lily/side-position-interface.cc

   1 /*
   2   staff-side.cc --  implement Staff_side_element
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 1998--2003 Han-Wen Nienhuys <hanwen@cs.uu.nl>
   7
   8  */
   9 #include <math.h>               // ceil.
  10
  11 #include "side-position-interface.hh"
  12 #include "warn.hh"
  13 #include "warn.hh"
  14 #include "dimensions.hh"
  15 #include "staff-symbol-referencer.hh"
  16 #include "group-interface.hh"
  17 #include "directional-element-interface.hh"
  18
  19 void
  20 Side_position_interface::add_support (Grob*me, Grob*e)
  21 {
  22   Pointer_group_interface::add_grob (me, ly_symbol2scm ("side-support-elements"), e);
  23 }
  24
  25
  26
  27 Direction
  28 Side_position_interface::get_direction (Grob*me)
  29 {
  30   SCM d = me->get_grob_property ("direction");
  31   if (ly_dir_p (d) && to_dir (d))
  32     return to_dir (d);
  33
  34   Direction relative_dir = Direction (1);
  35   SCM reldir = me->get_grob_property ("side-relative-direction");       // should use a lambda.
  36   if (ly_dir_p (reldir))
  37     {
  38       relative_dir = to_dir (reldir);
  39     }
  40
  41   SCM other_elt = me->get_grob_property ("direction-source");
  42   Grob * e = unsmob_grob (other_elt);
  43   if (e)
  44     {
  45       return (Direction) (relative_dir * Directional_element_interface::get (e));
  46     }
  47
  48   return CENTER;
  49 }
  50
  51
  52 MAKE_SCHEME_CALLBACK (Side_position_interface,aligned_on_support_extents, 2);
  53 SCM
  54 Side_position_interface::aligned_on_support_extents (SCM element_smob, SCM axis)
  55 {
  56   Grob *me = unsmob_grob (element_smob);
  57   Axis a = (Axis) gh_scm2int (axis);
  58
  59   return general_side_position (me, a, true);
  60 }
  61
  62
  63 /*
  64  Puts the element next to the support, optionally taking in
  65  account the extent of the support.
  66 */
  67 SCM
  68 Side_position_interface::general_side_position (Grob * me, Axis a, bool use_extents)
  69 {
  70
  71
  72   /*
  73     As this is only used as a callback, this is called only once. We
  74     could wipe SIDE-SUPPORT-ELEMENTS after we retrieve it to conserve
  75     memory; however -- we should look more into benefits of such actions?
  76
  77     The benefit is small, it seems: total GC times taken don't
  78     differ. Would this also hamper Generational GC ?
  79
  80   */
  81   SCM support = me->get_grob_property ("side-support-elements");
  82   Grob *common = common_refpoint_of_list (support, me->get_parent (a), a);
  83
  84   Interval dim;
  85   for (SCM s = support; s != SCM_EOL; s = ly_cdr (s))
  86     {
  87       Grob * e  = unsmob_grob (ly_car (s));
  88       if (e)
  89         if (use_extents)
  90           dim.unite (e->extent (common, a));
  91         else
  92           {
  93             Real x = e->relative_coordinate (common, a);
  94             dim.unite (Interval (x,x));
  95           }
  96     }
  97
  98   if (dim.empty_b ())
  99     {
 100       dim = Interval (0,0);
 101     }
 102
 103   Direction dir = Side_position_interface::get_direction (me);
 104
 105   Real off =  me->get_parent (a)->relative_coordinate (common, a);
 106   SCM minimum = me->get_grob_property ("minimum-space");
 107
 108   Real total_off = dim.linear_combination (dir) - off;
 109   SCM padding = me->get_grob_property ("padding");
 110   if (gh_number_p (padding))
 111     {
 112       total_off += gh_scm2double (padding) * dir;
 113     }
 114
 115   if (gh_number_p (minimum)
 116       && dir
 117       && total_off * dir < gh_scm2double (minimum))
 118     {
 119       total_off = gh_scm2double (minimum) * dir;
 120     }
 121
 122   if (fabs (total_off) > 100 CM)
 123     programming_error ("Huh ? Improbable staff side dim.");
 124
 125   return gh_double2scm (total_off);
 126 }
 127
 128 /*
 129   Cut & paste (ugh.)
 130  */
 131 MAKE_SCHEME_CALLBACK (Side_position_interface,aligned_on_support_refpoints,2);
 132 SCM
 133 Side_position_interface::aligned_on_support_refpoints (SCM smob, SCM axis)
 134 {
 135   Grob *me = unsmob_grob (smob);
 136   Axis a = (Axis) gh_scm2int (axis);
 137
 138   return  general_side_position (me, a, false);
 139 }
 140
 141
 142
 143
 144 Real
 145 directed_round (Real f, Direction d)
 146 {
 147   if (d < 0)
 148     return floor (f);
 149   else
 150     return ceil (f);
 151 }
 152
 153 /*
 154   Callback that quantises in staff-spaces, rounding in the direction
 155   of the elements "direction" elt property.
 156
 157   Only rounds when we're inside the staff, as determined by
 158   Staff_symbol_referencer::staff_radius () */
 159 MAKE_SCHEME_CALLBACK (Side_position_interface,quantised_position,2);
 160 SCM
 161 Side_position_interface::quantised_position (SCM element_smob, SCM)
 162 {
 163   Grob *me = unsmob_grob (element_smob);
 164
 165   Direction d = Side_position_interface::get_direction (me);
 166
 167   Grob * stsym = Staff_symbol_referencer::get_staff_symbol (me);
 168   if (stsym)
 169     {
 170       Real p = Staff_symbol_referencer::get_position (me);
 171       Real rp = directed_round (p, d);
 172       Real rad = Staff_symbol_referencer::staff_radius (me) *2 ;
 173       int ip = int (rp);
 174
 175       if (abs (ip) <= rad && Staff_symbol_referencer::on_staffline (me,ip))
 176         {
 177           ip += d;
 178           rp += d;
 179         }
 180
 181       return gh_double2scm ((rp - p) * Staff_symbol_referencer::staff_space (me) / 2.0);
 182     }
 183   return gh_double2scm (0.0);
 184 }
 185
 186 /*
 187   Position next to support, taking into account my own dimensions and padding.
 188  */
 189 MAKE_SCHEME_CALLBACK (Side_position_interface,aligned_side,2);
 190 SCM
 191 Side_position_interface::aligned_side (SCM element_smob, SCM axis)
 192 {
 193   Grob *me = unsmob_grob (element_smob);
 194   Axis a = (Axis) gh_scm2int (axis);
 195
 196   Direction d = Side_position_interface::get_direction (me);
 197
 198   Real o = gh_scm2double (aligned_on_support_extents (element_smob,axis));
 199
 200   Interval iv =  me->extent (me, a);
 201
 202   if (!iv.empty_b ())
 203     {
 204       if (!d)
 205         {
 206           programming_error ("Direction unknown, but aligned-side wanted.");
 207           d = DOWN;
 208         }
 209       o += - iv[-d];
 210     }
 211   return gh_double2scm (o);
 212 }
 213
 214 /*
 215   Maintain a minimum distance to the staff. This is similar to side
 216   position with padding, but it will put adjoining objects on a row if
 217   stuff sticks out of the staff a little.
 218  */
 219 MAKE_SCHEME_CALLBACK (Side_position_interface,out_of_staff,2);
 220 SCM
 221 Side_position_interface::out_of_staff (SCM element_smob, SCM axis)
 222 {
 223   Grob *me = unsmob_grob (element_smob);
 224   Axis a = (Axis) gh_scm2int (axis);
 225
 226   Grob * st = Staff_symbol_referencer::get_staff_symbol (me);
 227
 228   if (!st)
 229     return gh_int2scm (0);
 230
 231   Real padding=0.0;
 232   SCM spad = me->get_grob_property ("staff-padding");
 233
 234   if (gh_number_p (spad))
 235     padding = gh_scm2double (spad);
 236
 237   Grob *common = me->common_refpoint (st, Y_AXIS);
 238   Direction d = Side_position_interface::get_direction (me);
 239   Interval staff_size = st->extent (common, Y_AXIS);
 240   Interval me_ext = me->extent (common, a);
 241   Real diff =  d*staff_size[d] + padding - d*me_ext[-d];
 242   return gh_double2scm (diff >? 0);
 243 }
 244
 245 void
 246 Side_position_interface::add_staff_support (Grob*me)
 247 {
 248   Grob* st = Staff_symbol_referencer::get_staff_symbol (me);
 249   if (st && get_axis (me) == Y_AXIS)
 250     {
 251       add_support (me,st);
 252     }
 253 }
 254
 255 void
 256 Side_position_interface::set_axis (Grob*me, Axis a)
 257 {
 258   me->add_offset_callback (Side_position_interface::aligned_side_proc, a);
 259 }
 260
 261
 262
 263 // ugh. doesn't cactch all variants.
 264 Axis
 265 Side_position_interface::get_axis (Grob*me)
 266 {
 267   if (me->has_offset_callback_b (Side_position_interface::aligned_side_proc, X_AXIS)
 268       || me->has_offset_callback_b (Side_position_interface::aligned_side_proc , X_AXIS))
 269     return X_AXIS;
 270
 271
 272   return Y_AXIS;
 273 }
 274
 275 void
 276 Side_position_interface::set_direction (Grob*me, Direction d)
 277 {
 278   me->set_grob_property ("direction", gh_int2scm (d));
 279 }
 280
 281 void
 282 Side_position_interface::set_minimum_space (Grob*me, Real m)
 283 {
 284   me->set_grob_property ("minimum-space", gh_double2scm (m));
 285 }
 286
 287 void
 288 Side_position_interface::set_padding (Grob*me, Real p)
 289 {
 290   me->set_grob_property ("padding", gh_double2scm (p));
 291 }
 292
 293
 294 bool
 295 Side_position_interface::supported_b (Grob*me)
 296 {
 297   SCM s = me->get_grob_property ("side-support-elements");
 298   return gh_pair_p (s);
 299 }
 300
 301
 302
 303
 304 ADD_INTERFACE (Side_position_interface,"side-position-interface",
 305   "Position a victim object (this one) next to other objects (the "
 306 "support).  In this case, the property @code{direction} signifies where to put the  "
 307 "victim object relative to the support (left or right, up or down?) "
 308 ,
 309   "staff-padding side-support-elements direction-source direction side-relative-direction minimum-space padding");