lily/font-select.cc

   1 /*
   2   This file is part of LilyPond, the GNU music typesetter.
   3
   4   Copyright (C) 2003--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
  21 #include "dimensions.hh"
  22 #include "all-font-metrics.hh"
  23 #include "output-def.hh"
  24 #include "font-interface.hh"
  25 #include "warn.hh"
  26 #include "pango-font.hh"
  27 #include "main.hh"
  28
  29 Font_metric *
  30 get_font_by_design_size (Output_def *layout, Real requested,
  31                          SCM font_vector)
  32 {
  33   int n = scm_c_vector_length (font_vector);
  34   Real size = 1e6;
  35   Real last_size = -1e6;
  36   int i = 0;
  37
  38   SCM pango_description_string = SCM_EOL;
  39   SCM last_pango_description_string = SCM_EOL;
  40   for (; i < n; i++)
  41     {
  42       SCM entry = scm_c_vector_ref (font_vector, i);
  43
  44       if (scm_promise_p (entry) == SCM_BOOL_T)
  45         {
  46           Font_metric *fm = unsmob_metrics (scm_force (entry));
  47           size = fm->design_size ();
  48         }
  49 #if HAVE_PANGO_FT2
  50       else if (scm_is_pair (entry)
  51                && scm_is_number (scm_car (entry))
  52                && scm_is_string (scm_cdr (entry)))
  53         {
  54           size = scm_to_double (scm_car (entry));
  55           pango_description_string
  56             = scm_cdr (entry);
  57         }
  58 #endif
  59
  60       if (size > requested)
  61         break;
  62       last_size = size;
  63       last_pango_description_string = pango_description_string;
  64     }
  65
  66   if (i == n)
  67     i = n - 1;
  68   else if (i > 0)
  69     {
  70       if ((requested / last_size) < (size / requested))
  71         {
  72           i--;
  73           size = last_size;
  74           pango_description_string = last_pango_description_string;
  75         }
  76     }
  77
  78   Font_metric *fm = 0;
  79   if (scm_is_string (pango_description_string))
  80     {
  81 #if HAVE_PANGO_FT2
  82       return find_pango_font (layout,
  83                               pango_description_string,
  84                               requested / size);
  85 #else
  86       error ("Trying to retrieve pango font without HAVE_PANGO_FT2.");
  87 #endif
  88     }
  89   else
  90     fm = unsmob_metrics (scm_force (scm_c_vector_ref (font_vector, i)));
  91
  92   return find_scaled_font (layout, fm, requested / size);
  93 }
  94
  95 Font_metric *
  96 get_font_by_mag_step (Output_def *layout, Real requested_step,
  97                       SCM font_vector, Real default_size)
  98 {
  99   return get_font_by_design_size (layout, default_size
 100                                   * pow (2.0, requested_step / 6.0),
 101                                   font_vector);
 102 }
 103
 104 SCM
 105 properties_to_font_size_family (SCM fonts, SCM alist_chain)
 106 {
 107   return scm_call_2 (ly_lily_module_constant ("lookup-font"), fonts,
 108                      alist_chain);
 109 }
 110
 111 Font_metric *
 112 select_encoded_font (Output_def *layout, SCM chain)
 113 {
 114   SCM name = ly_chain_assoc_get (ly_symbol2scm ("font-name"), chain, SCM_BOOL_F);
 115
 116   if (!scm_is_string (name))
 117     {
 118       SCM fonts = layout->lookup_variable (ly_symbol2scm ("fonts"));
 119       name = properties_to_font_size_family (fonts, chain);
 120     }
 121
 122 #if HAVE_PANGO_FT2
 123   if (scm_is_string (name))
 124     return select_pango_font (layout, chain);
 125   else
 126 #endif
 127     if (scm_instance_p (name))
 128       {
 129         SCM base_size = scm_slot_ref (name, ly_symbol2scm ("default-size"));
 130         SCM vec = scm_slot_ref (name, ly_symbol2scm ("size-vector"));
 131
 132         Real req = robust_scm2double (ly_chain_assoc_get (ly_symbol2scm ("font-size"), chain, SCM_BOOL_F),
 133                                       0.0);
 134
 135         return get_font_by_mag_step (layout, req, vec,
 136                                      scm_to_double (base_size));
 137       }
 138
 139   assert (0);
 140   return 0;
 141 }
 142
 143 Font_metric *
 144 select_font (Output_def *layout, SCM chain)
 145 {
 146   return select_encoded_font (layout, chain);
 147 }