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"
30 #include "hb-ot-shape-complex-private.hh"
36 hb_tag_t default_features[] = {
37 HB_TAG('c','a','l','t'),
38 HB_TAG('c','c','m','p'),
39 HB_TAG('c','l','i','g'),
40 HB_TAG('c','s','w','h'),
41 HB_TAG('c','u','r','s'),
42 HB_TAG('k','e','r','n'),
43 HB_TAG('l','i','g','a'),
44 HB_TAG('l','o','c','l'),
45 HB_TAG('m','a','r','k'),
46 HB_TAG('m','k','m','k'),
47 HB_TAG('r','l','i','g')
51 hb_ot_shape_collect_features (hb_ot_shape_plan_t *plan,
52 const hb_segment_properties_t *props,
53 const hb_feature_t *user_features,
54 unsigned int num_user_features)
56 switch (props->direction) {
57 case HB_DIRECTION_LTR:
58 plan->map.add_bool_feature (HB_TAG ('l','t','r','a'));
59 plan->map.add_bool_feature (HB_TAG ('l','t','r','m'));
61 case HB_DIRECTION_RTL:
62 plan->map.add_bool_feature (HB_TAG ('r','t','l','a'));
63 plan->map.add_bool_feature (HB_TAG ('r','t','l','m'), false);
65 case HB_DIRECTION_TTB:
66 case HB_DIRECTION_BTT:
71 for (unsigned int i = 0; i < ARRAY_LENGTH (default_features); i++)
72 plan->map.add_bool_feature (default_features[i]);
74 hb_ot_shape_complex_collect_features (plan, props);
76 for (unsigned int i = 0; i < num_user_features; i++) {
77 const hb_feature_t *feature = &user_features[i];
78 plan->map.add_feature (feature->tag, feature->value, (feature->start == 0 && feature->end == (unsigned int) -1));
84 hb_ot_shape_setup_masks (hb_ot_shape_context_t *c)
86 hb_mask_t global_mask = c->plan->map.get_global_mask ();
87 c->buffer->reset_masks (global_mask);
89 hb_ot_shape_complex_setup_masks (c);
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->plan->map.get_mask (feature->tag, &shift);
97 c->buffer->set_masks (feature->value << shift, mask, feature->start, feature->end);
104 hb_ot_substitute_complex (hb_ot_shape_context_t *c)
106 if (!hb_ot_layout_has_substitution (c->face))
109 c->plan->map.substitute (c->face, c->buffer);
111 c->applied_substitute_complex = TRUE;
116 hb_ot_position_complex (hb_ot_shape_context_t *c)
119 if (!hb_ot_layout_has_positioning (c->face))
122 c->plan->map.position (c->font, c->face, c->buffer);
124 hb_ot_layout_position_finish (c->font, c->face, c->buffer);
126 c->applied_position_complex = TRUE;
135 static inline hb_bool_t
136 is_variation_selector (hb_codepoint_t unicode)
138 return unlikely ((unicode >= 0x180B && unicode <= 0x180D) || /* MONGOLIAN FREE VARIATION SELECTOR ONE..THREE */
139 (unicode >= 0xFE00 && unicode <= 0xFE0F) || /* VARIATION SELECTOR-1..16 */
140 (unicode >= 0xE0100 && unicode <= 0xE01EF)); /* VARIATION SELECTOR-17..256 */
144 hb_form_clusters (hb_ot_shape_context_t *c)
146 unsigned int count = c->buffer->len;
147 for (unsigned int i = 1; i < count; i++)
148 if (c->buffer->unicode->v.get_general_category (c->buffer->info[i].codepoint) == HB_CATEGORY_NON_SPACING_MARK)
149 c->buffer->info[i].cluster = c->buffer->info[i - 1].cluster;
153 hb_ensure_native_direction (hb_ot_shape_context_t *c)
155 hb_direction_t direction = c->buffer->props.direction;
158 if (HB_DIRECTION_IS_HORIZONTAL (direction) &&
159 direction != _hb_script_get_horizontal_direction (c->buffer->props.script))
161 hb_buffer_reverse_clusters (c->buffer);
162 c->buffer->props.direction = HB_DIRECTION_REVERSE (c->buffer->props.direction);
170 hb_mirror_chars (hb_ot_shape_context_t *c)
172 hb_unicode_get_mirroring_func_t get_mirroring = c->buffer->unicode->v.get_mirroring;
174 if (HB_DIRECTION_IS_FORWARD (c->buffer->props.direction))
177 hb_mask_t rtlm_mask = c->plan->map.get_1_mask (HB_TAG ('r','t','l','m'));
179 unsigned int count = c->buffer->len;
180 for (unsigned int i = 0; i < count; i++) {
181 hb_codepoint_t codepoint = get_mirroring (c->buffer->info[i].codepoint);
182 if (likely (codepoint == c->buffer->info[i].codepoint))
183 c->buffer->info[i].mask |= rtlm_mask; /* XXX this should be moved to before setting user-feature masks */
185 c->buffer->info[i].codepoint = codepoint;
190 hb_map_glyphs (hb_font_t *font,
194 if (unlikely (!buffer->len))
197 buffer->clear_output ();
198 unsigned int count = buffer->len - 1;
199 for (buffer->i = 0; buffer->i < count;) {
200 if (unlikely (is_variation_selector (buffer->info[buffer->i + 1].codepoint))) {
201 buffer->replace_glyph (hb_font_get_glyph (font, face, buffer->info[buffer->i].codepoint, buffer->info[buffer->i + 1].codepoint));
204 buffer->replace_glyph (hb_font_get_glyph (font, face, buffer->info[buffer->i].codepoint, 0));
207 if (likely (buffer->i < buffer->len))
208 buffer->replace_glyph (hb_font_get_glyph (font, face, buffer->info[buffer->i].codepoint, 0));
213 hb_substitute_default (hb_ot_shape_context_t *c)
215 hb_map_glyphs (c->font, c->face, c->buffer);
219 hb_substitute_complex_fallback (hb_ot_shape_context_t *c HB_UNUSED)
228 hb_position_default (hb_ot_shape_context_t *c)
230 hb_buffer_clear_positions (c->buffer);
232 unsigned int count = c->buffer->len;
233 for (unsigned int i = 0; i < count; i++) {
234 hb_font_get_glyph_advance (c->font, c->face, c->buffer->info[i].codepoint,
235 &c->buffer->pos[i].x_advance,
236 &c->buffer->pos[i].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_execute_internal (hb_ot_shape_context_t *c)
274 /* Save the original direction, we use it later. */
275 c->original_direction = c->buffer->props.direction;
277 hb_form_clusters (c);
279 hb_ot_shape_setup_masks (c);
283 /* Mirroring needs to see the original direction */
286 hb_ensure_native_direction (c);
288 hb_substitute_default (c);
290 hb_ot_substitute_complex (c);
292 if (!c->applied_substitute_complex)
293 hb_substitute_complex_fallback (c);
298 hb_position_default (c);
300 hb_ot_position_complex (c);
302 hb_bool_t position_fallback = !c->applied_position_complex;
303 if (position_fallback)
304 hb_position_complex_fallback (c);
306 if (HB_DIRECTION_IS_BACKWARD (c->buffer->props.direction))
307 hb_buffer_reverse (c->buffer);
309 if (position_fallback)
310 hb_position_complex_fallback_visual (c);
313 c->buffer->props.direction = c->original_direction;
317 hb_ot_shape_plan_internal (hb_ot_shape_plan_t *plan,
319 const hb_segment_properties_t *props,
320 const hb_feature_t *user_features,
321 unsigned int num_user_features)
323 plan->shaper = hb_ot_shape_complex_categorize (props);
325 hb_ot_shape_collect_features (plan, props, user_features, num_user_features);
327 plan->map.compile (face, props);
331 hb_ot_shape_execute (hb_ot_shape_plan_t *plan,
335 const hb_feature_t *user_features,
336 unsigned int num_user_features)
338 hb_ot_shape_context_t c = {plan, font, face, buffer, user_features, num_user_features};
339 hb_ot_shape_execute_internal (&c);
343 hb_ot_shape (hb_font_t *font,
346 const hb_feature_t *user_features,
347 unsigned int num_user_features)
349 hb_ot_shape_plan_t plan;
351 hb_ot_shape_plan_internal (&plan, face, &buffer->props, user_features, num_user_features);
352 hb_ot_shape_execute (&plan, font, face, buffer, user_features, num_user_features);