lily/freetype.cc

   1 /*
   2   This file is part of LilyPond, the GNU music typesetter.
   3
   4   Copyright (C) 2004--2015 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 "freetype.hh"
  21 #include "warn.hh"
  22
  23 #include FT_OUTLINE_H
  24 #include FT_BBOX_H
  25
  26 FT_Library freetype2_library;
  27
  28 void
  29 init_freetype ()
  30 {
  31   FT_Error errorcode = FT_Init_FreeType (&freetype2_library);
  32   if (errorcode)
  33     error ("cannot initialize FreeType");
  34 }
  35
  36 Box
  37 ly_FT_get_unscaled_indexed_char_dimensions (FT_Face const &face, size_t signed_idx)
  38 {
  39   FT_UInt idx = FT_UInt (signed_idx);
  40   FT_Load_Glyph (face, idx, FT_LOAD_NO_SCALE);
  41
  42   FT_Glyph_Metrics m = face->glyph->metrics;
  43   FT_Pos hb = m.horiBearingX;
  44   FT_Pos vb = m.horiBearingY;
  45
  46   // is this viable for all grobs?
  47   return Box (Interval (Real (hb), Real (hb + m.width)),
  48               Interval (Real (vb - m.height), Real (vb)));
  49 }
  50
  51 SCM
  52 box_to_scheme_lines (Box b)
  53 {
  54   return scm_list_4 (scm_list_4 (scm_from_double (b[X_AXIS][LEFT]),
  55                                  scm_from_double (b[Y_AXIS][DOWN]),
  56                                  scm_from_double (b[X_AXIS][RIGHT]),
  57                                  scm_from_double (b[Y_AXIS][DOWN])),
  58                      scm_list_4 (scm_from_double (b[X_AXIS][RIGHT]),
  59                                  scm_from_double (b[Y_AXIS][DOWN]),
  60                                  scm_from_double (b[X_AXIS][RIGHT]),
  61                                  scm_from_double (b[Y_AXIS][UP])),
  62                      scm_list_4 (scm_from_double (b[X_AXIS][RIGHT]),
  63                                  scm_from_double (b[Y_AXIS][UP]),
  64                                  scm_from_double (b[X_AXIS][LEFT]),
  65                                  scm_from_double (b[Y_AXIS][UP])),
  66                      scm_list_4 (scm_from_double (b[X_AXIS][LEFT]),
  67                                  scm_from_double (b[Y_AXIS][UP]),
  68                                  scm_from_double (b[X_AXIS][LEFT]),
  69                                  scm_from_double (b[Y_AXIS][DOWN])));
  70 }
  71
  72 Box
  73 ly_FT_get_glyph_outline_bbox (FT_Face const &face, size_t signed_idx)
  74 {
  75   FT_UInt idx = FT_UInt (signed_idx);
  76   FT_Load_Glyph (face, idx, FT_LOAD_NO_SCALE);
  77
  78   if (!(face->glyph->format == FT_GLYPH_FORMAT_OUTLINE))
  79     {
  80 #if 0
  81       // will generate a lot of warnings
  82       warning ("Cannot make glyph outline");
  83 #endif
  84       return Box (Interval (infinity_f, -infinity_f), Interval (infinity_f, -infinity_f));
  85     }
  86   FT_Outline *outline;
  87   outline = &(face->glyph->outline);
  88
  89   FT_BBox bbox;
  90   FT_Outline_Get_BBox (outline, &bbox);
  91
  92   return Box (Interval (bbox.xMin, bbox.xMax), Interval (bbox.yMin, bbox.yMax));
  93 }
  94
  95 SCM
  96 ly_FT_get_glyph_outline (FT_Face const &face, size_t signed_idx)
  97 {
  98   FT_UInt idx = FT_UInt (signed_idx);
  99   FT_Load_Glyph (face, idx, FT_LOAD_NO_SCALE);
 100
 101   if (!(face->glyph->format == FT_GLYPH_FORMAT_OUTLINE))
 102     {
 103 #if 0
 104       // will generate a lot of warnings
 105       warning ("Cannot make glyph outline");
 106 #endif
 107       return box_to_scheme_lines (ly_FT_get_unscaled_indexed_char_dimensions (face, signed_idx));
 108     }
 109
 110   FT_Outline *outline;
 111   outline = &(face->glyph->outline);
 112   SCM out = SCM_EOL;
 113   Offset lastpos;
 114   Offset firstpos;
 115   int j = 0;
 116   while (j < outline->n_points)
 117     {
 118       if (j == 0)
 119         {
 120           firstpos = Offset (outline->points[j].x, outline->points[j].y);
 121           lastpos = firstpos;
 122           j++;
 123         }
 124       else if (outline->tags[j] & 1)
 125         {
 126           // it is a line
 127           out = scm_cons (scm_list_4 (scm_from_double (lastpos[X_AXIS]),
 128                                       scm_from_double (lastpos[Y_AXIS]),
 129                                       scm_from_double (outline->points[j].x),
 130                                       scm_from_double (outline->points[j].y)),
 131                           out);
 132           lastpos = Offset (outline->points[j].x, outline->points[j].y);
 133           j++;
 134         }
 135       else if (outline->tags[j] & 2)
 136         {
 137           // it is a third order bezier
 138           out = scm_cons (scm_list_n (scm_from_double (lastpos[X_AXIS]),
 139                                       scm_from_double (lastpos[Y_AXIS]),
 140                                       scm_from_double (outline->points[j].x),
 141                                       scm_from_double (outline->points[j].y),
 142                                       scm_from_double (outline->points[j + 1].x),
 143                                       scm_from_double (outline->points[j + 1].y),
 144                                       scm_from_double (outline->points[j + 2].x),
 145                                       scm_from_double (outline->points[j + 2].y),
 146                                       SCM_UNDEFINED),
 147                           out);
 148           lastpos = Offset (outline->points[j + 2].x, outline->points[j + 2].y);
 149           j += 3;
 150         }
 151       else
 152         {
 153           // it is a second order bezier
 154           Real x0 = lastpos[X_AXIS];
 155           Real x1 = outline->points[j].x;
 156           Real x2 = outline->points[j + 1].x;
 157
 158           Real y0 = lastpos[Y_AXIS];
 159           Real y1 = outline->points[j].y;
 160           Real y2 = outline->points[j + 1].y;
 161
 162           out = scm_cons (scm_list_n (scm_from_double (x0),
 163                                       scm_from_double (y0),
 164                                       scm_from_double ((x0 + 2*x1)/3),
 165                                       scm_from_double ((y0 + 2*y1)/3),
 166                                       scm_from_double ((2*x1 + x2)/3),
 167                                       scm_from_double ((2*y1 + y2)/3),
 168                                       scm_from_double (x2),
 169                                       scm_from_double (y2),
 170                                       SCM_UNDEFINED),
 171                           out);
 172           lastpos = Offset (outline->points[j + 1].x, outline->points[j + 1].y);
 173           j += 2;
 174         }
 175     }
 176
 177   // just in case, close the figure
 178   out = scm_cons (scm_list_4 (scm_from_double (lastpos[X_AXIS]),
 179                               scm_from_double (lastpos[Y_AXIS]),
 180                               scm_from_double (firstpos[X_AXIS]),
 181                               scm_from_double (firstpos[Y_AXIS])),
 182                   out);
 183
 184   out = scm_reverse_x (out, SCM_EOL);
 185   return out;
 186 }