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 struct scriptshaping_cache
  27 {
  28     IDWriteFontFace *fontface;
  29 };
  30
  31 HRESULT create_scriptshaping_cache(IDWriteFontFace *fontface, struct scriptshaping_cache **cache)
  32 {
  33     struct scriptshaping_cache *ret;
  34
  35     ret = heap_alloc(sizeof(*ret));
  36     if (!ret)
  37         return E_OUTOFMEMORY;
  38
  39     ret->fontface = fontface;
  40     IDWriteFontFace_AddRef(fontface);
  41
  42     *cache = ret;
  43
  44     return S_OK;
  45 }
  46
  47 void release_scriptshaping_cache(struct scriptshaping_cache *cache)
  48 {
  49     if (!cache)
  50         return;
  51     IDWriteFontFace_Release(cache->fontface);
  52     heap_free(cache);
  53 }
  54
  55 static void shape_update_clusters_from_glyphprop(UINT32 glyphcount, UINT32 text_len, UINT16 *clustermap, DWRITE_SHAPING_GLYPH_PROPERTIES *glyph_props)
  56 {
  57     UINT32 i;
  58
  59     for (i = 0; i < glyphcount; i++) {
  60         if (!glyph_props[i].isClusterStart) {
  61             UINT32 j;
  62
  63             for (j = 0; j < text_len; j++) {
  64                 if (clustermap[j] == i) {
  65                     int k = j;
  66                     while (k >= 0 && k < text_len && !glyph_props[clustermap[k]].isClusterStart)
  67                         k--;
  68
  69                     if (k >= 0 && k < text_len && glyph_props[clustermap[k]].isClusterStart)
  70                         clustermap[j] = clustermap[k];
  71                 }
  72             }
  73         }
  74     }
  75 }
  76
  77 static int compare_clustersearch(const void *a, const void* b)
  78 {
  79     UINT16 target = *(UINT16*)a;
  80     UINT16 index = *(UINT16*)b;
  81     int ret = 0;
  82
  83     if (target > index)
  84         ret = 1;
  85     else if (target < index)
  86         ret = -1;
  87
  88     return ret;
  89 }
  90
  91 /* Maps given glyph position in glyph indices array to text index this glyph represents.
  92    Lowest possible index is returned.
  93
  94    clustermap [I] Text index to index in glyph indices array map
  95    len        [I] Clustermap size
  96    target     [I] Index in glyph indices array to map
  97  */
  98 static INT32 map_glyph_to_text_pos(const UINT16 *clustermap, UINT32 len, UINT16 target)
  99 {
 100     UINT16 *ptr;
 101     INT32 k;
 102
 103     ptr = bsearch(&target, clustermap, len, sizeof(UINT16), compare_clustersearch);
 104     if (!ptr)
 105         return -1;
 106
 107     /* get to the beginning */
 108     for (k = (ptr - clustermap) - 1; k >= 0 && clustermap[k] == target; k--)
 109         ;
 110     k++;
 111
 112     return k;
 113 }
 114
 115 static HRESULT default_set_text_glyphs_props(struct scriptshaping_context *context, UINT16 *clustermap, UINT16 *glyph_indices,
 116                                      UINT32 glyphcount, DWRITE_SHAPING_TEXT_PROPERTIES *text_props, DWRITE_SHAPING_GLYPH_PROPERTIES *glyph_props)
 117 {
 118     UINT32 i;
 119
 120     for (i = 0; i < glyphcount; i++) {
 121         UINT32 char_index[20];
 122         UINT32 char_count = 0;
 123         INT32 k;
 124
 125         k = map_glyph_to_text_pos(clustermap, context->length, i);
 126         if (k >= 0) {
 127             for (; k < context->length && clustermap[k] == i; k++)
 128                 char_index[char_count++] = k;
 129         }
 130
 131         if (char_count == 0)
 132             continue;
 133
 134         if (char_count == 1 && isspaceW(context->text[char_index[0]])) {
 135             glyph_props[i].justification = SCRIPT_JUSTIFY_BLANK;
 136             text_props[char_index[0]].isShapedAlone = context->text[char_index[0]] == ' ';
 137         }
 138         else
 139             glyph_props[i].justification = SCRIPT_JUSTIFY_CHARACTER;
 140     }
 141
 142     /* FIXME: update properties using GDEF table */
 143     shape_update_clusters_from_glyphprop(glyphcount, context->length, clustermap, glyph_props);
 144
 145     return S_OK;
 146 }
 147
 148 static HRESULT latn_set_text_glyphs_props(struct scriptshaping_context *context, UINT16 *clustermap, UINT16 *glyph_indices,
 149                                      UINT32 glyphcount, DWRITE_SHAPING_TEXT_PROPERTIES *text_props, DWRITE_SHAPING_GLYPH_PROPERTIES *glyph_props)
 150 {
 151     HRESULT hr;
 152     UINT32 i;
 153
 154     hr = default_set_text_glyphs_props(context, clustermap, glyph_indices, glyphcount, text_props, glyph_props);
 155
 156     for (i = 0; i < glyphcount; i++)
 157         if (glyph_props[i].isZeroWidthSpace)
 158             glyph_props[i].justification = SCRIPT_JUSTIFY_NONE;
 159
 160     return hr;
 161 }
 162
 163 const struct scriptshaping_ops latn_shaping_ops =
 164 {
 165     NULL,
 166     latn_set_text_glyphs_props
 167 };
 168
 169 const struct scriptshaping_ops default_shaping_ops =
 170 {
 171     NULL,
 172     default_set_text_glyphs_props
 173 };