diff options
Diffstat (limited to 'gfx/harfbuzz/src/hb-ot-shape-fallback.cc')
| -rw-r--r-- | gfx/harfbuzz/src/hb-ot-shape-fallback.cc | 553 |
1 files changed, 553 insertions, 0 deletions
diff --git a/gfx/harfbuzz/src/hb-ot-shape-fallback.cc b/gfx/harfbuzz/src/hb-ot-shape-fallback.cc new file mode 100644 index 000000000..ea8312b22 --- /dev/null +++ b/gfx/harfbuzz/src/hb-ot-shape-fallback.cc @@ -0,0 +1,553 @@ +/* + * Copyright © 2011,2012 Google, Inc. + * + * This is part of HarfBuzz, a text shaping library. + * + * Permission is hereby granted, without written agreement and without + * license or royalty fees, to use, copy, modify, and distribute this + * software and its documentation for any purpose, provided that the + * above copyright notice and the following two paragraphs appear in + * all copies of this software. + * + * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR + * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES + * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN + * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH + * DAMAGE. + * + * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, + * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND + * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS + * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO + * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. + * + * Google Author(s): Behdad Esfahbod + */ + +#include "hb-ot-shape-fallback-private.hh" +#include "hb-ot-layout-gsubgpos-private.hh" + +static unsigned int +recategorize_combining_class (hb_codepoint_t u, + unsigned int klass) +{ + if (klass >= 200) + return klass; + + /* Thai / Lao need some per-character work. */ + if ((u & ~0xFF) == 0x0E00u) + { + if (unlikely (klass == 0)) + { + switch (u) + { + case 0x0E31u: + case 0x0E34u: + case 0x0E35u: + case 0x0E36u: + case 0x0E37u: + case 0x0E47u: + case 0x0E4Cu: + case 0x0E4Du: + case 0x0E4Eu: + klass = HB_UNICODE_COMBINING_CLASS_ABOVE_RIGHT; + break; + + case 0x0EB1u: + case 0x0EB4u: + case 0x0EB5u: + case 0x0EB6u: + case 0x0EB7u: + case 0x0EBBu: + case 0x0ECCu: + case 0x0ECDu: + klass = HB_UNICODE_COMBINING_CLASS_ABOVE; + break; + + case 0x0EBCu: + klass = HB_UNICODE_COMBINING_CLASS_BELOW; + break; + } + } else { + /* Thai virama is below-right */ + if (u == 0x0E3Au) + klass = HB_UNICODE_COMBINING_CLASS_BELOW_RIGHT; + } + } + + switch (klass) + { + + /* Hebrew */ + + case HB_MODIFIED_COMBINING_CLASS_CCC10: /* sheva */ + case HB_MODIFIED_COMBINING_CLASS_CCC11: /* hataf segol */ + case HB_MODIFIED_COMBINING_CLASS_CCC12: /* hataf patah */ + case HB_MODIFIED_COMBINING_CLASS_CCC13: /* hataf qamats */ + case HB_MODIFIED_COMBINING_CLASS_CCC14: /* hiriq */ + case HB_MODIFIED_COMBINING_CLASS_CCC15: /* tsere */ + case HB_MODIFIED_COMBINING_CLASS_CCC16: /* segol */ + case HB_MODIFIED_COMBINING_CLASS_CCC17: /* patah */ + case HB_MODIFIED_COMBINING_CLASS_CCC18: /* qamats */ + case HB_MODIFIED_COMBINING_CLASS_CCC20: /* qubuts */ + case HB_MODIFIED_COMBINING_CLASS_CCC22: /* meteg */ + return HB_UNICODE_COMBINING_CLASS_BELOW; + + case HB_MODIFIED_COMBINING_CLASS_CCC23: /* rafe */ + return HB_UNICODE_COMBINING_CLASS_ATTACHED_ABOVE; + + case HB_MODIFIED_COMBINING_CLASS_CCC24: /* shin dot */ + return HB_UNICODE_COMBINING_CLASS_ABOVE_RIGHT; + + case HB_MODIFIED_COMBINING_CLASS_CCC25: /* sin dot */ + case HB_MODIFIED_COMBINING_CLASS_CCC19: /* holam */ + return HB_UNICODE_COMBINING_CLASS_ABOVE_LEFT; + + case HB_MODIFIED_COMBINING_CLASS_CCC26: /* point varika */ + return HB_UNICODE_COMBINING_CLASS_ABOVE; + + case HB_MODIFIED_COMBINING_CLASS_CCC21: /* dagesh */ + break; + + + /* Arabic and Syriac */ + + case HB_MODIFIED_COMBINING_CLASS_CCC27: /* fathatan */ + case HB_MODIFIED_COMBINING_CLASS_CCC28: /* dammatan */ + case HB_MODIFIED_COMBINING_CLASS_CCC30: /* fatha */ + case HB_MODIFIED_COMBINING_CLASS_CCC31: /* damma */ + case HB_MODIFIED_COMBINING_CLASS_CCC33: /* shadda */ + case HB_MODIFIED_COMBINING_CLASS_CCC34: /* sukun */ + case HB_MODIFIED_COMBINING_CLASS_CCC35: /* superscript alef */ + case HB_MODIFIED_COMBINING_CLASS_CCC36: /* superscript alaph */ + return HB_UNICODE_COMBINING_CLASS_ABOVE; + + case HB_MODIFIED_COMBINING_CLASS_CCC29: /* kasratan */ + case HB_MODIFIED_COMBINING_CLASS_CCC32: /* kasra */ + return HB_UNICODE_COMBINING_CLASS_BELOW; + + + /* Thai */ + + case HB_MODIFIED_COMBINING_CLASS_CCC103: /* sara u / sara uu */ + return HB_UNICODE_COMBINING_CLASS_BELOW_RIGHT; + + case HB_MODIFIED_COMBINING_CLASS_CCC107: /* mai */ + return HB_UNICODE_COMBINING_CLASS_ABOVE_RIGHT; + + + /* Lao */ + + case HB_MODIFIED_COMBINING_CLASS_CCC118: /* sign u / sign uu */ + return HB_UNICODE_COMBINING_CLASS_BELOW; + + case HB_MODIFIED_COMBINING_CLASS_CCC122: /* mai */ + return HB_UNICODE_COMBINING_CLASS_ABOVE; + + + /* Tibetan */ + + case HB_MODIFIED_COMBINING_CLASS_CCC129: /* sign aa */ + return HB_UNICODE_COMBINING_CLASS_BELOW; + + case HB_MODIFIED_COMBINING_CLASS_CCC130: /* sign i*/ + return HB_UNICODE_COMBINING_CLASS_ABOVE; + + case HB_MODIFIED_COMBINING_CLASS_CCC132: /* sign u */ + return HB_UNICODE_COMBINING_CLASS_BELOW; + + } + + return klass; +} + +void +_hb_ot_shape_fallback_position_recategorize_marks (const hb_ot_shape_plan_t *plan HB_UNUSED, + hb_font_t *font HB_UNUSED, + hb_buffer_t *buffer) +{ + unsigned int count = buffer->len; + hb_glyph_info_t *info = buffer->info; + for (unsigned int i = 0; i < count; i++) + if (_hb_glyph_info_get_general_category (&info[i]) == HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK) { + unsigned int combining_class = _hb_glyph_info_get_modified_combining_class (&info[i]); + combining_class = recategorize_combining_class (info[i].codepoint, combining_class); + _hb_glyph_info_set_modified_combining_class (&info[i], combining_class); + } +} + + +static void +zero_mark_advances (hb_buffer_t *buffer, + unsigned int start, + unsigned int end) +{ + hb_glyph_info_t *info = buffer->info; + for (unsigned int i = start; i < end; i++) + if (_hb_glyph_info_get_general_category (&info[i]) == HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK) + { + buffer->pos[i].x_advance = 0; + buffer->pos[i].y_advance = 0; + } +} + +static inline void +position_mark (const hb_ot_shape_plan_t *plan, + hb_font_t *font, + hb_buffer_t *buffer, + hb_glyph_extents_t &base_extents, + unsigned int i, + unsigned int combining_class) +{ + hb_glyph_extents_t mark_extents; + if (!font->get_glyph_extents (buffer->info[i].codepoint, + &mark_extents)) + return; + + hb_position_t y_gap = font->y_scale / 16; + + hb_glyph_position_t &pos = buffer->pos[i]; + pos.x_offset = pos.y_offset = 0; + + + /* We dont position LEFT and RIGHT marks. */ + + /* X positioning */ + switch (combining_class) + { + case HB_UNICODE_COMBINING_CLASS_DOUBLE_BELOW: + case HB_UNICODE_COMBINING_CLASS_DOUBLE_ABOVE: + if (buffer->props.direction == HB_DIRECTION_LTR) { + pos.x_offset += base_extents.x_bearing - mark_extents.width / 2 - mark_extents.x_bearing; + break; + } else if (buffer->props.direction == HB_DIRECTION_RTL) { + pos.x_offset += base_extents.x_bearing + base_extents.width - mark_extents.width / 2 - mark_extents.x_bearing; + break; + } + HB_FALLTHROUGH; + + default: + case HB_UNICODE_COMBINING_CLASS_ATTACHED_BELOW: + case HB_UNICODE_COMBINING_CLASS_ATTACHED_ABOVE: + case HB_UNICODE_COMBINING_CLASS_BELOW: + case HB_UNICODE_COMBINING_CLASS_ABOVE: + /* Center align. */ + pos.x_offset += base_extents.x_bearing + (base_extents.width - mark_extents.width) / 2 - mark_extents.x_bearing; + break; + + case HB_UNICODE_COMBINING_CLASS_ATTACHED_BELOW_LEFT: + case HB_UNICODE_COMBINING_CLASS_BELOW_LEFT: + case HB_UNICODE_COMBINING_CLASS_ABOVE_LEFT: + /* Left align. */ + pos.x_offset += base_extents.x_bearing - mark_extents.x_bearing; + break; + + case HB_UNICODE_COMBINING_CLASS_ATTACHED_ABOVE_RIGHT: + case HB_UNICODE_COMBINING_CLASS_BELOW_RIGHT: + case HB_UNICODE_COMBINING_CLASS_ABOVE_RIGHT: + /* Right align. */ + pos.x_offset += base_extents.x_bearing + base_extents.width - mark_extents.width - mark_extents.x_bearing; + break; + } + + /* Y positioning */ + switch (combining_class) + { + case HB_UNICODE_COMBINING_CLASS_DOUBLE_BELOW: + case HB_UNICODE_COMBINING_CLASS_BELOW_LEFT: + case HB_UNICODE_COMBINING_CLASS_BELOW: + case HB_UNICODE_COMBINING_CLASS_BELOW_RIGHT: + /* Add gap, fall-through. */ + base_extents.height -= y_gap; + HB_FALLTHROUGH; + + case HB_UNICODE_COMBINING_CLASS_ATTACHED_BELOW_LEFT: + case HB_UNICODE_COMBINING_CLASS_ATTACHED_BELOW: + pos.y_offset = base_extents.y_bearing + base_extents.height - mark_extents.y_bearing; + /* Never shift up "below" marks. */ + if ((y_gap > 0) == (pos.y_offset > 0)) + { + base_extents.height -= pos.y_offset; + pos.y_offset = 0; + } + base_extents.height += mark_extents.height; + break; + + case HB_UNICODE_COMBINING_CLASS_DOUBLE_ABOVE: + case HB_UNICODE_COMBINING_CLASS_ABOVE_LEFT: + case HB_UNICODE_COMBINING_CLASS_ABOVE: + case HB_UNICODE_COMBINING_CLASS_ABOVE_RIGHT: + /* Add gap, fall-through. */ + base_extents.y_bearing += y_gap; + base_extents.height -= y_gap; + HB_FALLTHROUGH; + + case HB_UNICODE_COMBINING_CLASS_ATTACHED_ABOVE: + case HB_UNICODE_COMBINING_CLASS_ATTACHED_ABOVE_RIGHT: + pos.y_offset = base_extents.y_bearing - (mark_extents.y_bearing + mark_extents.height); + /* Don't shift down "above" marks too much. */ + if ((y_gap > 0) != (pos.y_offset > 0)) + { + unsigned int correction = -pos.y_offset / 2; + base_extents.y_bearing += correction; + base_extents.height -= correction; + pos.y_offset += correction; + } + base_extents.y_bearing -= mark_extents.height; + base_extents.height += mark_extents.height; + break; + } +} + +static inline void +position_around_base (const hb_ot_shape_plan_t *plan, + hb_font_t *font, + hb_buffer_t *buffer, + unsigned int base, + unsigned int end) +{ + hb_direction_t horiz_dir = HB_DIRECTION_INVALID; + hb_glyph_extents_t base_extents; + if (!font->get_glyph_extents (buffer->info[base].codepoint, + &base_extents)) + { + /* If extents don't work, zero marks and go home. */ + zero_mark_advances (buffer, base + 1, end); + return; + } + base_extents.x_bearing += buffer->pos[base].x_offset; + base_extents.y_bearing += buffer->pos[base].y_offset; + + unsigned int lig_id = _hb_glyph_info_get_lig_id (&buffer->info[base]); + unsigned int num_lig_components = _hb_glyph_info_get_lig_num_comps (&buffer->info[base]); + + hb_position_t x_offset = 0, y_offset = 0; + if (HB_DIRECTION_IS_FORWARD (buffer->props.direction)) { + x_offset -= buffer->pos[base].x_advance; + y_offset -= buffer->pos[base].y_advance; + } + + hb_glyph_extents_t component_extents = base_extents; + unsigned int last_lig_component = (unsigned int) -1; + unsigned int last_combining_class = 255; + hb_glyph_extents_t cluster_extents = base_extents; /* Initialization is just to shut gcc up. */ + hb_glyph_info_t *info = buffer->info; + for (unsigned int i = base + 1; i < end; i++) + if (_hb_glyph_info_get_modified_combining_class (&info[i])) + { + if (num_lig_components > 1) { + unsigned int this_lig_id = _hb_glyph_info_get_lig_id (&info[i]); + unsigned int this_lig_component = _hb_glyph_info_get_lig_comp (&info[i]) - 1; + /* Conditions for attaching to the last component. */ + if (!lig_id || lig_id != this_lig_id || this_lig_component >= num_lig_components) + this_lig_component = num_lig_components - 1; + if (last_lig_component != this_lig_component) + { + last_lig_component = this_lig_component; + last_combining_class = 255; + component_extents = base_extents; + if (unlikely (horiz_dir == HB_DIRECTION_INVALID)) { + if (HB_DIRECTION_IS_HORIZONTAL (plan->props.direction)) + horiz_dir = plan->props.direction; + else + horiz_dir = hb_script_get_horizontal_direction (plan->props.script); + } + if (horiz_dir == HB_DIRECTION_LTR) + component_extents.x_bearing += (this_lig_component * component_extents.width) / num_lig_components; + else + component_extents.x_bearing += ((num_lig_components - 1 - this_lig_component) * component_extents.width) / num_lig_components; + component_extents.width /= num_lig_components; + } + } + + unsigned int this_combining_class = _hb_glyph_info_get_modified_combining_class (&info[i]); + if (last_combining_class != this_combining_class) + { + last_combining_class = this_combining_class; + cluster_extents = component_extents; + } + + position_mark (plan, font, buffer, cluster_extents, i, this_combining_class); + + buffer->pos[i].x_advance = 0; + buffer->pos[i].y_advance = 0; + buffer->pos[i].x_offset += x_offset; + buffer->pos[i].y_offset += y_offset; + + } else { + if (HB_DIRECTION_IS_FORWARD (buffer->props.direction)) { + x_offset -= buffer->pos[i].x_advance; + y_offset -= buffer->pos[i].y_advance; + } else { + x_offset += buffer->pos[i].x_advance; + y_offset += buffer->pos[i].y_advance; + } + } +} + +static inline void +position_cluster (const hb_ot_shape_plan_t *plan, + hb_font_t *font, + hb_buffer_t *buffer, + unsigned int start, + unsigned int end) +{ + if (end - start < 2) + return; + + /* Find the base glyph */ + hb_glyph_info_t *info = buffer->info; + for (unsigned int i = start; i < end; i++) + if (!HB_UNICODE_GENERAL_CATEGORY_IS_MARK (_hb_glyph_info_get_general_category (&info[i]))) + { + /* Find mark glyphs */ + unsigned int j; + for (j = i + 1; j < end; j++) + if (!HB_UNICODE_GENERAL_CATEGORY_IS_MARK (_hb_glyph_info_get_general_category (&info[j]))) + break; + + position_around_base (plan, font, buffer, i, j); + + i = j - 1; + } +} + +void +_hb_ot_shape_fallback_position (const hb_ot_shape_plan_t *plan, + hb_font_t *font, + hb_buffer_t *buffer) +{ + _hb_buffer_assert_gsubgpos_vars (buffer); + + unsigned int start = 0; + unsigned int count = buffer->len; + hb_glyph_info_t *info = buffer->info; + for (unsigned int i = 1; i < count; i++) + if (likely (!HB_UNICODE_GENERAL_CATEGORY_IS_MARK (_hb_glyph_info_get_general_category (&info[i])))) { + position_cluster (plan, font, buffer, start, i); + start = i; + } + position_cluster (plan, font, buffer, start, count); +} + + +/* Performs old-style TrueType kerning. */ +void +_hb_ot_shape_fallback_kern (const hb_ot_shape_plan_t *plan, + hb_font_t *font, + hb_buffer_t *buffer) +{ + if (!plan->has_kern) return; + + OT::hb_apply_context_t c (1, font, buffer); + c.set_lookup_mask (plan->kern_mask); + c.set_lookup_props (OT::LookupFlag::IgnoreMarks); + OT::hb_apply_context_t::skipping_iterator_t &skippy_iter = c.iter_input; + skippy_iter.init (&c); + + unsigned int count = buffer->len; + hb_glyph_info_t *info = buffer->info; + hb_glyph_position_t *pos = buffer->pos; + for (unsigned int idx = 0; idx < count;) + { + skippy_iter.reset (idx, 1); + if (!skippy_iter.next ()) + { + idx++; + continue; + } + + hb_position_t x_kern, y_kern; + font->get_glyph_kerning_for_direction (info[idx].codepoint, + info[skippy_iter.idx].codepoint, + buffer->props.direction, + &x_kern, &y_kern); + + if (x_kern) + { + hb_position_t kern1 = x_kern >> 1; + hb_position_t kern2 = x_kern - kern1; + pos[idx].x_advance += kern1; + pos[skippy_iter.idx].x_advance += kern2; + pos[skippy_iter.idx].x_offset += kern2; + } + + if (y_kern) + { + hb_position_t kern1 = y_kern >> 1; + hb_position_t kern2 = y_kern - kern1; + pos[idx].y_advance += kern1; + pos[skippy_iter.idx].y_advance += kern2; + pos[skippy_iter.idx].y_offset += kern2; + } + + idx = skippy_iter.idx; + } +} + + +/* Adjusts width of various spaces. */ +void +_hb_ot_shape_fallback_spaces (const hb_ot_shape_plan_t *plan, + hb_font_t *font, + hb_buffer_t *buffer) +{ + if (!HB_DIRECTION_IS_HORIZONTAL (buffer->props.direction)) + return; + + hb_glyph_info_t *info = buffer->info; + hb_glyph_position_t *pos = buffer->pos; + unsigned int count = buffer->len; + for (unsigned int i = 0; i < count; i++) + if (_hb_glyph_info_is_unicode_space (&info[i]) && !_hb_glyph_info_ligated (&info[i])) + { + hb_unicode_funcs_t::space_t space_type = _hb_glyph_info_get_unicode_space_fallback_type (&info[i]); + hb_codepoint_t glyph; + typedef hb_unicode_funcs_t t; + switch (space_type) + { + case t::NOT_SPACE: /* Shouldn't happen. */ + case t::SPACE: + break; + + case t::SPACE_EM: + case t::SPACE_EM_2: + case t::SPACE_EM_3: + case t::SPACE_EM_4: + case t::SPACE_EM_5: + case t::SPACE_EM_6: + case t::SPACE_EM_16: + pos[i].x_advance = (font->x_scale + ((int) space_type)/2) / (int) space_type; + break; + + case t::SPACE_4_EM_18: + pos[i].x_advance = font->x_scale * 4 / 18; + break; + + case t::SPACE_FIGURE: + for (char u = '0'; u <= '9'; u++) + if (font->get_nominal_glyph (u, &glyph)) + { + pos[i].x_advance = font->get_glyph_h_advance (glyph); + break; + } + break; + + case t::SPACE_PUNCTUATION: + if (font->get_nominal_glyph ('.', &glyph)) + pos[i].x_advance = font->get_glyph_h_advance (glyph); + else if (font->get_nominal_glyph (',', &glyph)) + pos[i].x_advance = font->get_glyph_h_advance (glyph); + break; + + case t::SPACE_NARROW: + /* Half-space? + * Unicode doc http://www.unicode.org/charts/PDF/U2000.pdf says ~1/4 or 1/5 of EM. + * However, in my testing, many fonts have their regular space being about that + * size. To me, a percentage of the space width makes more sense. Half is as + * good as any. */ + pos[i].x_advance /= 2; + break; + } + } +} |