2 * Copyright © 2011,2012 Google, Inc.
4 * This is part of HarfBuzz, a text shaping library.
6 * Permission is hereby granted, without written agreement and without
7 * license or royalty fees, to use, copy, modify, and distribute this
8 * software and its documentation for any purpose, provided that the
9 * above copyright notice and the following two paragraphs appear in
10 * all copies of this software.
12 * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
13 * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
14 * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
15 * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
18 * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
19 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
20 * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
21 * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
22 * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
24 * Google Author(s): Behdad Esfahbod
27 #include "hb-ot-shape-fallback-private.hh"
30 recategorize_combining_class (hb_codepoint_t u,
36 /* Thai / Lao need some per-character work. */
37 if ((u & ~0xFF) == 0x0E00)
39 if (unlikely (klass == 0))
52 klass = HB_UNICODE_COMBINING_CLASS_ABOVE_RIGHT;
63 klass = HB_UNICODE_COMBINING_CLASS_ABOVE;
67 klass = HB_UNICODE_COMBINING_CLASS_BELOW;
71 /* Thai virama is below-right */
73 klass = HB_UNICODE_COMBINING_CLASS_BELOW_RIGHT;
82 case HB_MODIFIED_COMBINING_CLASS_CCC10: /* sheva */
83 case HB_MODIFIED_COMBINING_CLASS_CCC11: /* hataf segol */
84 case HB_MODIFIED_COMBINING_CLASS_CCC12: /* hataf patah */
85 case HB_MODIFIED_COMBINING_CLASS_CCC13: /* hataf qamats */
86 case HB_MODIFIED_COMBINING_CLASS_CCC14: /* hiriq */
87 case HB_MODIFIED_COMBINING_CLASS_CCC15: /* tsere */
88 case HB_MODIFIED_COMBINING_CLASS_CCC16: /* segol */
89 case HB_MODIFIED_COMBINING_CLASS_CCC17: /* patah */
90 case HB_MODIFIED_COMBINING_CLASS_CCC18: /* qamats */
91 case HB_MODIFIED_COMBINING_CLASS_CCC20: /* qubuts */
92 case HB_MODIFIED_COMBINING_CLASS_CCC22: /* meteg */
93 return HB_UNICODE_COMBINING_CLASS_BELOW;
95 case HB_MODIFIED_COMBINING_CLASS_CCC23: /* rafe */
96 return HB_UNICODE_COMBINING_CLASS_ATTACHED_ABOVE;
98 case HB_MODIFIED_COMBINING_CLASS_CCC24: /* shin dot */
99 return HB_UNICODE_COMBINING_CLASS_ABOVE_RIGHT;
101 case HB_MODIFIED_COMBINING_CLASS_CCC25: /* sin dot */
102 case HB_MODIFIED_COMBINING_CLASS_CCC19: /* holam */
103 return HB_UNICODE_COMBINING_CLASS_ABOVE_LEFT;
105 case HB_MODIFIED_COMBINING_CLASS_CCC26: /* point varika */
106 return HB_UNICODE_COMBINING_CLASS_ABOVE;
108 case HB_MODIFIED_COMBINING_CLASS_CCC21: /* dagesh */
112 /* Arabic and Syriac */
114 case HB_MODIFIED_COMBINING_CLASS_CCC27: /* fathatan */
115 case HB_MODIFIED_COMBINING_CLASS_CCC28: /* dammatan */
116 case HB_MODIFIED_COMBINING_CLASS_CCC30: /* fatha */
117 case HB_MODIFIED_COMBINING_CLASS_CCC31: /* damma */
118 case HB_MODIFIED_COMBINING_CLASS_CCC33: /* shadda */
119 case HB_MODIFIED_COMBINING_CLASS_CCC34: /* sukun */
120 case HB_MODIFIED_COMBINING_CLASS_CCC35: /* superscript alef */
121 case HB_MODIFIED_COMBINING_CLASS_CCC36: /* superscript alaph */
122 return HB_UNICODE_COMBINING_CLASS_ABOVE;
124 case HB_MODIFIED_COMBINING_CLASS_CCC29: /* kasratan */
125 case HB_MODIFIED_COMBINING_CLASS_CCC32: /* kasra */
126 return HB_UNICODE_COMBINING_CLASS_BELOW;
131 case HB_MODIFIED_COMBINING_CLASS_CCC103: /* sara u / sara uu */
132 return HB_UNICODE_COMBINING_CLASS_BELOW_RIGHT;
134 case HB_MODIFIED_COMBINING_CLASS_CCC107: /* mai */
135 return HB_UNICODE_COMBINING_CLASS_ABOVE_RIGHT;
140 case HB_MODIFIED_COMBINING_CLASS_CCC118: /* sign u / sign uu */
141 return HB_UNICODE_COMBINING_CLASS_BELOW;
143 case HB_MODIFIED_COMBINING_CLASS_CCC122: /* mai */
144 return HB_UNICODE_COMBINING_CLASS_ABOVE;
149 case HB_MODIFIED_COMBINING_CLASS_CCC129: /* sign aa */
150 return HB_UNICODE_COMBINING_CLASS_BELOW;
152 case HB_MODIFIED_COMBINING_CLASS_CCC130: /* sign i*/
153 return HB_UNICODE_COMBINING_CLASS_ABOVE;
155 case HB_MODIFIED_COMBINING_CLASS_CCC132: /* sign u */
156 return HB_UNICODE_COMBINING_CLASS_BELOW;
164 _hb_ot_shape_fallback_position_recategorize_marks (const hb_ot_shape_plan_t *plan HB_UNUSED,
165 hb_font_t *font HB_UNUSED,
168 unsigned int count = buffer->len;
169 for (unsigned int i = 0; i < count; i++)
170 if (_hb_glyph_info_get_general_category (&buffer->info[i]) == HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK) {
171 unsigned int combining_class = _hb_glyph_info_get_modified_combining_class (&buffer->info[i]);
172 combining_class = recategorize_combining_class (buffer->info[i].codepoint, combining_class);
173 _hb_glyph_info_set_modified_combining_class (&buffer->info[i], combining_class);
179 zero_mark_advances (hb_buffer_t *buffer,
183 for (unsigned int i = start; i < end; i++)
184 if (_hb_glyph_info_get_general_category (&buffer->info[i]) == HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK)
186 buffer->pos[i].x_advance = 0;
187 buffer->pos[i].y_advance = 0;
192 position_mark (const hb_ot_shape_plan_t *plan,
195 hb_glyph_extents_t &base_extents,
197 unsigned int combining_class)
199 hb_glyph_extents_t mark_extents;
200 if (!font->get_glyph_extents (buffer->info[i].codepoint,
204 hb_position_t y_gap = font->y_scale / 16;
206 hb_glyph_position_t &pos = buffer->pos[i];
207 pos.x_offset = pos.y_offset = 0;
210 /* We dont position LEFT and RIGHT marks. */
213 switch (combining_class)
215 case HB_UNICODE_COMBINING_CLASS_DOUBLE_BELOW:
216 case HB_UNICODE_COMBINING_CLASS_DOUBLE_ABOVE:
217 if (buffer->props.direction == HB_DIRECTION_LTR) {
218 pos.x_offset += base_extents.x_bearing - mark_extents.width / 2 - mark_extents.x_bearing;
220 } else if (buffer->props.direction == HB_DIRECTION_RTL) {
221 pos.x_offset += base_extents.x_bearing + base_extents.width - mark_extents.width / 2 - mark_extents.x_bearing;
227 case HB_UNICODE_COMBINING_CLASS_ATTACHED_BELOW:
228 case HB_UNICODE_COMBINING_CLASS_ATTACHED_ABOVE:
229 case HB_UNICODE_COMBINING_CLASS_BELOW:
230 case HB_UNICODE_COMBINING_CLASS_ABOVE:
232 pos.x_offset += base_extents.x_bearing + (base_extents.width - mark_extents.width) / 2 - mark_extents.x_bearing;
235 case HB_UNICODE_COMBINING_CLASS_ATTACHED_BELOW_LEFT:
236 case HB_UNICODE_COMBINING_CLASS_BELOW_LEFT:
237 case HB_UNICODE_COMBINING_CLASS_ABOVE_LEFT:
239 pos.x_offset += base_extents.x_bearing - mark_extents.x_bearing;
242 case HB_UNICODE_COMBINING_CLASS_ATTACHED_ABOVE_RIGHT:
243 case HB_UNICODE_COMBINING_CLASS_BELOW_RIGHT:
244 case HB_UNICODE_COMBINING_CLASS_ABOVE_RIGHT:
246 pos.x_offset += base_extents.x_bearing + base_extents.width - mark_extents.width - mark_extents.x_bearing;
251 switch (combining_class)
253 case HB_UNICODE_COMBINING_CLASS_DOUBLE_BELOW:
254 case HB_UNICODE_COMBINING_CLASS_BELOW_LEFT:
255 case HB_UNICODE_COMBINING_CLASS_BELOW:
256 case HB_UNICODE_COMBINING_CLASS_BELOW_RIGHT:
257 /* Add gap, fall-through. */
258 base_extents.height -= y_gap;
260 case HB_UNICODE_COMBINING_CLASS_ATTACHED_BELOW_LEFT:
261 case HB_UNICODE_COMBINING_CLASS_ATTACHED_BELOW:
262 pos.y_offset += base_extents.y_bearing + base_extents.height - mark_extents.y_bearing;
263 base_extents.height += mark_extents.height;
266 case HB_UNICODE_COMBINING_CLASS_DOUBLE_ABOVE:
267 case HB_UNICODE_COMBINING_CLASS_ABOVE_LEFT:
268 case HB_UNICODE_COMBINING_CLASS_ABOVE:
269 case HB_UNICODE_COMBINING_CLASS_ABOVE_RIGHT:
270 /* Add gap, fall-through. */
271 base_extents.y_bearing += y_gap;
272 base_extents.height -= y_gap;
274 case HB_UNICODE_COMBINING_CLASS_ATTACHED_ABOVE:
275 case HB_UNICODE_COMBINING_CLASS_ATTACHED_ABOVE_RIGHT:
276 pos.y_offset += base_extents.y_bearing - (mark_extents.y_bearing + mark_extents.height);
277 base_extents.y_bearing -= mark_extents.height;
278 base_extents.height += mark_extents.height;
284 position_around_base (const hb_ot_shape_plan_t *plan,
290 hb_direction_t horiz_dir = HB_DIRECTION_INVALID;
291 hb_glyph_extents_t base_extents;
292 if (!font->get_glyph_extents (buffer->info[base].codepoint,
295 /* If extents don't work, zero marks and go home. */
296 zero_mark_advances (buffer, base + 1, end);
299 base_extents.x_bearing += buffer->pos[base].x_offset;
300 base_extents.y_bearing += buffer->pos[base].y_offset;
302 unsigned int lig_id = get_lig_id (buffer->info[base]);
303 unsigned int num_lig_components = get_lig_num_comps (buffer->info[base]);
305 hb_position_t x_offset = 0, y_offset = 0;
306 if (HB_DIRECTION_IS_FORWARD (buffer->props.direction)) {
307 x_offset -= buffer->pos[base].x_advance;
308 y_offset -= buffer->pos[base].y_advance;
311 hb_glyph_extents_t component_extents = base_extents;
312 unsigned int last_lig_component = (unsigned int) -1;
313 unsigned int last_combining_class = 255;
314 hb_glyph_extents_t cluster_extents = base_extents; /* Initialization is just to shut gcc up. */
315 for (unsigned int i = base + 1; i < end; i++)
316 if (_hb_glyph_info_get_modified_combining_class (&buffer->info[i]))
318 if (num_lig_components > 1) {
319 unsigned int this_lig_id = get_lig_id (buffer->info[i]);
320 unsigned int this_lig_component = get_lig_comp (buffer->info[i]) - 1;
321 /* Conditions for attaching to the last component. */
322 if (!lig_id || lig_id != this_lig_id || this_lig_component >= num_lig_components)
323 this_lig_component = num_lig_components - 1;
324 if (last_lig_component != this_lig_component)
326 last_lig_component = this_lig_component;
327 last_combining_class = 255;
328 component_extents = base_extents;
329 if (unlikely (horiz_dir == HB_DIRECTION_INVALID)) {
330 if (HB_DIRECTION_IS_HORIZONTAL (plan->props.direction))
331 horiz_dir = plan->props.direction;
333 horiz_dir = hb_script_get_horizontal_direction (plan->props.script);
335 if (horiz_dir == HB_DIRECTION_LTR)
336 component_extents.x_bearing += (this_lig_component * component_extents.width) / num_lig_components;
338 component_extents.x_bearing += ((num_lig_components - 1 - this_lig_component) * component_extents.width) / num_lig_components;
339 component_extents.width /= num_lig_components;
343 unsigned int this_combining_class = _hb_glyph_info_get_modified_combining_class (&buffer->info[i]);
344 if (last_combining_class != this_combining_class)
346 last_combining_class = this_combining_class;
347 cluster_extents = component_extents;
350 position_mark (plan, font, buffer, cluster_extents, i, this_combining_class);
352 buffer->pos[i].x_advance = 0;
353 buffer->pos[i].y_advance = 0;
354 buffer->pos[i].x_offset += x_offset;
355 buffer->pos[i].y_offset += y_offset;
358 if (HB_DIRECTION_IS_FORWARD (buffer->props.direction)) {
359 x_offset -= buffer->pos[i].x_advance;
360 y_offset -= buffer->pos[i].y_advance;
362 x_offset += buffer->pos[i].x_advance;
363 y_offset += buffer->pos[i].y_advance;
369 position_cluster (const hb_ot_shape_plan_t *plan,
378 /* Find the base glyph */
379 for (unsigned int i = start; i < end; i++)
380 if (!HB_UNICODE_GENERAL_CATEGORY_IS_MARK (_hb_glyph_info_get_general_category (&buffer->info[i])))
382 /* Find mark glyphs */
384 for (j = i + 1; j < end; j++)
385 if (!HB_UNICODE_GENERAL_CATEGORY_IS_MARK (_hb_glyph_info_get_general_category (&buffer->info[j])))
388 position_around_base (plan, font, buffer, i, j);
395 _hb_ot_shape_fallback_position (const hb_ot_shape_plan_t *plan,
399 unsigned int start = 0;
400 unsigned int last_cluster = buffer->info[0].cluster;
401 unsigned int count = buffer->len;
402 for (unsigned int i = 1; i < count; i++)
403 if (buffer->info[i].cluster != last_cluster) {
404 position_cluster (plan, font, buffer, start, i);
406 last_cluster = buffer->info[i].cluster;
408 position_cluster (plan, font, buffer, start, count);