1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/harfbuzz/src/hb-ot-shape-fallback.cc Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,479 @@
1.4 +/*
1.5 + * Copyright © 2011,2012 Google, Inc.
1.6 + *
1.7 + * This is part of HarfBuzz, a text shaping library.
1.8 + *
1.9 + * Permission is hereby granted, without written agreement and without
1.10 + * license or royalty fees, to use, copy, modify, and distribute this
1.11 + * software and its documentation for any purpose, provided that the
1.12 + * above copyright notice and the following two paragraphs appear in
1.13 + * all copies of this software.
1.14 + *
1.15 + * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
1.16 + * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
1.17 + * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
1.18 + * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
1.19 + * DAMAGE.
1.20 + *
1.21 + * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
1.22 + * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
1.23 + * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
1.24 + * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
1.25 + * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
1.26 + *
1.27 + * Google Author(s): Behdad Esfahbod
1.28 + */
1.29 +
1.30 +#include "hb-ot-shape-fallback-private.hh"
1.31 +#include "hb-ot-layout-gsubgpos-private.hh"
1.32 +
1.33 +static unsigned int
1.34 +recategorize_combining_class (hb_codepoint_t u,
1.35 + unsigned int klass)
1.36 +{
1.37 + if (klass >= 200)
1.38 + return klass;
1.39 +
1.40 + /* Thai / Lao need some per-character work. */
1.41 + if ((u & ~0xFF) == 0x0E00)
1.42 + {
1.43 + if (unlikely (klass == 0))
1.44 + {
1.45 + switch (u)
1.46 + {
1.47 + case 0x0E31:
1.48 + case 0x0E34:
1.49 + case 0x0E35:
1.50 + case 0x0E36:
1.51 + case 0x0E37:
1.52 + case 0x0E47:
1.53 + case 0x0E4C:
1.54 + case 0x0E4D:
1.55 + case 0x0E4E:
1.56 + klass = HB_UNICODE_COMBINING_CLASS_ABOVE_RIGHT;
1.57 + break;
1.58 +
1.59 + case 0x0EB1:
1.60 + case 0x0EB4:
1.61 + case 0x0EB5:
1.62 + case 0x0EB6:
1.63 + case 0x0EB7:
1.64 + case 0x0EBB:
1.65 + case 0x0ECC:
1.66 + case 0x0ECD:
1.67 + klass = HB_UNICODE_COMBINING_CLASS_ABOVE;
1.68 + break;
1.69 +
1.70 + case 0x0EBC:
1.71 + klass = HB_UNICODE_COMBINING_CLASS_BELOW;
1.72 + break;
1.73 + }
1.74 + } else {
1.75 + /* Thai virama is below-right */
1.76 + if (u == 0x0E3A)
1.77 + klass = HB_UNICODE_COMBINING_CLASS_BELOW_RIGHT;
1.78 + }
1.79 + }
1.80 +
1.81 + switch (klass)
1.82 + {
1.83 +
1.84 + /* Hebrew */
1.85 +
1.86 + case HB_MODIFIED_COMBINING_CLASS_CCC10: /* sheva */
1.87 + case HB_MODIFIED_COMBINING_CLASS_CCC11: /* hataf segol */
1.88 + case HB_MODIFIED_COMBINING_CLASS_CCC12: /* hataf patah */
1.89 + case HB_MODIFIED_COMBINING_CLASS_CCC13: /* hataf qamats */
1.90 + case HB_MODIFIED_COMBINING_CLASS_CCC14: /* hiriq */
1.91 + case HB_MODIFIED_COMBINING_CLASS_CCC15: /* tsere */
1.92 + case HB_MODIFIED_COMBINING_CLASS_CCC16: /* segol */
1.93 + case HB_MODIFIED_COMBINING_CLASS_CCC17: /* patah */
1.94 + case HB_MODIFIED_COMBINING_CLASS_CCC18: /* qamats */
1.95 + case HB_MODIFIED_COMBINING_CLASS_CCC20: /* qubuts */
1.96 + case HB_MODIFIED_COMBINING_CLASS_CCC22: /* meteg */
1.97 + return HB_UNICODE_COMBINING_CLASS_BELOW;
1.98 +
1.99 + case HB_MODIFIED_COMBINING_CLASS_CCC23: /* rafe */
1.100 + return HB_UNICODE_COMBINING_CLASS_ATTACHED_ABOVE;
1.101 +
1.102 + case HB_MODIFIED_COMBINING_CLASS_CCC24: /* shin dot */
1.103 + return HB_UNICODE_COMBINING_CLASS_ABOVE_RIGHT;
1.104 +
1.105 + case HB_MODIFIED_COMBINING_CLASS_CCC25: /* sin dot */
1.106 + case HB_MODIFIED_COMBINING_CLASS_CCC19: /* holam */
1.107 + return HB_UNICODE_COMBINING_CLASS_ABOVE_LEFT;
1.108 +
1.109 + case HB_MODIFIED_COMBINING_CLASS_CCC26: /* point varika */
1.110 + return HB_UNICODE_COMBINING_CLASS_ABOVE;
1.111 +
1.112 + case HB_MODIFIED_COMBINING_CLASS_CCC21: /* dagesh */
1.113 + break;
1.114 +
1.115 +
1.116 + /* Arabic and Syriac */
1.117 +
1.118 + case HB_MODIFIED_COMBINING_CLASS_CCC27: /* fathatan */
1.119 + case HB_MODIFIED_COMBINING_CLASS_CCC28: /* dammatan */
1.120 + case HB_MODIFIED_COMBINING_CLASS_CCC30: /* fatha */
1.121 + case HB_MODIFIED_COMBINING_CLASS_CCC31: /* damma */
1.122 + case HB_MODIFIED_COMBINING_CLASS_CCC33: /* shadda */
1.123 + case HB_MODIFIED_COMBINING_CLASS_CCC34: /* sukun */
1.124 + case HB_MODIFIED_COMBINING_CLASS_CCC35: /* superscript alef */
1.125 + case HB_MODIFIED_COMBINING_CLASS_CCC36: /* superscript alaph */
1.126 + return HB_UNICODE_COMBINING_CLASS_ABOVE;
1.127 +
1.128 + case HB_MODIFIED_COMBINING_CLASS_CCC29: /* kasratan */
1.129 + case HB_MODIFIED_COMBINING_CLASS_CCC32: /* kasra */
1.130 + return HB_UNICODE_COMBINING_CLASS_BELOW;
1.131 +
1.132 +
1.133 + /* Thai */
1.134 +
1.135 + case HB_MODIFIED_COMBINING_CLASS_CCC103: /* sara u / sara uu */
1.136 + return HB_UNICODE_COMBINING_CLASS_BELOW_RIGHT;
1.137 +
1.138 + case HB_MODIFIED_COMBINING_CLASS_CCC107: /* mai */
1.139 + return HB_UNICODE_COMBINING_CLASS_ABOVE_RIGHT;
1.140 +
1.141 +
1.142 + /* Lao */
1.143 +
1.144 + case HB_MODIFIED_COMBINING_CLASS_CCC118: /* sign u / sign uu */
1.145 + return HB_UNICODE_COMBINING_CLASS_BELOW;
1.146 +
1.147 + case HB_MODIFIED_COMBINING_CLASS_CCC122: /* mai */
1.148 + return HB_UNICODE_COMBINING_CLASS_ABOVE;
1.149 +
1.150 +
1.151 + /* Tibetan */
1.152 +
1.153 + case HB_MODIFIED_COMBINING_CLASS_CCC129: /* sign aa */
1.154 + return HB_UNICODE_COMBINING_CLASS_BELOW;
1.155 +
1.156 + case HB_MODIFIED_COMBINING_CLASS_CCC130: /* sign i*/
1.157 + return HB_UNICODE_COMBINING_CLASS_ABOVE;
1.158 +
1.159 + case HB_MODIFIED_COMBINING_CLASS_CCC132: /* sign u */
1.160 + return HB_UNICODE_COMBINING_CLASS_BELOW;
1.161 +
1.162 + }
1.163 +
1.164 + return klass;
1.165 +}
1.166 +
1.167 +void
1.168 +_hb_ot_shape_fallback_position_recategorize_marks (const hb_ot_shape_plan_t *plan HB_UNUSED,
1.169 + hb_font_t *font HB_UNUSED,
1.170 + hb_buffer_t *buffer)
1.171 +{
1.172 + unsigned int count = buffer->len;
1.173 + for (unsigned int i = 0; i < count; i++)
1.174 + if (_hb_glyph_info_get_general_category (&buffer->info[i]) == HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK) {
1.175 + unsigned int combining_class = _hb_glyph_info_get_modified_combining_class (&buffer->info[i]);
1.176 + combining_class = recategorize_combining_class (buffer->info[i].codepoint, combining_class);
1.177 + _hb_glyph_info_set_modified_combining_class (&buffer->info[i], combining_class);
1.178 + }
1.179 +}
1.180 +
1.181 +
1.182 +static void
1.183 +zero_mark_advances (hb_buffer_t *buffer,
1.184 + unsigned int start,
1.185 + unsigned int end)
1.186 +{
1.187 + for (unsigned int i = start; i < end; i++)
1.188 + if (_hb_glyph_info_get_general_category (&buffer->info[i]) == HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK)
1.189 + {
1.190 + buffer->pos[i].x_advance = 0;
1.191 + buffer->pos[i].y_advance = 0;
1.192 + }
1.193 +}
1.194 +
1.195 +static inline void
1.196 +position_mark (const hb_ot_shape_plan_t *plan,
1.197 + hb_font_t *font,
1.198 + hb_buffer_t *buffer,
1.199 + hb_glyph_extents_t &base_extents,
1.200 + unsigned int i,
1.201 + unsigned int combining_class)
1.202 +{
1.203 + hb_glyph_extents_t mark_extents;
1.204 + if (!font->get_glyph_extents (buffer->info[i].codepoint,
1.205 + &mark_extents))
1.206 + return;
1.207 +
1.208 + hb_position_t y_gap = font->y_scale / 16;
1.209 +
1.210 + hb_glyph_position_t &pos = buffer->pos[i];
1.211 + pos.x_offset = pos.y_offset = 0;
1.212 +
1.213 +
1.214 + /* We dont position LEFT and RIGHT marks. */
1.215 +
1.216 + /* X positioning */
1.217 + switch (combining_class)
1.218 + {
1.219 + case HB_UNICODE_COMBINING_CLASS_DOUBLE_BELOW:
1.220 + case HB_UNICODE_COMBINING_CLASS_DOUBLE_ABOVE:
1.221 + if (buffer->props.direction == HB_DIRECTION_LTR) {
1.222 + pos.x_offset += base_extents.x_bearing - mark_extents.width / 2 - mark_extents.x_bearing;
1.223 + break;
1.224 + } else if (buffer->props.direction == HB_DIRECTION_RTL) {
1.225 + pos.x_offset += base_extents.x_bearing + base_extents.width - mark_extents.width / 2 - mark_extents.x_bearing;
1.226 + break;
1.227 + }
1.228 + /* Fall through */
1.229 +
1.230 + default:
1.231 + case HB_UNICODE_COMBINING_CLASS_ATTACHED_BELOW:
1.232 + case HB_UNICODE_COMBINING_CLASS_ATTACHED_ABOVE:
1.233 + case HB_UNICODE_COMBINING_CLASS_BELOW:
1.234 + case HB_UNICODE_COMBINING_CLASS_ABOVE:
1.235 + /* Center align. */
1.236 + pos.x_offset += base_extents.x_bearing + (base_extents.width - mark_extents.width) / 2 - mark_extents.x_bearing;
1.237 + break;
1.238 +
1.239 + case HB_UNICODE_COMBINING_CLASS_ATTACHED_BELOW_LEFT:
1.240 + case HB_UNICODE_COMBINING_CLASS_BELOW_LEFT:
1.241 + case HB_UNICODE_COMBINING_CLASS_ABOVE_LEFT:
1.242 + /* Left align. */
1.243 + pos.x_offset += base_extents.x_bearing - mark_extents.x_bearing;
1.244 + break;
1.245 +
1.246 + case HB_UNICODE_COMBINING_CLASS_ATTACHED_ABOVE_RIGHT:
1.247 + case HB_UNICODE_COMBINING_CLASS_BELOW_RIGHT:
1.248 + case HB_UNICODE_COMBINING_CLASS_ABOVE_RIGHT:
1.249 + /* Right align. */
1.250 + pos.x_offset += base_extents.x_bearing + base_extents.width - mark_extents.width - mark_extents.x_bearing;
1.251 + break;
1.252 + }
1.253 +
1.254 + /* Y positioning */
1.255 + switch (combining_class)
1.256 + {
1.257 + case HB_UNICODE_COMBINING_CLASS_DOUBLE_BELOW:
1.258 + case HB_UNICODE_COMBINING_CLASS_BELOW_LEFT:
1.259 + case HB_UNICODE_COMBINING_CLASS_BELOW:
1.260 + case HB_UNICODE_COMBINING_CLASS_BELOW_RIGHT:
1.261 + /* Add gap, fall-through. */
1.262 + base_extents.height -= y_gap;
1.263 +
1.264 + case HB_UNICODE_COMBINING_CLASS_ATTACHED_BELOW_LEFT:
1.265 + case HB_UNICODE_COMBINING_CLASS_ATTACHED_BELOW:
1.266 + pos.y_offset = base_extents.y_bearing + base_extents.height - mark_extents.y_bearing;
1.267 + /* Never shift up "below" marks. */
1.268 + if ((y_gap > 0) == (pos.y_offset > 0))
1.269 + {
1.270 + base_extents.height -= pos.y_offset;
1.271 + pos.y_offset = 0;
1.272 + }
1.273 + base_extents.height += mark_extents.height;
1.274 + break;
1.275 +
1.276 + case HB_UNICODE_COMBINING_CLASS_DOUBLE_ABOVE:
1.277 + case HB_UNICODE_COMBINING_CLASS_ABOVE_LEFT:
1.278 + case HB_UNICODE_COMBINING_CLASS_ABOVE:
1.279 + case HB_UNICODE_COMBINING_CLASS_ABOVE_RIGHT:
1.280 + /* Add gap, fall-through. */
1.281 + base_extents.y_bearing += y_gap;
1.282 + base_extents.height -= y_gap;
1.283 +
1.284 + case HB_UNICODE_COMBINING_CLASS_ATTACHED_ABOVE:
1.285 + case HB_UNICODE_COMBINING_CLASS_ATTACHED_ABOVE_RIGHT:
1.286 + pos.y_offset = base_extents.y_bearing - (mark_extents.y_bearing + mark_extents.height);
1.287 + /* Don't shift down "above" marks too much. */
1.288 + if ((y_gap > 0) != (pos.y_offset > 0))
1.289 + {
1.290 + unsigned int correction = -pos.y_offset / 2;
1.291 + base_extents.y_bearing += correction;
1.292 + base_extents.height -= correction;
1.293 + pos.y_offset += correction;
1.294 + }
1.295 + base_extents.y_bearing -= mark_extents.height;
1.296 + base_extents.height += mark_extents.height;
1.297 + break;
1.298 + }
1.299 +}
1.300 +
1.301 +static inline void
1.302 +position_around_base (const hb_ot_shape_plan_t *plan,
1.303 + hb_font_t *font,
1.304 + hb_buffer_t *buffer,
1.305 + unsigned int base,
1.306 + unsigned int end)
1.307 +{
1.308 + hb_direction_t horiz_dir = HB_DIRECTION_INVALID;
1.309 + hb_glyph_extents_t base_extents;
1.310 + if (!font->get_glyph_extents (buffer->info[base].codepoint,
1.311 + &base_extents))
1.312 + {
1.313 + /* If extents don't work, zero marks and go home. */
1.314 + zero_mark_advances (buffer, base + 1, end);
1.315 + return;
1.316 + }
1.317 + base_extents.x_bearing += buffer->pos[base].x_offset;
1.318 + base_extents.y_bearing += buffer->pos[base].y_offset;
1.319 +
1.320 + unsigned int lig_id = _hb_glyph_info_get_lig_id (&buffer->info[base]);
1.321 + unsigned int num_lig_components = _hb_glyph_info_get_lig_num_comps (&buffer->info[base]);
1.322 +
1.323 + hb_position_t x_offset = 0, y_offset = 0;
1.324 + if (HB_DIRECTION_IS_FORWARD (buffer->props.direction)) {
1.325 + x_offset -= buffer->pos[base].x_advance;
1.326 + y_offset -= buffer->pos[base].y_advance;
1.327 + }
1.328 +
1.329 + hb_glyph_extents_t component_extents = base_extents;
1.330 + unsigned int last_lig_component = (unsigned int) -1;
1.331 + unsigned int last_combining_class = 255;
1.332 + hb_glyph_extents_t cluster_extents = base_extents; /* Initialization is just to shut gcc up. */
1.333 + for (unsigned int i = base + 1; i < end; i++)
1.334 + if (_hb_glyph_info_get_modified_combining_class (&buffer->info[i]))
1.335 + {
1.336 + if (num_lig_components > 1) {
1.337 + unsigned int this_lig_id = _hb_glyph_info_get_lig_id (&buffer->info[i]);
1.338 + unsigned int this_lig_component = _hb_glyph_info_get_lig_comp (&buffer->info[i]) - 1;
1.339 + /* Conditions for attaching to the last component. */
1.340 + if (!lig_id || lig_id != this_lig_id || this_lig_component >= num_lig_components)
1.341 + this_lig_component = num_lig_components - 1;
1.342 + if (last_lig_component != this_lig_component)
1.343 + {
1.344 + last_lig_component = this_lig_component;
1.345 + last_combining_class = 255;
1.346 + component_extents = base_extents;
1.347 + if (unlikely (horiz_dir == HB_DIRECTION_INVALID)) {
1.348 + if (HB_DIRECTION_IS_HORIZONTAL (plan->props.direction))
1.349 + horiz_dir = plan->props.direction;
1.350 + else
1.351 + horiz_dir = hb_script_get_horizontal_direction (plan->props.script);
1.352 + }
1.353 + if (horiz_dir == HB_DIRECTION_LTR)
1.354 + component_extents.x_bearing += (this_lig_component * component_extents.width) / num_lig_components;
1.355 + else
1.356 + component_extents.x_bearing += ((num_lig_components - 1 - this_lig_component) * component_extents.width) / num_lig_components;
1.357 + component_extents.width /= num_lig_components;
1.358 + }
1.359 + }
1.360 +
1.361 + unsigned int this_combining_class = _hb_glyph_info_get_modified_combining_class (&buffer->info[i]);
1.362 + if (last_combining_class != this_combining_class)
1.363 + {
1.364 + last_combining_class = this_combining_class;
1.365 + cluster_extents = component_extents;
1.366 + }
1.367 +
1.368 + position_mark (plan, font, buffer, cluster_extents, i, this_combining_class);
1.369 +
1.370 + buffer->pos[i].x_advance = 0;
1.371 + buffer->pos[i].y_advance = 0;
1.372 + buffer->pos[i].x_offset += x_offset;
1.373 + buffer->pos[i].y_offset += y_offset;
1.374 +
1.375 + } else {
1.376 + if (HB_DIRECTION_IS_FORWARD (buffer->props.direction)) {
1.377 + x_offset -= buffer->pos[i].x_advance;
1.378 + y_offset -= buffer->pos[i].y_advance;
1.379 + } else {
1.380 + x_offset += buffer->pos[i].x_advance;
1.381 + y_offset += buffer->pos[i].y_advance;
1.382 + }
1.383 + }
1.384 +}
1.385 +
1.386 +static inline void
1.387 +position_cluster (const hb_ot_shape_plan_t *plan,
1.388 + hb_font_t *font,
1.389 + hb_buffer_t *buffer,
1.390 + unsigned int start,
1.391 + unsigned int end)
1.392 +{
1.393 + if (end - start < 2)
1.394 + return;
1.395 +
1.396 + /* Find the base glyph */
1.397 + for (unsigned int i = start; i < end; i++)
1.398 + if (!HB_UNICODE_GENERAL_CATEGORY_IS_MARK (_hb_glyph_info_get_general_category (&buffer->info[i])))
1.399 + {
1.400 + /* Find mark glyphs */
1.401 + unsigned int j;
1.402 + for (j = i + 1; j < end; j++)
1.403 + if (!HB_UNICODE_GENERAL_CATEGORY_IS_MARK (_hb_glyph_info_get_general_category (&buffer->info[j])))
1.404 + break;
1.405 +
1.406 + position_around_base (plan, font, buffer, i, j);
1.407 +
1.408 + i = j - 1;
1.409 + }
1.410 +}
1.411 +
1.412 +void
1.413 +_hb_ot_shape_fallback_position (const hb_ot_shape_plan_t *plan,
1.414 + hb_font_t *font,
1.415 + hb_buffer_t *buffer)
1.416 +{
1.417 + unsigned int start = 0;
1.418 + unsigned int last_cluster = buffer->info[0].cluster;
1.419 + unsigned int count = buffer->len;
1.420 + for (unsigned int i = 1; i < count; i++)
1.421 + if (buffer->info[i].cluster != last_cluster) {
1.422 + position_cluster (plan, font, buffer, start, i);
1.423 + start = i;
1.424 + last_cluster = buffer->info[i].cluster;
1.425 + }
1.426 + position_cluster (plan, font, buffer, start, count);
1.427 +}
1.428 +
1.429 +
1.430 +/* Performs old-style TrueType kerning. */
1.431 +void
1.432 +_hb_ot_shape_fallback_kern (const hb_ot_shape_plan_t *plan,
1.433 + hb_font_t *font,
1.434 + hb_buffer_t *buffer)
1.435 +{
1.436 + if (!plan->has_kern) return;
1.437 +
1.438 + unsigned int count = buffer->len;
1.439 +
1.440 + OT::hb_apply_context_t c (1, font, buffer);
1.441 + c.set_lookup_mask (plan->kern_mask);
1.442 + c.set_lookup_props (OT::LookupFlag::IgnoreMarks);
1.443 +
1.444 + hb_glyph_info_t *info = buffer->info;
1.445 + hb_glyph_position_t *pos = buffer->pos;
1.446 +
1.447 + for (unsigned int idx = 0; idx < count;)
1.448 + {
1.449 + OT::hb_apply_context_t::skipping_forward_iterator_t skippy_iter (&c, idx, 1);
1.450 + if (!skippy_iter.next ())
1.451 + {
1.452 + idx++;
1.453 + continue;
1.454 + }
1.455 +
1.456 + hb_position_t x_kern, y_kern;
1.457 + font->get_glyph_kerning_for_direction (info[idx].codepoint,
1.458 + info[skippy_iter.idx].codepoint,
1.459 + buffer->props.direction,
1.460 + &x_kern, &y_kern);
1.461 +
1.462 + if (x_kern)
1.463 + {
1.464 + hb_position_t kern1 = x_kern >> 1;
1.465 + hb_position_t kern2 = x_kern - kern1;
1.466 + pos[idx].x_advance += kern1;
1.467 + pos[skippy_iter.idx].x_advance += kern2;
1.468 + pos[skippy_iter.idx].x_offset += kern2;
1.469 + }
1.470 +
1.471 + if (y_kern)
1.472 + {
1.473 + hb_position_t kern1 = y_kern >> 1;
1.474 + hb_position_t kern2 = y_kern - kern1;
1.475 + pos[idx].y_advance += kern1;
1.476 + pos[skippy_iter.idx].y_advance += kern2;
1.477 + pos[skippy_iter.idx].y_offset += kern2;
1.478 + }
1.479 +
1.480 + idx = skippy_iter.idx;
1.481 + }
1.482 +}
