projects / reactos.git / blob
? search:


26bba065bb58cea3bb2b4da3488cfbce34ed6634
[reactos.git] / reactos / sdk / lib / 3rdparty / freetype / src / autofit / afloader.c
1 /***************************************************************************/
2 /* */
3 /* afloader.c */
4 /* */
5 /* Auto-fitter glyph loading routines (body). */
6 /* */
7 /* Copyright 2003-2016 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
19 #include "afglobal.h"
20 #include "afloader.h"
21 #include "afhints.h"
22 #include "aferrors.h"
23 #include "afmodule.h"
24 #include "afpic.h"
25
26 #include FT_INTERNAL_CALC_H
27
28
29 /* Initialize glyph loader. */
30
31 FT_LOCAL_DEF( void )
32 af_loader_init( AF_Loader loader,
33 AF_GlyphHints hints )
34 {
35 FT_ZERO( loader );
36
37 loader->hints = hints;
38 }
39
40
41 /* Reset glyph loader and compute globals if necessary. */
42
43 FT_LOCAL_DEF( FT_Error )
44 af_loader_reset( AF_Loader loader,
45 AF_Module module,
46 FT_Face face )
47 {
48 FT_Error error = FT_Err_Ok;
49
50
51 loader->face = face;
52 loader->globals = (AF_FaceGlobals)face->autohint.data;
53
54 if ( loader->globals == NULL )
55 {
56 error = af_face_globals_new( face, &loader->globals, module );
57 if ( !error )
58 {
59 face->autohint.data =
60 (FT_Pointer)loader->globals;
61 face->autohint.finalizer =
62 (FT_Generic_Finalizer)af_face_globals_free;
63 }
64 }
65
66 return error;
67 }
68
69
70 /* Finalize glyph loader. */
71
72 FT_LOCAL_DEF( void )
73 af_loader_done( AF_Loader loader )
74 {
75 loader->face = NULL;
76 loader->globals = NULL;
77 loader->hints = NULL;
78 }
79
80
81 #define af_intToFixed( i ) \
82 ( (FT_Fixed)( (FT_UInt32)(i) << 16 ) )
83 #define af_fixedToInt( x ) \
84 ( (FT_Short)( ( (FT_UInt32)(x) + 0x8000U ) >> 16 ) )
85 #define af_floatToFixed( f ) \
86 ( (FT_Fixed)( (f) * 65536.0 + 0.5 ) )
87
88
89 /* Do the main work of `af_loader_load_glyph'. Note that we never */
90 /* have to deal with composite glyphs as those get loaded into */
91 /* FT_GLYPH_FORMAT_OUTLINE by the recursed `FT_Load_Glyph' function. */
92 /* In the rare cases where FT_LOAD_NO_RECURSE is set, it implies */
93 /* FT_LOAD_NO_SCALE and as such the auto-hinter is never called. */
94
95 static FT_Error
96 af_loader_load_g( AF_Loader loader,
97 AF_Scaler scaler,
98 FT_UInt glyph_index,
99 FT_Int32 load_flags )
100 {
101 AF_Module module = loader->globals->module;
102
103 FT_Error error;
104 FT_Face face = loader->face;
105 AF_StyleMetrics metrics = loader->metrics;
106 AF_GlyphHints hints = loader->hints;
107 FT_GlyphSlot slot = face->glyph;
108 FT_Slot_Internal internal = slot->internal;
109 FT_GlyphLoader gloader = internal->loader;
110 FT_Int32 flags;
111
112
113 flags = load_flags | FT_LOAD_LINEAR_DESIGN;
114 error = FT_Load_Glyph( face, glyph_index, flags );
115 if ( error )
116 goto Exit;
117
118 /*
119 * Apply stem darkening (emboldening) here before hints are applied to
120 * the outline. Glyphs are scaled down proportionally to the
121 * emboldening so that curve points don't fall outside their precomputed
122 * blue zones.
123 *
124 * Any emboldening done by the font driver (e.g., the CFF driver)
125 * doesn't reach here because the autohinter loads the unprocessed
126 * glyphs in font units for analysis (functions `af_*_metrics_init_*')
127 * and then above to prepare it for the rasterizers by itself,
128 * independently of the font driver. So emboldening must be done here,
129 * within the autohinter.
130 *
131 * All glyphs to be autohinted pass through here one by one. The
132 * standard widths can therefore change from one glyph to the next,
133 * depending on what script a glyph is assigned to (each script has its
134 * own set of standard widths and other metrics). The darkening amount
135 * must therefore be recomputed for each size and
136 * `standard_{vertical,horizontal}_width' change.
137 */
138 if ( !module->no_stem_darkening )
139 {
140 AF_FaceGlobals globals = loader->globals;
141 AF_WritingSystemClass writing_system_class;
142
143 FT_Pos stdVW = 0;
144 FT_Pos stdHW = 0;
145
146 FT_Bool size_changed = face->size->metrics.x_ppem
147 != globals->stem_darkening_for_ppem;
148
149 FT_Fixed em_size = af_intToFixed( face->units_per_EM );
150 FT_Fixed em_ratio = FT_DivFix( af_intToFixed( 1000 ), em_size );
151
152 FT_Matrix scale_down_matrix = { 0x10000L, 0, 0, 0x10000L };
153
154
155 /* Skip stem darkening for broken fonts. */
156 if ( !face->units_per_EM )
157 goto After_Emboldening;
158
159 /*
160 * We depend on the writing system (script analyzers) to supply
161 * standard widths for the script of the glyph we are looking at. If
162 * it can't deliver, stem darkening is effectively disabled.
163 */
164 writing_system_class =
165 AF_WRITING_SYSTEM_CLASSES_GET[metrics->style_class->writing_system];
166
167 if ( writing_system_class->style_metrics_getstdw )
168 writing_system_class->style_metrics_getstdw( metrics,
169 &stdHW,
170 &stdVW );
171 else
172 goto After_Emboldening;
173
174
175 if ( size_changed ||
176 ( stdVW > 0 && stdVW != globals->standard_vertical_width ) )
177 {
178 FT_Fixed darken_by_font_units_x, darken_x;
179
180
181 darken_by_font_units_x =
182 af_intToFixed( af_loader_compute_darkening( loader,
183 face,
184 stdVW ) );
185 darken_x = FT_DivFix( FT_MulFix( darken_by_font_units_x,
186 face->size->metrics.x_scale ),
187 em_ratio );
188
189 globals->standard_vertical_width = stdVW;
190 globals->stem_darkening_for_ppem = face->size->metrics.x_ppem;
191 globals->darken_x = af_fixedToInt( darken_x );
192 }
193
194 if ( size_changed ||
195 ( stdHW > 0 && stdHW != globals->standard_horizontal_width ) )
196 {
197 FT_Fixed darken_by_font_units_y, darken_y;
198
199
200 darken_by_font_units_y =
201 af_intToFixed( af_loader_compute_darkening( loader,
202 face,
203 stdHW ) );
204 darken_y = FT_DivFix( FT_MulFix( darken_by_font_units_y,
205 face->size->metrics.y_scale ),
206 em_ratio );
207
208 globals->standard_horizontal_width = stdHW;
209 globals->stem_darkening_for_ppem = face->size->metrics.x_ppem;
210 globals->darken_y = af_fixedToInt( darken_y );
211
212 /*
213 * Scale outlines down on the Y-axis to keep them inside their blue
214 * zones. The stronger the emboldening, the stronger the
215 * downscaling (plus heuristical padding to prevent outlines still
216 * falling out their zones due to rounding).
217 *
218 * Reason: `FT_Outline_Embolden' works by shifting the rightmost
219 * points of stems farther to the right, and topmost points farther
220 * up. This positions points on the Y-axis outside their
221 * pre-computed blue zones and leads to distortion when applying the
222 * hints in the code further below. Code outside this emboldening
223 * block doesn't know we are presenting it with modified outlines
224 * the analyzer didn't see!
225 *
226 * An unfortunate side effect of downscaling is that the emboldening
227 * effect is slightly decreased. The loss becomes more pronounced
228 * versus the CFF driver at smaller sizes, e.g., at 9ppem and below.
229 */
230 globals->scale_down_factor =
231 FT_DivFix( em_size - ( darken_by_font_units_y + af_intToFixed( 8 ) ),
232 em_size );
233 }
234
235 FT_Outline_EmboldenXY( &slot->outline,
236 globals->darken_x,
237 globals->darken_y );
238
239 scale_down_matrix.yy = globals->scale_down_factor;
240 FT_Outline_Transform( &slot->outline, &scale_down_matrix );
241 }
242
243 After_Emboldening:
244 loader->transformed = internal->glyph_transformed;
245 if ( loader->transformed )
246 {
247 FT_Matrix inverse;
248
249
250 loader->trans_matrix = internal->glyph_matrix;
251 loader->trans_delta = internal->glyph_delta;
252
253 inverse = loader->trans_matrix;
254 if ( !FT_Matrix_Invert( &inverse ) )
255 FT_Vector_Transform( &loader->trans_delta, &inverse );
256 }
257
258 switch ( slot->format )
259 {
260 case FT_GLYPH_FORMAT_OUTLINE:
261 /* translate the loaded glyph when an internal transform is needed */
262 if ( loader->transformed )
263 FT_Outline_Translate( &slot->outline,
264 loader->trans_delta.x,
265 loader->trans_delta.y );
266
267 /* compute original horizontal phantom points (and ignore */
268 /* vertical ones) */
269 loader->pp1.x = hints->x_delta;
270 loader->pp1.y = hints->y_delta;
271 loader->pp2.x = FT_MulFix( slot->metrics.horiAdvance,
272 hints->x_scale ) + hints->x_delta;
273 loader->pp2.y = hints->y_delta;
274
275 /* be sure to check for spacing glyphs */
276 if ( slot->outline.n_points == 0 )
277 goto Hint_Metrics;
278
279 /* now load the slot image into the auto-outline and run the */
280 /* automatic hinting process */
281 {
282 #ifdef FT_CONFIG_OPTION_PIC
283 AF_FaceGlobals globals = loader->globals;
284 #endif
285 AF_StyleClass style_class = metrics->style_class;
286 AF_WritingSystemClass writing_system_class =
287 AF_WRITING_SYSTEM_CLASSES_GET[style_class->writing_system];
288
289
290 if ( writing_system_class->style_hints_apply )
291 writing_system_class->style_hints_apply( glyph_index,
292 hints,
293 &gloader->base.outline,
294 metrics );
295 }
296
297 /* we now need to adjust the metrics according to the change in */
298 /* width/positioning that occurred during the hinting process */
299 if ( scaler->render_mode != FT_RENDER_MODE_LIGHT )
300 {
301 FT_Pos old_rsb, old_lsb, new_lsb;
302 FT_Pos pp1x_uh, pp2x_uh;
303 AF_AxisHints axis = &hints->axis[AF_DIMENSION_HORZ];
304 AF_Edge edge1 = axis->edges; /* leftmost edge */
305 AF_Edge edge2 = edge1 +
306 axis->num_edges - 1; /* rightmost edge */
307
308
309 if ( axis->num_edges > 1 && AF_HINTS_DO_ADVANCE( hints ) )
310 {
311 old_rsb = loader->pp2.x - edge2->opos;
312 old_lsb = edge1->opos;
313 new_lsb = edge1->pos;
314
315 /* remember unhinted values to later account */
316 /* for rounding errors */
317
318 pp1x_uh = new_lsb - old_lsb;
319 pp2x_uh = edge2->pos + old_rsb;
320
321 /* prefer too much space over too little space */
322 /* for very small sizes */
323
324 if ( old_lsb < 24 )
325 pp1x_uh -= 8;
326
327 if ( old_rsb < 24 )
328 pp2x_uh += 8;
329
330 loader->pp1.x = FT_PIX_ROUND( pp1x_uh );
331 loader->pp2.x = FT_PIX_ROUND( pp2x_uh );
332
333 if ( loader->pp1.x >= new_lsb && old_lsb > 0 )
334 loader->pp1.x -= 64;
335
336 if ( loader->pp2.x <= edge2->pos && old_rsb > 0 )
337 loader->pp2.x += 64;
338
339 slot->lsb_delta = loader->pp1.x - pp1x_uh;
340 slot->rsb_delta = loader->pp2.x - pp2x_uh;
341 }
342 else
343 {
344 FT_Pos pp1x = loader->pp1.x;
345 FT_Pos pp2x = loader->pp2.x;
346
347
348 loader->pp1.x = FT_PIX_ROUND( pp1x );
349 loader->pp2.x = FT_PIX_ROUND( pp2x );
350
351 slot->lsb_delta = loader->pp1.x - pp1x;
352 slot->rsb_delta = loader->pp2.x - pp2x;
353 }
354 }
355 else
356 {
357 FT_Pos pp1x = loader->pp1.x;
358 FT_Pos pp2x = loader->pp2.x;
359
360
361 loader->pp1.x = FT_PIX_ROUND( pp1x + hints->xmin_delta );
362 loader->pp2.x = FT_PIX_ROUND( pp2x + hints->xmax_delta );
363
364 slot->lsb_delta = loader->pp1.x - pp1x;
365 slot->rsb_delta = loader->pp2.x - pp2x;
366 }
367
368 break;
369
370 default:
371 /* we don't support other formats (yet?) */
372 error = FT_THROW( Unimplemented_Feature );
373 }
374
375 Hint_Metrics:
376 {
377 FT_BBox bbox;
378 FT_Vector vvector;
379
380
381 vvector.x = slot->metrics.vertBearingX - slot->metrics.horiBearingX;
382 vvector.y = slot->metrics.vertBearingY - slot->metrics.horiBearingY;
383 vvector.x = FT_MulFix( vvector.x, metrics->scaler.x_scale );
384 vvector.y = FT_MulFix( vvector.y, metrics->scaler.y_scale );
385
386 /* transform the hinted outline if needed */
387 if ( loader->transformed )
388 {
389 FT_Outline_Transform( &gloader->base.outline, &loader->trans_matrix );
390 FT_Vector_Transform( &vvector, &loader->trans_matrix );
391 }
392 #if 1
393 /* we must translate our final outline by -pp1.x and compute */
394 /* the new metrics */
395 if ( loader->pp1.x )
396 FT_Outline_Translate( &gloader->base.outline, -loader->pp1.x, 0 );
397 #endif
398 FT_Outline_Get_CBox( &gloader->base.outline, &bbox );
399
400 bbox.xMin = FT_PIX_FLOOR( bbox.xMin );
401 bbox.yMin = FT_PIX_FLOOR( bbox.yMin );
402 bbox.xMax = FT_PIX_CEIL( bbox.xMax );
403 bbox.yMax = FT_PIX_CEIL( bbox.yMax );
404
405 slot->metrics.width = bbox.xMax - bbox.xMin;
406 slot->metrics.height = bbox.yMax - bbox.yMin;
407 slot->metrics.horiBearingX = bbox.xMin;
408 slot->metrics.horiBearingY = bbox.yMax;
409
410 slot->metrics.vertBearingX = FT_PIX_FLOOR( bbox.xMin + vvector.x );
411 slot->metrics.vertBearingY = FT_PIX_FLOOR( bbox.yMax + vvector.y );
412
413 /* for mono-width fonts (like Andale, Courier, etc.) we need */
414 /* to keep the original rounded advance width; ditto for */
415 /* digits if all have the same advance width */
416 #if 0
417 if ( !FT_IS_FIXED_WIDTH( slot->face ) )
418 slot->metrics.horiAdvance = loader->pp2.x - loader->pp1.x;
419 else
420 slot->metrics.horiAdvance = FT_MulFix( slot->metrics.horiAdvance,
421 x_scale );
422 #else
423 if ( scaler->render_mode != FT_RENDER_MODE_LIGHT &&
424 ( FT_IS_FIXED_WIDTH( slot->face ) ||
425 ( af_face_globals_is_digit( loader->globals, glyph_index ) &&
426 metrics->digits_have_same_width ) ) )
427 {
428 slot->metrics.horiAdvance = FT_MulFix( slot->metrics.horiAdvance,
429 metrics->scaler.x_scale );
430
431 /* Set delta values to 0. Otherwise code that uses them is */
432 /* going to ruin the fixed advance width. */
433 slot->lsb_delta = 0;
434 slot->rsb_delta = 0;
435 }
436 else
437 {
438 /* non-spacing glyphs must stay as-is */
439 if ( slot->metrics.horiAdvance )
440 slot->metrics.horiAdvance = loader->pp2.x - loader->pp1.x;
441 }
442 #endif
443
444 slot->metrics.vertAdvance = FT_MulFix( slot->metrics.vertAdvance,
445 metrics->scaler.y_scale );
446
447 slot->metrics.horiAdvance = FT_PIX_ROUND( slot->metrics.horiAdvance );
448 slot->metrics.vertAdvance = FT_PIX_ROUND( slot->metrics.vertAdvance );
449
450 #if 0
451 /* reassign all outline fields except flags to protect them */
452 slot->outline.n_contours = internal->loader->base.outline.n_contours;
453 slot->outline.n_points = internal->loader->base.outline.n_points;
454 slot->outline.points = internal->loader->base.outline.points;
455 slot->outline.tags = internal->loader->base.outline.tags;
456 slot->outline.contours = internal->loader->base.outline.contours;
457 #endif
458
459 slot->format = FT_GLYPH_FORMAT_OUTLINE;
460 }
461
462 Exit:
463 return error;
464 }
465
466
467 /* Load a glyph. */
468
469 FT_LOCAL_DEF( FT_Error )
470 af_loader_load_glyph( AF_Loader loader,
471 AF_Module module,
472 FT_Face face,
473 FT_UInt gindex,
474 FT_Int32 load_flags )
475 {
476 FT_Error error;
477 FT_Size size = face->size;
478 AF_ScalerRec scaler;
479
480
481 if ( !size )
482 return FT_THROW( Invalid_Size_Handle );
483
484 FT_ZERO( &scaler );
485
486 scaler.face = face;
487 scaler.x_scale = size->metrics.x_scale;
488 scaler.x_delta = 0; /* XXX: TODO: add support for sub-pixel hinting */
489 scaler.y_scale = size->metrics.y_scale;
490 scaler.y_delta = 0; /* XXX: TODO: add support for sub-pixel hinting */
491
492 scaler.render_mode = FT_LOAD_TARGET_MODE( load_flags );
493 scaler.flags = 0; /* XXX: fix this */
494
495 error = af_loader_reset( loader, module, face );
496 if ( !error )
497 {
498 AF_StyleMetrics metrics;
499 FT_UInt options = AF_STYLE_NONE_DFLT;
500
501
502 #ifdef FT_OPTION_AUTOFIT2
503 /* XXX: undocumented hook to activate the latin2 writing system */
504 if ( load_flags & ( 1UL << 20 ) )
505 options = AF_STYLE_LTN2_DFLT;
506 #endif
507
508 error = af_face_globals_get_metrics( loader->globals, gindex,
509 options, &metrics );
510 if ( !error )
511 {
512 #ifdef FT_CONFIG_OPTION_PIC
513 AF_FaceGlobals globals = loader->globals;
514 #endif
515 AF_StyleClass style_class = metrics->style_class;
516 AF_WritingSystemClass writing_system_class =
517 AF_WRITING_SYSTEM_CLASSES_GET[style_class->writing_system];
518
519
520 loader->metrics = metrics;
521
522 if ( writing_system_class->style_metrics_scale )
523 writing_system_class->style_metrics_scale( metrics, &scaler );
524 else
525 metrics->scaler = scaler;
526
527 load_flags |= FT_LOAD_NO_SCALE | FT_LOAD_IGNORE_TRANSFORM;
528 load_flags &= ~FT_LOAD_RENDER;
529
530 if ( writing_system_class->style_hints_init )
531 {
532 error = writing_system_class->style_hints_init( loader->hints,
533 metrics );
534 if ( error )
535 goto Exit;
536 }
537
538 error = af_loader_load_g( loader, &scaler, gindex, load_flags );
539 }
540 }
541 Exit:
542 return error;
543 }
544
545
546 /*
547 * Compute amount of font units the face should be emboldened by, in
548 * analogy to the CFF driver's `cf2_computeDarkening' function. See there
549 * for details of the algorithm.
550 *
551 * XXX: Currently a crude adaption of the original algorithm. Do better?
552 */
553 FT_LOCAL_DEF( FT_Int32 )
554 af_loader_compute_darkening( AF_Loader loader,
555 FT_Face face,
556 FT_Pos standard_width )
557 {
558 AF_Module module = loader->globals->module;
559
560 FT_UShort units_per_EM;
561 FT_Fixed ppem, em_ratio;
562 FT_Fixed stem_width, stem_width_per_1000, scaled_stem, darken_amount;
563 FT_Int log_base_2;
564 FT_Int x1, y1, x2, y2, x3, y3, x4, y4;
565
566
567 ppem = FT_MAX( af_intToFixed( 4 ),
568 af_intToFixed( face->size->metrics.x_ppem ) );
569 units_per_EM = face->units_per_EM;
570
571 em_ratio = FT_DivFix( af_intToFixed( 1000 ),
572 af_intToFixed ( units_per_EM ) );
573 if ( em_ratio < af_floatToFixed( .01 ) )
574 {
575 /* If something goes wrong, don't embolden. */
576 return 0;
577 }
578
579 x1 = module->darken_params[0];
580 y1 = module->darken_params[1];
581 x2 = module->darken_params[2];
582 y2 = module->darken_params[3];
583 x3 = module->darken_params[4];
584 y3 = module->darken_params[5];
585 x4 = module->darken_params[6];
586 y4 = module->darken_params[7];
587
588 if ( standard_width <= 0 )
589 {
590 stem_width = af_intToFixed( 75 ); /* taken from cf2font.c */
591 stem_width_per_1000 = stem_width;
592 }
593 else
594 {
595 stem_width = af_intToFixed( standard_width );
596 stem_width_per_1000 = FT_MulFix( stem_width, em_ratio );
597 }
598
599 log_base_2 = FT_MSB( (FT_UInt32)stem_width_per_1000 ) +
600 FT_MSB( (FT_UInt32)ppem );
601
602 if ( log_base_2 >= 46 )
603 {
604 /* possible overflow */
605 scaled_stem = af_intToFixed( x4 );
606 }
607 else
608 scaled_stem = FT_MulFix( stem_width_per_1000, ppem );
609
610 /* now apply the darkening parameters */
611 if ( scaled_stem < af_intToFixed( x1 ) )
612 darken_amount = FT_DivFix( af_intToFixed( y1 ), ppem );
613
614 else if ( scaled_stem < af_intToFixed( x2 ) )
615 {
616 FT_Int xdelta = x2 - x1;
617 FT_Int ydelta = y2 - y1;
618 FT_Int x = stem_width_per_1000 -
619 FT_DivFix( af_intToFixed( x1 ), ppem );
620
621
622 if ( !xdelta )
623 goto Try_x3;
624
625 darken_amount = FT_MulDiv( x, ydelta, xdelta ) +
626 FT_DivFix( af_intToFixed( y1 ), ppem );
627 }
628
629 else if ( scaled_stem < af_intToFixed( x3 ) )
630 {
631 Try_x3:
632 {
633 FT_Int xdelta = x3 - x2;
634 FT_Int ydelta = y3 - y2;
635 FT_Int x = stem_width_per_1000 -
636 FT_DivFix( af_intToFixed( x2 ), ppem );
637
638
639 if ( !xdelta )
640 goto Try_x4;
641
642 darken_amount = FT_MulDiv( x, ydelta, xdelta ) +
643 FT_DivFix( af_intToFixed( y2 ), ppem );
644 }
645 }
646
647 else if ( scaled_stem < af_intToFixed( x4 ) )
648 {
649 Try_x4:
650 {
651 FT_Int xdelta = x4 - x3;
652 FT_Int ydelta = y4 - y3;
653 FT_Int x = stem_width_per_1000 -
654 FT_DivFix( af_intToFixed( x3 ), ppem );
655
656
657 if ( !xdelta )
658 goto Use_y4;
659
660 darken_amount = FT_MulDiv( x, ydelta, xdelta ) +
661 FT_DivFix( af_intToFixed( y3 ), ppem );
662 }
663 }
664
665 else
666 {
667 Use_y4:
668 darken_amount = FT_DivFix( af_intToFixed( y4 ), ppem );
669 }
670
671 /* Convert darken_amount from per 1000 em to true character space. */
672 return af_fixedToInt( FT_DivFix( darken_amount, em_ratio ) );
673 }
674
675
676 /* END */
A free Windows-compatible Operating System