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--2006 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 ("translate-stencil"))
  25         {
  26           o += ly_scm2offset (scm_cadr (expr));
  27           expr = scm_caddr (expr);
  28         }
  29       else if (head == ly_symbol2scm ("combine-stencil"))
  30         {
  31
  32           for (SCM x = scm_cdr (expr); scm_is_pair (x); x = scm_cdr (x))
  33             interpret_stencil_expression (scm_car (x), func, func_arg, o);
  34           return;
  35         }
  36       else if (head == ly_symbol2scm ("grob-cause"))
  37         {
  38           SCM grob = scm_cadr (expr);
  39
  40           (*func) (func_arg, scm_list_3 (head,
  41                                          ly_quote_scm (ly_offset2scm (o)), grob));
  42           interpret_stencil_expression (scm_caddr (expr), func, func_arg, o);
  43           (*func) (func_arg, scm_list_1 (ly_symbol2scm ("no-origin")));
  44           return;
  45         }
  46       else if (head == ly_symbol2scm ("color"))
  47         {
  48           SCM color = scm_cadr (expr);
  49           SCM r = scm_car (color);
  50           SCM g = scm_cadr (color);
  51           SCM b = scm_caddr (color);
  52
  53           (*func) (func_arg, scm_list_4 (ly_symbol2scm ("setcolor"), r, g, b));
  54           interpret_stencil_expression (scm_caddr (expr), func, func_arg, o);
  55           (*func) (func_arg, scm_list_1 (ly_symbol2scm ("resetcolor")));
  56
  57           return;
  58         }
  59       else if (head == ly_symbol2scm ("rotate-stencil"))
  60         {
  61           SCM args = scm_cadr (expr);
  62           SCM angle = scm_car (args);
  63           Offset tmp = o + robust_scm2offset (scm_cadr (args), Offset (0.0, 0.0));
  64
  65           SCM offset = ly_offset2scm (tmp);
  66           SCM x = scm_car (offset);
  67           SCM y = scm_cdr (offset);
  68
  69           (*func) (func_arg, scm_list_4 (ly_symbol2scm ("setrotation"), angle, x, y));
  70           interpret_stencil_expression (scm_caddr (expr), func, func_arg, o);
  71           (*func) (func_arg, scm_list_4 (ly_symbol2scm ("resetrotation"), angle, x, y));
  72
  73           return;
  74         }
  75       else
  76         {
  77           (*func) (func_arg,
  78                    scm_list_4 (ly_symbol2scm ("placebox"),
  79                                scm_from_double (o[X_AXIS]),
  80                                scm_from_double (o[Y_AXIS]),
  81                                expr));
  82           return;
  83         }
  84     }
  85 }
  86
  87 struct Font_list
  88 {
  89   SCM fonts_;
  90 };
  91
  92 static void
  93 find_font_function (void *fs, SCM x)
  94 {
  95   Font_list *me = (Font_list *) fs;
  96
  97   if (scm_car (x) == ly_symbol2scm ("placebox"))
  98     {
  99       SCM args = scm_cdr (x);
 100       SCM what = scm_caddr (args);
 101
 102       if (scm_is_pair (what))
 103         {
 104           SCM head = scm_car (what);
 105           if (ly_symbol2scm ("text") == head)
 106             me->fonts_ = scm_cons (scm_cadr (what), me->fonts_);
 107           else if (head == ly_symbol2scm ("char"))
 108             me->fonts_ = scm_cons (scm_cadr (what), me->fonts_);
 109         }
 110     }
 111 }
 112
 113 SCM
 114 find_expression_fonts (SCM expr)
 115 {
 116   Font_list fl;
 117
 118   fl.fonts_ = SCM_EOL;
 119
 120   interpret_stencil_expression (expr, &find_font_function,
 121                                 (void *) & fl, Offset (0, 0));
 122
 123   return fl.fonts_;
 124 }