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_shape_context_t *c)
54 switch (c->original_direction) {
55 case HB_DIRECTION_LTR:
56 c->map->add_bool_feature (HB_TAG ('l','t','r','a'));
57 c->map->add_bool_feature (HB_TAG ('l','t','r','m'));
59 case HB_DIRECTION_RTL:
60 c->map->add_bool_feature (HB_TAG ('r','t','l','a'));
61 c->map->add_bool_feature (HB_TAG ('r','t','l','m'), false);
63 case HB_DIRECTION_TTB:
64 case HB_DIRECTION_BTT:
69 for (unsigned int i = 0; i < ARRAY_LENGTH (default_features); i++)
70 c->map->add_bool_feature (default_features[i]);
74 for (unsigned int i = 0; i < c->num_features; i++) {
75 const hb_feature_t *feature = &c->features[i];
76 c->map->add_feature (feature->tag, feature->value, (feature->start == 0 && feature->end == (unsigned int) -1));
82 hb_ot_shape_setup_masks (hb_ot_shape_context_t *c)
84 hb_mask_t global_mask = c->map->get_global_mask ();
86 c->buffer->set_masks (global_mask, global_mask, 0, (unsigned int) -1);
88 for (unsigned int i = 0; i < c->num_features; i++)
90 hb_feature_t *feature = &c->features[i];
91 if (!(feature->start == 0 && feature->end == (unsigned int)-1)) {
93 hb_mask_t mask = c->map->get_mask (feature->tag, &shift);
94 c->buffer->set_masks (feature->value << shift, mask, feature->start, feature->end);
103 hb_ot_substitute_complex (hb_ot_shape_context_t *c)
105 if (!hb_ot_layout_has_substitution (c->face))
108 c->map->substitute (c);
110 c->applied_substitute_complex = TRUE;
115 hb_ot_position_complex (hb_ot_shape_context_t *c)
118 if (!hb_ot_layout_has_positioning (c->face))
121 c->map->position (c);
123 hb_ot_layout_position_finish (c->font, c->face, c->buffer);
125 c->applied_position_complex = TRUE;
134 static inline hb_bool_t
135 is_variation_selector (hb_codepoint_t unicode)
137 return unlikely ((unicode >= 0x180B && unicode <= 0x180D) || /* MONGOLIAN FREE VARIATION SELECTOR ONE..THREE */
138 (unicode >= 0xFE00 && unicode <= 0xFE0F) || /* VARIATION SELECTOR-1..16 */
139 (unicode >= 0xE0100 && unicode <= 0xE01EF)); /* VARIATION SELECTOR-17..256 */
143 hb_form_clusters (hb_ot_shape_context_t *c)
145 unsigned int count = c->buffer->len;
146 for (unsigned int i = 1; i < count; i++)
147 if (c->buffer->unicode->v.get_general_category (c->buffer->info[i].codepoint) == HB_CATEGORY_NON_SPACING_MARK)
148 c->buffer->info[i].cluster = c->buffer->info[i - 1].cluster;
152 hb_ensure_native_direction (hb_ot_shape_context_t *c)
154 hb_direction_t direction = c->buffer->props.direction;
157 if (HB_DIRECTION_IS_HORIZONTAL (direction) &&
158 direction != _hb_script_get_horizontal_direction (c->buffer->props.script))
160 hb_buffer_reverse_clusters (c->buffer);
161 c->buffer->props.direction = HB_DIRECTION_REVERSE (c->buffer->props.direction);
169 hb_mirror_chars (hb_ot_shape_context_t *c)
171 hb_unicode_get_mirroring_func_t get_mirroring = c->buffer->unicode->v.get_mirroring;
173 if (HB_DIRECTION_IS_FORWARD (c->buffer->props.direction))
176 hb_mask_t rtlm_mask = c->map->get_mask (HB_TAG ('r','t','l','m'));
178 unsigned int count = c->buffer->len;
179 for (unsigned int i = 0; i < count; i++) {
180 hb_codepoint_t codepoint = get_mirroring (c->buffer->info[i].codepoint);
181 if (likely (codepoint == c->buffer->info[i].codepoint))
182 c->buffer->info[i].mask |= rtlm_mask;
184 c->buffer->info[i].codepoint = codepoint;
189 hb_map_glyphs (hb_font_t *font,
193 if (unlikely (!buffer->len))
196 buffer->clear_output ();
197 unsigned int count = buffer->len - 1;
198 for (buffer->i = 0; buffer->i < count;) {
199 if (unlikely (is_variation_selector (buffer->info[buffer->i + 1].codepoint))) {
200 buffer->add_output_glyph (hb_font_get_glyph (font, face, buffer->info[buffer->i].codepoint, buffer->info[buffer->i + 1].codepoint));
203 buffer->add_output_glyph (hb_font_get_glyph (font, face, buffer->info[buffer->i].codepoint, 0));
206 if (likely (buffer->i < buffer->len))
207 buffer->add_output_glyph (hb_font_get_glyph (font, face, buffer->info[buffer->i].codepoint, 0));
212 hb_substitute_default (hb_ot_shape_context_t *c)
214 hb_map_glyphs (c->font, c->face, c->buffer);
218 hb_substitute_complex_fallback (hb_ot_shape_context_t *c HB_UNUSED)
227 hb_position_default (hb_ot_shape_context_t *c)
229 hb_buffer_clear_positions (c->buffer);
231 unsigned int count = c->buffer->len;
232 for (unsigned int i = 0; i < count; i++) {
233 hb_glyph_metrics_t metrics;
234 hb_font_get_glyph_metrics (c->font, c->face, c->buffer->info[i].codepoint, &metrics);
235 c->buffer->pos[i].x_advance = metrics.x_advance;
236 c->buffer->pos[i].y_advance = metrics.y_advance;
241 hb_position_complex_fallback (hb_ot_shape_context_t *c HB_UNUSED)
247 hb_truetype_kern (hb_ot_shape_context_t *c)
249 /* TODO Check for kern=0 */
250 unsigned int count = c->buffer->len;
251 for (unsigned int i = 1; i < count; i++) {
252 hb_position_t kern, kern1, kern2;
253 kern = hb_font_get_kerning (c->font, c->face, c->buffer->info[i - 1].codepoint, c->buffer->info[i].codepoint);
255 kern2 = kern - kern1;
256 c->buffer->pos[i - 1].x_advance += kern1;
257 c->buffer->pos[i].x_advance += kern2;
258 c->buffer->pos[i].x_offset += kern2;
263 hb_position_complex_fallback_visual (hb_ot_shape_context_t *c)
265 hb_truetype_kern (c);
272 hb_ot_shape_internal (hb_ot_shape_context_t *c)
274 hb_ot_shape_setup_masks (c);
276 hb_form_clusters (c);
280 c->buffer->clear_masks ();
282 /* Mirroring needs to see the original direction */
285 hb_ensure_native_direction (c);
287 hb_substitute_default (c);
289 hb_ot_substitute_complex (c);
291 if (!c->applied_substitute_complex)
292 hb_substitute_complex_fallback (c);
297 c->buffer->clear_masks ();
299 hb_position_default (c);
301 hb_ot_position_complex (c);
303 hb_bool_t position_fallback = !c->applied_position_complex;
304 if (position_fallback)
305 hb_position_complex_fallback (c);
307 if (HB_DIRECTION_IS_BACKWARD (c->buffer->props.direction))
308 hb_buffer_reverse (c->buffer);
310 if (position_fallback)
311 hb_position_complex_fallback_visual (c);
314 c->buffer->props.direction = c->original_direction;
318 hb_ot_shape (hb_font_t *font,
321 hb_feature_t *features,
322 unsigned int num_features)
324 hb_ot_shape_context_t c = {font, face, buffer, features, num_features};
327 /* Setup transient context members */
328 c.original_direction = buffer->props.direction;
331 hb_ot_shape_collect_features (&c);
334 hb_ot_shape_internal (&c);