lily/stencil.cc

   1 /*
   2   stencil.cc -- implement Stencil
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1997--2004 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7 */
   8
   9 #include <math.h>
  10 #include <libc-extension.hh>    // isinf
  11
  12 #include "input-smob.hh"
  13 #include "font-metric.hh"
  14 #include "dimensions.hh"
  15 #include "interval.hh"
  16 #include "string.hh"
  17 #include "stencil.hh"
  18 #include "warn.hh"
  19
  20 #include "ly-smobs.icc"
  21
  22 Stencil::Stencil ()
  23 {
  24   expr_ = SCM_EOL;
  25   set_empty (true);
  26 }
  27
  28 Stencil::Stencil (Box b, SCM func)
  29 {
  30   expr_ = func;
  31   dim_ = b;
  32 }
  33
  34 int
  35 Stencil::print_smob (SCM, SCM port, scm_print_state *)
  36 {
  37   scm_puts ("#<Stencil ", port);
  38   scm_puts (" >", port);
  39   return 1;
  40 }
  41
  42 SCM
  43 Stencil::mark_smob (SCM smob)
  44 {
  45   Stencil *s = (Stencil*) ly_cdr (smob);
  46   return s->expr_;
  47 }
  48
  49 IMPLEMENT_SIMPLE_SMOBS (Stencil);
  50 IMPLEMENT_TYPE_P (Stencil, "ly:stencil?");
  51 IMPLEMENT_DEFAULT_EQUAL_P (Stencil);
  52
  53 Interval
  54 Stencil::extent (Axis a) const
  55 {
  56   return dim_[a];
  57 }
  58
  59 /* Hmm... maybe this is not such a good idea ; stuff can be empty,
  60    while expr_ == '()  */
  61 bool
  62 Stencil::is_empty () const
  63 {
  64   return expr_ == SCM_EOL;
  65 }
  66
  67 SCM
  68 Stencil::expr () const
  69 {
  70   return expr_;
  71 }
  72
  73 Box
  74 Stencil::extent_box () const
  75 {
  76   return dim_;
  77 }
  78 Offset
  79 Stencil::origin () const
  80 {
  81   return origin_;
  82 }
  83
  84 void
  85 Stencil::translate (Offset o)
  86 {
  87   Axis a = X_AXIS;
  88   while (a < NO_AXES)
  89     {
  90       if (abs (o[a]) > 100 CM
  91           || isinf (o[a]) || isnan (o[a]))
  92         {
  93           programming_error ("Improbable offset for translation: setting to zero");
  94           o[a] =  0.0;
  95         }
  96       incr (a);
  97     }
  98
  99   expr_ = scm_list_n (ly_symbol2scm ("translate-stencil"),
 100                       ly_offset2scm (o),
 101                       expr_, SCM_UNDEFINED);
 102   if (!is_empty ())
 103     dim_.translate (o);
 104   origin_ += o;
 105 }
 106
 107 void
 108 Stencil::translate_axis (Real x, Axis a)
 109 {
 110   Offset o (0,0);
 111   o[a] = x;
 112   translate (o);
 113 }
 114
 115 void
 116 Stencil::add_stencil (Stencil const &s)
 117 {
 118   expr_ = scm_list_3 (ly_symbol2scm ("combine-stencil"), s.expr_, expr_);
 119   dim_.unite (s.dim_);
 120 }
 121
 122
 123
 124 void
 125 Stencil::set_empty (bool e)
 126 {
 127   if (e)
 128     {
 129       dim_[X_AXIS].set_empty ();
 130       dim_[Y_AXIS].set_empty ();
 131     }
 132   else
 133     {
 134       dim_[X_AXIS] = Interval (0,0);
 135       dim_[Y_AXIS] = Interval (0,0);
 136     }
 137 }
 138
 139 void
 140 Stencil::align_to (Axis a, Real x)
 141 {
 142   if (is_empty ())
 143     return;
 144
 145   Interval i (extent (a));
 146   translate_axis (-i.linear_combination (x), a);
 147 }
 148
 149 /* FIXME: unintuitive naming, you would expect *this to be moved.
 150    Kept (keeping?) API for compat with add_at_edge ().
 151
 152    What is PADDING, what is MINIMUM, exactly?  */
 153 Stencil
 154 Stencil::moved_to_edge (Axis a, Direction d, Stencil const &s,
 155                         Real padding, Real minimum) const
 156 {
 157   Interval my_extent = dim_[a];
 158   Interval i (s.extent (a));
 159   Real his_extent;
 160   if (i.is_empty ())
 161     {
 162       programming_error ("Stencil::moved_to_edge: adding empty stencil.");
 163       his_extent = 0.0;
 164     }
 165   else
 166     his_extent = i[-d];
 167
 168   Real offset = (my_extent.is_empty () ? 0.0 : my_extent[d] - his_extent)
 169     + d * padding;
 170
 171   Stencil toadd (s);
 172   toadd.translate_axis (offset,a);
 173
 174   if (minimum > 0 && d * (-origin ()[a] + toadd.origin ()[a]) < minimum)
 175     toadd.translate_axis ( -toadd.origin ()[a]
 176                            + origin ()[a] + d * minimum, a);
 177
 178   return toadd;
 179 }
 180
 181 /*  See scheme Function.  */
 182 void
 183 Stencil::add_at_edge (Axis a, Direction d, Stencil const &s, Real padding,
 184                       Real minimum)
 185 {
 186   add_stencil (moved_to_edge (a, d, s, padding, minimum));
 187 }
 188
 189
 190 /****************************************************************/
 191
 192
 193 void
 194 interpret_stencil_expression (SCM expr,
 195                               void (*func) (void*, SCM),
 196                               void *func_arg,
 197                               Offset o)
 198 {
 199   while (1)
 200     {
 201       if (!ly_c_pair_p (expr))
 202         return;
 203
 204       SCM head = ly_car (expr);
 205
 206       if (head == ly_symbol2scm ("translate-stencil"))
 207         {
 208           o += ly_scm2offset (ly_cadr (expr));
 209           expr = ly_caddr (expr);
 210         }
 211       else if (head == ly_symbol2scm ("combine-stencil"))
 212         {
 213           for (SCM x = ly_cdr (expr); ly_c_pair_p (x); x = ly_cdr (x))
 214             interpret_stencil_expression (ly_car (x), func, func_arg, o);
 215           return;
 216         }
 217       else if (head == ly_symbol2scm ("grob-cause"))
 218         {
 219           SCM grob = ly_cadr (expr);
 220
 221           (*func) (func_arg, scm_list_2 (head, grob));
 222           interpret_stencil_expression (ly_caddr (expr), func, func_arg, o);
 223           (*func) (func_arg, scm_list_1 (ly_symbol2scm ("no-origin")));
 224
 225           return ;
 226         }
 227       else
 228         {
 229           (*func) (func_arg,
 230                    scm_list_4 (ly_symbol2scm ("placebox"),
 231                                scm_make_real (o[X_AXIS]),
 232                                scm_make_real (o[Y_AXIS]),
 233                                expr));
 234            return;
 235         }
 236     }
 237 }
 238
 239
 240 struct Font_list
 241 {
 242   SCM fonts_;
 243 };
 244
 245 static void
 246 find_font_function (void *fs, SCM x)
 247 {
 248   Font_list *me = (Font_list*) fs;
 249
 250   if (ly_car (x) == ly_symbol2scm ("placebox"))
 251     {
 252       SCM args = ly_cdr (x);
 253       SCM what = ly_caddr (args);
 254
 255       if (ly_c_pair_p (what))
 256         {
 257           SCM head = ly_car (what);
 258           if (ly_symbol2scm ("text") == head)
 259             me->fonts_ = scm_cons (ly_cadr (what), me->fonts_);
 260           else if (head == ly_symbol2scm ("char"))
 261             me->fonts_ = scm_cons (ly_cadr (what), me->fonts_);
 262         }
 263     }
 264 }
 265
 266 SCM
 267 find_expression_fonts (SCM expr)
 268 {
 269   Font_list fl;
 270
 271   fl.fonts_ = SCM_EOL;
 272
 273   interpret_stencil_expression (expr, &find_font_function,
 274                                 (void*) &fl, Offset (0,0));
 275
 276   return fl.fonts_;
 277 }
 278
 279
 280 LY_DEFINE (ly_stencil_fonts, "ly:stencil-fonts",
 281            1, 0, 0, (SCM s),
 282           " Analyse @var{s}, and return a list of fonts used in @var{s}.")
 283 {
 284   Stencil *stil = unsmob_stencil (s);
 285   SCM_ASSERT_TYPE (stil, s, SCM_ARG1, __FUNCTION__, "Stencil");
 286   return find_expression_fonts (stil->expr ());
 287 }
 288
 289 struct Stencil_interpret_arguments
 290 {
 291   SCM func;
 292   SCM arg1;
 293 };
 294
 295 void stencil_interpret_in_scm (void *p, SCM expr)
 296 {
 297   Stencil_interpret_arguments *ap = (Stencil_interpret_arguments*) p;
 298   scm_call_2 (ap->func, ap->arg1, expr);
 299 }
 300
 301
 302
 303 LY_DEFINE (ly_interpret_stencil_expression, "ly:interpret-stencil-expression",
 304            4, 0, 0, (SCM expr, SCM func, SCM arg1, SCM offset),
 305            "Parse EXPR, feed bits to FUNC with first arg ARG1")
 306 {
 307   SCM_ASSERT_TYPE (ly_c_procedure_p(func), func, SCM_ARG1, __FUNCTION__,
 308                    "procedure");
 309
 310   Stencil_interpret_arguments a;
 311   a.func = func;
 312   a.arg1 = arg1;
 313   Offset o = ly_scm2offset (offset);
 314
 315   interpret_stencil_expression (expr, stencil_interpret_in_scm, (void*) &a, o);
 316
 317   return SCM_UNSPECIFIED;
 318 }