lily/stencil.cc

   1 /*
   2   stencil.cc -- implement Stencil
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1997--2007 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 RELATIVE_OFF.
  84
  85   RELATIVE_OFF is measured in terms of the extent of the stencil, so
  86   -1 = LEFT/DOWN edge, 1 = RIGHT/UP edge.
  87  */
  88 void
  89 Stencil::rotate_degrees (Real a, Offset relative_off)
  90 {
  91   const Real x_cen = extent (X_AXIS).center ();
  92   const Real y_cen = extent (Y_AXIS).center ();
  93
  94   /*
  95    * Calculate the center of rotation
  96    */
  97   const Real x = x_cen + relative_off[X_AXIS] * x_cen;
  98   const Real y = y_cen + relative_off[Y_AXIS] * y_cen;
  99
 100   /*
 101    * Build scheme expression (processed in stencil-interpret.cc)
 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   vector<Offset> pts;
 112   pts.push_back (Offset (-x_cen, -y_cen));
 113   pts.push_back (Offset (x_cen, -y_cen));
 114   pts.push_back (Offset (x_cen, y_cen));
 115   pts.push_back (Offset (-x_cen, y_cen));
 116
 117   const Offset rot = complex_exp (Offset (0, a * M_PI / 180.0));
 118   dim_.set_empty ();
 119   for (vsize i = 0; i < pts.size (); i++)
 120     dim_.add_point (pts[i] * rot + Offset (x_cen, y_cen));
 121 }
 122
 123 void
 124 Stencil::translate (Offset o)
 125 {
 126   Axis a = X_AXIS;
 127   while (a < NO_AXES)
 128     {
 129       if (isinf (o[a])
 130           || isnan (o[a])
 131
 132           // ugh, hardcoded.
 133           || fabs (o[a]) > 1e6)
 134         {
 135           programming_error (String_convert::form_string ("Improbable offset for stencil: %f staff space", o[a])
 136                              + "\n"
 137                              + "Setting to zero.");
 138           o[a] = 0.0;
 139           if (strict_infinity_checking)
 140             scm_misc_error (__FUNCTION__, "Improbable offset.", SCM_EOL);
 141         }
 142       incr (a);
 143     }
 144
 145   expr_ = scm_list_n (ly_symbol2scm ("translate-stencil"),
 146                       ly_offset2scm (o),
 147                       expr_, SCM_UNDEFINED);
 148   if (!is_empty ())
 149     dim_.translate (o);
 150 }
 151
 152 void
 153 Stencil::translate_axis (Real x, Axis a)
 154 {
 155   Offset o (0, 0);
 156   o[a] = x;
 157   translate (o);
 158 }
 159
 160 void
 161 Stencil::add_stencil (Stencil const &s)
 162 {
 163   expr_ = scm_list_3 (ly_symbol2scm ("combine-stencil"), s.expr_, expr_);
 164   dim_.unite (s.dim_);
 165 }
 166
 167 void
 168 Stencil::set_empty (bool e)
 169 {
 170   if (e)
 171     {
 172       dim_[X_AXIS].set_empty ();
 173       dim_[Y_AXIS].set_empty ();
 174     }
 175   else
 176     {
 177       dim_[X_AXIS] = Interval (0, 0);
 178       dim_[Y_AXIS] = Interval (0, 0);
 179     }
 180 }
 181
 182 void
 183 Stencil::align_to (Axis a, Real x)
 184 {
 185   if (is_empty ())
 186     return;
 187
 188   Interval i (extent (a));
 189   translate_axis (-i.linear_combination (x), a);
 190 }
 191
 192 /*  See scheme Function.  */
 193 void
 194 Stencil::add_at_edge (Axis a, Direction d, Stencil const &s, Real padding)
 195 {
 196   Interval my_extent = dim_[a];
 197   Interval i (s.extent (a));
 198   Real his_extent;
 199   if (i.is_empty ())
 200     {
 201       programming_error ("Stencil::add_at_edge: adding empty stencil.");
 202       his_extent = 0.0;
 203     }
 204   else
 205     his_extent = i[-d];
 206
 207   Real offset = (my_extent.is_empty () ? 0.0 : my_extent[d] - his_extent)
 208     + d * padding;
 209
 210   Stencil toadd (s);
 211   toadd.translate_axis (offset, a);
 212   add_stencil (toadd);
 213 }
 214
 215 Stencil
 216 Stencil::in_color (Real r, Real g, Real b) const
 217 {
 218   Stencil new_stencil (extent_box (),
 219                        scm_list_3 (ly_symbol2scm ("color"),
 220                                    scm_list_3 (scm_from_double (r),
 221                                                scm_from_double (g),
 222                                                scm_from_double (b)),
 223                                    expr ()));
 224   return new_stencil;
 225 }
 226
 227 /* convenience */
 228 Stencil
 229 Stencil::translated (Offset z) const
 230 {
 231   Stencil s (*this);
 232   s.translate (z);
 233   return s;
 234 }