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--2004 Han-Wen Nienhuys <hanwen@xs4all.nl>
   7
   8  */
   9
  10 #include <math.h>
  11
  12
  13 #include "all-font-metrics.hh"
  14 #include "output-def.hh"
  15 #include "font-interface.hh"
  16 #include "warn.hh"
  17
  18 LY_DEFINE (ly_paper_get_font, "ly:paper-get-font", 2, 0, 0,
  19            (SCM paper, SCM chain),
  20
  21            "Return a font metric satisfying the font-qualifiers "
  22            "in the alist chain @var{chain}.\n"
  23            "(An alist chain is a list of alists, containing grob properties).\n")
  24 {
  25   Output_def *pap = unsmob_output_def (paper);
  26   SCM_ASSERT_TYPE (pap, paper, SCM_ARG1, __FUNCTION__, "paper definition");
  27
  28   Font_metric *fm = select_font (pap, chain);
  29   return fm->self_scm ();
  30 }
  31
  32 LY_DEFINE (ly_paper_get_number, "ly:paper-get-number", 2, 0, 0,
  33            (SCM paper, SCM name),
  34            "Return the paper variable @var{name}.")
  35 {
  36   Output_def *pap = unsmob_output_def (paper);
  37   SCM_ASSERT_TYPE (pap, paper, SCM_ARG1, __FUNCTION__, "paper definition");
  38   return scm_make_real (pap->get_dimension (name));
  39 }
  40
  41 bool
  42 wild_compare (SCM field_val, SCM val)
  43 {
  44   return (val == SCM_BOOL_F || field_val == ly_symbol2scm ("*") || field_val == val);
  45 }
  46
  47
  48 /*
  49   TODO: this triggers a great number of font-loads (feta11 upto
  50   parmesan23). We could make a Delayed_load_font_metric for which the
  51   design size is specced in advance.
  52  */
  53 Font_metric*
  54 get_font_by_design_size (Output_def* paper, Real requested,
  55                          SCM font_vector, SCM input_encoding_name)
  56 {
  57   int n = SCM_VECTOR_LENGTH (font_vector);
  58   Real size = 1e6;
  59   Real last_size = -1e6;
  60   int i = 0;
  61
  62   for (; i < n; i++)
  63     {
  64       SCM entry = SCM_VECTOR_REF (font_vector, i);
  65       Font_metric *fm = unsmob_metrics (scm_force (entry));
  66       size = fm->design_size ();
  67
  68       if (size > requested)
  69         break ;
  70       last_size = size;
  71     }
  72
  73   if (i == n)
  74     {
  75       i = n-1;
  76     }
  77   else if (i > 0)
  78     {
  79       if ((requested / last_size) < (size / requested))
  80         {
  81           i -- ;
  82           size = last_size;
  83         }
  84     }
  85
  86   Font_metric *fm = unsmob_metrics (scm_force (SCM_VECTOR_REF (font_vector, i)));
  87   return
  88     find_scaled_font (paper, fm, requested / size, input_encoding_name);
  89
  90 }
  91
  92
  93 Font_metric*
  94 get_font_by_mag_step (Output_def* paper, Real requested_step,
  95                       SCM font_vector, Real default_size, SCM input_encoding_name)
  96 {
  97   return get_font_by_design_size (paper,
  98                                   default_size * pow (2.0, requested_step / 6.0),
  99                                   font_vector, input_encoding_name);
 100 }
 101
 102
 103
 104 SCM
 105 properties_to_font_size_family (SCM fonts, SCM alist_chain)
 106 {
 107   return scm_call_2 (ly_scheme_function ("lookup-font"), fonts, alist_chain);
 108 }
 109
 110
 111 Font_metric *
 112 select_encoded_font (Output_def *paper, SCM chain, SCM encoding_name)
 113 {
 114   SCM name = ly_assoc_chain (ly_symbol2scm  ("font-name"), chain);
 115
 116   if (!ly_c_pair_p (name) || !ly_c_string_p (ly_cdr (name)))
 117     {
 118       SCM fonts = paper->lookup_variable (ly_symbol2scm ("fonts"));
 119       name = properties_to_font_size_family (fonts, chain);
 120     }
 121   else
 122     name  = ly_cdr (name);
 123
 124   if (ly_c_string_p (name))
 125     {
 126       SCM mag = ly_assoc_chain (ly_symbol2scm ("font-magnification"), chain);
 127
 128       Real rmag = ly_c_pair_p (mag) ? robust_scm2double (ly_cdr (mag), 1.0) : 1;
 129
 130       Font_metric * fm = all_fonts_global->find_font (ly_scm2string (name));
 131
 132
 133       return find_scaled_font (paper, fm, rmag, encoding_name);
 134     }
 135   else if (scm_instance_p (name))
 136     {
 137       SCM base_size  = scm_slot_ref (name, ly_symbol2scm ("default-size"));
 138       SCM vec = scm_slot_ref (name, ly_symbol2scm ("size-vector"));
 139
 140       SCM font_size = ly_assoc_chain (ly_symbol2scm ("font-size"), chain);
 141       Real req = 0.0;
 142       if (ly_c_pair_p (font_size))
 143         req = ly_scm2double (ly_cdr (font_size));
 144
 145       return get_font_by_mag_step (paper, req,
 146                                    vec, ly_scm2double (base_size), encoding_name);
 147     }
 148
 149   assert (0);
 150
 151   return 0;
 152 }
 153
 154 Font_metric *
 155 select_font (Output_def *paper, SCM chain)
 156 {
 157   return select_encoded_font (paper, chain, SCM_EOL);
 158 }