2 * Copyright © 2009,2010 Red Hat, Inc.
3 * Copyright © 2010,2011 Google, Inc.
5 * This is part of HarfBuzz, a text shaping library.
7 * Permission is hereby granted, without written agreement and without
8 * license or royalty fees, to use, copy, modify, and distribute this
9 * software and its documentation for any purpose, provided that the
10 * above copyright notice and the following two paragraphs appear in
11 * all copies of this software.
13 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
14 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
15 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
16 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
19 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
20 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
21 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
22 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
23 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
25 * Red Hat Author(s): Behdad Esfahbod
26 * Google Author(s): Behdad Esfahbod
29 #include "hb-ot-shape-private.hh"
30 #include "hb-ot-shape-complex-private.hh"
32 #include "hb-font-private.hh"
37 hb_tag_t common_features[] = {
38 HB_TAG('c','c','m','p'),
39 HB_TAG('l','o','c','l'),
40 HB_TAG('m','a','r','k'),
41 HB_TAG('m','k','m','k'),
42 HB_TAG('r','l','i','g'),
45 hb_tag_t horizontal_features[] = {
46 HB_TAG('c','a','l','t'),
47 HB_TAG('c','l','i','g'),
48 HB_TAG('c','u','r','s'),
49 HB_TAG('k','e','r','n'),
50 HB_TAG('l','i','g','a'),
54 * Technically speaking, vrt2 and vert are mutually exclusive.
55 * According to the spec, valt and vpal are also mutually exclusive.
56 * But we apply them all for now.
58 hb_tag_t vertical_features[] = {
59 HB_TAG('v','a','l','t'),
60 HB_TAG('v','e','r','t'),
61 HB_TAG('v','k','r','n'),
62 HB_TAG('v','p','a','l'),
63 HB_TAG('v','r','t','2'),
67 hb_ot_shape_collect_features (hb_ot_shape_planner_t *planner,
68 const hb_segment_properties_t *props,
69 const hb_feature_t *user_features,
70 unsigned int num_user_features)
72 switch (props->direction) {
73 case HB_DIRECTION_LTR:
74 planner->map.add_bool_feature (HB_TAG ('l','t','r','a'));
75 planner->map.add_bool_feature (HB_TAG ('l','t','r','m'));
77 case HB_DIRECTION_RTL:
78 planner->map.add_bool_feature (HB_TAG ('r','t','l','a'));
79 planner->map.add_bool_feature (HB_TAG ('r','t','l','m'), false);
81 case HB_DIRECTION_TTB:
82 case HB_DIRECTION_BTT:
83 case HB_DIRECTION_INVALID:
88 #define ADD_FEATURES(array) \
90 for (unsigned int i = 0; i < ARRAY_LENGTH (array); i++) \
91 planner->map.add_bool_feature (array[i]); \
94 hb_ot_shape_complex_collect_features (planner->shaper, &planner->map, props);
96 ADD_FEATURES (common_features);
98 if (HB_DIRECTION_IS_HORIZONTAL (props->direction))
99 ADD_FEATURES (horizontal_features);
101 ADD_FEATURES (vertical_features);
105 for (unsigned int i = 0; i < num_user_features; i++) {
106 const hb_feature_t *feature = &user_features[i];
107 planner->map.add_feature (feature->tag, feature->value, (feature->start == 0 && feature->end == (unsigned int) -1));
113 hb_ot_shape_setup_masks (hb_ot_shape_context_t *c)
115 hb_mask_t global_mask = c->plan->map.get_global_mask ();
116 c->buffer->reset_masks (global_mask);
118 hb_ot_shape_complex_setup_masks (c->plan->shaper, &c->plan->map, c->buffer);
120 for (unsigned int i = 0; i < c->num_user_features; i++)
122 const hb_feature_t *feature = &c->user_features[i];
123 if (!(feature->start == 0 && feature->end == (unsigned int)-1)) {
125 hb_mask_t mask = c->plan->map.get_mask (feature->tag, &shift);
126 c->buffer->set_masks (feature->value << shift, mask, feature->start, feature->end);
137 _hb_set_unicode_props (hb_buffer_t *buffer)
139 unsigned int count = buffer->len;
140 for (unsigned int i = 1; i < count; i++)
141 hb_glyph_info_set_unicode_props (&buffer->info[i], buffer->unicode);
145 hb_form_clusters (hb_buffer_t *buffer)
147 unsigned int count = buffer->len;
148 for (unsigned int i = 1; i < count; i++)
149 if (FLAG (buffer->info[i].general_category()) &
150 (FLAG (HB_UNICODE_GENERAL_CATEGORY_SPACING_MARK) |
151 FLAG (HB_UNICODE_GENERAL_CATEGORY_ENCLOSING_MARK) |
152 FLAG (HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK)))
153 buffer->info[i].cluster = buffer->info[i - 1].cluster;
157 hb_ensure_native_direction (hb_buffer_t *buffer)
159 hb_direction_t direction = buffer->props.direction;
162 * The only BTT vertical script is Ogham, but it's not clear to me whether OpenType
163 * Ogham fonts are supposed to be implemented BTT or not. Need to research that
165 if ((HB_DIRECTION_IS_HORIZONTAL (direction) && direction != hb_script_get_horizontal_direction (buffer->props.script)) ||
166 (HB_DIRECTION_IS_VERTICAL (direction) && direction != HB_DIRECTION_TTB))
168 hb_buffer_reverse_clusters (buffer);
169 buffer->props.direction = HB_DIRECTION_REVERSE (buffer->props.direction);
177 hb_mirror_chars (hb_ot_shape_context_t *c)
179 hb_unicode_funcs_t *unicode = c->buffer->unicode;
181 if (HB_DIRECTION_IS_FORWARD (c->target_direction))
184 hb_mask_t rtlm_mask = c->plan->map.get_1_mask (HB_TAG ('r','t','l','m'));
186 unsigned int count = c->buffer->len;
187 for (unsigned int i = 0; i < count; i++) {
188 hb_codepoint_t codepoint = hb_unicode_mirroring (unicode, c->buffer->info[i].codepoint);
189 if (likely (codepoint == c->buffer->info[i].codepoint))
190 c->buffer->info[i].mask |= rtlm_mask; /* XXX this should be moved to before setting user-feature masks */
192 c->buffer->info[i].codepoint = codepoint;
197 hb_map_glyphs (hb_font_t *font,
200 hb_codepoint_t glyph;
202 if (unlikely (!buffer->len))
205 buffer->clear_output ();
207 unsigned int count = buffer->len - 1;
208 for (buffer->idx = 0; buffer->idx < count;) {
209 if (unlikely (is_variation_selector (buffer->info[buffer->idx + 1].codepoint))) {
210 hb_font_get_glyph (font, buffer->info[buffer->idx].codepoint, buffer->info[buffer->idx + 1].codepoint, &glyph);
211 buffer->replace_glyph (glyph);
212 buffer->skip_glyph ();
214 hb_font_get_glyph (font, buffer->info[buffer->idx].codepoint, 0, &glyph);
215 buffer->replace_glyph (glyph);
218 if (likely (buffer->idx < buffer->len)) {
219 hb_font_get_glyph (font, buffer->info[buffer->idx].codepoint, 0, &glyph);
220 buffer->replace_glyph (glyph);
222 buffer->swap_buffers ();
226 hb_substitute_default (hb_ot_shape_context_t *c)
228 hb_ot_layout_substitute_start (c->buffer);
232 hb_map_glyphs (c->font, c->buffer);
236 hb_ot_substitute_complex (hb_ot_shape_context_t *c)
238 if (hb_ot_layout_has_substitution (c->face))
239 c->plan->map.substitute (c->face, c->buffer);
241 hb_ot_layout_substitute_finish (c->buffer);
243 c->applied_substitute_complex = TRUE;
248 hb_substitute_complex_fallback (hb_ot_shape_context_t *c HB_UNUSED)
257 hb_position_default (hb_ot_shape_context_t *c)
259 hb_ot_layout_position_start (c->buffer);
261 unsigned int count = c->buffer->len;
262 for (unsigned int i = 0; i < count; i++) {
263 hb_font_get_glyph_advance_for_direction (c->font, c->buffer->info[i].codepoint,
264 c->buffer->props.direction,
265 &c->buffer->pos[i].x_advance,
266 &c->buffer->pos[i].y_advance);
267 hb_font_subtract_glyph_origin_for_direction (c->font, c->buffer->info[i].codepoint,
268 c->buffer->props.direction,
269 &c->buffer->pos[i].x_offset,
270 &c->buffer->pos[i].y_offset);
275 hb_ot_position_complex (hb_ot_shape_context_t *c)
278 if (hb_ot_layout_has_positioning (c->face))
280 /* Change glyph origin to what GPOS expects, apply GPOS, change it back. */
282 unsigned int count = c->buffer->len;
283 for (unsigned int i = 0; i < count; i++) {
284 hb_font_add_glyph_origin_for_direction (c->font, c->buffer->info[i].codepoint,
286 &c->buffer->pos[i].x_offset,
287 &c->buffer->pos[i].y_offset);
290 c->plan->map.position (c->font, c->buffer);
292 for (unsigned int i = 0; i < count; i++) {
293 hb_font_subtract_glyph_origin_for_direction (c->font, c->buffer->info[i].codepoint,
295 &c->buffer->pos[i].x_offset,
296 &c->buffer->pos[i].y_offset);
300 hb_ot_layout_position_finish (c->buffer);
302 c->applied_position_complex = TRUE;
307 hb_position_complex_fallback (hb_ot_shape_context_t *c HB_UNUSED)
313 hb_truetype_kern (hb_ot_shape_context_t *c)
315 /* TODO Check for kern=0 */
316 unsigned int count = c->buffer->len;
317 for (unsigned int i = 1; i < count; i++) {
318 hb_position_t x_kern, y_kern, kern1, kern2;
319 hb_font_get_glyph_kerning_for_direction (c->font,
320 c->buffer->info[i - 1].codepoint, c->buffer->info[i].codepoint,
321 c->buffer->props.direction,
325 kern2 = x_kern - kern1;
326 c->buffer->pos[i - 1].x_advance += kern1;
327 c->buffer->pos[i].x_advance += kern2;
328 c->buffer->pos[i].x_offset += kern2;
331 kern2 = y_kern - kern1;
332 c->buffer->pos[i - 1].y_advance += kern1;
333 c->buffer->pos[i].y_advance += kern2;
334 c->buffer->pos[i].y_offset += kern2;
339 hb_position_complex_fallback_visual (hb_ot_shape_context_t *c)
341 hb_truetype_kern (c);
348 hb_ot_shape_execute_internal (hb_ot_shape_context_t *c)
350 c->buffer->deallocate_var_all ();
352 /* Save the original direction, we use it later. */
353 c->target_direction = c->buffer->props.direction;
355 HB_BUFFER_ALLOCATE_VAR (c->buffer, general_category);
356 HB_BUFFER_ALLOCATE_VAR (c->buffer, combining_class);
358 _hb_set_unicode_props (c->buffer); /* BUFFER: Set general_category and combining_class */
360 hb_form_clusters (c->buffer);
362 hb_ensure_native_direction (c->buffer);
364 _hb_ot_shape_normalize (c);
366 hb_ot_shape_setup_masks (c);
370 hb_substitute_default (c);
372 hb_ot_substitute_complex (c);
374 if (!c->applied_substitute_complex)
375 hb_substitute_complex_fallback (c);
380 hb_position_default (c);
382 hb_ot_position_complex (c);
384 hb_bool_t position_fallback = !c->applied_position_complex;
385 if (position_fallback)
386 hb_position_complex_fallback (c);
388 if (HB_DIRECTION_IS_BACKWARD (c->buffer->props.direction))
389 hb_buffer_reverse (c->buffer);
391 if (position_fallback)
392 hb_position_complex_fallback_visual (c);
395 HB_BUFFER_DEALLOCATE_VAR (c->buffer, combining_class);
396 HB_BUFFER_DEALLOCATE_VAR (c->buffer, general_category);
398 c->buffer->props.direction = c->target_direction;
400 c->buffer->deallocate_var_all ();
404 hb_ot_shape_plan_internal (hb_ot_shape_plan_t *plan,
406 const hb_segment_properties_t *props,
407 const hb_feature_t *user_features,
408 unsigned int num_user_features)
410 hb_ot_shape_planner_t planner;
412 planner.shaper = hb_ot_shape_complex_categorize (props);
414 hb_ot_shape_collect_features (&planner, props, user_features, num_user_features);
416 planner.compile (face, props, *plan);
420 hb_ot_shape_execute (hb_ot_shape_plan_t *plan,
423 const hb_feature_t *user_features,
424 unsigned int num_user_features)
426 hb_ot_shape_context_t c = {plan, font, font->face, buffer, user_features, num_user_features};
427 hb_ot_shape_execute_internal (&c);
431 hb_ot_shape (hb_font_t *font,
433 const hb_feature_t *features,
434 unsigned int num_features)
436 hb_ot_shape_plan_t plan;
438 hb_ot_shape_plan_internal (&plan, font->face, &buffer->props, features, num_features);
439 hb_ot_shape_execute (&plan, font, buffer, features, num_features);