lily/stencil.cc

   1 /*
   2   stencil.cc -- implement Stencil
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1997--2006 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 Offset
  76 Stencil::origin () const
  77 {
  78   return origin_;
  79 }
  80
  81 /*
  82  * Rotate this stencil around the point [x, y]
  83  */
  84 void
  85 Stencil::rotate (Real a, Offset off)
  86 {
  87   const Real x_cen = extent (X_AXIS).center ();
  88   const Real y_cen = extent (Y_AXIS).center ();
  89
  90   /*
  91    * Calculate the center of rotation
  92    */
  93   const Real x = x_cen + off[X_AXIS] * x_cen;
  94   const Real y = y_cen + off[Y_AXIS] * y_cen;
  95
  96   /*
  97    * Build scheme expression (processed in stencil-interpret.cc)
  98    */
  99   expr_ = scm_list_n (ly_symbol2scm ("rotate-stencil"),
 100                       scm_list_2 (scm_from_double (a),
 101                       scm_cons (scm_from_double (x), scm_from_double (y))),
 102                       expr_, SCM_UNDEFINED);
 103
 104   /*
 105    * Calculate the new bounding box
 106    */
 107   vector<Offset> pts;
 108   pts.push_back (Offset (-x_cen, -y_cen));
 109   pts.push_back (Offset (x_cen, -y_cen));
 110   pts.push_back (Offset (x_cen, y_cen));
 111   pts.push_back (Offset (-x_cen, y_cen));
 112
 113   const Offset rot = complex_exp (Offset (0, a * M_PI / 180.0));
 114   dim_.set_empty ();
 115   for (vsize i = 0; i < pts.size (); i++)
 116     dim_.add_point (pts[i] * rot + Offset (x_cen, y_cen));
 117 }
 118
 119 void
 120 Stencil::translate (Offset o)
 121 {
 122   Axis a = X_AXIS;
 123   while (a < NO_AXES)
 124     {
 125       if (isinf (o[a])
 126           || isnan (o[a])
 127
 128           // ugh, hardcoded.
 129           || fabs (o[a]) > 1e6)
 130         {
 131           programming_error (String_convert::form_string ("Improbable offset for stencil: %f staff space", o[a])
 132                              + "\n"
 133                              + "Setting to zero.");
 134           o[a] = 0.0;
 135           if (strict_infinity_checking)
 136             scm_misc_error (__FUNCTION__, "Improbable offset.", SCM_EOL);
 137         }
 138       incr (a);
 139     }
 140
 141   expr_ = scm_list_n (ly_symbol2scm ("translate-stencil"),
 142                       ly_offset2scm (o),
 143                       expr_, SCM_UNDEFINED);
 144   if (!is_empty ())
 145     dim_.translate (o);
 146   origin_ += o;
 147 }
 148
 149 void
 150 Stencil::translate_axis (Real x, Axis a)
 151 {
 152   Offset o (0, 0);
 153   o[a] = x;
 154   translate (o);
 155 }
 156
 157 void
 158 Stencil::add_stencil (Stencil const &s)
 159 {
 160   expr_ = scm_list_3 (ly_symbol2scm ("combine-stencil"), s.expr_, expr_);
 161   dim_.unite (s.dim_);
 162 }
 163
 164 void
 165 Stencil::set_empty (bool e)
 166 {
 167   if (e)
 168     {
 169       dim_[X_AXIS].set_empty ();
 170       dim_[Y_AXIS].set_empty ();
 171     }
 172   else
 173     {
 174       dim_[X_AXIS] = Interval (0, 0);
 175       dim_[Y_AXIS] = Interval (0, 0);
 176     }
 177 }
 178
 179 void
 180 Stencil::align_to (Axis a, Real x)
 181 {
 182   if (is_empty ())
 183     return;
 184
 185   Interval i (extent (a));
 186   translate_axis (-i.linear_combination (x), a);
 187 }
 188
 189 /* FIXME: unintuitive naming, you would expect *this to be moved.
 190    Kept (keeping?) API for compat with add_at_edge ().
 191
 192    What is PADDING, what is MINIMUM, exactly?  */
 193 Stencil
 194 Stencil::moved_to_edge (Axis a, Direction d, Stencil const &s,
 195                         Real padding, Real minimum) const
 196 {
 197   Interval my_extent = dim_[a];
 198   Interval i (s.extent (a));
 199   Real his_extent;
 200   if (i.is_empty ())
 201     {
 202       programming_error ("Stencil::moved_to_edge: adding empty stencil.");
 203       his_extent = 0.0;
 204     }
 205   else
 206     his_extent = i[-d];
 207
 208   Real offset = (my_extent.is_empty () ? 0.0 : my_extent[d] - his_extent)
 209     + d * padding;
 210
 211   Stencil toadd (s);
 212   toadd.translate_axis (offset, a);
 213
 214   if (minimum > 0 && d * (-origin ()[a] + toadd.origin ()[a]) < minimum)
 215     toadd.translate_axis (-toadd.origin ()[a]
 216                           + origin ()[a] + d * minimum, a);
 217
 218   return toadd;
 219 }
 220
 221 /*  See scheme Function.  */
 222 void
 223 Stencil::add_at_edge (Axis a, Direction d, Stencil const &s, Real padding,
 224                       Real minimum)
 225 {
 226   add_stencil (moved_to_edge (a, d, s, padding, minimum));
 227 }
 228
 229 Stencil
 230 Stencil::in_color (Real r, Real g, Real b) const
 231 {
 232   Stencil new_stencil (extent_box (),
 233                        scm_list_3 (ly_symbol2scm ("color"),
 234                                    scm_list_3 (scm_from_double (r),
 235                                                scm_from_double (g),
 236                                                scm_from_double (b)),
 237                                    expr ()));
 238   return new_stencil;
 239 }