lily/font-select.cc

   1 /*
   2   font-select.cc -- implement property -> font_metric routines.
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 2003--2005 Han-Wen Nienhuys <hanwen@xs4all.nl>
   7 */
   8
   9 #include <cmath>
  10 using namespace std;
  11
  12 #include "dimensions.hh"
  13 #include "all-font-metrics.hh"
  14 #include "output-def.hh"
  15 #include "font-interface.hh"
  16 #include "warn.hh"
  17 #include "pango-font.hh"
  18 #include "main.hh"
  19
  20 Font_metric *
  21 get_font_by_design_size (Output_def *layout, Real requested,
  22                          SCM font_vector)
  23 {
  24   int n = scm_c_vector_length (font_vector);
  25   Real size = 1e6;
  26   Real last_size = -1e6;
  27   int i = 0;
  28
  29   SCM pango_description_string = SCM_EOL;
  30   SCM last_pango_description_string = SCM_EOL;
  31   for (; i < n; i++)
  32     {
  33       SCM entry = scm_c_vector_ref (font_vector, i);
  34
  35       if (scm_promise_p (entry) == SCM_BOOL_T)
  36         {
  37           Font_metric *fm = unsmob_metrics (scm_force (entry));
  38           size = fm->design_size ();
  39         }
  40 #if HAVE_PANGO_FT2
  41       else if (scm_is_pair (entry)
  42                && scm_is_number (scm_car (entry))
  43                && scm_is_string (scm_cdr (entry)))
  44         {
  45           size = scm_to_double (scm_car (entry));
  46           pango_description_string
  47             = scm_cdr (entry);
  48         }
  49 #endif
  50
  51       if (size > requested)
  52         break;
  53       last_size = size;
  54       last_pango_description_string = pango_description_string;
  55     }
  56
  57   if (i == n)
  58     i = n - 1;
  59   else if (i > 0)
  60     {
  61       if ((requested / last_size) < (size / requested))
  62         {
  63           i--;
  64           size = last_size;
  65           pango_description_string = last_pango_description_string;
  66         }
  67     }
  68
  69   Font_metric *fm = 0;
  70   if (scm_is_string (pango_description_string))
  71     {
  72 #if HAVE_PANGO_FT2
  73       return find_pango_font (layout,
  74                               pango_description_string,
  75                               requested / size);
  76 #else
  77       error ("Trying to retrieve pango font without HAVE_PANGO_FT2.");
  78 #endif
  79     }
  80   else
  81     fm = unsmob_metrics (scm_force (scm_c_vector_ref (font_vector, i)));
  82
  83   return find_scaled_font (layout, fm, requested / size);
  84 }
  85
  86 Font_metric *
  87 get_font_by_mag_step (Output_def *layout, Real requested_step,
  88                       SCM font_vector, Real default_size)
  89 {
  90   return get_font_by_design_size (layout, default_size
  91                                   * pow (2.0, requested_step / 6.0),
  92                                   font_vector);
  93 }
  94
  95 SCM
  96 properties_to_font_size_family (SCM fonts, SCM alist_chain)
  97 {
  98   return scm_call_2 (ly_lily_module_constant ("lookup-font"), fonts,
  99                      alist_chain);
 100 }
 101
 102 Font_metric *
 103 select_encoded_font (Output_def *layout, SCM chain)
 104 {
 105   SCM name = ly_chain_assoc_get (ly_symbol2scm ("font-name"), chain, SCM_BOOL_F);
 106
 107   if (!scm_is_string (name))
 108     {
 109       SCM fonts = layout->lookup_variable (ly_symbol2scm ("fonts"));
 110       name = properties_to_font_size_family (fonts, chain);
 111     }
 112
 113 #if HAVE_PANGO_FT2
 114   if (scm_is_string (name)
 115       && is_pango_format_global)
 116     return select_pango_font (layout, chain);
 117   else
 118 #endif
 119     if (scm_is_string (name))
 120       {
 121         Real rmag
 122           = robust_scm2double (ly_chain_assoc_get (ly_symbol2scm ("font-magnification"), chain, SCM_BOOL_F),
 123                                1.0);
 124         Font_metric *fm = all_fonts_global->find_font (ly_scm2string (name));
 125
 126         return find_scaled_font (layout, fm, rmag);
 127       }
 128     else if (scm_instance_p (name))
 129       {
 130         SCM base_size = scm_slot_ref (name, ly_symbol2scm ("default-size"));
 131         SCM vec = scm_slot_ref (name, ly_symbol2scm ("size-vector"));
 132
 133         Real req = robust_scm2double (ly_chain_assoc_get (ly_symbol2scm ("font-size"), chain, SCM_BOOL_F),
 134                                       0.0);
 135
 136         return get_font_by_mag_step (layout, req, vec,
 137                                      scm_to_double (base_size));
 138       }
 139
 140   assert (0);
 141   return 0;
 142 }
 143
 144 Font_metric *
 145 select_font (Output_def *layout, SCM chain)
 146 {
 147   return select_encoded_font (layout, chain);
 148 }