lily/open-type-font.cc

   1 /*
   2   This file is part of LilyPond, the GNU music typesetter.
   3
   4   Copyright (C) 2004--2011 Han-Wen Nienhuys <hanwen@xs4all.nl>
   5
   6   LilyPond 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 3 of the License, or
   9   (at your option) any later version.
  10
  11   LilyPond 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 LilyPond.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include "open-type-font.hh"
  21
  22 #include <cstdio>
  23
  24 using namespace std;
  25
  26 #include <freetype/tttables.h>
  27
  28 #include "dimensions.hh"
  29 #include "international.hh"
  30 #include "modified-font-metric.hh"
  31 #include "warn.hh"
  32
  33 FT_Byte *
  34 load_table (char const *tag_str, FT_Face face, FT_ULong *length)
  35 {
  36   *length = 0;
  37   FT_ULong tag = FT_MAKE_TAG (tag_str[0], tag_str[1], tag_str[2], tag_str[3]);
  38
  39   FT_Error error_code = FT_Load_Sfnt_Table (face, tag, 0, NULL, length);
  40   if (!error_code)
  41     {
  42       FT_Byte *buffer = (FT_Byte *) malloc (*length);
  43       if (buffer == NULL)
  44         error (_f ("cannot allocate %lu bytes", *length));
  45
  46       error_code = FT_Load_Sfnt_Table (face, tag, 0, buffer, length);
  47       if (error_code)
  48         error (_f ("cannot load font table: %s", tag_str));
  49
  50       return buffer;
  51     }
  52   else
  53     programming_error (_f ("FreeType error: %s",
  54                            freetype_error_string (error_code).c_str ()
  55                            ));
  56
  57   return 0;
  58 }
  59
  60 string
  61 Open_type_font::get_otf_table (string tag) const
  62 {
  63   return ::get_otf_table (face_, tag);
  64 }
  65
  66 SCM
  67 load_scheme_table (char const *tag_str, FT_Face face)
  68 {
  69   FT_ULong length = 0;
  70   FT_Byte *buffer = load_table (tag_str, face, &length);
  71
  72   SCM tab = SCM_EOL;
  73   if (buffer)
  74     {
  75       string contents ((char const*)buffer, length);
  76       contents = "(quote (" + contents + "))";
  77
  78       tab = scm_c_eval_string (contents.c_str ());
  79       free (buffer);
  80     }
  81   return tab;
  82 }
  83
  84
  85 Open_type_font::~Open_type_font ()
  86 {
  87   FT_Done_Face (face_);
  88 }
  89
  90 /*
  91   UGH fix naming
  92 */
  93 string
  94 get_otf_table (FT_Face face, string tag)
  95 {
  96   FT_ULong len;
  97   FT_Byte *tab = load_table (tag.c_str (), face, &len);
  98   string ret ((char const*) tab, len);
  99   free (tab);
 100
 101   return ret;
 102 }
 103
 104 FT_Face
 105 open_ft_face (string str, FT_Long idx)
 106 {
 107   FT_Face face;
 108   FT_Error error_code = FT_New_Face (freetype2_library, str.c_str (), idx, &face);
 109
 110   if (error_code == FT_Err_Unknown_File_Format)
 111     error (_f ("unsupported font format: %s", str.c_str ()));
 112   else if (error_code)
 113     error (_f ("error reading font file %s: %s",
 114                str.c_str (),
 115                freetype_error_string (error_code).c_str ()));
 116   return face;
 117 }
 118
 119 SCM
 120 Open_type_font::make_otf (string str)
 121 {
 122   FT_Face face = open_ft_face (str, 0 /* index */);
 123   Open_type_font *otf = new Open_type_font (face);
 124
 125   return otf->self_scm ();
 126 }
 127
 128 Open_type_font::Open_type_font (FT_Face face)
 129 {
 130   face_ = face;
 131   lily_character_table_ = SCM_EOL;
 132   lily_global_table_ = SCM_EOL;
 133   lily_subfonts_ = SCM_EOL;
 134   lily_index_to_bbox_table_ = SCM_EOL;
 135
 136   lily_character_table_ = alist_to_hashq (load_scheme_table ("LILC", face_));
 137   lily_global_table_ = alist_to_hashq (load_scheme_table ("LILY", face_));
 138   lily_subfonts_ = load_scheme_table ("LILF", face_);
 139   index_to_charcode_map_ = make_index_to_charcode_map (face_);
 140
 141   lily_index_to_bbox_table_ = scm_c_make_hash_table (257);
 142 }
 143
 144 void
 145 Open_type_font::derived_mark () const
 146 {
 147   scm_gc_mark (lily_character_table_);
 148   scm_gc_mark (lily_global_table_);
 149   scm_gc_mark (lily_subfonts_);
 150   scm_gc_mark (lily_index_to_bbox_table_);
 151 }
 152
 153 Offset
 154 Open_type_font::attachment_point (string glyph_name) const
 155 {
 156   SCM sym = ly_symbol2scm (glyph_name.c_str ());
 157   SCM entry = scm_hashq_ref (lily_character_table_, sym, SCM_BOOL_F);
 158
 159   Offset o;
 160   if (entry == SCM_BOOL_F)
 161     return o;
 162
 163   SCM char_alist = entry;
 164   SCM att_scm = scm_cdr (scm_assq (ly_symbol2scm ("attachment"), char_alist));
 165
 166   return point_constant * ly_scm2offset (att_scm);
 167 }
 168
 169 Box
 170 Open_type_font::get_indexed_char_dimensions (size_t signed_idx) const
 171 {
 172   if (SCM_HASHTABLE_P (lily_index_to_bbox_table_))
 173     {
 174       SCM box = scm_hashq_ref (lily_index_to_bbox_table_,
 175                                scm_from_unsigned_integer (signed_idx), SCM_BOOL_F);
 176       Box *box_ptr = Box::unsmob (box);
 177       if (box_ptr)
 178         return *box_ptr;
 179     }
 180
 181   if (SCM_HASHTABLE_P (lily_character_table_))
 182     {
 183       const size_t len = 256;
 184       char name[len];
 185       FT_Error code = FT_Get_Glyph_Name (face_, FT_UInt (signed_idx),
 186                                          name, FT_UInt (len));
 187       if (code)
 188         warning (_f ("FT_Get_Glyph_Name () Freetype error: %s",
 189                      freetype_error_string (code)));
 190
 191       SCM sym = ly_symbol2scm (name);
 192       SCM alist = scm_hashq_ref (lily_character_table_, sym, SCM_BOOL_F);
 193
 194       if (alist != SCM_BOOL_F)
 195         {
 196           SCM bbox = scm_cdr (scm_assq (ly_symbol2scm ("bbox"), alist));
 197
 198           Box b;
 199           b[X_AXIS][LEFT] = scm_to_double (scm_car (bbox));
 200           bbox = scm_cdr (bbox);
 201           b[Y_AXIS][LEFT] = scm_to_double (scm_car (bbox));
 202           bbox = scm_cdr (bbox);
 203           b[X_AXIS][RIGHT] = scm_to_double (scm_car (bbox));
 204           bbox = scm_cdr (bbox);
 205           b[Y_AXIS][RIGHT] = scm_to_double (scm_car (bbox));
 206           bbox = scm_cdr (bbox);
 207
 208           b.scale (point_constant);
 209
 210           scm_hashq_set_x (lily_index_to_bbox_table_,
 211                            scm_from_unsigned_integer (signed_idx),
 212                            b.smobbed_copy ());
 213           return b;
 214         }
 215     }
 216
 217   FT_UInt idx = FT_UInt (signed_idx);
 218   FT_Load_Glyph (face_, idx, FT_LOAD_NO_SCALE);
 219
 220   FT_Glyph_Metrics m = face_->glyph->metrics;
 221   FT_Pos hb = m.horiBearingX;
 222   FT_Pos vb = m.horiBearingY;
 223   Box b (Interval (Real (-hb), Real (m.width - hb)),
 224          Interval (Real (-vb), Real (m.height - vb)));
 225
 226   b.scale (design_size () / Real (face_->units_per_EM));
 227   return b;
 228 }
 229
 230 size_t
 231 Open_type_font::name_to_index (string nm) const
 232 {
 233   char *nm_str = (char *) nm.c_str ();
 234   if (FT_UInt idx = FT_Get_Name_Index (face_, nm_str))
 235     return (size_t) idx;
 236
 237   return (size_t) -1;
 238 }
 239
 240 size_t
 241 Open_type_font::index_to_charcode (size_t i) const
 242 {
 243   map<FT_UInt, FT_ULong>::const_iterator iter;
 244   iter = index_to_charcode_map_.find (FT_UInt (i));
 245
 246   if (iter != index_to_charcode_map_.end ())
 247     return (size_t) iter->second;
 248   else
 249     {
 250       programming_error ("Invalid index for character");
 251       return 0;
 252     }
 253 }
 254
 255 size_t
 256 Open_type_font::count () const
 257 {
 258   return index_to_charcode_map_.size ();
 259 }
 260
 261 Real
 262 Open_type_font::design_size () const
 263 {
 264   SCM entry = scm_hashq_ref (lily_global_table_,
 265                              ly_symbol2scm ("design_size"),
 266
 267                              /*
 268                                Hmm. Design size is arbitrary for
 269                                non-design-size fonts. I vote for 1 -
 270                                which will trip errors more
 271                                quickly. --hwn.
 272                              */
 273                              scm_from_unsigned_integer (1));
 274   return scm_to_double (entry) * Real (point_constant);
 275 }
 276
 277 SCM
 278 Open_type_font::sub_fonts () const
 279 {
 280   return lily_subfonts_;
 281 }
 282
 283 SCM
 284 Open_type_font::get_char_table () const
 285 {
 286   return lily_character_table_;
 287 }
 288
 289 SCM
 290 Open_type_font::get_subfonts () const
 291 {
 292   return lily_subfonts_;
 293 }
 294
 295 SCM
 296 Open_type_font::get_global_table () const
 297 {
 298   return lily_global_table_;
 299 }
 300
 301 string
 302 Open_type_font::font_name () const
 303 {
 304   return FT_Get_Postscript_Name (face_);
 305 }
 306
 307 SCM
 308 Open_type_font::glyph_list () const
 309 {
 310   SCM retval = SCM_EOL;
 311   SCM *tail = &retval;
 312
 313   for (int i = 0; i < face_->num_glyphs; i++)
 314     {
 315       const size_t len = 256;
 316       char name[len];
 317       FT_Error code = FT_Get_Glyph_Name (face_, i, name, len);
 318       if (code)
 319         warning (_f ("FT_Get_Glyph_Name () error: %s",
 320                      freetype_error_string (code).c_str ()));
 321
 322       *tail = scm_cons (scm_from_locale_string (name), SCM_EOL);
 323       tail = SCM_CDRLOC (*tail);
 324     }
 325
 326   return retval;
 327 }