lily/stencil.cc

   1 /*
   2   stencil.cc -- implement Stencil
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1997--2009 Han-Wen Nienhuys <hanwen@xs4all.nl>
   7 */
   8
   9 #include "stencil.hh"
  10
  11 #include "main.hh"
  12 #include "font-metric.hh"
  13 #include "input.hh"
  14 #include "string-convert.hh"
  15 #include "warn.hh"
  16
  17 #include "ly-smobs.icc"
  18
  19 Stencil::Stencil ()
  20 {
  21   expr_ = SCM_EOL;
  22   set_empty (true);
  23 }
  24
  25 Stencil::Stencil (Box b, SCM func)
  26 {
  27   expr_ = func;
  28   dim_ = b;
  29 }
  30
  31 int
  32 Stencil::print_smob (SCM, SCM port, scm_print_state *)
  33 {
  34   scm_puts ("#<Stencil ", port);
  35   scm_puts (" >", port);
  36   return 1;
  37 }
  38
  39 SCM
  40 Stencil::mark_smob (SCM smob)
  41 {
  42   Stencil *s = (Stencil *) SCM_CELL_WORD_1 (smob);
  43   return s->expr_;
  44 }
  45
  46 IMPLEMENT_SIMPLE_SMOBS (Stencil);
  47 IMPLEMENT_TYPE_P (Stencil, "ly:stencil?");
  48 IMPLEMENT_DEFAULT_EQUAL_P (Stencil);
  49
  50 Interval
  51 Stencil::extent (Axis a) const
  52 {
  53   return dim_[a];
  54 }
  55
  56 bool
  57 Stencil::is_empty () const
  58 {
  59   return (expr_ == SCM_EOL
  60           || dim_[X_AXIS].is_empty ()
  61           || dim_[Y_AXIS].is_empty ());
  62 }
  63
  64 SCM
  65 Stencil::expr () const
  66 {
  67   return expr_;
  68 }
  69
  70 Box
  71 Stencil::extent_box () const
  72 {
  73   return dim_;
  74 }
  75
  76 void
  77 Stencil::rotate (Real a, Offset off)
  78 {
  79   rotate_degrees (a * 180/M_PI, off);
  80 }
  81
  82 /*
  83   Rotate this stencil around the point ABSOLUTE_OFF.
  84
  85  */
  86 void
  87 Stencil::rotate_degrees_absolute (Real a, Offset absolute_off)
  88 {
  89   const Real x = absolute_off[X_AXIS];
  90   const Real y = absolute_off[Y_AXIS];
  91
  92   /*
  93    * Build scheme expression (processed in stencil-interpret.cc)
  94    */
  95   /* TODO: by hanwenn 2008/09/10 14:38:56:
  96    * in effect, this copies the underlying expression.  It might be a
  97    * little bit nicer to mirror this in the api, ie. make a
  98    *         Stencil::rotated()
  99    * and have Stencil::rotate be an abbrev of
 100    *         *this = rotated()
 101    */
 102
 103   expr_ = scm_list_n (ly_symbol2scm ("rotate-stencil"),
 104                       scm_list_2 (scm_from_double (a),
 105                       scm_cons (scm_from_double (x), scm_from_double (y))),
 106                       expr_, SCM_UNDEFINED);
 107
 108   /*
 109    * Calculate the new bounding box
 110    */
 111   Box shifted_box = extent_box ();
 112   shifted_box.translate (-absolute_off);
 113
 114   vector<Offset> pts;
 115   pts.push_back (Offset (shifted_box.x ().at(LEFT), shifted_box.y ().at(DOWN)));
 116   pts.push_back (Offset (shifted_box.x ().at(RIGHT), shifted_box.y ().at(DOWN)));
 117   pts.push_back (Offset (shifted_box.x ().at(RIGHT), shifted_box.y ().at(UP)));
 118   pts.push_back (Offset (shifted_box.x ().at(LEFT), shifted_box.y ().at(UP)));
 119
 120   const Offset rot = complex_exp (Offset (0, a * M_PI / 180.0));
 121   dim_.set_empty ();
 122   for (vsize i = 0; i < pts.size (); i++)
 123     dim_.add_point (pts[i] * rot + absolute_off);
 124 }
 125
 126 /*
 127   Rotate this stencil around the point RELATIVE_OFF.
 128
 129   RELATIVE_OFF is measured in terms of the extent of the stencil, so
 130   -1 = LEFT/DOWN edge, 1 = RIGHT/UP edge.
 131  */
 132 void
 133 Stencil::rotate_degrees (Real a, Offset relative_off)
 134 {
 135   /*
 136    * Calculate the center of rotation
 137    */
 138   const Real x = extent (X_AXIS).linear_combination (relative_off[X_AXIS]);
 139   const Real y = extent (Y_AXIS).linear_combination (relative_off[Y_AXIS]);
 140   rotate_degrees_absolute (a, Offset (x, y));
 141 }
 142
 143 void
 144 Stencil::translate (Offset o)
 145 {
 146   Axis a = X_AXIS;
 147   while (a < NO_AXES)
 148     {
 149       if (isinf (o[a])
 150           || isnan (o[a])
 151
 152           // ugh, hardcoded.
 153           || fabs (o[a]) > 1e6)
 154         {
 155           programming_error (String_convert::form_string ("Improbable offset for stencil: %f staff space", o[a])
 156                              + "\n"
 157                              + "Setting to zero.");
 158           o[a] = 0.0;
 159           if (strict_infinity_checking)
 160             scm_misc_error (__FUNCTION__, "Improbable offset.", SCM_EOL);
 161         }
 162       incr (a);
 163     }
 164
 165   expr_ = scm_list_n (ly_symbol2scm ("translate-stencil"),
 166                       ly_offset2scm (o),
 167                       expr_, SCM_UNDEFINED);
 168   if (!is_empty ())
 169     dim_.translate (o);
 170 }
 171
 172 void
 173 Stencil::translate_axis (Real x, Axis a)
 174 {
 175   Offset o (0, 0);
 176   o[a] = x;
 177   translate (o);
 178 }
 179
 180 void
 181 Stencil::add_stencil (Stencil const &s)
 182 {
 183   expr_ = scm_list_3 (ly_symbol2scm ("combine-stencil"), s.expr_, expr_);
 184   dim_.unite (s.dim_);
 185 }
 186
 187 void
 188 Stencil::set_empty (bool e)
 189 {
 190   if (e)
 191     {
 192       dim_[X_AXIS].set_empty ();
 193       dim_[Y_AXIS].set_empty ();
 194     }
 195   else
 196     {
 197       dim_[X_AXIS] = Interval (0, 0);
 198       dim_[Y_AXIS] = Interval (0, 0);
 199     }
 200 }
 201
 202 void
 203 Stencil::align_to (Axis a, Real x)
 204 {
 205   if (is_empty ())
 206     return;
 207
 208   Interval i (extent (a));
 209   translate_axis (-i.linear_combination (x), a);
 210 }
 211
 212 /*  See scheme Function.  */
 213 void
 214 Stencil::add_at_edge (Axis a, Direction d, Stencil const &s, Real padding)
 215 {
 216   Interval my_extent = dim_[a];
 217   Interval i (s.extent (a));
 218   Real his_extent;
 219   if (i.is_empty ())
 220     {
 221       programming_error ("Stencil::add_at_edge: adding empty stencil.");
 222       his_extent = 0.0;
 223     }
 224   else
 225     his_extent = i[-d];
 226
 227   Real offset = (my_extent.is_empty () ? 0.0 : my_extent[d] - his_extent)
 228     + d * padding;
 229
 230   Stencil toadd (s);
 231   toadd.translate_axis (offset, a);
 232   add_stencil (toadd);
 233 }
 234
 235 Stencil
 236 Stencil::in_color (Real r, Real g, Real b) const
 237 {
 238   Stencil new_stencil (extent_box (),
 239                        scm_list_3 (ly_symbol2scm ("color"),
 240                                    scm_list_3 (scm_from_double (r),
 241                                                scm_from_double (g),
 242                                                scm_from_double (b)),
 243                                    expr ()));
 244   return new_stencil;
 245 }
 246
 247 /* convenience */
 248 Stencil
 249 Stencil::translated (Offset z) const
 250 {
 251   Stencil s (*this);
 252   s.translate (z);
 253   return s;
 254 }