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 <math.h>
  10
  11 #include "dimensions.hh"
  12 #include "all-font-metrics.hh"
  13 #include "output-def.hh"
  14 #include "font-interface.hh"
  15 #include "warn.hh"
  16 #include "pango-font.hh"
  17 #include "main.hh"
  18
  19 Font_metric *
  20 get_font_by_design_size (Output_def *layout, Real requested,
  21                          SCM font_vector)
  22 {
  23   int n = scm_c_vector_length (font_vector);
  24   Real size = 1e6;
  25   Real last_size = -1e6;
  26   int i = 0;
  27
  28   SCM pango_description_string = SCM_EOL;
  29   SCM last_pango_description_string = SCM_EOL;
  30   for (; i < n; i++)
  31     {
  32       SCM entry = scm_c_vector_ref (font_vector, i);
  33
  34       if (scm_promise_p (entry) == SCM_BOOL_T)
  35         {
  36           Font_metric *fm = unsmob_metrics (scm_force (entry));
  37           size = fm->design_size ();
  38         }
  39 #if HAVE_PANGO_FT2
  40       else if (scm_is_pair (entry)
  41                && scm_is_number (scm_car (entry))
  42                && scm_is_string (scm_cdr (entry)))
  43         {
  44           size = scm_to_double (scm_car (entry));
  45           pango_description_string
  46             = scm_cdr (entry);
  47         }
  48 #endif
  49
  50       if (size > requested)
  51         break;
  52       last_size = size;
  53       last_pango_description_string = pango_description_string;
  54     }
  55
  56   if (i == n)
  57     i = n - 1;
  58   else if (i > 0)
  59     {
  60       if ((requested / last_size) < (size / requested))
  61         {
  62           i--;
  63           size = last_size;
  64           pango_description_string = last_pango_description_string;
  65         }
  66     }
  67
  68   Font_metric *fm = 0;
  69   if (scm_is_string (pango_description_string))
  70     {
  71 #if HAVE_PANGO_FT2
  72       return find_pango_font (layout,
  73                               pango_description_string,
  74                               requested / size);
  75 #else
  76       error ("Trying to retrieve pango font without HAVE_PANGO_FT2.");
  77 #endif
  78     }
  79   else
  80     fm = unsmob_metrics (scm_force (scm_c_vector_ref (font_vector, i)));
  81
  82   return find_scaled_font (layout, fm, requested / size);
  83 }
  84
  85 Font_metric *
  86 get_font_by_mag_step (Output_def *layout, Real requested_step,
  87                       SCM font_vector, Real default_size)
  88 {
  89   return get_font_by_design_size (layout, default_size
  90                                   * pow (2.0, requested_step / 6.0),
  91                                   font_vector);
  92 }
  93
  94 SCM
  95 properties_to_font_size_family (SCM fonts, SCM alist_chain)
  96 {
  97   return scm_call_2 (ly_lily_module_constant ("lookup-font"), fonts,
  98                      alist_chain);
  99 }
 100
 101 Font_metric *
 102 select_encoded_font (Output_def *layout, SCM chain)
 103 {
 104   SCM name = ly_chain_assoc_get (ly_symbol2scm ("font-name"), chain, SCM_BOOL_F);
 105
 106   if (!scm_is_string (name))
 107     {
 108       SCM fonts = layout->lookup_variable (ly_symbol2scm ("fonts"));
 109       name = properties_to_font_size_family (fonts, chain);
 110     }
 111
 112 #if HAVE_PANGO_FT2
 113   if (scm_is_string (name)
 114       && is_pango_format_global)
 115     return select_pango_font (layout, chain);
 116   else
 117 #endif
 118     if (scm_is_string (name))
 119       {
 120         Real rmag
 121           = robust_scm2double (ly_chain_assoc_get (ly_symbol2scm ("font-magnification"), chain, SCM_BOOL_F),
 122                                1.0);
 123         Font_metric *fm = all_fonts_global->find_font (ly_scm2string (name));
 124
 125         return find_scaled_font (layout, fm, rmag);
 126       }
 127     else 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 }