lily/stencil-interpret.cc

   1 /*
   2   stencil-interpret.cc --  implement Stencil expression interpreting
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 2005--2009 Han-Wen Nienhuys <hanwen@xs4all.nl>
   7 */
   8
   9 #include "stencil.hh"
  10
  11 void
  12 interpret_stencil_expression (SCM expr,
  13                               void (*func) (void *, SCM),
  14                               void *func_arg,
  15                               Offset o)
  16 {
  17   while (1)
  18     {
  19       if (!scm_is_pair (expr))
  20         return;
  21
  22       SCM head = scm_car (expr);
  23
  24       if (head == ly_symbol2scm ("delay-stencil-evaluation"))
  25         {
  26           interpret_stencil_expression (scm_force (scm_cadr (expr)), func, func_arg, o);
  27           return;
  28         }
  29       if (head == ly_symbol2scm ("translate-stencil"))
  30         {
  31           o += ly_scm2offset (scm_cadr (expr));
  32           expr = scm_caddr (expr);
  33         }
  34       else if (head == ly_symbol2scm ("combine-stencil"))
  35         {
  36
  37           for (SCM x = scm_cdr (expr); scm_is_pair (x); x = scm_cdr (x))
  38             interpret_stencil_expression (scm_car (x), func, func_arg, o);
  39           return;
  40         }
  41       else if (head == ly_symbol2scm ("grob-cause"))
  42         {
  43           SCM grob = scm_cadr (expr);
  44
  45           (*func) (func_arg, scm_list_3 (head,
  46                                          ly_quote_scm (ly_offset2scm (o)), grob));
  47           interpret_stencil_expression (scm_caddr (expr), func, func_arg, o);
  48           (*func) (func_arg, scm_list_1 (ly_symbol2scm ("no-origin")));
  49           return;
  50         }
  51       else if (head == ly_symbol2scm ("color"))
  52         {
  53           SCM color = scm_cadr (expr);
  54           SCM r = scm_car (color);
  55           SCM g = scm_cadr (color);
  56           SCM b = scm_caddr (color);
  57
  58           (*func) (func_arg, scm_list_4 (ly_symbol2scm ("setcolor"), r, g, b));
  59           interpret_stencil_expression (scm_caddr (expr), func, func_arg, o);
  60           (*func) (func_arg, scm_list_1 (ly_symbol2scm ("resetcolor")));
  61
  62           return;
  63         }
  64       else if (head == ly_symbol2scm ("rotate-stencil"))
  65         {
  66           SCM args = scm_cadr (expr);
  67           SCM angle = scm_car (args);
  68           Offset tmp = o + robust_scm2offset (scm_cadr (args), Offset (0.0, 0.0));
  69
  70           SCM offset = ly_offset2scm (tmp);
  71           SCM x = scm_car (offset);
  72           SCM y = scm_cdr (offset);
  73
  74           (*func) (func_arg, scm_list_4 (ly_symbol2scm ("setrotation"), angle, x, y));
  75           interpret_stencil_expression (scm_caddr (expr), func, func_arg, o);
  76           (*func) (func_arg, scm_list_4 (ly_symbol2scm ("resetrotation"), angle, x, y));
  77
  78           return;
  79         }
  80       else
  81         {
  82           (*func) (func_arg,
  83                    scm_list_4 (ly_symbol2scm ("placebox"),
  84                                scm_from_double (o[X_AXIS]),
  85                                scm_from_double (o[Y_AXIS]),
  86                                expr));
  87           return;
  88         }
  89     }
  90 }
  91
  92 struct Font_list
  93 {
  94   SCM fonts_;
  95 };
  96
  97 static void
  98 find_font_function (void *fs, SCM x)
  99 {
 100   Font_list *me = (Font_list *) fs;
 101
 102   if (scm_car (x) == ly_symbol2scm ("placebox"))
 103     {
 104       SCM args = scm_cdr (x);
 105       SCM what = scm_caddr (args);
 106
 107       if (scm_is_pair (what))
 108         {
 109           SCM head = scm_car (what);
 110           if (ly_symbol2scm ("text") == head)
 111             me->fonts_ = scm_cons (scm_cadr (what), me->fonts_);
 112           else if (head == ly_symbol2scm ("char"))
 113             me->fonts_ = scm_cons (scm_cadr (what), me->fonts_);
 114         }
 115     }
 116 }
 117
 118 SCM
 119 find_expression_fonts (SCM expr)
 120 {
 121   Font_list fl;
 122
 123   fl.fonts_ = SCM_EOL;
 124
 125   interpret_stencil_expression (expr, &find_font_function,
 126                                 (void *) & fl, Offset (0, 0));
 127
 128   return fl.fonts_;
 129 }