266 lines
7.5 KiB
C++
266 lines
7.5 KiB
C++
/*
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* Copyright (C) 2009 Red Hat, 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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* Red Hat Author(s): Behdad Esfahbod
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*/
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#include "hb-private.h"
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#include "hb-shape.h"
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#include "hb-buffer-private.hh"
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#include "hb-ot-shape-private.hh"
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#ifdef HAVE_GRAPHITE
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#include "hb-graphite.h"
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#endif
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/* Prepare */
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static inline hb_bool_t
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is_variation_selector (hb_codepoint_t unicode)
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{
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return unlikely ((unicode >= 0x180B && unicode <= 0x180D) || /* MONGOLIAN FREE VARIATION SELECTOR ONE..THREE */
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(unicode >= 0xFE00 && unicode <= 0xFE0F) || /* VARIATION SELECTOR-1..16 */
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(unicode >= 0xE0100 && unicode <= 0xE01EF)); /* VARIATION SELECTOR-17..256 */
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}
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static void
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hb_form_clusters (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 = 1; i < count; i++)
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if (buffer->unicode->get_general_category (buffer->info[i].codepoint) == HB_CATEGORY_NON_SPACING_MARK)
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buffer->info[i].cluster = buffer->info[i - 1].cluster;
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}
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static hb_direction_t
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hb_ensure_native_direction (hb_buffer_t *buffer)
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{
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hb_direction_t original_direction = buffer->direction;
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/* TODO vertical */
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if (HB_DIRECTION_IS_HORIZONTAL (original_direction) &&
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original_direction != _hb_script_get_horizontal_direction (buffer->script))
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{
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hb_buffer_reverse_clusters (buffer);
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buffer->direction = HB_DIRECTION_REVERSE (buffer->direction);
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}
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return original_direction;
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}
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/* Substitute */
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static void
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hb_mirror_chars (hb_buffer_t *buffer)
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{
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hb_unicode_get_mirroring_func_t get_mirroring = buffer->unicode->get_mirroring;
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if (HB_DIRECTION_IS_FORWARD (buffer->direction))
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return;
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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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buffer->info[i].codepoint = get_mirroring (buffer->info[i].codepoint);
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}
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}
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static void
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hb_map_glyphs (hb_font_t *font,
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hb_face_t *face,
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hb_buffer_t *buffer)
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{
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if (unlikely (!buffer->len))
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return;
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unsigned int count = buffer->len - 1;
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for (unsigned int i = 0; i < count; i++) {
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if (unlikely (is_variation_selector (buffer->info[i + 1].codepoint))) {
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buffer->info[i].codepoint = hb_font_get_glyph (font, face, buffer->info[i].codepoint, buffer->info[i + 1].codepoint);
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i++;
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} else {
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buffer->info[i].codepoint = hb_font_get_glyph (font, face, buffer->info[i].codepoint, 0);
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}
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}
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buffer->info[count].codepoint = hb_font_get_glyph (font, face, buffer->info[count].codepoint, 0);
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}
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static void
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hb_substitute_default (hb_font_t *font,
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hb_face_t *face,
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hb_buffer_t *buffer,
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hb_feature_t *features HB_UNUSED,
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unsigned int num_features HB_UNUSED)
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{
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hb_mirror_chars (buffer);
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hb_map_glyphs (font, face, buffer);
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}
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static hb_bool_t
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hb_substitute_complex (hb_font_t *font,
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hb_face_t *face,
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hb_buffer_t *buffer,
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hb_feature_t *features,
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unsigned int num_features)
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{
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return _hb_ot_substitute_complex (font, face, buffer, features, num_features);
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}
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static void
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hb_substitute_fallback (hb_font_t *font HB_UNUSED,
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hb_face_t *face HB_UNUSED,
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hb_buffer_t *buffer HB_UNUSED,
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hb_feature_t *features HB_UNUSED,
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unsigned int num_features HB_UNUSED)
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{
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/* TODO Arabic */
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}
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/* Position */
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static void
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hb_position_default (hb_font_t *font,
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hb_face_t *face,
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hb_buffer_t *buffer,
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hb_feature_t *features HB_UNUSED,
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unsigned int num_features HB_UNUSED)
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{
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hb_buffer_clear_positions (buffer);
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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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hb_glyph_metrics_t metrics;
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hb_font_get_glyph_metrics (font, face, buffer->info[i].codepoint, &metrics);
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buffer->pos[i].x_advance = metrics.x_advance;
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buffer->pos[i].y_advance = metrics.y_advance;
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}
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}
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static hb_bool_t
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hb_position_complex (hb_font_t *font,
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hb_face_t *face,
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hb_buffer_t *buffer,
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hb_feature_t *features,
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unsigned int num_features)
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{
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return _hb_ot_position_complex (font, face, buffer, features, num_features);
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}
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static void
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hb_position_fallback (hb_font_t *font HB_UNUSED,
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hb_face_t *face HB_UNUSED,
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hb_buffer_t *buffer HB_UNUSED,
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hb_feature_t *features HB_UNUSED,
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unsigned int num_features HB_UNUSED)
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{
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/* TODO Mark pos */
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}
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static void
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hb_truetype_kern (hb_font_t *font,
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hb_face_t *face,
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hb_buffer_t *buffer,
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hb_feature_t *features HB_UNUSED,
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unsigned int num_features HB_UNUSED)
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{
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/* TODO Check for kern=0 */
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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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hb_position_t kern, kern1, kern2;
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kern = hb_font_get_kerning (font, face, buffer->info[i - 1].codepoint, buffer->info[i].codepoint);
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kern1 = kern >> 1;
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kern2 = kern - kern1;
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buffer->pos[i - 1].x_advance += kern1;
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buffer->pos[i].x_advance += kern2;
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buffer->pos[i].x_offset += kern2;
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}
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}
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static void
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hb_position_fallback_visual (hb_font_t *font,
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hb_face_t *face,
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hb_buffer_t *buffer,
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hb_feature_t *features,
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unsigned int num_features)
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{
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hb_truetype_kern (font, face, buffer, features, num_features);
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}
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/* Shape */
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void
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hb_shape (hb_font_t *font,
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hb_face_t *face,
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hb_buffer_t *buffer,
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hb_feature_t *features,
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unsigned int num_features)
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{
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hb_direction_t original_direction;
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hb_bool_t substitute_fallback, position_fallback;
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#ifdef HAVE_GRAPHITE
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hb_blob_t *silf_blob;
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silf_blob = hb_face_get_table (face, HB_GRAPHITE_TAG_Silf);
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if (hb_blob_get_length(silf_blob))
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{
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hb_graphite_shape(font, face, buffer, features, num_features);
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hb_blob_destroy(silf_blob);
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return;
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}
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hb_blob_destroy(silf_blob);
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#endif
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hb_form_clusters (buffer);
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hb_substitute_default (font, face, buffer, features, num_features);
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/* We do this after substitute_default because mirroring needs to
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* see the original direction. */
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original_direction = hb_ensure_native_direction (buffer);
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substitute_fallback = !hb_substitute_complex (font, face, buffer, features, num_features);
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if (substitute_fallback)
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hb_substitute_fallback (font, face, buffer, features, num_features);
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hb_position_default (font, face, buffer, features, num_features);
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position_fallback = !hb_position_complex (font, face, buffer, features, num_features);
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if (position_fallback)
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hb_position_fallback (font, face, buffer, features, num_features);
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if (HB_DIRECTION_IS_BACKWARD (buffer->direction))
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hb_buffer_reverse (buffer);
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if (position_fallback)
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hb_position_fallback_visual (font, face, buffer, features, num_features);
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buffer->direction = original_direction;
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}
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