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--2005 Han-Wen Nienhuys <hanwen@xs4all.nl>
   7 */
   8
   9 #include "open-type-font.hh"
  10
  11 #include <freetype/tttables.h>
  12 #include <stdio.h>
  13
  14 #include "dimensions.hh"
  15 #include "modified-font-metric.hh"
  16 #include "warn.hh"
  17
  18 FT_Byte *
  19 load_table (char const *tag_str, FT_Face face, FT_ULong *length)
  20 {
  21   *length = 0;
  22   FT_ULong tag = FT_MAKE_TAG (tag_str[0], tag_str[1], tag_str[2], tag_str[3]);
  23
  24   int error_code = FT_Load_Sfnt_Table (face, tag, 0, NULL, length);
  25   if (!error_code)
  26     {
  27       FT_Byte *buffer = (FT_Byte *) malloc (*length);
  28       if (buffer == NULL)
  29         error (_f ("can't allocate %d bytes", *length));
  30
  31       error_code = FT_Load_Sfnt_Table (face, tag, 0, buffer, length);
  32       if (error_code)
  33         error (_f ("can't load font table: %s", tag_str));
  34
  35       return buffer;
  36     }
  37   else
  38     {
  39       programming_error ("Cannot find OpenType table.");
  40     }
  41
  42   return 0;
  43 }
  44
  45
  46 String
  47 Open_type_font::get_otf_table (String tag) const
  48 {
  49   return ::get_otf_table (face_, tag);
  50 }
  51
  52 SCM
  53 load_scheme_table (char const *tag_str, FT_Face face)
  54 {
  55   FT_ULong length = 0;
  56   FT_Byte *buffer = load_table (tag_str, face, &length);
  57
  58   SCM tab = SCM_EOL;
  59   if (buffer)
  60     {
  61       String contents ((Byte const *)buffer, length);
  62       contents = "(quote (" + contents + "))";
  63
  64       tab = scm_c_eval_string (contents.to_str0 ());
  65       free (buffer);
  66     }
  67   return tab;
  68 }
  69
  70 Index_to_charcode_map
  71 make_index_to_charcode_map (FT_Face face)
  72 {
  73   Index_to_charcode_map m;
  74   FT_ULong charcode;
  75   FT_UInt gindex;
  76
  77   for (charcode = FT_Get_First_Char (face, &gindex); gindex != 0;
  78        charcode = FT_Get_Next_Char (face, charcode, &gindex))
  79     m[gindex] = charcode;
  80   return m;
  81 }
  82
  83 Open_type_font::~Open_type_font ()
  84 {
  85   FT_Done_Face (face_);
  86 }
  87
  88
  89 /*
  90   UGH fix naming
  91 */
  92 String
  93 get_otf_table (FT_Face face, String tag)
  94 {
  95   FT_ULong len;
  96   FT_Byte *tab = load_table (tag.to_str0 (), face,  &len);
  97
  98   return String (tab, len);
  99 }
 100
 101 FT_Face
 102 open_ft_face (String str)
 103 {
 104   FT_Face face;
 105   int error_code = FT_New_Face (freetype2_library, str.to_str0 (), 0, &face);
 106
 107   if (error_code == FT_Err_Unknown_File_Format)
 108     error (_f ("unsupported font format: %s", str.to_str0 ()));
 109   else if (error_code)
 110     error (_f ("unknown error: %d reading font file: %s", error_code,
 111                str.to_str0 ()));
 112   return face;
 113 }
 114
 115 SCM
 116 Open_type_font::make_otf (String str)
 117 {
 118   FT_Face face = open_ft_face (str);
 119   Open_type_font *otf = new Open_type_font (face);
 120
 121   return otf->self_scm ();
 122 }
 123
 124 Open_type_font::Open_type_font (FT_Face face)
 125 {
 126   face_ = face;
 127   lily_character_table_ = SCM_EOL;
 128   lily_global_table_ = SCM_EOL;
 129   lily_subfonts_ = SCM_EOL;
 130
 131   lily_character_table_ = alist_to_hashq (load_scheme_table ("LILC", face_));
 132   lily_global_table_ = alist_to_hashq (load_scheme_table ("LILY", face_));
 133   lily_subfonts_ = load_scheme_table ("LILF", face_);
 134   index_to_charcode_map_ = make_index_to_charcode_map (face_);
 135 }
 136
 137 void
 138 Open_type_font::derived_mark () const
 139 {
 140   scm_gc_mark (lily_character_table_);
 141   scm_gc_mark (lily_global_table_);
 142   scm_gc_mark (lily_subfonts_);
 143 }
 144
 145 Offset
 146 Open_type_font::attachment_point (String glyph_name) const
 147 {
 148   SCM sym = ly_symbol2scm (glyph_name.to_str0 ());
 149   SCM entry = scm_hashq_ref (lily_character_table_, sym, SCM_BOOL_F);
 150
 151   Offset o;
 152   if (entry == SCM_BOOL_F)
 153     return o;
 154
 155   SCM char_alist = entry;
 156   SCM att_scm = scm_cdr (scm_assq (ly_symbol2scm ("attachment"), char_alist));
 157
 158   return point_constant * ly_scm2offset (att_scm);
 159 }
 160
 161 Box
 162 Open_type_font::get_indexed_char (int signed_idx) const
 163 {
 164   if (SCM_HASHTABLE_P (lily_character_table_))
 165     {
 166       const int len = 256;
 167       char name[len];
 168       int code = FT_Get_Glyph_Name (face_, signed_idx, name, len);
 169       if (code)
 170         warning (_f ("FT_Get_Glyph_Name() returned error: %d", code));
 171
 172       SCM sym = ly_symbol2scm (name);
 173       SCM alist = scm_hashq_ref (lily_character_table_, sym, SCM_BOOL_F);
 174
 175       if (alist != SCM_BOOL_F)
 176         {
 177           SCM bbox = scm_cdr (scm_assq (ly_symbol2scm ("bbox"), alist));
 178
 179           Box b;
 180           b[X_AXIS][LEFT] = scm_to_double (scm_car (bbox));
 181           bbox = scm_cdr (bbox);
 182           b[Y_AXIS][LEFT] = scm_to_double (scm_car (bbox));
 183           bbox = scm_cdr (bbox);
 184           b[X_AXIS][RIGHT] = scm_to_double (scm_car (bbox));
 185           bbox = scm_cdr (bbox);
 186           b[Y_AXIS][RIGHT] = scm_to_double (scm_car (bbox));
 187           bbox = scm_cdr (bbox);
 188
 189           b.scale (point_constant);
 190           return b;
 191         }
 192     }
 193
 194   FT_UInt idx = signed_idx;
 195   FT_Load_Glyph (face_,
 196                  idx,
 197                  FT_LOAD_NO_SCALE);
 198
 199   FT_Glyph_Metrics m = face_->glyph->metrics;
 200   int hb = m.horiBearingX;
 201   int vb = m.horiBearingY;
 202   Box b (Interval (-hb, m.width - hb),
 203          Interval (-vb, m.height - vb));
 204
 205   b.scale (design_size () / Real (face_->units_per_EM));
 206   return b;
 207 }
 208
 209 int
 210 Open_type_font::name_to_index (String nm) const
 211 {
 212   char *nm_str = (char *) nm.to_str0 ();
 213   if (int idx = FT_Get_Name_Index (face_, nm_str))
 214     return idx;
 215   return -1;
 216 }
 217
 218 unsigned
 219 Open_type_font::index_to_charcode (int i) const
 220 {
 221   return ((Open_type_font *) this)->index_to_charcode_map_[i];
 222 }
 223
 224 int
 225 Open_type_font::count () const
 226 {
 227   return ((Open_type_font *) this)->index_to_charcode_map_.size ();
 228 }
 229
 230 Real
 231 Open_type_font::design_size () const
 232 {
 233   SCM entry = scm_hashq_ref (lily_global_table_,
 234                              ly_symbol2scm ("design_size"),
 235
 236                              /*
 237                                Hmm. Design size is arbitrary for
 238                                non-design-size fonts. I vote for 1 -
 239                                which will trip errors more
 240                                quickly. --hwn.
 241                              */
 242                              scm_from_int (1));
 243   return scm_to_double (entry) * Real (point_constant);
 244 }
 245
 246 SCM
 247 Open_type_font::sub_fonts () const
 248 {
 249   return lily_subfonts_;
 250 }
 251
 252 SCM
 253 Open_type_font::get_char_table () const
 254 {
 255   return lily_character_table_;
 256 }
 257
 258 SCM
 259 Open_type_font::get_subfonts () const
 260 {
 261   return lily_subfonts_;
 262 }
 263
 264 SCM
 265 Open_type_font::get_global_table () const
 266 {
 267   return lily_global_table_;
 268 }
 269
 270 String
 271 Open_type_font::font_name () const
 272 {
 273   return FT_Get_Postscript_Name (face_);
 274 }
 275