src/hb-icu-le.cc

   1 /*
   2  * Copyright © 2012  Google, Inc.
   3  *
   4  *  This is part of HarfBuzz, a text shaping library.
   5  *
   6  * Permission is hereby granted, without written agreement and without
   7  * license or royalty fees, to use, copy, modify, and distribute this
   8  * software and its documentation for any purpose, provided that the
   9  * above copyright notice and the following two paragraphs appear in
  10  * all copies of this software.
  11  *
  12  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
  13  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
  14  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
  15  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
  16  * DAMAGE.
  17  *
  18  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
  19  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
  20  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
  21  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
  22  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
  23  *
  24  * Google Author(s): Behdad Esfahbod
  25  */
  26
  27 #define HB_SHAPER icu_le
  28 #define hb_icu_le_shaper_font_data_t PortableFontInstance
  29 #include "hb-shaper-impl-private.hh"
  30
  31 #include "hb-icu-le/PortableFontInstance.h"
  32
  33 #include "layout/loengine.h"
  34 #include "unicode/unistr.h"
  35
  36 #include "hb-icu.h"
  37
  38
  39 /*
  40  * shaper face data
  41  */
  42
  43 struct hb_icu_le_shaper_face_data_t {};
  44
  45 hb_icu_le_shaper_face_data_t *
  46 _hb_icu_le_shaper_face_data_create (hb_face_t *face HB_UNUSED)
  47 {
  48   return (hb_icu_le_shaper_face_data_t *) HB_SHAPER_DATA_SUCCEEDED;
  49 }
  50
  51 void
  52 _hb_icu_le_shaper_face_data_destroy (hb_icu_le_shaper_face_data_t *data HB_UNUSED)
  53 {
  54 }
  55
  56
  57 /*
  58  * shaper font data
  59  */
  60
  61 hb_icu_le_shaper_font_data_t *
  62 _hb_icu_le_shaper_font_data_create (hb_font_t *font)
  63 {
  64   LEErrorCode status = LE_NO_ERROR;
  65   hb_icu_le_shaper_font_data_t *data = new PortableFontInstance (font->face,
  66                                                                  font->x_scale,
  67                                                                  font->y_scale,
  68                                                                  status);
  69   if (status != LE_NO_ERROR) {
  70     delete (data);
  71     return NULL;
  72   }
  73
  74   return data;
  75 }
  76
  77 void
  78 _hb_icu_le_shaper_font_data_destroy (hb_icu_le_shaper_font_data_t *data)
  79 {
  80   delete (data);
  81 }
  82
  83
  84 /*
  85  * shaper shape_plan data
  86  */
  87
  88 struct hb_icu_le_shaper_shape_plan_data_t {};
  89
  90 hb_icu_le_shaper_shape_plan_data_t *
  91 _hb_icu_le_shaper_shape_plan_data_create (hb_shape_plan_t    *shape_plan HB_UNUSED,
  92                                           const hb_feature_t *user_features,
  93                                           unsigned int        num_user_features)
  94 {
  95   return (hb_icu_le_shaper_shape_plan_data_t *) HB_SHAPER_DATA_SUCCEEDED;
  96 }
  97
  98 void
  99 _hb_icu_le_shaper_shape_plan_data_destroy (hb_icu_le_shaper_shape_plan_data_t *data)
 100 {
 101 }
 102
 103
 104 /*
 105  * shaper
 106  */
 107
 108 hb_bool_t
 109 _hb_icu_le_shape (hb_shape_plan_t    *shape_plan,
 110                   hb_font_t          *font,
 111                   hb_buffer_t        *buffer,
 112                   const hb_feature_t *features,
 113                   unsigned int        num_features)
 114 {
 115   LEFontInstance *font_instance = HB_SHAPER_DATA_GET (font);
 116   le_int32 script_code = hb_icu_script_from_script (shape_plan->props.script);
 117   le_int32 language_code = -1 /* TODO */;
 118   le_int32 typography_flags = 3; /* Needed for ligatures and kerning */
 119   LEErrorCode status = LE_NO_ERROR;
 120   le_engine *le = le_create ((const le_font *) font_instance,
 121                              script_code,
 122                              language_code,
 123                              typography_flags,
 124                              &status);
 125   if (status != LE_NO_ERROR)
 126   { le_close (le); return false; }
 127
 128 retry:
 129
 130   unsigned int scratch_size;
 131   char *scratch = (char *) buffer->get_scratch_buffer (&scratch_size);
 132
 133 #define ALLOCATE_ARRAY(Type, name, len) \
 134   Type *name = (Type *) scratch; \
 135   scratch += (len) * sizeof ((name)[0]); \
 136   scratch_size -= (len) * sizeof ((name)[0]);
 137
 138   ALLOCATE_ARRAY (LEUnicode, chars, buffer->len);
 139   ALLOCATE_ARRAY (unsigned int, clusters, buffer->len);
 140
 141   /* XXX Use UTF-16 decoder! */
 142   for (unsigned int i = 0; i < buffer->len; i++) {
 143     chars[i] = buffer->info[i].codepoint;
 144     clusters[i] = buffer->info[i].cluster;
 145   }
 146
 147   unsigned int glyph_count = le_layoutChars (le,
 148                                              chars,
 149                                              0,
 150                                              buffer->len,
 151                                              buffer->len,
 152                                              HB_DIRECTION_IS_BACKWARD (buffer->props.direction),
 153                                              0., 0.,
 154                                              &status);
 155   if (status != LE_NO_ERROR)
 156   { le_close (le); return false; }
 157
 158   unsigned int num_glyphs = scratch_size / (sizeof (LEGlyphID) +
 159                                             sizeof (le_int32) +
 160                                             sizeof (float) * 2);
 161
 162   if (unlikely (glyph_count >= num_glyphs || glyph_count > buffer->allocated)) {
 163     buffer->ensure (buffer->allocated * 2);
 164     if (buffer->in_error)
 165     { le_close (le); return false; }
 166     goto retry;
 167   }
 168
 169   ALLOCATE_ARRAY (LEGlyphID, glyphs, glyph_count);
 170   ALLOCATE_ARRAY (le_int32, indices, glyph_count);
 171   ALLOCATE_ARRAY (float, positions, glyph_count * 2 + 2);
 172
 173   le_getGlyphs (le, glyphs, &status);
 174   le_getCharIndices (le, indices, &status);
 175   le_getGlyphPositions (le, positions, &status);
 176
 177 #undef ALLOCATE_ARRAY
 178
 179   /* Ok, we've got everything we need, now compose output buffer,
 180    * very, *very*, carefully! */
 181
 182   unsigned int j = 0;
 183   hb_glyph_info_t *info = buffer->info;
 184   for (unsigned int i = 0; i < glyph_count; i++)
 185   {
 186     if (glyphs[i] >= 0xFFFE)
 187         continue;
 188
 189     info[j].codepoint = glyphs[i];
 190     info[j].cluster = clusters[indices[i]];
 191
 192     /* icu-le doesn't seem to have separate advance values. */
 193     info[j].mask = positions[2 * i + 2] - positions[2 * i];
 194     info[j].var1.u32 = 0;
 195     info[j].var2.u32 = -positions[2 * i + 1];
 196
 197     j++;
 198   }
 199   buffer->len = j;
 200
 201   buffer->clear_positions ();
 202
 203   for (unsigned int i = 0; i < buffer->len; i++) {
 204     hb_glyph_info_t *info = &buffer->info[i];
 205     hb_glyph_position_t *pos = &buffer->pos[i];
 206
 207     /* TODO vertical */
 208     pos->x_advance = info->mask;
 209     pos->x_offset = info->var1.u32;
 210     pos->y_offset = info->var2.u32;
 211   }
 212
 213   le_close (le);
 214   return true;
 215 }