dlls/dwrite/shape.c

   1 /*
   2  *    Glyph shaping support
   3  *
   4  * Copyright 2010 Aric Stewart for CodeWeavers
   5  * Copyright 2014 Nikolay Sivov for CodeWeavers
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with this library; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  20  */
  21
  22 #define COBJMACROS
  23
  24 #include "dwrite_private.h"
  25
  26 WINE_DEFAULT_DEBUG_CHANNEL(dwrite);
  27
  28 struct scriptshaping_cache
  29 {
  30     IDWriteFontFace *fontface;
  31     UINT32 language_tag;
  32 };
  33
  34 HRESULT create_scriptshaping_cache(IDWriteFontFace *fontface, const WCHAR *locale, struct scriptshaping_cache **cache)
  35 {
  36     struct scriptshaping_cache *ret;
  37
  38     ret = heap_alloc(sizeof(*ret));
  39     if (!ret)
  40         return E_OUTOFMEMORY;
  41
  42     ret->fontface = fontface;
  43     IDWriteFontFace_AddRef(fontface);
  44
  45     ret->language_tag = DWRITE_MAKE_OPENTYPE_TAG('d','f','l','t');
  46     if (locale) {
  47         WCHAR tag[5];
  48         if (GetLocaleInfoEx(locale, LOCALE_SOPENTYPELANGUAGETAG, tag, sizeof(tag)/sizeof(WCHAR)))
  49             ret->language_tag = DWRITE_MAKE_OPENTYPE_TAG(tag[0],tag[1],tag[2],tag[3]);
  50     }
  51
  52     *cache = ret;
  53
  54     return S_OK;
  55 }
  56
  57 void release_scriptshaping_cache(struct scriptshaping_cache *cache)
  58 {
  59     if (!cache)
  60         return;
  61     IDWriteFontFace_Release(cache->fontface);
  62     heap_free(cache);
  63 }
  64
  65 static void shape_update_clusters_from_glyphprop(UINT32 glyphcount, UINT32 text_len, UINT16 *clustermap, DWRITE_SHAPING_GLYPH_PROPERTIES *glyph_props)
  66 {
  67     UINT32 i;
  68
  69     for (i = 0; i < glyphcount; i++) {
  70         if (!glyph_props[i].isClusterStart) {
  71             UINT32 j;
  72
  73             for (j = 0; j < text_len; j++) {
  74                 if (clustermap[j] == i) {
  75                     int k = j;
  76                     while (k >= 0 && k < text_len && !glyph_props[clustermap[k]].isClusterStart)
  77                         k--;
  78
  79                     if (k >= 0 && k < text_len && glyph_props[clustermap[k]].isClusterStart)
  80                         clustermap[j] = clustermap[k];
  81                 }
  82             }
  83         }
  84     }
  85 }
  86
  87 static int compare_clustersearch(const void *a, const void* b)
  88 {
  89     UINT16 target = *(UINT16*)a;
  90     UINT16 index = *(UINT16*)b;
  91     int ret = 0;
  92
  93     if (target > index)
  94         ret = 1;
  95     else if (target < index)
  96         ret = -1;
  97
  98     return ret;
  99 }
 100
 101 /* Maps given glyph position in glyph indices array to text index this glyph represents.
 102    Lowest possible index is returned.
 103
 104    clustermap [I] Text index to index in glyph indices array map
 105    len        [I] Clustermap size
 106    target     [I] Index in glyph indices array to map
 107  */
 108 static INT32 map_glyph_to_text_pos(const UINT16 *clustermap, UINT32 len, UINT16 target)
 109 {
 110     UINT16 *ptr;
 111     INT32 k;
 112
 113     ptr = bsearch(&target, clustermap, len, sizeof(UINT16), compare_clustersearch);
 114     if (!ptr)
 115         return -1;
 116
 117     /* get to the beginning */
 118     for (k = (ptr - clustermap) - 1; k >= 0 && clustermap[k] == target; k--)
 119         ;
 120     k++;
 121
 122     return k;
 123 }
 124
 125 static HRESULT default_set_text_glyphs_props(struct scriptshaping_cache *cache, const WCHAR *text, UINT32 len, UINT16 *clustermap, UINT16 *glyph_indices,
 126                                      UINT32 glyphcount, DWRITE_SHAPING_TEXT_PROPERTIES *text_props, DWRITE_SHAPING_GLYPH_PROPERTIES *glyph_props)
 127 {
 128     UINT32 i;
 129
 130     for (i = 0; i < glyphcount; i++) {
 131         UINT32 char_index[20];
 132         UINT32 char_count = 0;
 133         INT32 k;
 134
 135         k = map_glyph_to_text_pos(clustermap, len, i);
 136         if (k >= 0) {
 137             for (; k < len && clustermap[k] == i; k++)
 138                 char_index[char_count++] = k;
 139         }
 140
 141         if (char_count == 0)
 142             continue;
 143
 144         if (char_count == 1 && isspaceW(text[char_index[0]])) {
 145             glyph_props[i].justification = SCRIPT_JUSTIFY_BLANK;
 146             text_props[char_index[0]].isShapedAlone = text[char_index[0]] == ' ';
 147         }
 148         else
 149             glyph_props[i].justification = SCRIPT_JUSTIFY_CHARACTER;
 150     }
 151
 152     /* FIXME: update properties using GDEF table */
 153     shape_update_clusters_from_glyphprop(glyphcount, len, clustermap, glyph_props);
 154
 155     return S_OK;
 156 }
 157
 158 static HRESULT latn_set_text_glyphs_props(struct scriptshaping_cache *cache, const WCHAR *text, UINT32 len, UINT16 *clustermap, UINT16 *glyph_indices,
 159                                      UINT32 glyphcount, DWRITE_SHAPING_TEXT_PROPERTIES *text_props, DWRITE_SHAPING_GLYPH_PROPERTIES *glyph_props)
 160 {
 161     HRESULT hr;
 162     UINT32 i;
 163
 164     hr = default_set_text_glyphs_props(cache, text, len, clustermap, glyph_indices, glyphcount, text_props, glyph_props);
 165
 166     for (i = 0; i < glyphcount; i++)
 167         if (glyph_props[i].isZeroWidthSpace)
 168             glyph_props[i].justification = SCRIPT_JUSTIFY_NONE;
 169
 170     return hr;
 171 }
 172
 173 const struct scriptshaping_ops latn_shaping_ops =
 174 {
 175     NULL,
 176     latn_set_text_glyphs_props
 177 };
 178
 179 const struct scriptshaping_ops default_shaping_ops =
 180 {
 181     NULL,
 182     default_set_text_glyphs_props
 183 };