lily/stencil.cc

   1 /*
   2   This file is part of LilyPond, the GNU music typesetter.
   3
   4   Copyright (C) 1997--2010 Han-Wen Nienhuys <hanwen@xs4all.nl>
   5
   6   LilyPond is free software: you can redistribute it and/or modify
   7   it under the terms of the GNU General Public License as published by
   8   the Free Software Foundation, either version 3 of the License, or
   9   (at your option) any later version.
  10
  11   LilyPond is distributed in the hope that it will be useful,
  12   but WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14   GNU General Public License for more details.
  15
  16   You should have received a copy of the GNU General Public License
  17   along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.
  18 */
  19
  20 #include "stencil.hh"
  21
  22 #include "main.hh"
  23 #include "font-metric.hh"
  24 #include "input.hh"
  25 #include "string-convert.hh"
  26 #include "warn.hh"
  27
  28 #include "ly-smobs.icc"
  29
  30 Stencil::Stencil ()
  31 {
  32   expr_ = SCM_EOL;
  33   set_empty (true);
  34 }
  35
  36 Stencil::Stencil (Box b, SCM func)
  37 {
  38   expr_ = func;
  39   dim_ = b;
  40 }
  41
  42 int
  43 Stencil::print_smob (SCM, SCM port, scm_print_state *)
  44 {
  45   scm_puts ("#<Stencil ", port);
  46   scm_puts (" >", port);
  47   return 1;
  48 }
  49
  50 SCM
  51 Stencil::mark_smob (SCM smob)
  52 {
  53   Stencil *s = (Stencil *) SCM_CELL_WORD_1 (smob);
  54   return s->expr_;
  55 }
  56
  57 IMPLEMENT_SIMPLE_SMOBS (Stencil);
  58 IMPLEMENT_TYPE_P (Stencil, "ly:stencil?");
  59 IMPLEMENT_DEFAULT_EQUAL_P (Stencil);
  60
  61 Interval
  62 Stencil::extent (Axis a) const
  63 {
  64   return dim_[a];
  65 }
  66
  67 bool
  68 Stencil::is_empty () const
  69 {
  70   return (expr_ == SCM_EOL
  71           || dim_[X_AXIS].is_empty ()
  72           || dim_[Y_AXIS].is_empty ());
  73 }
  74
  75 SCM
  76 Stencil::expr () const
  77 {
  78   return expr_;
  79 }
  80
  81 Box
  82 Stencil::extent_box () const
  83 {
  84   return dim_;
  85 }
  86
  87 void
  88 Stencil::rotate (Real a, Offset off)
  89 {
  90   rotate_degrees (a * 180/M_PI, off);
  91 }
  92
  93 /*
  94   Rotate this stencil around the point ABSOLUTE_OFF.
  95
  96  */
  97 void
  98 Stencil::rotate_degrees_absolute (Real a, Offset absolute_off)
  99 {
 100   const Real x = absolute_off[X_AXIS];
 101   const Real y = absolute_off[Y_AXIS];
 102
 103   /*
 104    * Build scheme expression (processed in stencil-interpret.cc)
 105    */
 106   /* TODO: by hanwenn 2008/09/10 14:38:56:
 107    * in effect, this copies the underlying expression.  It might be a
 108    * little bit nicer to mirror this in the api, ie. make a
 109    *         Stencil::rotated()
 110    * and have Stencil::rotate be an abbrev of
 111    *         *this = rotated()
 112    */
 113
 114   expr_ = scm_list_n (ly_symbol2scm ("rotate-stencil"),
 115                       scm_list_2 (scm_from_double (a),
 116                       scm_cons (scm_from_double (x), scm_from_double (y))),
 117                       expr_, SCM_UNDEFINED);
 118
 119   /*
 120    * Calculate the new bounding box
 121    */
 122   Box shifted_box = extent_box ();
 123   shifted_box.translate (-absolute_off);
 124
 125   vector<Offset> pts;
 126   pts.push_back (Offset (shifted_box.x ().at(LEFT), shifted_box.y ().at(DOWN)));
 127   pts.push_back (Offset (shifted_box.x ().at(RIGHT), shifted_box.y ().at(DOWN)));
 128   pts.push_back (Offset (shifted_box.x ().at(RIGHT), shifted_box.y ().at(UP)));
 129   pts.push_back (Offset (shifted_box.x ().at(LEFT), shifted_box.y ().at(UP)));
 130
 131   const Offset rot = complex_exp (Offset (0, a * M_PI / 180.0));
 132   dim_.set_empty ();
 133   for (vsize i = 0; i < pts.size (); i++)
 134     dim_.add_point (pts[i] * rot + absolute_off);
 135 }
 136
 137 /*
 138   Rotate this stencil around the point RELATIVE_OFF.
 139
 140   RELATIVE_OFF is measured in terms of the extent of the stencil, so
 141   -1 = LEFT/DOWN edge, 1 = RIGHT/UP edge.
 142  */
 143 void
 144 Stencil::rotate_degrees (Real a, Offset relative_off)
 145 {
 146   /*
 147    * Calculate the center of rotation
 148    */
 149   const Real x = extent (X_AXIS).linear_combination (relative_off[X_AXIS]);
 150   const Real y = extent (Y_AXIS).linear_combination (relative_off[Y_AXIS]);
 151   rotate_degrees_absolute (a, Offset (x, y));
 152 }
 153
 154 void
 155 Stencil::translate (Offset o)
 156 {
 157   Axis a = X_AXIS;
 158   while (a < NO_AXES)
 159     {
 160       if (isinf (o[a])
 161           || isnan (o[a])
 162
 163           // ugh, hardcoded.
 164           || fabs (o[a]) > 1e6)
 165         {
 166           programming_error (String_convert::form_string ("Improbable offset for stencil: %f staff space", o[a])
 167                              + "\n"
 168                              + "Setting to zero.");
 169           o[a] = 0.0;
 170           if (strict_infinity_checking)
 171             scm_misc_error (__FUNCTION__, "Improbable offset.", SCM_EOL);
 172         }
 173       incr (a);
 174     }
 175
 176   expr_ = scm_list_n (ly_symbol2scm ("translate-stencil"),
 177                       ly_offset2scm (o),
 178                       expr_, SCM_UNDEFINED);
 179   if (!is_empty ())
 180     dim_.translate (o);
 181 }
 182
 183 void
 184 Stencil::translate_axis (Real x, Axis a)
 185 {
 186   Offset o (0, 0);
 187   o[a] = x;
 188   translate (o);
 189 }
 190
 191 void
 192 Stencil::add_stencil (Stencil const &s)
 193 {
 194   expr_ = scm_list_3 (ly_symbol2scm ("combine-stencil"), s.expr_, expr_);
 195   dim_.unite (s.dim_);
 196 }
 197
 198 void
 199 Stencil::set_empty (bool e)
 200 {
 201   if (e)
 202     {
 203       dim_[X_AXIS].set_empty ();
 204       dim_[Y_AXIS].set_empty ();
 205     }
 206   else
 207     {
 208       dim_[X_AXIS] = Interval (0, 0);
 209       dim_[Y_AXIS] = Interval (0, 0);
 210     }
 211 }
 212
 213 void
 214 Stencil::align_to (Axis a, Real x)
 215 {
 216   if (is_empty ())
 217     return;
 218
 219   Interval i (extent (a));
 220   translate_axis (-i.linear_combination (x), a);
 221 }
 222
 223 /*  See scheme Function.  */
 224 void
 225 Stencil::add_at_edge (Axis a, Direction d, Stencil const &s, Real padding)
 226 {
 227   Interval my_extent = dim_[a];
 228   Interval i (s.extent (a));
 229   Real his_extent;
 230   if (i.is_empty ())
 231     {
 232       programming_error ("Stencil::add_at_edge: adding empty stencil.");
 233       his_extent = 0.0;
 234     }
 235   else
 236     his_extent = i[-d];
 237
 238   Real offset = (my_extent.is_empty () ? 0.0 : my_extent[d] - his_extent)
 239     + d * padding;
 240
 241   Stencil toadd (s);
 242   toadd.translate_axis (offset, a);
 243   add_stencil (toadd);
 244 }
 245
 246 Stencil
 247 Stencil::in_color (Real r, Real g, Real b) const
 248 {
 249   Stencil new_stencil (extent_box (),
 250                        scm_list_3 (ly_symbol2scm ("color"),
 251                                    scm_list_3 (scm_from_double (r),
 252                                                scm_from_double (g),
 253                                                scm_from_double (b)),
 254                                    expr ()));
 255   return new_stencil;
 256 }
 257
 258 /* convenience */
 259 Stencil
 260 Stencil::translated (Offset z) const
 261 {
 262   Stencil s (*this);
 263   s.translate (z);
 264   return s;
 265 }