gfx/harfbuzz/src/hb-ft.c

   1 /*
   2  * Copyright (C) 2009  Red Hat, Inc.
   3  * Copyright (C) 2009  Keith Stribley <devel@thanlwinsoft.org>
   4  *
   5  *  This is part of HarfBuzz, a text shaping library.
   6  *
   7  * Permission is hereby granted, without written agreement and without
   8  * license or royalty fees, to use, copy, modify, and distribute this
   9  * software and its documentation for any purpose, provided that the
  10  * above copyright notice and the following two paragraphs appear in
  11  * all copies of this software.
  12  *
  13  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
  14  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
  15  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
  16  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
  17  * DAMAGE.
  18  *
  19  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
  20  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
  21  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
  22  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
  23  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
  24  *
  25  * Red Hat Author(s): Behdad Esfahbod
  26  */
  27
  28 #include "hb-private.h"
  29
  30 #include "hb-ft.h"
  31
  32 #include "hb-font-private.h"
  33
  34 #include FT_TRUETYPE_TABLES_H
  35
  36 HB_BEGIN_DECLS
  37
  38
  39 static hb_codepoint_t
  40 hb_ft_get_glyph (hb_font_t *font HB_UNUSED,
  41                  hb_face_t *face HB_UNUSED,
  42                  const void *user_data,
  43                  hb_codepoint_t unicode,
  44                  hb_codepoint_t variation_selector)
  45 {
  46   FT_Face ft_face = (FT_Face) user_data;
  47
  48 #ifdef HAVE_FT_FACE_GETCHARVARIANTINDEX
  49   if (unlikely (variation_selector)) {
  50     hb_codepoint_t glyph = FT_Face_GetCharVariantIndex (ft_face, unicode, variation_selector);
  51     if (glyph)
  52       return glyph;
  53   }
  54 #endif
  55
  56   return FT_Get_Char_Index (ft_face, unicode);
  57 }
  58
  59 static void
  60 hb_ft_get_glyph_advance (hb_font_t *font HB_UNUSED,
  61                          hb_face_t *face HB_UNUSED,
  62                          const void *user_data,
  63                          hb_codepoint_t glyph,
  64                          hb_position_t *x_advance,
  65                          hb_position_t *y_advance)
  66 {
  67   FT_Face ft_face = (FT_Face) user_data;
  68   int load_flags = FT_LOAD_DEFAULT;
  69
  70   /* TODO: load_flags, embolden, etc */
  71
  72   if (likely (!FT_Load_Glyph (ft_face, glyph, load_flags)))
  73   {
  74     *x_advance = ft_face->glyph->advance.x;
  75     *y_advance = ft_face->glyph->advance.y;
  76   }
  77 }
  78
  79 static void
  80 hb_ft_get_glyph_extents (hb_font_t *font HB_UNUSED,
  81                          hb_face_t *face HB_UNUSED,
  82                          const void *user_data,
  83                          hb_codepoint_t glyph,
  84                          hb_glyph_extents_t *extents)
  85 {
  86   FT_Face ft_face = (FT_Face) user_data;
  87   int load_flags = FT_LOAD_DEFAULT;
  88
  89   /* TODO: load_flags, embolden, etc */
  90
  91   if (likely (!FT_Load_Glyph (ft_face, glyph, load_flags)))
  92   {
  93     /* XXX: A few negations should be in order here, not sure. */
  94     extents->x_bearing = ft_face->glyph->metrics.horiBearingX;
  95     extents->y_bearing = ft_face->glyph->metrics.horiBearingY;
  96     extents->width = ft_face->glyph->metrics.width;
  97     extents->height = ft_face->glyph->metrics.height;
  98   }
  99 }
 100
 101 static hb_bool_t
 102 hb_ft_get_contour_point (hb_font_t *font HB_UNUSED,
 103                          hb_face_t *face HB_UNUSED,
 104                          const void *user_data,
 105                          unsigned int point_index,
 106                          hb_codepoint_t glyph,
 107                          hb_position_t *x,
 108                          hb_position_t *y)
 109 {
 110   FT_Face ft_face = (FT_Face) user_data;
 111   int load_flags = FT_LOAD_DEFAULT;
 112
 113   /* TODO: load_flags, embolden, etc */
 114
 115   if (unlikely (FT_Load_Glyph (ft_face, glyph, load_flags)))
 116       return FALSE;
 117
 118   if (unlikely (ft_face->glyph->format != FT_GLYPH_FORMAT_OUTLINE))
 119       return FALSE;
 120
 121   if (unlikely (point_index >= (unsigned int) ft_face->glyph->outline.n_points))
 122       return FALSE;
 123
 124   *x = ft_face->glyph->outline.points[point_index].x;
 125   *y = ft_face->glyph->outline.points[point_index].y;
 126
 127   return TRUE;
 128 }
 129
 130 static hb_position_t
 131 hb_ft_get_kerning (hb_font_t *font HB_UNUSED,
 132                    hb_face_t *face HB_UNUSED,
 133                    const void *user_data,
 134                    hb_codepoint_t first_glyph,
 135                    hb_codepoint_t second_glyph)
 136 {
 137   FT_Face ft_face = (FT_Face) user_data;
 138   FT_Vector kerning;
 139
 140   /* TODO: Kern type? */
 141   if (FT_Get_Kerning (ft_face, first_glyph, second_glyph, FT_KERNING_DEFAULT, &kerning))
 142       return 0;
 143
 144   return kerning.x;
 145 }
 146
 147 static hb_font_funcs_t ft_ffuncs = {
 148   HB_REFERENCE_COUNT_INVALID, /* ref_count */
 149   TRUE, /* immutable */
 150   {
 151     hb_ft_get_glyph,
 152     hb_ft_get_glyph_advance,
 153     hb_ft_get_glyph_extents,
 154     hb_ft_get_contour_point,
 155     hb_ft_get_kerning
 156   }
 157 };
 158
 159 hb_font_funcs_t *
 160 hb_ft_get_font_funcs (void)
 161 {
 162   return &ft_ffuncs;
 163 }
 164
 165
 166 static hb_blob_t *
 167 get_table  (hb_tag_t tag, void *user_data)
 168 {
 169   FT_Face ft_face = (FT_Face) user_data;
 170   FT_Byte *buffer;
 171   FT_ULong  length = 0;
 172   FT_Error error;
 173
 174   if (unlikely (tag == HB_TAG_NONE))
 175     return NULL;
 176
 177   error = FT_Load_Sfnt_Table (ft_face, tag, 0, NULL, &length);
 178   if (error)
 179     return NULL;
 180
 181   /* TODO Use FT_Memory? */
 182   buffer = (FT_Byte *) malloc (length);
 183   if (buffer == NULL)
 184     return NULL;
 185
 186   error = FT_Load_Sfnt_Table (ft_face, tag, 0, buffer, &length);
 187   if (error)
 188     return NULL;
 189
 190   return hb_blob_create ((const char *) buffer, length,
 191                          HB_MEMORY_MODE_WRITABLE,
 192                          free, buffer);
 193 }
 194
 195
 196 hb_face_t *
 197 hb_ft_face_create (FT_Face           ft_face,
 198                    hb_destroy_func_t destroy)
 199 {
 200   hb_face_t *face;
 201
 202   if (ft_face->stream->read == NULL) {
 203     hb_blob_t *blob;
 204
 205     blob = hb_blob_create ((const char *) ft_face->stream->base,
 206                            (unsigned int) ft_face->stream->size,
 207                            /* TODO: Check FT_FACE_FLAG_EXTERNAL_STREAM? */
 208                            HB_MEMORY_MODE_READONLY_MAY_MAKE_WRITABLE,
 209                            destroy, ft_face);
 210     face = hb_face_create_for_data (blob, ft_face->face_index);
 211     hb_blob_destroy (blob);
 212   } else {
 213     face = hb_face_create_for_tables (get_table, destroy, ft_face);
 214   }
 215
 216   return face;
 217 }
 218
 219 static void
 220 hb_ft_face_finalize (FT_Face ft_face)
 221 {
 222   hb_face_destroy ((hb_face_t *) ft_face->generic.data);
 223 }
 224
 225 hb_face_t *
 226 hb_ft_face_create_cached (FT_Face ft_face)
 227 {
 228   if (unlikely (!ft_face->generic.data || ft_face->generic.finalizer != (FT_Generic_Finalizer) hb_ft_face_finalize))
 229   {
 230     if (ft_face->generic.finalizer)
 231       ft_face->generic.finalizer (ft_face);
 232
 233     ft_face->generic.data = hb_ft_face_create (ft_face, NULL);
 234     ft_face->generic.finalizer = (FT_Generic_Finalizer) hb_ft_face_finalize;
 235   }
 236
 237   return hb_face_reference ((hb_face_t *) ft_face->generic.data);
 238 }
 239
 240
 241 hb_font_t *
 242 hb_ft_font_create (FT_Face           ft_face,
 243                    hb_destroy_func_t destroy)
 244 {
 245   hb_font_t *font;
 246
 247   font = hb_font_create ();
 248   hb_font_set_funcs (font,
 249                      hb_ft_get_font_funcs (),
 250                      destroy, ft_face);
 251   hb_font_set_scale (font,
 252                      ((uint64_t) ft_face->size->metrics.x_scale * (uint64_t) ft_face->units_per_EM) >> 16,
 253                      ((uint64_t) ft_face->size->metrics.y_scale * (uint64_t) ft_face->units_per_EM) >> 16);
 254   hb_font_set_ppem (font,
 255                     ft_face->size->metrics.x_ppem,
 256                     ft_face->size->metrics.y_ppem);
 257
 258   return font;
 259 }
 260
 261
 262 HB_END_DECLS