lily/paper-def.cc

   1 /*
   2   paper-def.cc -- implement Paper_def
   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 "dimensions.hh"
  10 #include "output-def.hh"
  11 #include "modified-font-metric.hh"
  12 #include "pango-font.hh"
  13 #include "all-font-metrics.hh"
  14
  15 Real
  16 output_scale (Output_def *od)
  17 {
  18   return scm_to_double (od->lookup_variable (ly_symbol2scm ("output-scale")));
  19 }
  20
  21 SCM
  22 get_font_table (Output_def *def)
  23 {
  24   SCM font_table = def->lookup_variable (ly_symbol2scm ("scaled-fonts"));
  25   if (scm_hash_table_p (font_table) != SCM_BOOL_T)
  26     {
  27       font_table = scm_c_make_hash_table (11);
  28       def->set_variable (ly_symbol2scm ("scaled-fonts"), font_table);
  29     }
  30   return font_table;
  31 }
  32
  33 SCM
  34 get_pango_font_table (Output_def *def)
  35 {
  36   SCM font_table = def->lookup_variable (ly_symbol2scm ("pango-fonts"));
  37   if (scm_hash_table_p (font_table) != SCM_BOOL_T)
  38     {
  39       font_table = scm_c_make_hash_table (11);
  40       def->set_variable (ly_symbol2scm ("pango-fonts"), font_table);
  41     }
  42   return font_table;
  43 }
  44
  45 /* TODO: should add nesting for Output_def here too. */
  46 Font_metric *
  47 find_scaled_font (Output_def *mod, Font_metric *f, Real m)
  48 {
  49   if (mod->parent_)
  50     return find_scaled_font (mod->parent_, f, m);
  51
  52   Real lookup_mag = m / output_scale (mod);
  53
  54   SCM font_table = get_font_table (mod);
  55   SCM sizes = scm_hashq_ref (font_table, f->self_scm (), SCM_EOL);
  56   SCM handle = scm_assoc (scm_from_double (lookup_mag), sizes);
  57   if (scm_is_pair (handle))
  58     return unsmob_metrics (scm_cdr (handle));
  59
  60   SCM val = Modified_font_metric::make_scaled_font_metric (f, lookup_mag);
  61
  62   sizes = scm_acons (scm_from_double (lookup_mag), val, sizes);
  63   unsmob_metrics (val)->unprotect ();
  64   scm_hashq_set_x (font_table, f->self_scm (), sizes);
  65   return unsmob_metrics (val);
  66 }
  67
  68 Font_metric *
  69 find_pango_font (Output_def *layout, SCM descr, Real factor)
  70 {
  71   if (layout->parent_)
  72     return find_pango_font (layout->parent_, descr, factor);
  73
  74   SCM table = get_pango_font_table (layout);
  75   SCM sizes = scm_hash_ref (table, descr, SCM_EOL);
  76   SCM size_key = scm_from_double (factor);
  77   SCM handle = scm_assoc (size_key, sizes);
  78   if (scm_is_pair (handle))
  79     return unsmob_metrics (scm_cdr (handle));
  80
  81   PangoFontDescription *description
  82     = pango_font_description_from_string (scm_i_string_chars (descr));
  83
  84   pango_font_description_set_size (description,
  85                                    gint (factor *
  86                                          pango_font_description_get_size (description)));
  87
  88
  89   Font_metric *fm = all_fonts_global->find_pango_font (description,
  90                                                        output_scale (layout));
  91
  92   pango_font_description_free (description);
  93
  94   sizes = scm_acons (size_key, fm->self_scm (), sizes);
  95   scm_hash_set_x (table, descr, sizes);
  96
  97   return fm;
  98 }
  99
 100 /* TODO: this is a nasty interface. During formatting,
 101    the Output_def should be scaled to the output_scale_
 102    specified in the toplevel Output_def.  */
 103 Output_def *
 104 scale_output_def (Output_def *o, Real amount)
 105 {
 106   SCM proc = ly_lily_module_constant ("scale-layout");
 107   SCM new_pap = scm_call_2 (proc, o->self_scm (), scm_double2num (amount));
 108
 109   o = unsmob_output_def (new_pap);
 110   o->protect ();
 111   return o;
 112 }
 113