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--2009 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, FT_Long idx)
  95 {
  96   FT_Face face;
  97   int error_code = FT_New_Face (freetype2_library, str.c_str (), idx, &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   return face;
 106 }
 107
 108 SCM
 109 Open_type_font::make_otf (string str)
 110 {
 111   FT_Face face = open_ft_face (str, 0 /* index */);
 112   Open_type_font *otf = new Open_type_font (face);
 113
 114   return otf->self_scm ();
 115 }
 116
 117 Open_type_font::Open_type_font (FT_Face face)
 118 {
 119   face_ = face;
 120   lily_character_table_ = SCM_EOL;
 121   lily_global_table_ = SCM_EOL;
 122   lily_subfonts_ = SCM_EOL;
 123   lily_index_to_bbox_table_ = SCM_EOL;
 124
 125   lily_character_table_ = alist_to_hashq (load_scheme_table ("LILC", face_));
 126   lily_global_table_ = alist_to_hashq (load_scheme_table ("LILY", face_));
 127   lily_subfonts_ = load_scheme_table ("LILF", face_);
 128   index_to_charcode_map_ = make_index_to_charcode_map (face_);
 129
 130   lily_index_to_bbox_table_ = scm_c_make_hash_table (257);
 131 }
 132
 133 void
 134 Open_type_font::derived_mark () const
 135 {
 136   scm_gc_mark (lily_character_table_);
 137   scm_gc_mark (lily_global_table_);
 138   scm_gc_mark (lily_subfonts_);
 139   scm_gc_mark (lily_index_to_bbox_table_);
 140 }
 141
 142 Offset
 143 Open_type_font::attachment_point (string glyph_name) const
 144 {
 145   SCM sym = ly_symbol2scm (glyph_name.c_str ());
 146   SCM entry = scm_hashq_ref (lily_character_table_, sym, SCM_BOOL_F);
 147
 148   Offset o;
 149   if (entry == SCM_BOOL_F)
 150     return o;
 151
 152   SCM char_alist = entry;
 153   SCM att_scm = scm_cdr (scm_assq (ly_symbol2scm ("attachment"), char_alist));
 154
 155   return point_constant * ly_scm2offset (att_scm);
 156 }
 157
 158 Box
 159 Open_type_font::get_indexed_char (size_t signed_idx) const
 160 {
 161   if (SCM_HASHTABLE_P (lily_index_to_bbox_table_))
 162     {
 163       SCM box = scm_hashq_ref (lily_index_to_bbox_table_,
 164                                scm_from_unsigned (signed_idx), SCM_BOOL_F);
 165       Box *box_ptr = Box::unsmob (box);
 166       if (box_ptr)
 167         return *box_ptr;
 168     }
 169
 170   if (SCM_HASHTABLE_P (lily_character_table_))
 171     {
 172       const size_t len = 256;
 173       char name[len];
 174       size_t code = FT_Get_Glyph_Name (face_, signed_idx, name, len);
 175       if (code)
 176         warning (_f ("FT_Get_Glyph_Name () Freetype error: %s",
 177                      freetype_error_string (code)));
 178
 179       SCM sym = ly_symbol2scm (name);
 180       SCM alist = scm_hashq_ref (lily_character_table_, sym, SCM_BOOL_F);
 181
 182       if (alist != SCM_BOOL_F)
 183         {
 184           SCM bbox = scm_cdr (scm_assq (ly_symbol2scm ("bbox"), alist));
 185
 186           Box b;
 187           b[X_AXIS][LEFT] = scm_to_double (scm_car (bbox));
 188           bbox = scm_cdr (bbox);
 189           b[Y_AXIS][LEFT] = scm_to_double (scm_car (bbox));
 190           bbox = scm_cdr (bbox);
 191           b[X_AXIS][RIGHT] = scm_to_double (scm_car (bbox));
 192           bbox = scm_cdr (bbox);
 193           b[Y_AXIS][RIGHT] = scm_to_double (scm_car (bbox));
 194           bbox = scm_cdr (bbox);
 195
 196           b.scale (point_constant);
 197
 198           scm_hashq_set_x (lily_index_to_bbox_table_,
 199                            scm_from_unsigned (signed_idx),
 200                            b.smobbed_copy ());
 201           return b;
 202         }
 203     }
 204
 205   FT_UInt idx = signed_idx;
 206   FT_Load_Glyph (face_,
 207                  idx,
 208                  FT_LOAD_NO_SCALE);
 209
 210   FT_Glyph_Metrics m = face_->glyph->metrics;
 211   int hb = m.horiBearingX;
 212   int vb = m.horiBearingY;
 213   Box b (Interval (-hb, m.width - hb),
 214          Interval (-vb, m.height - vb));
 215
 216   b.scale (design_size () / Real (face_->units_per_EM));
 217   return b;
 218 }
 219
 220 size_t
 221 Open_type_font::name_to_index (string nm) const
 222 {
 223   char *nm_str = (char *) nm.c_str ();
 224   if (size_t idx = FT_Get_Name_Index (face_, nm_str))
 225     return idx;
 226
 227   return (size_t) -1;
 228 }
 229
 230 size_t
 231 Open_type_font::index_to_charcode (size_t i) const
 232 {
 233   return ((Open_type_font *) this)->index_to_charcode_map_[i];
 234 }
 235
 236 size_t
 237 Open_type_font::count () const
 238 {
 239   return ((Open_type_font *) this)->index_to_charcode_map_.size ();
 240 }
 241
 242 Real
 243 Open_type_font::design_size () const
 244 {
 245   SCM entry = scm_hashq_ref (lily_global_table_,
 246                              ly_symbol2scm ("design_size"),
 247
 248                              /*
 249                                Hmm. Design size is arbitrary for
 250                                non-design-size fonts. I vote for 1 -
 251                                which will trip errors more
 252                                quickly. --hwn.
 253                              */
 254                              scm_from_unsigned (1));
 255   return scm_to_double (entry) * Real (point_constant);
 256 }
 257
 258 SCM
 259 Open_type_font::sub_fonts () const
 260 {
 261   return lily_subfonts_;
 262 }
 263
 264 SCM
 265 Open_type_font::get_char_table () const
 266 {
 267   return lily_character_table_;
 268 }
 269
 270 SCM
 271 Open_type_font::get_subfonts () const
 272 {
 273   return lily_subfonts_;
 274 }
 275
 276 SCM
 277 Open_type_font::get_global_table () const
 278 {
 279   return lily_global_table_;
 280 }
 281
 282 string
 283 Open_type_font::font_name () const
 284 {
 285   return FT_Get_Postscript_Name (face_);
 286 }
 287
 288
 289 SCM
 290 Open_type_font::glyph_list () const
 291 {
 292   SCM retval = SCM_EOL;
 293   SCM *tail = &retval;
 294
 295   for (int i = 0; i < face_->num_glyphs; i++)
 296     {
 297       const size_t len = 256;
 298       char name[len];
 299       size_t code = FT_Get_Glyph_Name (face_, i, name, len);
 300       if (code)
 301         warning (_f ("FT_Get_Glyph_Name () error: %s",
 302                      freetype_error_string (code).c_str ()));
 303
 304       *tail = scm_cons (scm_from_locale_string (name), SCM_EOL);
 305       tail = SCM_CDRLOC (*tail);
 306     }
 307
 308   return retval;
 309 }