480 lines
15 KiB
C++
480 lines
15 KiB
C++
/*
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* Copyright © 2011,2012 Google, Inc.
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*
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* This is part of HarfBuzz, a text shaping library.
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*
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* Permission is hereby granted, without written agreement and without
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* license or royalty fees, to use, copy, modify, and distribute this
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* software and its documentation for any purpose, provided that the
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* above copyright notice and the following two paragraphs appear in
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* all copies of this software.
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*
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* IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
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* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
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* ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
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* IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
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* DAMAGE.
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*
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* THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
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* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
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* FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
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* ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
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* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
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*
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* Google Author(s): Behdad Esfahbod
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*/
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#include "hb-ot-shape-fallback-private.hh"
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#include "hb-ot-layout-gsubgpos-private.hh"
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static unsigned int
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recategorize_combining_class (hb_codepoint_t u,
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unsigned int klass)
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{
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if (klass >= 200)
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return klass;
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/* Thai / Lao need some per-character work. */
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if ((u & ~0xFF) == 0x0E00)
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{
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if (unlikely (klass == 0))
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{
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switch (u)
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{
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case 0x0E31:
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case 0x0E34:
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case 0x0E35:
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case 0x0E36:
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case 0x0E37:
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case 0x0E47:
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case 0x0E4C:
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case 0x0E4D:
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case 0x0E4E:
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klass = HB_UNICODE_COMBINING_CLASS_ABOVE_RIGHT;
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break;
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case 0x0EB1:
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case 0x0EB4:
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case 0x0EB5:
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case 0x0EB6:
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case 0x0EB7:
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case 0x0EBB:
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case 0x0ECC:
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case 0x0ECD:
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klass = HB_UNICODE_COMBINING_CLASS_ABOVE;
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break;
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case 0x0EBC:
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klass = HB_UNICODE_COMBINING_CLASS_BELOW;
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break;
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}
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} else {
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/* Thai virama is below-right */
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if (u == 0x0E3A)
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klass = HB_UNICODE_COMBINING_CLASS_BELOW_RIGHT;
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}
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}
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switch (klass)
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{
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/* Hebrew */
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case HB_MODIFIED_COMBINING_CLASS_CCC10: /* sheva */
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case HB_MODIFIED_COMBINING_CLASS_CCC11: /* hataf segol */
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case HB_MODIFIED_COMBINING_CLASS_CCC12: /* hataf patah */
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case HB_MODIFIED_COMBINING_CLASS_CCC13: /* hataf qamats */
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case HB_MODIFIED_COMBINING_CLASS_CCC14: /* hiriq */
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case HB_MODIFIED_COMBINING_CLASS_CCC15: /* tsere */
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case HB_MODIFIED_COMBINING_CLASS_CCC16: /* segol */
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case HB_MODIFIED_COMBINING_CLASS_CCC17: /* patah */
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case HB_MODIFIED_COMBINING_CLASS_CCC18: /* qamats */
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case HB_MODIFIED_COMBINING_CLASS_CCC20: /* qubuts */
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case HB_MODIFIED_COMBINING_CLASS_CCC22: /* meteg */
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return HB_UNICODE_COMBINING_CLASS_BELOW;
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case HB_MODIFIED_COMBINING_CLASS_CCC23: /* rafe */
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return HB_UNICODE_COMBINING_CLASS_ATTACHED_ABOVE;
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case HB_MODIFIED_COMBINING_CLASS_CCC24: /* shin dot */
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return HB_UNICODE_COMBINING_CLASS_ABOVE_RIGHT;
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case HB_MODIFIED_COMBINING_CLASS_CCC25: /* sin dot */
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case HB_MODIFIED_COMBINING_CLASS_CCC19: /* holam */
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return HB_UNICODE_COMBINING_CLASS_ABOVE_LEFT;
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case HB_MODIFIED_COMBINING_CLASS_CCC26: /* point varika */
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return HB_UNICODE_COMBINING_CLASS_ABOVE;
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case HB_MODIFIED_COMBINING_CLASS_CCC21: /* dagesh */
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break;
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/* Arabic and Syriac */
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case HB_MODIFIED_COMBINING_CLASS_CCC27: /* fathatan */
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case HB_MODIFIED_COMBINING_CLASS_CCC28: /* dammatan */
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case HB_MODIFIED_COMBINING_CLASS_CCC30: /* fatha */
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case HB_MODIFIED_COMBINING_CLASS_CCC31: /* damma */
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case HB_MODIFIED_COMBINING_CLASS_CCC33: /* shadda */
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case HB_MODIFIED_COMBINING_CLASS_CCC34: /* sukun */
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case HB_MODIFIED_COMBINING_CLASS_CCC35: /* superscript alef */
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case HB_MODIFIED_COMBINING_CLASS_CCC36: /* superscript alaph */
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return HB_UNICODE_COMBINING_CLASS_ABOVE;
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case HB_MODIFIED_COMBINING_CLASS_CCC29: /* kasratan */
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case HB_MODIFIED_COMBINING_CLASS_CCC32: /* kasra */
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return HB_UNICODE_COMBINING_CLASS_BELOW;
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/* Thai */
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case HB_MODIFIED_COMBINING_CLASS_CCC103: /* sara u / sara uu */
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return HB_UNICODE_COMBINING_CLASS_BELOW_RIGHT;
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case HB_MODIFIED_COMBINING_CLASS_CCC107: /* mai */
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return HB_UNICODE_COMBINING_CLASS_ABOVE_RIGHT;
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/* Lao */
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case HB_MODIFIED_COMBINING_CLASS_CCC118: /* sign u / sign uu */
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return HB_UNICODE_COMBINING_CLASS_BELOW;
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case HB_MODIFIED_COMBINING_CLASS_CCC122: /* mai */
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return HB_UNICODE_COMBINING_CLASS_ABOVE;
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/* Tibetan */
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case HB_MODIFIED_COMBINING_CLASS_CCC129: /* sign aa */
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return HB_UNICODE_COMBINING_CLASS_BELOW;
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case HB_MODIFIED_COMBINING_CLASS_CCC130: /* sign i*/
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return HB_UNICODE_COMBINING_CLASS_ABOVE;
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case HB_MODIFIED_COMBINING_CLASS_CCC132: /* sign u */
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return HB_UNICODE_COMBINING_CLASS_BELOW;
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}
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return klass;
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}
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void
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_hb_ot_shape_fallback_position_recategorize_marks (const hb_ot_shape_plan_t *plan HB_UNUSED,
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hb_font_t *font HB_UNUSED,
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hb_buffer_t *buffer)
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{
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unsigned int count = buffer->len;
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for (unsigned int i = 0; i < count; i++)
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if (_hb_glyph_info_get_general_category (&buffer->info[i]) == HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK) {
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unsigned int combining_class = _hb_glyph_info_get_modified_combining_class (&buffer->info[i]);
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combining_class = recategorize_combining_class (buffer->info[i].codepoint, combining_class);
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_hb_glyph_info_set_modified_combining_class (&buffer->info[i], combining_class);
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}
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}
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static void
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zero_mark_advances (hb_buffer_t *buffer,
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unsigned int start,
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unsigned int end)
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{
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for (unsigned int i = start; i < end; i++)
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if (_hb_glyph_info_get_general_category (&buffer->info[i]) == HB_UNICODE_GENERAL_CATEGORY_NON_SPACING_MARK)
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{
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buffer->pos[i].x_advance = 0;
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buffer->pos[i].y_advance = 0;
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}
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}
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static inline void
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position_mark (const hb_ot_shape_plan_t *plan,
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hb_font_t *font,
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hb_buffer_t *buffer,
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hb_glyph_extents_t &base_extents,
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unsigned int i,
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unsigned int combining_class)
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{
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hb_glyph_extents_t mark_extents;
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if (!font->get_glyph_extents (buffer->info[i].codepoint,
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&mark_extents))
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return;
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hb_position_t y_gap = font->y_scale / 16;
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hb_glyph_position_t &pos = buffer->pos[i];
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pos.x_offset = pos.y_offset = 0;
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/* We dont position LEFT and RIGHT marks. */
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/* X positioning */
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switch (combining_class)
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{
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case HB_UNICODE_COMBINING_CLASS_DOUBLE_BELOW:
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case HB_UNICODE_COMBINING_CLASS_DOUBLE_ABOVE:
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if (buffer->props.direction == HB_DIRECTION_LTR) {
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pos.x_offset += base_extents.x_bearing - mark_extents.width / 2 - mark_extents.x_bearing;
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break;
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} else if (buffer->props.direction == HB_DIRECTION_RTL) {
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pos.x_offset += base_extents.x_bearing + base_extents.width - mark_extents.width / 2 - mark_extents.x_bearing;
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break;
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}
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/* Fall through */
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default:
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case HB_UNICODE_COMBINING_CLASS_ATTACHED_BELOW:
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case HB_UNICODE_COMBINING_CLASS_ATTACHED_ABOVE:
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case HB_UNICODE_COMBINING_CLASS_BELOW:
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case HB_UNICODE_COMBINING_CLASS_ABOVE:
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/* Center align. */
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pos.x_offset += base_extents.x_bearing + (base_extents.width - mark_extents.width) / 2 - mark_extents.x_bearing;
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break;
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case HB_UNICODE_COMBINING_CLASS_ATTACHED_BELOW_LEFT:
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case HB_UNICODE_COMBINING_CLASS_BELOW_LEFT:
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case HB_UNICODE_COMBINING_CLASS_ABOVE_LEFT:
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/* Left align. */
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pos.x_offset += base_extents.x_bearing - mark_extents.x_bearing;
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break;
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case HB_UNICODE_COMBINING_CLASS_ATTACHED_ABOVE_RIGHT:
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case HB_UNICODE_COMBINING_CLASS_BELOW_RIGHT:
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case HB_UNICODE_COMBINING_CLASS_ABOVE_RIGHT:
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/* Right align. */
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pos.x_offset += base_extents.x_bearing + base_extents.width - mark_extents.width - mark_extents.x_bearing;
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break;
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}
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/* Y positioning */
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switch (combining_class)
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{
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case HB_UNICODE_COMBINING_CLASS_DOUBLE_BELOW:
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case HB_UNICODE_COMBINING_CLASS_BELOW_LEFT:
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case HB_UNICODE_COMBINING_CLASS_BELOW:
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case HB_UNICODE_COMBINING_CLASS_BELOW_RIGHT:
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/* Add gap, fall-through. */
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base_extents.height -= y_gap;
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case HB_UNICODE_COMBINING_CLASS_ATTACHED_BELOW_LEFT:
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case HB_UNICODE_COMBINING_CLASS_ATTACHED_BELOW:
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pos.y_offset = base_extents.y_bearing + base_extents.height - mark_extents.y_bearing;
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/* Never shift up "below" marks. */
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if ((y_gap > 0) == (pos.y_offset > 0))
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{
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base_extents.height -= pos.y_offset;
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pos.y_offset = 0;
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}
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base_extents.height += mark_extents.height;
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break;
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case HB_UNICODE_COMBINING_CLASS_DOUBLE_ABOVE:
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case HB_UNICODE_COMBINING_CLASS_ABOVE_LEFT:
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case HB_UNICODE_COMBINING_CLASS_ABOVE:
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case HB_UNICODE_COMBINING_CLASS_ABOVE_RIGHT:
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/* Add gap, fall-through. */
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base_extents.y_bearing += y_gap;
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base_extents.height -= y_gap;
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case HB_UNICODE_COMBINING_CLASS_ATTACHED_ABOVE:
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case HB_UNICODE_COMBINING_CLASS_ATTACHED_ABOVE_RIGHT:
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pos.y_offset = base_extents.y_bearing - (mark_extents.y_bearing + mark_extents.height);
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/* Don't shift down "above" marks too much. */
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if ((y_gap > 0) != (pos.y_offset > 0))
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{
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unsigned int correction = -pos.y_offset / 2;
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base_extents.y_bearing += correction;
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base_extents.height -= correction;
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pos.y_offset += correction;
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}
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base_extents.y_bearing -= mark_extents.height;
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base_extents.height += mark_extents.height;
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break;
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}
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}
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static inline void
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position_around_base (const hb_ot_shape_plan_t *plan,
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hb_font_t *font,
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hb_buffer_t *buffer,
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unsigned int base,
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unsigned int end)
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{
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hb_direction_t horiz_dir = HB_DIRECTION_INVALID;
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hb_glyph_extents_t base_extents;
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if (!font->get_glyph_extents (buffer->info[base].codepoint,
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&base_extents))
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{
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/* If extents don't work, zero marks and go home. */
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zero_mark_advances (buffer, base + 1, end);
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return;
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}
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base_extents.x_bearing += buffer->pos[base].x_offset;
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base_extents.y_bearing += buffer->pos[base].y_offset;
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unsigned int lig_id = _hb_glyph_info_get_lig_id (&buffer->info[base]);
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unsigned int num_lig_components = _hb_glyph_info_get_lig_num_comps (&buffer->info[base]);
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hb_position_t x_offset = 0, y_offset = 0;
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if (HB_DIRECTION_IS_FORWARD (buffer->props.direction)) {
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x_offset -= buffer->pos[base].x_advance;
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y_offset -= buffer->pos[base].y_advance;
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}
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hb_glyph_extents_t component_extents = base_extents;
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unsigned int last_lig_component = (unsigned int) -1;
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unsigned int last_combining_class = 255;
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hb_glyph_extents_t cluster_extents = base_extents; /* Initialization is just to shut gcc up. */
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for (unsigned int i = base + 1; i < end; i++)
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if (_hb_glyph_info_get_modified_combining_class (&buffer->info[i]))
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{
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if (num_lig_components > 1) {
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unsigned int this_lig_id = _hb_glyph_info_get_lig_id (&buffer->info[i]);
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unsigned int this_lig_component = _hb_glyph_info_get_lig_comp (&buffer->info[i]) - 1;
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/* Conditions for attaching to the last component. */
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if (!lig_id || lig_id != this_lig_id || this_lig_component >= num_lig_components)
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this_lig_component = num_lig_components - 1;
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if (last_lig_component != this_lig_component)
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{
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last_lig_component = this_lig_component;
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last_combining_class = 255;
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component_extents = base_extents;
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if (unlikely (horiz_dir == HB_DIRECTION_INVALID)) {
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if (HB_DIRECTION_IS_HORIZONTAL (plan->props.direction))
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horiz_dir = plan->props.direction;
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else
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horiz_dir = hb_script_get_horizontal_direction (plan->props.script);
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}
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if (horiz_dir == HB_DIRECTION_LTR)
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component_extents.x_bearing += (this_lig_component * component_extents.width) / num_lig_components;
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else
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component_extents.x_bearing += ((num_lig_components - 1 - this_lig_component) * component_extents.width) / num_lig_components;
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component_extents.width /= num_lig_components;
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}
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}
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unsigned int this_combining_class = _hb_glyph_info_get_modified_combining_class (&buffer->info[i]);
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if (last_combining_class != this_combining_class)
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{
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last_combining_class = this_combining_class;
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cluster_extents = component_extents;
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}
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position_mark (plan, font, buffer, cluster_extents, i, this_combining_class);
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buffer->pos[i].x_advance = 0;
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buffer->pos[i].y_advance = 0;
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buffer->pos[i].x_offset += x_offset;
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buffer->pos[i].y_offset += y_offset;
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} else {
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if (HB_DIRECTION_IS_FORWARD (buffer->props.direction)) {
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x_offset -= buffer->pos[i].x_advance;
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y_offset -= buffer->pos[i].y_advance;
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} else {
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x_offset += buffer->pos[i].x_advance;
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y_offset += buffer->pos[i].y_advance;
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}
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}
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}
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static inline void
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position_cluster (const hb_ot_shape_plan_t *plan,
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hb_font_t *font,
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hb_buffer_t *buffer,
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unsigned int start,
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unsigned int end)
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{
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if (end - start < 2)
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return;
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/* Find the base glyph */
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for (unsigned int i = start; i < end; i++)
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if (!HB_UNICODE_GENERAL_CATEGORY_IS_MARK (_hb_glyph_info_get_general_category (&buffer->info[i])))
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{
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/* Find mark glyphs */
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unsigned int j;
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for (j = i + 1; j < end; j++)
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if (!HB_UNICODE_GENERAL_CATEGORY_IS_MARK (_hb_glyph_info_get_general_category (&buffer->info[j])))
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break;
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position_around_base (plan, font, buffer, i, j);
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i = j - 1;
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}
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}
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void
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_hb_ot_shape_fallback_position (const hb_ot_shape_plan_t *plan,
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hb_font_t *font,
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hb_buffer_t *buffer)
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{
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unsigned int start = 0;
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unsigned int last_cluster = buffer->info[0].cluster;
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unsigned int count = buffer->len;
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for (unsigned int i = 1; i < count; i++)
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if (buffer->info[i].cluster != last_cluster) {
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position_cluster (plan, font, buffer, start, i);
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start = i;
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last_cluster = buffer->info[i].cluster;
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}
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position_cluster (plan, font, buffer, start, count);
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}
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/* Performs old-style TrueType kerning. */
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void
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_hb_ot_shape_fallback_kern (const hb_ot_shape_plan_t *plan,
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hb_font_t *font,
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hb_buffer_t *buffer)
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{
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if (!plan->has_kern) return;
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unsigned int count = buffer->len;
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OT::hb_apply_context_t c (1, font, buffer);
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c.set_lookup_mask (plan->kern_mask);
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c.set_lookup_props (OT::LookupFlag::IgnoreMarks);
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hb_glyph_info_t *info = buffer->info;
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hb_glyph_position_t *pos = buffer->pos;
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for (unsigned int idx = 0; idx < count;)
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{
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OT::hb_apply_context_t::skipping_forward_iterator_t skippy_iter (&c, idx, 1);
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if (!skippy_iter.next ())
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{
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idx++;
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continue;
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}
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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;
|
|
}
|
|
}
|