2 * Copyright (C) 2009,2010 Red Hat, Inc.
3 * Copyright (C) 2010 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"
31 #include "hb-ot-map-private.hh"
37 hb_tag_t default_features[] = {
38 HB_TAG('c','a','l','t'),
39 HB_TAG('c','c','m','p'),
40 HB_TAG('c','l','i','g'),
41 HB_TAG('c','s','w','h'),
42 HB_TAG('c','u','r','s'),
43 HB_TAG('k','e','r','n'),
44 HB_TAG('l','i','g','a'),
45 HB_TAG('l','o','c','l'),
46 HB_TAG('m','a','r','k'),
47 HB_TAG('m','k','m','k'),
48 HB_TAG('r','l','i','g')
52 hb_ot_shape_collect_features (hb_ot_map_t *map,
53 hb_segment_properties_t *props,
54 const hb_feature_t *user_features,
55 unsigned int num_user_features)
57 switch (props->direction) {
58 case HB_DIRECTION_LTR:
59 map->add_bool_feature (HB_TAG ('l','t','r','a'));
60 map->add_bool_feature (HB_TAG ('l','t','r','m'));
62 case HB_DIRECTION_RTL:
63 map->add_bool_feature (HB_TAG ('r','t','l','a'));
64 map->add_bool_feature (HB_TAG ('r','t','l','m'), false);
66 case HB_DIRECTION_TTB:
67 case HB_DIRECTION_BTT:
72 for (unsigned int i = 0; i < ARRAY_LENGTH (default_features); i++)
73 map->add_bool_feature (default_features[i]);
77 for (unsigned int i = 0; i < num_user_features; i++) {
78 const hb_feature_t *feature = &user_features[i];
79 map->add_feature (feature->tag, feature->value, (feature->start == 0 && feature->end == (unsigned int) -1));
85 hb_ot_shape_setup_masks (hb_ot_shape_context_t *c)
87 hb_mask_t global_mask = c->map->get_global_mask ();
89 c->buffer->set_masks (global_mask, global_mask, 0, (unsigned int) -1);
91 for (unsigned int i = 0; i < c->num_user_features; i++)
93 const hb_feature_t *feature = &c->user_features[i];
94 if (!(feature->start == 0 && feature->end == (unsigned int)-1)) {
96 hb_mask_t mask = c->map->get_mask (feature->tag, &shift);
97 c->buffer->set_masks (feature->value << shift, mask, feature->start, feature->end);
106 hb_ot_substitute_complex (hb_ot_shape_context_t *c)
108 if (!hb_ot_layout_has_substitution (c->face))
111 c->map->substitute (c->face, c->buffer);
113 c->applied_substitute_complex = TRUE;
118 hb_ot_position_complex (hb_ot_shape_context_t *c)
121 if (!hb_ot_layout_has_positioning (c->face))
124 c->map->position (c->font, c->face, c->buffer);
126 hb_ot_layout_position_finish (c->font, c->face, c->buffer);
128 c->applied_position_complex = TRUE;
137 static inline hb_bool_t
138 is_variation_selector (hb_codepoint_t unicode)
140 return unlikely ((unicode >= 0x180B && unicode <= 0x180D) || /* MONGOLIAN FREE VARIATION SELECTOR ONE..THREE */
141 (unicode >= 0xFE00 && unicode <= 0xFE0F) || /* VARIATION SELECTOR-1..16 */
142 (unicode >= 0xE0100 && unicode <= 0xE01EF)); /* VARIATION SELECTOR-17..256 */
146 hb_form_clusters (hb_ot_shape_context_t *c)
148 unsigned int count = c->buffer->len;
149 for (unsigned int i = 1; i < count; i++)
150 if (c->buffer->unicode->v.get_general_category (c->buffer->info[i].codepoint) == HB_CATEGORY_NON_SPACING_MARK)
151 c->buffer->info[i].cluster = c->buffer->info[i - 1].cluster;
155 hb_ensure_native_direction (hb_ot_shape_context_t *c)
157 hb_direction_t direction = c->buffer->props.direction;
160 if (HB_DIRECTION_IS_HORIZONTAL (direction) &&
161 direction != _hb_script_get_horizontal_direction (c->buffer->props.script))
163 hb_buffer_reverse_clusters (c->buffer);
164 c->buffer->props.direction = HB_DIRECTION_REVERSE (c->buffer->props.direction);
172 hb_mirror_chars (hb_ot_shape_context_t *c)
174 hb_unicode_get_mirroring_func_t get_mirroring = c->buffer->unicode->v.get_mirroring;
176 if (HB_DIRECTION_IS_FORWARD (c->buffer->props.direction))
179 hb_mask_t rtlm_mask = c->map->get_mask (HB_TAG ('r','t','l','m'));
181 unsigned int count = c->buffer->len;
182 for (unsigned int i = 0; i < count; i++) {
183 hb_codepoint_t codepoint = get_mirroring (c->buffer->info[i].codepoint);
184 if (likely (codepoint == c->buffer->info[i].codepoint))
185 c->buffer->info[i].mask |= rtlm_mask;
187 c->buffer->info[i].codepoint = codepoint;
192 hb_map_glyphs (hb_font_t *font,
196 if (unlikely (!buffer->len))
199 buffer->clear_output ();
200 unsigned int count = buffer->len - 1;
201 for (buffer->i = 0; buffer->i < count;) {
202 if (unlikely (is_variation_selector (buffer->info[buffer->i + 1].codepoint))) {
203 buffer->add_output_glyph (hb_font_get_glyph (font, face, buffer->info[buffer->i].codepoint, buffer->info[buffer->i + 1].codepoint));
206 buffer->add_output_glyph (hb_font_get_glyph (font, face, buffer->info[buffer->i].codepoint, 0));
209 if (likely (buffer->i < buffer->len))
210 buffer->add_output_glyph (hb_font_get_glyph (font, face, buffer->info[buffer->i].codepoint, 0));
215 hb_substitute_default (hb_ot_shape_context_t *c)
217 hb_map_glyphs (c->font, c->face, c->buffer);
221 hb_substitute_complex_fallback (hb_ot_shape_context_t *c HB_UNUSED)
230 hb_position_default (hb_ot_shape_context_t *c)
232 hb_buffer_clear_positions (c->buffer);
234 unsigned int count = c->buffer->len;
235 for (unsigned int i = 0; i < count; i++) {
236 hb_glyph_metrics_t metrics;
237 hb_font_get_glyph_metrics (c->font, c->face, c->buffer->info[i].codepoint, &metrics);
238 c->buffer->pos[i].x_advance = metrics.x_advance;
239 c->buffer->pos[i].y_advance = metrics.y_advance;
244 hb_position_complex_fallback (hb_ot_shape_context_t *c HB_UNUSED)
250 hb_truetype_kern (hb_ot_shape_context_t *c)
252 /* TODO Check for kern=0 */
253 unsigned int count = c->buffer->len;
254 for (unsigned int i = 1; i < count; i++) {
255 hb_position_t kern, kern1, kern2;
256 kern = hb_font_get_kerning (c->font, c->face, c->buffer->info[i - 1].codepoint, c->buffer->info[i].codepoint);
258 kern2 = kern - kern1;
259 c->buffer->pos[i - 1].x_advance += kern1;
260 c->buffer->pos[i].x_advance += kern2;
261 c->buffer->pos[i].x_offset += kern2;
266 hb_position_complex_fallback_visual (hb_ot_shape_context_t *c)
268 hb_truetype_kern (c);
275 hb_ot_shape_internal (hb_ot_shape_context_t *c)
277 /* Save the original direction, we use it later. */
278 c->original_direction = c->buffer->props.direction;
280 hb_ot_shape_setup_masks (c);
282 hb_form_clusters (c);
286 c->buffer->clear_masks ();
288 /* Mirroring needs to see the original direction */
291 hb_ensure_native_direction (c);
293 hb_substitute_default (c);
295 hb_ot_substitute_complex (c);
297 if (!c->applied_substitute_complex)
298 hb_substitute_complex_fallback (c);
303 c->buffer->clear_masks ();
305 hb_position_default (c);
307 hb_ot_position_complex (c);
309 hb_bool_t position_fallback = !c->applied_position_complex;
310 if (position_fallback)
311 hb_position_complex_fallback (c);
313 if (HB_DIRECTION_IS_BACKWARD (c->buffer->props.direction))
314 hb_buffer_reverse (c->buffer);
316 if (position_fallback)
317 hb_position_complex_fallback_visual (c);
320 c->buffer->props.direction = c->original_direction;
324 hb_ot_shape_plan_internal (hb_ot_map_t *map,
326 hb_segment_properties_t *props,
327 const hb_feature_t *user_features,
328 unsigned int num_user_features)
330 hb_ot_shape_collect_features (map, props, user_features, num_user_features);
332 map->compile (face, props);
336 hb_ot_shape (hb_font_t *font,
339 const hb_feature_t *user_features,
340 unsigned int num_user_features)
344 hb_ot_shape_plan_internal (&map, face, &buffer->props, user_features, num_user_features);
346 hb_ot_shape_context_t c = {font, face, buffer, user_features, num_user_features};
348 hb_ot_shape_internal (&c);