libass/ass_font.c

   1 // -*- c-basic-offset: 8; indent-tabs-mode: t -*-
   2 // vim:ts=8:sw=8:noet:ai:
   3 /*
   4   Copyright (C) 2006 Evgeniy Stepanov <eugeni.stepanov@gmail.com>
   5
   6   This program is free software; you can redistribute it and/or modify
   7   it under the terms of the GNU General Public License as published by
   8   the Free Software Foundation; either version 2 of the License, or
   9   (at your option) any later version.
  10
  11   This program is distributed in the hope that it will be useful,
  12   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14   GNU General Public License for more details.
  15
  16   You should have received a copy of the GNU General Public License
  17   along with this program; if not, write to the Free Software
  18   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  19 */
  20
  21 #include "config.h"
  22
  23 #include <inttypes.h>
  24 #include <ft2build.h>
  25 #include FT_FREETYPE_H
  26 #include FT_SYNTHESIS_H
  27 #include FT_GLYPH_H
  28
  29 #include "ass.h"
  30 #include "ass_library.h"
  31 #include "ass_font.h"
  32 #include "ass_bitmap.h"
  33 #include "ass_cache.h"
  34 #include "ass_fontconfig.h"
  35 #include "mputils.h"
  36
  37 /**
  38  * Select Microfost Unicode CharMap, if the font has one.
  39  * Otherwise, let FreeType decide.
  40  */
  41 static void charmap_magic(FT_Face face)
  42 {
  43         int i;
  44         for (i = 0; i < face->num_charmaps; ++i) {
  45                 FT_CharMap cmap = face->charmaps[i];
  46                 unsigned pid = cmap->platform_id;
  47                 unsigned eid = cmap->encoding_id;
  48                 if (pid == 3 /*microsoft*/ && (eid == 1 /*unicode bmp*/ || eid == 10 /*full unicode*/)) {
  49                         FT_Set_Charmap(face, cmap);
  50                         return;
  51                 }
  52         }
  53
  54         if (!face->charmap) {
  55                 if (face->num_charmaps == 0) {
  56                         mp_msg(MSGT_ASS, MSGL_WARN, MSGTR_LIBASS_NoCharmaps);
  57                         return;
  58                 }
  59                 mp_msg(MSGT_ASS, MSGL_WARN, MSGTR_LIBASS_NoCharmapAutodetected);
  60                 FT_Set_Charmap(face, face->charmaps[0]);
  61                 return;
  62         }
  63 }
  64
  65 /**
  66  * \brief find a memory font by name
  67  */
  68 static int find_font(ass_library_t* library, char* name)
  69 {
  70         int i;
  71         for (i = 0; i < library->num_fontdata; ++i)
  72                 if (strcasecmp(name, library->fontdata[i].name) == 0)
  73                         return i;
  74         return -1;
  75 }
  76
  77 /**
  78  * \brief Create a new ass_font_t according to "desc" argument
  79  */
  80 ass_font_t* ass_font_new(ass_library_t* library, FT_Library ftlibrary, void* fc_priv, ass_font_desc_t* desc)
  81 {
  82         char* path;
  83         int index;
  84         FT_Face face;
  85         int error;
  86         ass_font_t* font;
  87         int mem_idx;
  88
  89         font = ass_font_cache_find(desc);
  90         if (font)
  91                 return font;
  92
  93         path = fontconfig_select(fc_priv, desc->family, desc->bold, desc->italic, &index);
  94
  95         mem_idx = find_font(library, path);
  96         if (mem_idx >= 0) {
  97                 error = FT_New_Memory_Face(ftlibrary, (unsigned char*)library->fontdata[mem_idx].data,
  98                                            library->fontdata[mem_idx].size, 0, &face);
  99                 if (error) {
 100                         mp_msg(MSGT_ASS, MSGL_WARN, MSGTR_LIBASS_ErrorOpeningMemoryFont, path);
 101                         return 0;
 102                 }
 103         } else {
 104                 error = FT_New_Face(ftlibrary, path, index, &face);
 105                 if (error) {
 106                         mp_msg(MSGT_ASS, MSGL_WARN, MSGTR_LIBASS_ErrorOpeningFont, path, index);
 107                         return 0;
 108                 }
 109         }
 110
 111         charmap_magic(face);
 112
 113         font = calloc(1, sizeof(ass_font_t));
 114         font->ftlibrary = ftlibrary;
 115         font->faces[0] = face;
 116         font->n_faces = 1;
 117         font->desc.family = strdup(desc->family);
 118         font->desc.bold = desc->bold;
 119         font->desc.italic = desc->italic;
 120
 121         font->m.xx = font->m.yy = (FT_Fixed)0x10000L;
 122         font->m.xy = font->m.yy = 0;
 123         font->v.x = font->v.y = 0;
 124         font->size = 0;
 125
 126 #ifdef HAVE_FONTCONFIG
 127         font->charset = FcCharSetCreate();
 128 #endif
 129
 130         ass_font_cache_add(font);
 131
 132         return font;
 133 }
 134
 135 /**
 136  * \brief Set font transformation matrix and shift vector
 137  **/
 138 void ass_font_set_transform(ass_font_t* font, FT_Matrix* m, FT_Vector* v)
 139 {
 140         int i;
 141         font->m.xx = m->xx;
 142         font->m.xy = m->xy;
 143         font->m.yx = m->yx;
 144         font->m.yy = m->yy;
 145         font->v.x = v->x;
 146         font->v.y = v->y;
 147         for (i = 0; i < font->n_faces; ++i)
 148                 FT_Set_Transform(font->faces[i], &font->m, &font->v);
 149 }
 150
 151 /**
 152  * \brief Set font size
 153  **/
 154 void ass_font_set_size(ass_font_t* font, int size)
 155 {
 156         int i;
 157         if (font->size != size) {
 158                 font->size = size;
 159                 for (i = 0; i < font->n_faces; ++i)
 160                         FT_Set_Pixel_Sizes(font->faces[i], 0, size);
 161         }
 162 }
 163
 164 #ifdef HAVE_FONTCONFIG
 165 /**
 166  * \brief Select a new FT_Face with the given character
 167  * The new face is added to the end of font->faces.
 168  **/
 169 static void ass_font_reselect(void* fontconfig_priv, ass_font_t* font, uint32_t ch)
 170 {
 171         char* path;
 172         int index;
 173         FT_Face face;
 174         int error;
 175
 176         if (font->n_faces == ASS_FONT_MAX_FACES)
 177                 return;
 178
 179         path = fontconfig_select_with_charset(fontconfig_priv, font->desc.family, font->desc.bold,
 180                                               font->desc.italic, &index, font->charset);
 181
 182         error = FT_New_Face(font->ftlibrary, path, index, &face);
 183         if (error) {
 184                 mp_msg(MSGT_ASS, MSGL_WARN, MSGTR_LIBASS_ErrorOpeningFont, path, index);
 185                 return;
 186         }
 187         charmap_magic(face);
 188
 189         error = FT_Get_Char_Index(face, ch);
 190         if (error == 0) { // the new font face is not better then the old one
 191                 FT_Done_Face(face);
 192                 return;
 193         }
 194
 195         font->faces[font->n_faces++] = face;
 196
 197         FT_Set_Transform(face, &font->m, &font->v);
 198         FT_Set_Pixel_Sizes(face, 0, font->size);
 199 }
 200 #endif
 201
 202 /**
 203  * \brief Get maximal font ascender and descender.
 204  * \param ch character code
 205  * The values are extracted from the font face that provides glyphs for the given character
 206  **/
 207 void ass_font_get_asc_desc(ass_font_t* font, uint32_t ch, int* asc, int* desc)
 208 {
 209         int i;
 210         for (i = 0; i < font->n_faces; ++i) {
 211                 FT_Face face = font->faces[i];
 212                 if (FT_Get_Char_Index(face, ch)) {
 213                         int v, v2;
 214                         v = face->size->metrics.ascender;
 215                         v2 = FT_MulFix(face->bbox.yMax, face->size->metrics.y_scale);
 216                         *asc = (v > v2 * 0.9) ? v : v2;
 217
 218                         v = - face->size->metrics.descender;
 219                         v2 = - FT_MulFix(face->bbox.yMin, face->size->metrics.y_scale);
 220                         *desc = (v > v2 * 0.9) ? v : v2;
 221                         return;
 222                 }
 223         }
 224
 225         *asc = *desc = 0;
 226 }
 227
 228 /**
 229  * \brief Get a glyph
 230  * \param ch character code
 231  **/
 232 FT_Glyph ass_font_get_glyph(void* fontconfig_priv, ass_font_t* font, uint32_t ch)
 233 {
 234         int error;
 235         int index = 0;
 236         int i;
 237         FT_Glyph glyph;
 238         FT_Face face = 0;
 239
 240         if (ch < 0x20)
 241                 return 0;
 242         if (font->n_faces == 0)
 243                 return 0;
 244
 245         for (i = 0; i < font->n_faces; ++i) {
 246                 face = font->faces[i];
 247                 index = FT_Get_Char_Index(face, ch);
 248                 if (index)
 249                         break;
 250         }
 251
 252 #ifdef HAVE_FONTCONFIG
 253         FcCharSetAddChar(font->charset, ch);
 254         if (index == 0) {
 255                 mp_msg(MSGT_ASS, MSGL_INFO, MSGTR_LIBASS_GlyphNotFoundReselectingFont,
 256                        ch, font->desc.family, font->desc.bold, font->desc.italic);
 257                 ass_font_reselect(fontconfig_priv, font, ch);
 258                 face = font->faces[font->n_faces - 1];
 259                 index = FT_Get_Char_Index(face, ch);
 260                 if (index == 0) {
 261                         mp_msg(MSGT_ASS, MSGL_ERR, MSGTR_LIBASS_GlyphNotFound,
 262                                ch, font->desc.family, font->desc.bold, font->desc.italic);
 263                 }
 264         }
 265 #endif
 266
 267         error = FT_Load_Glyph(face, index, FT_LOAD_NO_BITMAP );
 268         if (error) {
 269                 mp_msg(MSGT_ASS, MSGL_WARN, MSGTR_LIBASS_ErrorLoadingGlyph);
 270                 return 0;
 271         }
 272
 273 #if (FREETYPE_MAJOR > 2) || \
 274     ((FREETYPE_MAJOR == 2) && (FREETYPE_MINOR >= 2)) || \
 275     ((FREETYPE_MAJOR == 2) && (FREETYPE_MINOR == 1) && (FREETYPE_PATCH >= 10))
 276 // FreeType >= 2.1.10 required
 277         if (!(face->style_flags & FT_STYLE_FLAG_ITALIC) &&
 278                         (font->desc.italic > 55)) {
 279                 FT_GlyphSlot_Oblique(face->glyph);
 280         }
 281 #endif
 282         error = FT_Get_Glyph(face->glyph, &glyph);
 283         if (error) {
 284                 mp_msg(MSGT_ASS, MSGL_WARN, MSGTR_LIBASS_ErrorLoadingGlyph);
 285                 return 0;
 286         }
 287
 288         return glyph;
 289 }
 290
 291 /**
 292  * \brief Get kerning for the pair of glyphs.
 293  **/
 294 FT_Vector ass_font_get_kerning(ass_font_t* font, uint32_t c1, uint32_t c2)
 295 {
 296         FT_Vector v = {0, 0};
 297         int i;
 298
 299         for (i = 0; i < font->n_faces; ++i) {
 300                 FT_Face face = font->faces[i];
 301                 int i1 = FT_Get_Char_Index(face, c1);
 302                 int i2 = FT_Get_Char_Index(face, c2);
 303                 if (i1 && i2) {
 304                         if (FT_HAS_KERNING(face))
 305                                 FT_Get_Kerning(face, i1, i2, FT_KERNING_DEFAULT, &v);
 306                         return v;
 307                 }
 308                 if (i1 || i2) // these glyphs are from different font faces, no kerning information
 309                         return v;
 310         }
 311         return v;
 312 }
 313
 314 /**
 315  * \brief Deallocate ass_font_t
 316  **/
 317 void ass_font_free(ass_font_t* font)
 318 {
 319         int i;
 320         for (i = 0; i < font->n_faces; ++i)
 321                 if (font->faces[i]) FT_Done_Face(font->faces[i]);
 322         if (font->desc.family) free(font->desc.family);
 323 #ifdef HAVE_FONTCONFIG
 324         if (font->charset) FcCharSetDestroy(font->charset);
 325 #endif
 326         free(font);
 327 }