hb-ot-shape-normalize.cc revision c311d852080b50ffc85e80168de62abb05a6be59
1655586fe5e1fadf2a2ef7826e61ee9a445ffa37aBehdad Esfahbod/* 2655586fe5e1fadf2a2ef7826e61ee9a445ffa37aBehdad Esfahbod * Copyright © 2011 Google, Inc. 3655586fe5e1fadf2a2ef7826e61ee9a445ffa37aBehdad Esfahbod * 4655586fe5e1fadf2a2ef7826e61ee9a445ffa37aBehdad Esfahbod * This is part of HarfBuzz, a text shaping library. 5655586fe5e1fadf2a2ef7826e61ee9a445ffa37aBehdad Esfahbod * 6655586fe5e1fadf2a2ef7826e61ee9a445ffa37aBehdad Esfahbod * Permission is hereby granted, without written agreement and without 7655586fe5e1fadf2a2ef7826e61ee9a445ffa37aBehdad Esfahbod * license or royalty fees, to use, copy, modify, and distribute this 8655586fe5e1fadf2a2ef7826e61ee9a445ffa37aBehdad Esfahbod * software and its documentation for any purpose, provided that the 9655586fe5e1fadf2a2ef7826e61ee9a445ffa37aBehdad Esfahbod * above copyright notice and the following two paragraphs appear in 10655586fe5e1fadf2a2ef7826e61ee9a445ffa37aBehdad Esfahbod * all copies of this software. 11655586fe5e1fadf2a2ef7826e61ee9a445ffa37aBehdad Esfahbod * 12655586fe5e1fadf2a2ef7826e61ee9a445ffa37aBehdad Esfahbod * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR 13655586fe5e1fadf2a2ef7826e61ee9a445ffa37aBehdad Esfahbod * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES 14655586fe5e1fadf2a2ef7826e61ee9a445ffa37aBehdad Esfahbod * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN 15655586fe5e1fadf2a2ef7826e61ee9a445ffa37aBehdad Esfahbod * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH 16655586fe5e1fadf2a2ef7826e61ee9a445ffa37aBehdad Esfahbod * DAMAGE. 17655586fe5e1fadf2a2ef7826e61ee9a445ffa37aBehdad Esfahbod * 18655586fe5e1fadf2a2ef7826e61ee9a445ffa37aBehdad Esfahbod * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, 19655586fe5e1fadf2a2ef7826e61ee9a445ffa37aBehdad Esfahbod * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND 20655586fe5e1fadf2a2ef7826e61ee9a445ffa37aBehdad Esfahbod * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS 21655586fe5e1fadf2a2ef7826e61ee9a445ffa37aBehdad Esfahbod * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO 22655586fe5e1fadf2a2ef7826e61ee9a445ffa37aBehdad Esfahbod * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. 23655586fe5e1fadf2a2ef7826e61ee9a445ffa37aBehdad Esfahbod * 24655586fe5e1fadf2a2ef7826e61ee9a445ffa37aBehdad Esfahbod * Google Author(s): Behdad Esfahbod 25655586fe5e1fadf2a2ef7826e61ee9a445ffa37aBehdad Esfahbod */ 26655586fe5e1fadf2a2ef7826e61ee9a445ffa37aBehdad Esfahbod 27655586fe5e1fadf2a2ef7826e61ee9a445ffa37aBehdad Esfahbod#include "hb-ot-shape-private.hh" 285d90a342e319068716429bf7af76c3896b61a0e5Behdad Esfahbod#include "hb-ot-shape-complex-private.hh" 29655586fe5e1fadf2a2ef7826e61ee9a445ffa37aBehdad Esfahbod 30655586fe5e1fadf2a2ef7826e61ee9a445ffa37aBehdad EsfahbodHB_BEGIN_DECLS 31655586fe5e1fadf2a2ef7826e61ee9a445ffa37aBehdad Esfahbod 325d90a342e319068716429bf7af76c3896b61a0e5Behdad Esfahbod/* 335d90a342e319068716429bf7af76c3896b61a0e5Behdad Esfahbod * HIGHLEVEL DESIGN: 345d90a342e319068716429bf7af76c3896b61a0e5Behdad Esfahbod * 355d90a342e319068716429bf7af76c3896b61a0e5Behdad Esfahbod * This file exports one main function: _hb_ot_shape_normalize(). 365d90a342e319068716429bf7af76c3896b61a0e5Behdad Esfahbod * 375d90a342e319068716429bf7af76c3896b61a0e5Behdad Esfahbod * This function closely reflects the Unicode Normalization Algorithm, 385d90a342e319068716429bf7af76c3896b61a0e5Behdad Esfahbod * yet it's different. The shaper an either prefer decomposed (NFD) or 395d90a342e319068716429bf7af76c3896b61a0e5Behdad Esfahbod * composed (NFC). 405d90a342e319068716429bf7af76c3896b61a0e5Behdad Esfahbod * 415d90a342e319068716429bf7af76c3896b61a0e5Behdad Esfahbod * In general what happens is that: each grapheme is decomposed in a chain 425d90a342e319068716429bf7af76c3896b61a0e5Behdad Esfahbod * of 1:2 decompositions, marks reordered, and then recomposed if desires, 435d90a342e319068716429bf7af76c3896b61a0e5Behdad Esfahbod * so far it's like Unicode Normalization. However, the decomposition and 445d90a342e319068716429bf7af76c3896b61a0e5Behdad Esfahbod * recomposition only happens if the font supports the resulting characters. 455d90a342e319068716429bf7af76c3896b61a0e5Behdad Esfahbod * 465d90a342e319068716429bf7af76c3896b61a0e5Behdad Esfahbod * The goals are: 475d90a342e319068716429bf7af76c3896b61a0e5Behdad Esfahbod * 485d90a342e319068716429bf7af76c3896b61a0e5Behdad Esfahbod * - Try to render all canonically equivalent strings similarly. To really 495d90a342e319068716429bf7af76c3896b61a0e5Behdad Esfahbod * achieve this we have to always do the full decomposition and then 505d90a342e319068716429bf7af76c3896b61a0e5Behdad Esfahbod * selectively recompose from there. It's kinda too expensive though, so 515d90a342e319068716429bf7af76c3896b61a0e5Behdad Esfahbod * we skip some cases. For example, if composed is desired, we simply 525d90a342e319068716429bf7af76c3896b61a0e5Behdad Esfahbod * don't touch 1-character clusters that are supported by the font, even 535d90a342e319068716429bf7af76c3896b61a0e5Behdad Esfahbod * though their NFC may be different. 545d90a342e319068716429bf7af76c3896b61a0e5Behdad Esfahbod * 555d90a342e319068716429bf7af76c3896b61a0e5Behdad Esfahbod * - When a font has a precomposed character for a sequence but the 'ccmp' 565d90a342e319068716429bf7af76c3896b61a0e5Behdad Esfahbod * feature in the font is not adequate, form use the precomposed character 575d90a342e319068716429bf7af76c3896b61a0e5Behdad Esfahbod * which typically has better mark positioning. 585d90a342e319068716429bf7af76c3896b61a0e5Behdad Esfahbod * 595d90a342e319068716429bf7af76c3896b61a0e5Behdad Esfahbod * - When a font does not support a character but supports its decomposition, 605d90a342e319068716429bf7af76c3896b61a0e5Behdad Esfahbod * well, use the decomposition. 615d90a342e319068716429bf7af76c3896b61a0e5Behdad Esfahbod * 625d90a342e319068716429bf7af76c3896b61a0e5Behdad Esfahbod * - The Indic shaper requests decomposed output. This will handle splitting 635d90a342e319068716429bf7af76c3896b61a0e5Behdad Esfahbod * matra for the Indic shaper. 645d90a342e319068716429bf7af76c3896b61a0e5Behdad Esfahbod */ 655d90a342e319068716429bf7af76c3896b61a0e5Behdad Esfahbod 66c311d852080b50ffc85e80168de62abb05a6be59Behdad Esfahbodstatic void 67c311d852080b50ffc85e80168de62abb05a6be59Behdad Esfahbodoutput_glyph (hb_ot_shape_context_t *c, 68c311d852080b50ffc85e80168de62abb05a6be59Behdad Esfahbod hb_codepoint_t glyph) 69c311d852080b50ffc85e80168de62abb05a6be59Behdad Esfahbod{ 70c311d852080b50ffc85e80168de62abb05a6be59Behdad Esfahbod hb_buffer_t *buffer = c->buffer; 71c311d852080b50ffc85e80168de62abb05a6be59Behdad Esfahbod 72c311d852080b50ffc85e80168de62abb05a6be59Behdad Esfahbod buffer->output_glyph (glyph); 73c311d852080b50ffc85e80168de62abb05a6be59Behdad Esfahbod hb_glyph_info_set_unicode_props (&buffer->out_info[buffer->out_len - 1], buffer->unicode); 74c311d852080b50ffc85e80168de62abb05a6be59Behdad Esfahbod} 7545412523dc295cb5ee12e096bfacb282cc925843Behdad Esfahbod 765c6f5982d78e2d7fadc2fbb8b4f3a4be9420c59aBehdad Esfahbodstatic bool 7745412523dc295cb5ee12e096bfacb282cc925843Behdad Esfahboddecompose (hb_ot_shape_context_t *c, 784ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod bool shortest, 7945412523dc295cb5ee12e096bfacb282cc925843Behdad Esfahbod hb_codepoint_t ab) 80655586fe5e1fadf2a2ef7826e61ee9a445ffa37aBehdad Esfahbod{ 8145412523dc295cb5ee12e096bfacb282cc925843Behdad Esfahbod hb_codepoint_t a, b, glyph; 8245412523dc295cb5ee12e096bfacb282cc925843Behdad Esfahbod 834ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod if (!hb_unicode_decompose (c->buffer->unicode, ab, &a, &b) || 84dcdc51cdc0ba9d9fb75f84dd5fa7a49aa0b24ea0Behdad Esfahbod (b && !hb_font_get_glyph (c->font, b, 0, &glyph))) 854ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod return FALSE; 8645412523dc295cb5ee12e096bfacb282cc925843Behdad Esfahbod 874ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod bool has_a = hb_font_get_glyph (c->font, a, 0, &glyph); 884ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod if (shortest && has_a) { 894ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod /* Output a and b */ 90c311d852080b50ffc85e80168de62abb05a6be59Behdad Esfahbod output_glyph (c, a); 91dcdc51cdc0ba9d9fb75f84dd5fa7a49aa0b24ea0Behdad Esfahbod if (b) 92c311d852080b50ffc85e80168de62abb05a6be59Behdad Esfahbod output_glyph (c, b); 934ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod return TRUE; 944ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod } 95655586fe5e1fadf2a2ef7826e61ee9a445ffa37aBehdad Esfahbod 964ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod if (decompose (c, shortest, a)) { 97dcdc51cdc0ba9d9fb75f84dd5fa7a49aa0b24ea0Behdad Esfahbod if (b) 98c311d852080b50ffc85e80168de62abb05a6be59Behdad Esfahbod output_glyph (c, b); 994ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod return TRUE; 1004ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod } 10145412523dc295cb5ee12e096bfacb282cc925843Behdad Esfahbod 1024ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod if (has_a) { 103c311d852080b50ffc85e80168de62abb05a6be59Behdad Esfahbod output_glyph (c, a); 104dcdc51cdc0ba9d9fb75f84dd5fa7a49aa0b24ea0Behdad Esfahbod if (b) 105c311d852080b50ffc85e80168de62abb05a6be59Behdad Esfahbod output_glyph (c, b); 10645412523dc295cb5ee12e096bfacb282cc925843Behdad Esfahbod return TRUE; 10745412523dc295cb5ee12e096bfacb282cc925843Behdad Esfahbod } 10845412523dc295cb5ee12e096bfacb282cc925843Behdad Esfahbod 1094ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod return FALSE; 1105c6f5982d78e2d7fadc2fbb8b4f3a4be9420c59aBehdad Esfahbod} 1115c6f5982d78e2d7fadc2fbb8b4f3a4be9420c59aBehdad Esfahbod 112c311d852080b50ffc85e80168de62abb05a6be59Behdad Esfahbodstatic void 1134ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahboddecompose_current_glyph (hb_ot_shape_context_t *c, 1144ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod bool shortest) 115d6b9c6d20041b4f4fa11befc179aee757c41904dBehdad Esfahbod{ 116c311d852080b50ffc85e80168de62abb05a6be59Behdad Esfahbod if (decompose (c, shortest, c->buffer->info[c->buffer->idx].codepoint)) 1174ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod c->buffer->skip_glyph (); 118c311d852080b50ffc85e80168de62abb05a6be59Behdad Esfahbod else 1194ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod c->buffer->next_glyph (); 120d6b9c6d20041b4f4fa11befc179aee757c41904dBehdad Esfahbod} 121d6b9c6d20041b4f4fa11befc179aee757c41904dBehdad Esfahbod 122c311d852080b50ffc85e80168de62abb05a6be59Behdad Esfahbodstatic void 1234ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahboddecompose_single_char_cluster (hb_ot_shape_context_t *c, 1244ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod bool will_recompose) 1255c6f5982d78e2d7fadc2fbb8b4f3a4be9420c59aBehdad Esfahbod{ 1264ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod hb_codepoint_t glyph; 1274ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod 1284ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod /* If recomposing and font supports this, we're good to go */ 1294ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod if (will_recompose && hb_font_get_glyph (c->font, c->buffer->info[c->buffer->idx].codepoint, 0, &glyph)) { 1304ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod c->buffer->next_glyph (); 131c311d852080b50ffc85e80168de62abb05a6be59Behdad Esfahbod return; 1324ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod } 1334ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod 134c311d852080b50ffc85e80168de62abb05a6be59Behdad Esfahbod decompose_current_glyph (c, will_recompose); 135655586fe5e1fadf2a2ef7826e61ee9a445ffa37aBehdad Esfahbod} 136655586fe5e1fadf2a2ef7826e61ee9a445ffa37aBehdad Esfahbod 137c311d852080b50ffc85e80168de62abb05a6be59Behdad Esfahbodstatic void 1384ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahboddecompose_multi_char_cluster (hb_ot_shape_context_t *c, 1394ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod unsigned int end) 140655586fe5e1fadf2a2ef7826e61ee9a445ffa37aBehdad Esfahbod{ 1415d90a342e319068716429bf7af76c3896b61a0e5Behdad Esfahbod /* TODO Currently if there's a variation-selector we give-up, it's just too hard. */ 1424ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod for (unsigned int i = c->buffer->idx; i < end; i++) 143d6b9c6d20041b4f4fa11befc179aee757c41904dBehdad Esfahbod if (unlikely (is_variation_selector (c->buffer->info[i].codepoint))) 144c311d852080b50ffc85e80168de62abb05a6be59Behdad Esfahbod return; 145d6b9c6d20041b4f4fa11befc179aee757c41904dBehdad Esfahbod 1464ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod while (c->buffer->idx < end) 147c311d852080b50ffc85e80168de62abb05a6be59Behdad Esfahbod decompose_current_glyph (c, FALSE); 148655586fe5e1fadf2a2ef7826e61ee9a445ffa37aBehdad Esfahbod} 149655586fe5e1fadf2a2ef7826e61ee9a445ffa37aBehdad Esfahbod 15045412523dc295cb5ee12e096bfacb282cc925843Behdad Esfahbodvoid 1515d90a342e319068716429bf7af76c3896b61a0e5Behdad Esfahbod_hb_ot_shape_normalize (hb_ot_shape_context_t *c) 152655586fe5e1fadf2a2ef7826e61ee9a445ffa37aBehdad Esfahbod{ 1535d90a342e319068716429bf7af76c3896b61a0e5Behdad Esfahbod hb_buffer_t *buffer = c->buffer; 1545d90a342e319068716429bf7af76c3896b61a0e5Behdad Esfahbod bool recompose = !hb_ot_shape_complex_prefer_decomposed (c->plan->shaper); 1554ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod bool has_multichar_clusters = FALSE; 15634c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod unsigned int count; 1575d90a342e319068716429bf7af76c3896b61a0e5Behdad Esfahbod 158c311d852080b50ffc85e80168de62abb05a6be59Behdad Esfahbod /* We do a fairly straightforward yet custom normalization process in three 1595389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod * separate rounds: decompose, reorder, recompose (if desired). Currently 1605389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod * this makes two buffer swaps. We can make it faster by moving the last 1615389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod * two rounds into the inner loop for the first round, but it's more readable 1625389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod * this way. */ 1635d90a342e319068716429bf7af76c3896b61a0e5Behdad Esfahbod 16434c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod 1654ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod /* First round, decompose */ 1664ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod 1675389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod buffer->clear_output (); 16834c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod count = buffer->len; 169468e9cb25c9bc14781b7013e447d763f93bf76a3Behdad Esfahbod for (buffer->idx = 0; buffer->idx < count;) 1705d90a342e319068716429bf7af76c3896b61a0e5Behdad Esfahbod { 171655586fe5e1fadf2a2ef7826e61ee9a445ffa37aBehdad Esfahbod unsigned int end; 172468e9cb25c9bc14781b7013e447d763f93bf76a3Behdad Esfahbod for (end = buffer->idx + 1; end < count; end++) 173468e9cb25c9bc14781b7013e447d763f93bf76a3Behdad Esfahbod if (buffer->info[buffer->idx].cluster != buffer->info[end].cluster) 174655586fe5e1fadf2a2ef7826e61ee9a445ffa37aBehdad Esfahbod break; 1755d90a342e319068716429bf7af76c3896b61a0e5Behdad Esfahbod 176468e9cb25c9bc14781b7013e447d763f93bf76a3Behdad Esfahbod if (buffer->idx + 1 == end) 177c311d852080b50ffc85e80168de62abb05a6be59Behdad Esfahbod decompose_single_char_cluster (c, recompose); 1784ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod else { 179c311d852080b50ffc85e80168de62abb05a6be59Behdad Esfahbod decompose_multi_char_cluster (c, end); 1804ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod has_multichar_clusters = TRUE; 1814ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod } 182655586fe5e1fadf2a2ef7826e61ee9a445ffa37aBehdad Esfahbod } 183468e9cb25c9bc14781b7013e447d763f93bf76a3Behdad Esfahbod buffer->swap_buffers (); 1844ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod 18534c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod 1864ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod /* Technically speaking, two characters with ccc=0 may combine. But all 1874ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod * those cases are in languages that the indic module handles (which expects 1884ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod * decomposed), or in Hangul jamo, which again, we want decomposed anyway. 1895389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod * So we don't bother combining across cluster boundaries. 1905389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod * 1915389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod * TODO: Am I right about Hangul? If I am, we should add a Hangul module 1925389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod * that requests decomposed. */ 1934ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod 1944ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod if (!has_multichar_clusters) 1954ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod return; /* Done! */ 1964ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod 19734c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod 1984ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod /* Second round, reorder (inplace) */ 1994ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod 20034c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod count = buffer->len; 20134c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod for (unsigned int i = 0; i < count; i++) 20234c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod { 20334c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod if (buffer->info[i].combining_class() == 0) 20434c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod continue; 20534c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod 20634c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod unsigned int end; 20734c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod for (end = i + 1; end < count; end++) 20834c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod if (buffer->info[end].combining_class() == 0) 20934c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod break; 21034c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod 21134c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod /* We are going to do a bubble-sort. Only do this if the 21234c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod * sequence is short. Doing it on long sequences can result 21334c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod * in an O(n^2) DoS. */ 21434c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod if (end - i > 10) { 21534c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod i = end; 21634c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod continue; 21734c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod } 21834c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod 21934c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod unsigned int k = end - i - 1; 22034c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod do { 22134c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod hb_glyph_info_t *pinfo = buffer->info + i; 22234c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod unsigned int new_k = 0; 22334c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod 22434c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod for (unsigned int j = 0; j < k; j++) 22534c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod if (pinfo[j].combining_class() > pinfo[j+1].combining_class()) { 22634c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod hb_glyph_info_t t; 22734c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod t = pinfo[j]; 22834c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod pinfo[j] = pinfo[j + 1]; 22934c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod pinfo[j + 1] = t; 23034c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod 23134c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod new_k = j; 23234c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod } 23334c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod k = new_k; 23434c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod } while (k); 23534c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod 23634c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod i = end; 23734c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod } 23834c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod 2394ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod 2405389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod if (!recompose) 2415389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod return; 2425389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod 2434ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod /* Third round, recompose */ 24434c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod 2455389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod /* As noted in the comment earlier, we don't try to combine 2465389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod * ccc=0 chars with their previous Starter. */ 2474ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod 2485389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod buffer->clear_output (); 2495389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod count = buffer->len; 2505389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod unsigned int starter = 0; 2515389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod buffer->next_glyph (); 2525389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod while (buffer->idx < count) 2535389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod { 2545389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod if (buffer->info[buffer->idx].combining_class() == 0) { 2555389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod starter = buffer->out_len; 2565389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod buffer->next_glyph (); 2575389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod continue; 2585389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod } 2595389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod 2605389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod hb_codepoint_t composed, glyph; 2615389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod if ((buffer->out_info[buffer->out_len - 1].combining_class() >= 2625389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod buffer->info[buffer->idx].combining_class()) || 2635389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod !hb_unicode_compose (c->buffer->unicode, 2645389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod buffer->out_info[starter].codepoint, 2655389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod buffer->info[buffer->idx].codepoint, 2665389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod &composed) || 2675389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod !hb_font_get_glyph (c->font, composed, 0, &glyph)) 2685389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod { 2695389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod /* Blocked, or doesn't compose. */ 2705389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod buffer->next_glyph (); 2715389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod continue; 2725389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod } 2735389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod 2745389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod /* Composes. Modify starter and carry on. */ 2755389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod buffer->out_info[starter].codepoint = composed; 2765389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod hb_glyph_info_set_unicode_props (&buffer->out_info[starter], buffer->unicode); 2774ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod 2785389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod buffer->skip_glyph (); 2794ff0d2d9dfc4f7e4880a4e964ca9872624508ea0Behdad Esfahbod } 2805389ff4dbc46c76c9483e3c95f22524b60e21166Behdad Esfahbod buffer->swap_buffers (); 28134c22f816808d061a980cffca12de03beb437fa0Behdad Esfahbod 282655586fe5e1fadf2a2ef7826e61ee9a445ffa37aBehdad Esfahbod} 283655586fe5e1fadf2a2ef7826e61ee9a445ffa37aBehdad Esfahbod 284655586fe5e1fadf2a2ef7826e61ee9a445ffa37aBehdad EsfahbodHB_END_DECLS 285