lily/open-type-font.cc

   1 /*
   2   open-type-font.cc -- implement Open_type_font
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 2004--2007 Han-Wen Nienhuys <hanwen@xs4all.nl>
   7 */
   8
   9 #include "open-type-font.hh"
  10
  11 #include <cstdio>
  12
  13 using namespace std;
  14
  15 #include <freetype/tttables.h>
  16
  17 #include "dimensions.hh"
  18 #include "international.hh"
  19 #include "modified-font-metric.hh"
  20 #include "warn.hh"
  21
  22 FT_Byte *
  23 load_table (char const *tag_str, FT_Face face, FT_ULong *length)
  24 {
  25   *length = 0;
  26   FT_ULong tag = FT_MAKE_TAG (tag_str[0], tag_str[1], tag_str[2], tag_str[3]);
  27
  28   int error_code = FT_Load_Sfnt_Table (face, tag, 0, NULL, length);
  29   if (!error_code)
  30     {
  31       FT_Byte *buffer = (FT_Byte *) malloc (*length);
  32       if (buffer == NULL)
  33         error (_f ("cannot allocate %lu bytes", *length));
  34
  35       error_code = FT_Load_Sfnt_Table (face, tag, 0, buffer, length);
  36       if (error_code)
  37         error (_f ("cannot load font table: %s", tag_str));
  38
  39       return buffer;
  40     }
  41   else
  42     programming_error (_f ("Free type error: %s",
  43                            freetype_error_string (error_code).c_str ()
  44                            ));
  45
  46   return 0;
  47 }
  48
  49 string
  50 Open_type_font::get_otf_table (string tag) const
  51 {
  52   return ::get_otf_table (face_, tag);
  53 }
  54
  55 SCM
  56 load_scheme_table (char const *tag_str, FT_Face face)
  57 {
  58   FT_ULong length = 0;
  59   FT_Byte *buffer = load_table (tag_str, face, &length);
  60
  61   SCM tab = SCM_EOL;
  62   if (buffer)
  63     {
  64       string contents ((char const*)buffer, length);
  65       contents = "(quote (" + contents + "))";
  66
  67       tab = scm_c_eval_string (contents.c_str ());
  68       free (buffer);
  69     }
  70   return tab;
  71 }
  72
  73
  74 Open_type_font::~Open_type_font ()
  75 {
  76   FT_Done_Face (face_);
  77 }
  78
  79 /*
  80   UGH fix naming
  81 */
  82 string
  83 get_otf_table (FT_Face face, string tag)
  84 {
  85   FT_ULong len;
  86   FT_Byte *tab = load_table (tag.c_str (), face, &len);
  87   string ret ((char const*) tab, len);
  88   free (tab);
  89
  90   return ret;
  91 }
  92
  93 FT_Face
  94 open_ft_face (string str)
  95 {
  96   FT_Face face;
  97   int error_code = FT_New_Face (freetype2_library, str.c_str (), 0, &face);
  98
  99   if (error_code == FT_Err_Unknown_File_Format)
 100     error (_f ("unsupported font format: %s", str.c_str ()));
 101   else if (error_code)
 102     error (_f ("error reading font file %s: %s",
 103                str.c_str (),
 104                freetype_error_string (error_code).c_str ()
 105                ));
 106   return face;
 107 }
 108
 109 SCM
 110 Open_type_font::make_otf (string str)
 111 {
 112   FT_Face face = open_ft_face (str);
 113   Open_type_font *otf = new Open_type_font (face);
 114
 115   return otf->self_scm ();
 116 }
 117
 118 Open_type_font::Open_type_font (FT_Face face)
 119 {
 120   face_ = face;
 121   lily_character_table_ = SCM_EOL;
 122   lily_global_table_ = SCM_EOL;
 123   lily_subfonts_ = SCM_EOL;
 124   lily_index_to_bbox_table_ = SCM_EOL;
 125
 126   lily_character_table_ = alist_to_hashq (load_scheme_table ("LILC", face_));
 127   lily_global_table_ = alist_to_hashq (load_scheme_table ("LILY", face_));
 128   lily_subfonts_ = load_scheme_table ("LILF", face_);
 129   index_to_charcode_map_ = make_index_to_charcode_map (face_);
 130
 131   lily_index_to_bbox_table_ = scm_c_make_hash_table (257);
 132 }
 133
 134 void
 135 Open_type_font::derived_mark () const
 136 {
 137   scm_gc_mark (lily_character_table_);
 138   scm_gc_mark (lily_global_table_);
 139   scm_gc_mark (lily_subfonts_);
 140   scm_gc_mark (lily_index_to_bbox_table_);
 141 }
 142
 143 Offset
 144 Open_type_font::attachment_point (string glyph_name) const
 145 {
 146   SCM sym = ly_symbol2scm (glyph_name.c_str ());
 147   SCM entry = scm_hashq_ref (lily_character_table_, sym, SCM_BOOL_F);
 148
 149   Offset o;
 150   if (entry == SCM_BOOL_F)
 151     return o;
 152
 153   SCM char_alist = entry;
 154   SCM att_scm = scm_cdr (scm_assq (ly_symbol2scm ("attachment"), char_alist));
 155
 156   return point_constant * ly_scm2offset (att_scm);
 157 }
 158
 159 Box
 160 Open_type_font::get_indexed_char (size_t signed_idx) const
 161 {
 162   if (SCM_HASHTABLE_P (lily_index_to_bbox_table_))
 163     {
 164       SCM box = scm_hashq_ref (lily_index_to_bbox_table_,
 165                                scm_from_unsigned (signed_idx), SCM_BOOL_F);
 166       Box *box_ptr = Box::unsmob (box);
 167       if (box_ptr)
 168         return *box_ptr;
 169     }
 170
 171   if (SCM_HASHTABLE_P (lily_character_table_))
 172     {
 173       const size_t len = 256;
 174       char name[len];
 175       size_t code = FT_Get_Glyph_Name (face_, signed_idx, name, len);
 176       if (code)
 177         warning (_f ("FT_Get_Glyph_Name () Freetype error: %s",
 178                      freetype_error_string (code)));
 179
 180       SCM sym = ly_symbol2scm (name);
 181       SCM alist = scm_hashq_ref (lily_character_table_, sym, SCM_BOOL_F);
 182
 183       if (alist != SCM_BOOL_F)
 184         {
 185           SCM bbox = scm_cdr (scm_assq (ly_symbol2scm ("bbox"), alist));
 186
 187           Box b;
 188           b[X_AXIS][LEFT] = scm_to_double (scm_car (bbox));
 189           bbox = scm_cdr (bbox);
 190           b[Y_AXIS][LEFT] = scm_to_double (scm_car (bbox));
 191           bbox = scm_cdr (bbox);
 192           b[X_AXIS][RIGHT] = scm_to_double (scm_car (bbox));
 193           bbox = scm_cdr (bbox);
 194           b[Y_AXIS][RIGHT] = scm_to_double (scm_car (bbox));
 195           bbox = scm_cdr (bbox);
 196
 197           b.scale (point_constant);
 198
 199           scm_hashq_set_x (lily_index_to_bbox_table_,
 200                            scm_from_unsigned (signed_idx),
 201                            b.smobbed_copy ());
 202           return b;
 203         }
 204     }
 205
 206   FT_UInt idx = signed_idx;
 207   FT_Load_Glyph (face_,
 208                  idx,
 209                  FT_LOAD_NO_SCALE);
 210
 211   FT_Glyph_Metrics m = face_->glyph->metrics;
 212   int hb = m.horiBearingX;
 213   int vb = m.horiBearingY;
 214   Box b (Interval (-hb, m.width - hb),
 215          Interval (-vb, m.height - vb));
 216
 217   b.scale (design_size () / Real (face_->units_per_EM));
 218   return b;
 219 }
 220
 221 size_t
 222 Open_type_font::name_to_index (string nm) const
 223 {
 224   char *nm_str = (char *) nm.c_str ();
 225   if (size_t idx = FT_Get_Name_Index (face_, nm_str))
 226     return idx;
 227
 228   return (size_t) -1;
 229 }
 230
 231 size_t
 232 Open_type_font::index_to_charcode (size_t i) const
 233 {
 234   return ((Open_type_font *) this)->index_to_charcode_map_[i];
 235 }
 236
 237 size_t
 238 Open_type_font::count () const
 239 {
 240   return ((Open_type_font *) this)->index_to_charcode_map_.size ();
 241 }
 242
 243 Real
 244 Open_type_font::design_size () const
 245 {
 246   SCM entry = scm_hashq_ref (lily_global_table_,
 247                              ly_symbol2scm ("design_size"),
 248
 249                              /*
 250                                Hmm. Design size is arbitrary for
 251                                non-design-size fonts. I vote for 1 -
 252                                which will trip errors more
 253                                quickly. --hwn.
 254                              */
 255                              scm_from_unsigned (1));
 256   return scm_to_double (entry) * Real (point_constant);
 257 }
 258
 259 SCM
 260 Open_type_font::sub_fonts () const
 261 {
 262   return lily_subfonts_;
 263 }
 264
 265 SCM
 266 Open_type_font::get_char_table () const
 267 {
 268   return lily_character_table_;
 269 }
 270
 271 SCM
 272 Open_type_font::get_subfonts () const
 273 {
 274   return lily_subfonts_;
 275 }
 276
 277 SCM
 278 Open_type_font::get_global_table () const
 279 {
 280   return lily_global_table_;
 281 }
 282
 283 string
 284 Open_type_font::font_name () const
 285 {
 286   return FT_Get_Postscript_Name (face_);
 287 }
 288
 289
 290 SCM
 291 Open_type_font::glyph_list () const
 292 {
 293   SCM retval = SCM_EOL;
 294   SCM *tail = &retval;
 295
 296   for (int i = 0; i < face_->num_glyphs; i++)
 297     {
 298       const size_t len = 256;
 299       char name[len];
 300       size_t code = FT_Get_Glyph_Name (face_, i, name, len);
 301       if (code)
 302         warning (_f ("FT_Get_Glyph_Name () error: %s",
 303                      freetype_error_string (code).c_str ()));
 304
 305       *tail = scm_cons (scm_from_locale_string (name), SCM_EOL);
 306       tail = SCM_CDRLOC (*tail);
 307     }
 308
 309   return retval;
 310 }