64 ) >> 1; |
1775 | |
1776 | else if ( dist < 128 ) |
1777 | { |
1778 | /* We only round to an integer width if the corresponding */ |
1779 | /* distortion is less than 1/4 pixel. Otherwise this */ |
1780 | /* makes everything worse since the diagonals, which are */ |
1781 | /* not hinted, appear a lot bolder or thinner than the */ |
1782 | /* vertical stems. */ |
1783 | |
1784 | FT_Int delta; |
1785 | |
1786 | |
1787 | dist = ( dist + 22 ) & ~63; |
1788 | delta = dist - org_dist; |
1789 | if ( delta < 0 ) |
1790 | delta = -delta; |
1791 | |
1792 | if ( delta >= 16 ) |
1793 | { |
1794 | dist = org_dist; |
1795 | if ( dist < 48 ) |
1796 | dist = ( dist + 64 ) >> 1; |
1797 | } |
1798 | } |
1799 | else |
1800 | /* round otherwise to prevent color fringes in LCD mode */ |
1801 | dist = ( dist + 32 ) & ~63; |
1802 | } |
1803 | } |
1804 | } |
1805 | |
1806 | Done_Width: |
1807 | if ( sign ) |
1808 | dist = -dist; |
1809 | |
1810 | return dist; |
1811 | } |
1812 | |
1813 | |
1814 | /* align one stem edge relative to the previous stem edge */ |
1815 | |
1816 | static void |
1817 | af_latin2_align_linked_edge( AF_GlyphHints hints, |
1818 | AF_Dimension dim, |
1819 | AF_Edge base_edge, |
1820 | AF_Edge stem_edge ) |
1821 | { |
1822 | FT_Pos dist = stem_edge->opos - base_edge->opos; |
1823 | |
1824 | FT_Pos fitted_width = af_latin2_compute_stem_width( hints, dim, dist, |
1825 | base_edge->flags, |
1826 | stem_edge->flags ); |
1827 | |
1828 | |
1829 | stem_edge->pos = base_edge->pos + fitted_width; |
1830 | |
1831 | FT_TRACE5(( "LINK: edge %d (opos=%.2f) linked to (%.2f), " |
1832 | "dist was %.2f, now %.2f\n" , |
1833 | stem_edge-hints->axis[dim].edges, stem_edge->opos / 64.0, |
1834 | stem_edge->pos / 64.0, dist / 64.0, fitted_width / 64.0 )); |
1835 | } |
1836 | |
1837 | |
1838 | static void |
1839 | af_latin2_align_serif_edge( AF_GlyphHints hints, |
1840 | AF_Edge base, |
1841 | AF_Edge serif ) |
1842 | { |
1843 | FT_UNUSED( hints ); |
1844 | |
1845 | serif->pos = base->pos + ( serif->opos - base->opos ); |
1846 | } |
1847 | |
1848 | |
1849 | /*************************************************************************/ |
1850 | /*************************************************************************/ |
1851 | /*************************************************************************/ |
1852 | /**** ****/ |
1853 | /**** E D G E H I N T I N G ****/ |
1854 | /**** ****/ |
1855 | /*************************************************************************/ |
1856 | /*************************************************************************/ |
1857 | /*************************************************************************/ |
1858 | |
1859 | |
1860 | static void |
1861 | af_latin2_hint_edges( AF_GlyphHints hints, |
1862 | AF_Dimension dim ) |
1863 | { |
1864 | AF_AxisHints axis = &hints->axis[dim]; |
1865 | AF_Edge edges = axis->edges; |
1866 | AF_Edge edge_limit = edges + axis->num_edges; |
1867 | AF_Edge edge; |
1868 | AF_Edge anchor = NULL; |
1869 | FT_Int has_serifs = 0; |
1870 | FT_Pos anchor_drift = 0; |
1871 | |
1872 | |
1873 | |
1874 | FT_TRACE5(( "==== hinting %s edges =====\n" , |
1875 | dim == AF_DIMENSION_HORZ ? "vertical" : "horizontal" )); |
1876 | |
1877 | /* we begin by aligning all stems relative to the blue zone */ |
1878 | /* if needed -- that's only for horizontal edges */ |
1879 | |
1880 | if ( dim == AF_DIMENSION_VERT && AF_HINTS_DO_BLUES( hints ) ) |
1881 | { |
1882 | for ( edge = edges; edge < edge_limit; edge++ ) |
1883 | { |
1884 | AF_Width blue; |
1885 | AF_Edge edge1, edge2; |
1886 | |
1887 | |
1888 | if ( edge->flags & AF_EDGE_DONE ) |
1889 | continue; |
1890 | |
1891 | blue = edge->blue_edge; |
1892 | edge1 = NULL; |
1893 | edge2 = edge->link; |
1894 | |
1895 | if ( blue ) |
1896 | { |
1897 | edge1 = edge; |
1898 | } |
1899 | else if ( edge2 && edge2->blue_edge ) |
1900 | { |
1901 | blue = edge2->blue_edge; |
1902 | edge1 = edge2; |
1903 | edge2 = edge; |
1904 | } |
1905 | |
1906 | if ( !edge1 ) |
1907 | continue; |
1908 | |
1909 | FT_TRACE5(( "BLUE: edge %d (opos=%.2f) snapped to (%.2f), " |
1910 | "was (%.2f)\n" , |
1911 | edge1-edges, edge1->opos / 64.0, blue->fit / 64.0, |
1912 | edge1->pos / 64.0 )); |
1913 | |
1914 | edge1->pos = blue->fit; |
1915 | edge1->flags |= AF_EDGE_DONE; |
1916 | |
1917 | if ( edge2 && !edge2->blue_edge ) |
1918 | { |
1919 | af_latin2_align_linked_edge( hints, dim, edge1, edge2 ); |
1920 | edge2->flags |= AF_EDGE_DONE; |
1921 | } |
1922 | |
1923 | if ( !anchor ) |
1924 | { |
1925 | anchor = edge; |
1926 | |
1927 | anchor_drift = ( anchor->pos - anchor->opos ); |
1928 | if ( edge2 ) |
1929 | anchor_drift = ( anchor_drift + |
1930 | ( edge2->pos - edge2->opos ) ) >> 1; |
1931 | } |
1932 | } |
1933 | } |
1934 | |
1935 | /* now we will align all stem edges, trying to maintain the */ |
1936 | /* relative order of stems in the glyph */ |
1937 | for ( edge = edges; edge < edge_limit; edge++ ) |
1938 | { |
1939 | AF_Edge edge2; |
1940 | |
1941 | |
1942 | if ( edge->flags & AF_EDGE_DONE ) |
1943 | continue; |
1944 | |
1945 | /* skip all non-stem edges */ |
1946 | edge2 = edge->link; |
1947 | if ( !edge2 ) |
1948 | { |
1949 | has_serifs++; |
1950 | continue; |
1951 | } |
1952 | |
1953 | /* now align the stem */ |
1954 | |
1955 | /* this should not happen, but it's better to be safe */ |
1956 | if ( edge2->blue_edge ) |
1957 | { |
1958 | FT_TRACE5(( "ASSERTION FAILED for edge %d\n" , edge2-edges )); |
1959 | |
1960 | af_latin2_align_linked_edge( hints, dim, edge2, edge ); |
1961 | edge->flags |= AF_EDGE_DONE; |
1962 | continue; |
1963 | } |
1964 | |
1965 | if ( !anchor ) |
1966 | { |
1967 | FT_Pos org_len, org_center, cur_len; |
1968 | FT_Pos cur_pos1, error1, error2, u_off, d_off; |
1969 | |
1970 | |
1971 | org_len = edge2->opos - edge->opos; |
1972 | cur_len = af_latin2_compute_stem_width( hints, dim, org_len, |
1973 | edge->flags, |
1974 | edge2->flags ); |
1975 | if ( cur_len <= 64 ) |
1976 | u_off = d_off = 32; |
1977 | else |
1978 | { |
1979 | u_off = 38; |
1980 | d_off = 26; |
1981 | } |
1982 | |
1983 | if ( cur_len < 96 ) |
1984 | { |
1985 | org_center = edge->opos + ( org_len >> 1 ); |
1986 | |
1987 | cur_pos1 = FT_PIX_ROUND( org_center ); |
1988 | |
1989 | error1 = org_center - ( cur_pos1 - u_off ); |
1990 | if ( error1 < 0 ) |
1991 | error1 = -error1; |
1992 | |
1993 | error2 = org_center - ( cur_pos1 + d_off ); |
1994 | if ( error2 < 0 ) |
1995 | error2 = -error2; |
1996 | |
1997 | if ( error1 < error2 ) |
1998 | cur_pos1 -= u_off; |
1999 | else |
2000 | cur_pos1 += d_off; |
2001 | |
2002 | edge->pos = cur_pos1 - cur_len / 2; |
2003 | edge2->pos = edge->pos + cur_len; |
2004 | } |
2005 | else |
2006 | edge->pos = FT_PIX_ROUND( edge->opos ); |
2007 | |
2008 | FT_TRACE5(( "ANCHOR: edge %d (opos=%.2f) and %d (opos=%.2f)" |
2009 | " snapped to (%.2f) (%.2f)\n" , |
2010 | edge-edges, edge->opos / 64.0, |
2011 | edge2-edges, edge2->opos / 64.0, |
2012 | edge->pos / 64.0, edge2->pos / 64.0 )); |
2013 | anchor = edge; |
2014 | |
2015 | edge->flags |= AF_EDGE_DONE; |
2016 | |
2017 | af_latin2_align_linked_edge( hints, dim, edge, edge2 ); |
2018 | |
2019 | edge2->flags |= AF_EDGE_DONE; |
2020 | |
2021 | anchor_drift = ( ( anchor->pos - anchor->opos ) + |
2022 | ( edge2->pos - edge2->opos ) ) >> 1; |
2023 | |
2024 | FT_TRACE5(( "DRIFT: %.2f\n" , anchor_drift/64.0 )); |
2025 | } |
2026 | else |
2027 | { |
2028 | FT_Pos org_pos, org_len, org_center, cur_center, cur_len; |
2029 | FT_Pos org_left, org_right; |
2030 | |
2031 | |
2032 | org_pos = edge->opos + anchor_drift; |
2033 | org_len = edge2->opos - edge->opos; |
2034 | org_center = org_pos + ( org_len >> 1 ); |
2035 | |
2036 | cur_len = af_latin2_compute_stem_width( hints, dim, org_len, |
2037 | edge->flags, |
2038 | edge2->flags ); |
2039 | |
2040 | org_left = org_pos + ( ( org_len - cur_len ) >> 1 ); |
2041 | org_right = org_pos + ( ( org_len + cur_len ) >> 1 ); |
2042 | |
2043 | FT_TRACE5(( "ALIGN: left=%.2f right=%.2f " , |
2044 | org_left / 64.0, org_right / 64.0 )); |
2045 | cur_center = org_center; |
2046 | |
2047 | if ( edge2->flags & AF_EDGE_DONE ) |
2048 | { |
2049 | FT_TRACE5(( "\n" )); |
2050 | edge->pos = edge2->pos - cur_len; |
2051 | } |
2052 | else |
2053 | { |
2054 | /* we want to compare several displacement, and choose |
2055 | * the one that increases fitness while minimizing |
2056 | * distortion as well |
2057 | */ |
2058 | FT_Pos displacements[6], scores[6], org, fit, delta; |
2059 | FT_UInt count = 0; |
2060 | |
2061 | /* note: don't even try to fit tiny stems */ |
2062 | if ( cur_len < 32 ) |
2063 | { |
2064 | FT_TRACE5(( "tiny stem\n" )); |
2065 | goto AlignStem; |
2066 | } |
2067 | |
2068 | /* if the span is within a single pixel, don't touch it */ |
2069 | if ( FT_PIX_FLOOR( org_left ) == FT_PIX_CEIL( org_right ) ) |
2070 | { |
2071 | FT_TRACE5(( "single pixel stem\n" )); |
2072 | goto AlignStem; |
2073 | } |
2074 | |
2075 | if ( cur_len <= 96 ) |
2076 | { |
2077 | /* we want to avoid the absolute worst case which is |
2078 | * when the left and right edges of the span each represent |
2079 | * about 50% of the gray. we'd better want to change this |
2080 | * to 25/75%, since this is much more pleasant to the eye with |
2081 | * very acceptable distortion |
2082 | */ |
2083 | FT_Pos frac_left = org_left & 63; |
2084 | FT_Pos frac_right = org_right & 63; |
2085 | |
2086 | if ( frac_left >= 22 && frac_left <= 42 && |
2087 | frac_right >= 22 && frac_right <= 42 ) |
2088 | { |
2089 | org = frac_left; |
2090 | fit = ( org <= 32 ) ? 16 : 48; |
2091 | delta = FT_ABS( fit - org ); |
2092 | displacements[count] = fit - org; |
2093 | scores[count++] = delta; |
2094 | FT_TRACE5(( "dispA=%.2f (%d) " , ( fit - org ) / 64.0, delta )); |
2095 | |
2096 | org = frac_right; |
2097 | fit = ( org <= 32 ) ? 16 : 48; |
2098 | delta = FT_ABS( fit - org ); |
2099 | displacements[count] = fit - org; |
2100 | scores[count++] = delta; |
2101 | FT_TRACE5(( "dispB=%.2f (%d) " , ( fit - org ) / 64.0, delta )); |
2102 | } |
2103 | } |
2104 | |
2105 | /* snapping the left edge to the grid */ |
2106 | org = org_left; |
2107 | fit = FT_PIX_ROUND( org ); |
2108 | delta = FT_ABS( fit - org ); |
2109 | displacements[count] = fit - org; |
2110 | scores[count++] = delta; |
2111 | FT_TRACE5(( "dispC=%.2f (%d) " , ( fit - org ) / 64.0, delta )); |
2112 | |
2113 | /* snapping the right edge to the grid */ |
2114 | org = org_right; |
2115 | fit = FT_PIX_ROUND( org ); |
2116 | delta = FT_ABS( fit - org ); |
2117 | displacements[count] = fit - org; |
2118 | scores[count++] = delta; |
2119 | FT_TRACE5(( "dispD=%.2f (%d) " , ( fit - org ) / 64.0, delta )); |
2120 | |
2121 | /* now find the best displacement */ |
2122 | { |
2123 | FT_Pos best_score = scores[0]; |
2124 | FT_Pos best_disp = displacements[0]; |
2125 | FT_UInt nn; |
2126 | |
2127 | for ( nn = 1; nn < count; nn++ ) |
2128 | { |
2129 | if ( scores[nn] < best_score ) |
2130 | { |
2131 | best_score = scores[nn]; |
2132 | best_disp = displacements[nn]; |
2133 | } |
2134 | } |
2135 | |
2136 | cur_center = org_center + best_disp; |
2137 | } |
2138 | FT_TRACE5(( "\n" )); |
2139 | } |
2140 | |
2141 | AlignStem: |
2142 | edge->pos = cur_center - ( cur_len >> 1 ); |
2143 | edge2->pos = edge->pos + cur_len; |
2144 | |
2145 | FT_TRACE5(( "STEM1: %d (opos=%.2f) to %d (opos=%.2f)" |
2146 | " snapped to (%.2f) and (%.2f)," |
2147 | " org_len=%.2f cur_len=%.2f\n" , |
2148 | edge-edges, edge->opos / 64.0, |
2149 | edge2-edges, edge2->opos / 64.0, |
2150 | edge->pos / 64.0, edge2->pos / 64.0, |
2151 | org_len / 64.0, cur_len / 64.0 )); |
2152 | |
2153 | edge->flags |= AF_EDGE_DONE; |
2154 | edge2->flags |= AF_EDGE_DONE; |
2155 | |
2156 | if ( edge > edges && edge->pos < edge[-1].pos ) |
2157 | { |
2158 | FT_TRACE5(( "BOUND: %d (pos=%.2f) to (%.2f)\n" , |
2159 | edge-edges, edge->pos / 64.0, edge[-1].pos / 64.0 )); |
2160 | edge->pos = edge[-1].pos; |
2161 | } |
2162 | } |
2163 | } |
2164 | |
2165 | /* make sure that lowercase m's maintain their symmetry */ |
2166 | |
2167 | /* In general, lowercase m's have six vertical edges if they are sans */ |
2168 | /* serif, or twelve if they are with serifs. This implementation is */ |
2169 | /* based on that assumption, and seems to work very well with most */ |
2170 | /* faces. However, if for a certain face this assumption is not */ |
2171 | /* true, the m is just rendered like before. In addition, any stem */ |
2172 | /* correction will only be applied to symmetrical glyphs (even if the */ |
2173 | /* glyph is not an m), so the potential for unwanted distortion is */ |
2174 | /* relatively low. */ |
2175 | |
2176 | /* We don't handle horizontal edges since we can't easily assure that */ |
2177 | /* the third (lowest) stem aligns with the base line; it might end up */ |
2178 | /* one pixel higher or lower. */ |
2179 | |
2180 | #if 0 |
2181 | { |
2182 | FT_Int n_edges = edge_limit - edges; |
2183 | |
2184 | |
2185 | if ( dim == AF_DIMENSION_HORZ && ( n_edges == 6 || n_edges == 12 ) ) |
2186 | { |
2187 | AF_Edge edge1, edge2, edge3; |
2188 | FT_Pos dist1, dist2, span, delta; |
2189 | |
2190 | |
2191 | if ( n_edges == 6 ) |
2192 | { |
2193 | edge1 = edges; |
2194 | edge2 = edges + 2; |
2195 | edge3 = edges + 4; |
2196 | } |
2197 | else |
2198 | { |
2199 | edge1 = edges + 1; |
2200 | edge2 = edges + 5; |
2201 | edge3 = edges + 9; |
2202 | } |
2203 | |
2204 | dist1 = edge2->opos - edge1->opos; |
2205 | dist2 = edge3->opos - edge2->opos; |
2206 | |
2207 | span = dist1 - dist2; |
2208 | if ( span < 0 ) |
2209 | span = -span; |
2210 | |
2211 | if ( span < 8 ) |
2212 | { |
2213 | delta = edge3->pos - ( 2 * edge2->pos - edge1->pos ); |
2214 | edge3->pos -= delta; |
2215 | if ( edge3->link ) |
2216 | edge3->link->pos -= delta; |
2217 | |
2218 | /* move the serifs along with the stem */ |
2219 | if ( n_edges == 12 ) |
2220 | { |
2221 | ( edges + 8 )->pos -= delta; |
2222 | ( edges + 11 )->pos -= delta; |
2223 | } |
2224 | |
2225 | edge3->flags |= AF_EDGE_DONE; |
2226 | if ( edge3->link ) |
2227 | edge3->link->flags |= AF_EDGE_DONE; |
2228 | } |
2229 | } |
2230 | } |
2231 | #endif |
2232 | |
2233 | if ( has_serifs || !anchor ) |
2234 | { |
2235 | /* |
2236 | * now hint the remaining edges (serifs and single) in order |
2237 | * to complete our processing |
2238 | */ |
2239 | for ( edge = edges; edge < edge_limit; edge++ ) |
2240 | { |
2241 | FT_Pos delta; |
2242 | |
2243 | |
2244 | if ( edge->flags & AF_EDGE_DONE ) |
2245 | continue; |
2246 | |
2247 | delta = 1000; |
2248 | |
2249 | if ( edge->serif ) |
2250 | { |
2251 | delta = edge->serif->opos - edge->opos; |
2252 | if ( delta < 0 ) |
2253 | delta = -delta; |
2254 | } |
2255 | |
2256 | if ( delta < 64 + 16 ) |
2257 | { |
2258 | af_latin2_align_serif_edge( hints, edge->serif, edge ); |
2259 | FT_TRACE5(( "SERIF: edge %d (opos=%.2f) serif to %d (opos=%.2f)" |
2260 | " aligned to (%.2f)\n" , |
2261 | edge-edges, edge->opos / 64.0, |
2262 | edge->serif - edges, edge->serif->opos / 64.0, |
2263 | edge->pos / 64.0 )); |
2264 | } |
2265 | else if ( !anchor ) |
2266 | { |
2267 | FT_TRACE5(( "SERIF_ANCHOR: edge %d (opos=%.2f)" |
2268 | " snapped to (%.2f)\n" , |
2269 | edge-edges, edge->opos / 64.0, edge->pos / 64.0 )); |
2270 | edge->pos = FT_PIX_ROUND( edge->opos ); |
2271 | anchor = edge; |
2272 | } |
2273 | else |
2274 | { |
2275 | AF_Edge before, after; |
2276 | |
2277 | |
2278 | for ( before = edge - 1; before >= edges; before-- ) |
2279 | if ( before->flags & AF_EDGE_DONE ) |
2280 | break; |
2281 | |
2282 | for ( after = edge + 1; after < edge_limit; after++ ) |
2283 | if ( after->flags & AF_EDGE_DONE ) |
2284 | break; |
2285 | |
2286 | if ( before >= edges && before < edge && |
2287 | after < edge_limit && after > edge ) |
2288 | { |
2289 | if ( after->opos == before->opos ) |
2290 | edge->pos = before->pos; |
2291 | else |
2292 | edge->pos = before->pos + |
2293 | FT_MulDiv( edge->opos - before->opos, |
2294 | after->pos - before->pos, |
2295 | after->opos - before->opos ); |
2296 | FT_TRACE5(( "SERIF_LINK1: edge %d (opos=%.2f) snapped to (%.2f)" |
2297 | " from %d (opos=%.2f)\n" , |
2298 | edge-edges, edge->opos / 64.0, edge->pos / 64.0, |
2299 | before - edges, before->opos / 64.0 )); |
2300 | } |
2301 | else |
2302 | { |
2303 | edge->pos = anchor->pos + |
2304 | ( ( edge->opos - anchor->opos + 16 ) & ~31 ); |
2305 | |
2306 | FT_TRACE5(( "SERIF_LINK2: edge %d (opos=%.2f)" |
2307 | " snapped to (%.2f)\n" , |
2308 | edge-edges, edge->opos / 64.0, edge->pos / 64.0 )); |
2309 | } |
2310 | } |
2311 | |
2312 | edge->flags |= AF_EDGE_DONE; |
2313 | |
2314 | if ( edge > edges && edge->pos < edge[-1].pos ) |
2315 | edge->pos = edge[-1].pos; |
2316 | |
2317 | if ( edge + 1 < edge_limit && |
2318 | edge[1].flags & AF_EDGE_DONE && |
2319 | edge->pos > edge[1].pos ) |
2320 | edge->pos = edge[1].pos; |
2321 | } |
2322 | } |
2323 | } |
2324 | |
2325 | |
2326 | static FT_Error |
2327 | af_latin2_hints_apply( FT_UInt glyph_index, |
2328 | AF_GlyphHints hints, |
2329 | FT_Outline* outline, |
2330 | AF_LatinMetrics metrics ) |
2331 | { |
2332 | FT_Error error; |
2333 | int dim; |
2334 | |
2335 | FT_UNUSED( glyph_index ); |
2336 | |
2337 | |
2338 | error = af_glyph_hints_reload( hints, outline ); |
2339 | if ( error ) |
2340 | goto Exit; |
2341 | |
2342 | /* analyze glyph outline */ |
2343 | if ( AF_HINTS_DO_HORIZONTAL( hints ) ) |
2344 | { |
2345 | error = af_latin2_hints_detect_features( hints, AF_DIMENSION_HORZ ); |
2346 | if ( error ) |
2347 | goto Exit; |
2348 | } |
2349 | |
2350 | if ( AF_HINTS_DO_VERTICAL( hints ) ) |
2351 | { |
2352 | error = af_latin2_hints_detect_features( hints, AF_DIMENSION_VERT ); |
2353 | if ( error ) |
2354 | goto Exit; |
2355 | |
2356 | af_latin2_hints_compute_blue_edges( hints, metrics ); |
2357 | } |
2358 | |
2359 | /* grid-fit the outline */ |
2360 | for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ ) |
2361 | { |
2362 | #ifdef AF_CONFIG_OPTION_USE_WARPER |
2363 | if ( dim == AF_DIMENSION_HORZ && |
2364 | metrics->root.scaler.render_mode == FT_RENDER_MODE_NORMAL && |
2365 | AF_HINTS_DO_WARP( hints ) ) |
2366 | { |
2367 | AF_WarperRec warper; |
2368 | FT_Fixed scale; |
2369 | FT_Pos delta; |
2370 | |
2371 | |
2372 | af_warper_compute( &warper, hints, dim, &scale, &delta ); |
2373 | af_glyph_hints_scale_dim( hints, dim, scale, delta ); |
2374 | continue; |
2375 | } |
2376 | #endif /* AF_CONFIG_OPTION_USE_WARPER */ |
2377 | |
2378 | if ( ( dim == AF_DIMENSION_HORZ && AF_HINTS_DO_HORIZONTAL( hints ) ) || |
2379 | ( dim == AF_DIMENSION_VERT && AF_HINTS_DO_VERTICAL( hints ) ) ) |
2380 | { |
2381 | af_latin2_hint_edges( hints, (AF_Dimension)dim ); |
2382 | af_glyph_hints_align_edge_points( hints, (AF_Dimension)dim ); |
2383 | af_glyph_hints_align_strong_points( hints, (AF_Dimension)dim ); |
2384 | af_glyph_hints_align_weak_points( hints, (AF_Dimension)dim ); |
2385 | } |
2386 | } |
2387 | af_glyph_hints_save( hints, outline ); |
2388 | |
2389 | Exit: |
2390 | return error; |
2391 | } |
2392 | |
2393 | |
2394 | /*************************************************************************/ |
2395 | /*************************************************************************/ |
2396 | /***** *****/ |
2397 | /***** L A T I N S C R I P T C L A S S *****/ |
2398 | /***** *****/ |
2399 | /*************************************************************************/ |
2400 | /*************************************************************************/ |
2401 | |
2402 | |
2403 | AF_DEFINE_WRITING_SYSTEM_CLASS( |
2404 | af_latin2_writing_system_class, |
2405 | |
2406 | AF_WRITING_SYSTEM_LATIN2, |
2407 | |
2408 | sizeof ( AF_LatinMetricsRec ), |
2409 | |
2410 | (AF_WritingSystem_InitMetricsFunc) af_latin2_metrics_init, /* style_metrics_init */ |
2411 | (AF_WritingSystem_ScaleMetricsFunc)af_latin2_metrics_scale, /* style_metrics_scale */ |
2412 | (AF_WritingSystem_DoneMetricsFunc) NULL, /* style_metrics_done */ |
2413 | (AF_WritingSystem_GetStdWidthsFunc)af_latin2_get_standard_widths, /* style_metrics_getstdw */ |
2414 | |
2415 | (AF_WritingSystem_InitHintsFunc) af_latin2_hints_init, /* style_hints_init */ |
2416 | (AF_WritingSystem_ApplyHintsFunc) af_latin2_hints_apply /* style_hints_apply */ |
2417 | ) |
2418 | |
2419 | #else /* !FT_OPTION_AUTOFIT2 */ |
2420 | |
2421 | /* ANSI C doesn't like empty source files */ |
2422 | typedef int _af_latin2_dummy; |
2423 | |
2424 | #endif /* !FT_OPTION_AUTOFIT2 */ |
2425 | |
2426 | |
2427 | /* END */ |
2428 | |