lily/line-spanner.cc

   1 /*
   2   line-spanner.cc -- implement Line_spanner
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 2000--2001 Jan Nieuwenhuizen <janneke@gnu.org>
   7 */
   8
   9 #include "molecule.hh"
  10 #include "item.hh"
  11 #include "spanner.hh"
  12 #include "line-spanner.hh"
  13 #include "paper-def.hh"
  14 #include "paper-column.hh"
  15 #include "staff-symbol-referencer.hh"
  16 #include "font-interface.hh"
  17
  18 #include <math.h>
  19
  20 SCM
  21 Line_spanner::line_atom (Grob* me, Real dx, Real dy)
  22 {
  23   SCM type = me->get_grob_property ("type");
  24   Real staff_space = Staff_symbol_referencer::staff_space (me);
  25   Real thick = me->paper_l ()->get_var ("stafflinethickness");
  26
  27   SCM s = me->get_grob_property ("line-thickness");
  28   if (gh_number_p (s))
  29     thick *= gh_scm2double (s);
  30
  31       // maybe these should be in line-thickness?
  32   Real length = staff_space;
  33   s = me->get_grob_property ("dash-length");
  34   if (gh_number_p (s))
  35     length = gh_scm2double (s) * staff_space;
  36
  37   Real period = 2 * length + thick;
  38   s = me->get_grob_property ("dash-period");
  39   if (gh_number_p (s))
  40     period = gh_scm2double (s) * staff_space;
  41
  42   if (type == ly_symbol2scm ("dotted-line"))
  43     length = thick;
  44
  45   if (type == ly_symbol2scm ("line"))
  46     length = period + thick;
  47
  48   Real on = length - thick;
  49   Real off = period - on;
  50
  51   SCM list = gh_list (ly_symbol2scm ("dashed-line"),
  52                       gh_double2scm (thick),
  53                       gh_double2scm (on),
  54                       gh_double2scm (off),
  55                       gh_double2scm (dx),
  56                       gh_double2scm (dy),
  57                       SCM_UNDEFINED);
  58
  59   return list;
  60 }
  61
  62 Molecule
  63 Line_spanner::line_molecule (Grob* me, Real dx, Real dy)
  64 {
  65   Molecule mol;
  66   SCM type = me->get_grob_property ("type");
  67   if (gh_symbol_p (type)
  68       && (type == ly_symbol2scm ("line")
  69           || type == ly_symbol2scm ("dashed-line")
  70           || type == ly_symbol2scm ("dotted-line")
  71           || (type == ly_symbol2scm ("trill") && dy != 0)))
  72     {
  73       Box b (Interval (0, dx), Interval (0, dy));
  74       mol = Molecule (b, line_atom (me, dx, dy));
  75     }
  76   else if (gh_symbol_p (type)
  77            && type == ly_symbol2scm ("trill"))
  78     {
  79       SCM alist_chain = Font_interface::font_alist_chain (me);
  80       SCM style_chain = gh_list (gh_cons (ly_symbol2scm ("font-family"),
  81                                           ly_symbol2scm ("music")),
  82                                  SCM_UNDEFINED);
  83
  84       Font_metric *fm = Font_interface::get_font (me,
  85                                                   gh_list (style_chain,
  86                                                            alist_chain,
  87                                                            SCM_UNDEFINED));
  88       Molecule m = fm->find_by_name ("scripts-trill-element");
  89       do
  90         mol.add_at_edge (X_AXIS, RIGHT, m, 0);
  91       while (m.extent (X_AXIS).length ()
  92              && mol.extent (X_AXIS).length ()
  93              + m.extent (X_AXIS).length () < dx);
  94
  95       /*
  96         FIXME: should center element on x/y
  97        */
  98       mol.translate_axis (m.extent (X_AXIS).length () / 2, X_AXIS);
  99       mol.translate_axis (-(mol.extent (Y_AXIS)[DOWN]
 100                             + mol.extent (Y_AXIS).length ())/2, Y_AXIS);
 101     }
 102   return mol;
 103 }
 104
 105 Offset
 106 Line_spanner::get_broken_offset (Grob *me, Direction dir)
 107 {
 108   Spanner *spanner = dynamic_cast<Spanner*> (me);
 109   Item* bound = spanner->get_bound (dir);
 110
 111   if (!bound->break_status_dir ())
 112     {
 113       Grob *common[] = {
 114         bound->common_refpoint (Staff_symbol_referencer::staff_symbol_l (me),
 115                                 X_AXIS),
 116         bound->common_refpoint (Staff_symbol_referencer::staff_symbol_l (me),
 117                                 Y_AXIS)
 118       };
 119
 120       return Offset (abs (bound->extent (common[X_AXIS], X_AXIS)[-dir]),
 121                       bound->extent (common[Y_AXIS], Y_AXIS).center ());
 122     }
 123   return Offset ();
 124 }
 125
 126 Offset
 127 Line_spanner::broken_trend_offset (Grob *me, Direction dir)
 128 {
 129   /* A broken line-spaner should maintain the same vertical trend
 130      the unbroken line-spanner would have had.
 131      From slur */
 132   Offset o;
 133   if (Spanner *mother =  dynamic_cast<Spanner*> (me->original_l_))
 134     {
 135       for (int i = dir == LEFT ? 0 : mother->broken_into_l_arr_.size () - 1;
 136            dir == LEFT ? i < mother->broken_into_l_arr_.size () : i > 0;
 137            dir == LEFT ? i++ : i--)
 138         {
 139           if (mother->broken_into_l_arr_[i - dir] == me)
 140             {
 141               Grob *neighbour = mother->broken_into_l_arr_[i];
 142               Offset neighbour_o = get_broken_offset (neighbour, dir);
 143               Offset me_o = get_broken_offset (me, -dir);
 144               // Hmm, why not return me_o[X], but recalc in brew_mol?
 145               o = Offset (0,
 146  (neighbour_o[Y_AXIS]*me_o[X_AXIS]
 147                            - me_o[Y_AXIS]*neighbour_o[X_AXIS]) * dir /
 148  (me_o[X_AXIS] + neighbour_o[X_AXIS]));
 149               break;
 150             }
 151         }
 152     }
 153   return o;
 154 }
 155
 156
 157 /*
 158   Warning: this thing is a cross-staff object, so it should have empty Y-dimensions.
 159
 160  (If not, you risk that this is called from the staff-alignment
 161   routine, via molecule_extent. At this point, the staves aren't
 162   separated yet, so it doesn't work cross-staff.
 163
 164 */
 165
 166 MAKE_SCHEME_CALLBACK (Line_spanner, brew_molecule, 1);
 167 SCM
 168 Line_spanner::brew_molecule (SCM smob)
 169 {
 170   Grob *me= unsmob_grob (smob);
 171
 172   Spanner *spanner = dynamic_cast<Spanner*> (me);
 173   Item* bound_drul[] = {
 174     spanner->get_bound (LEFT),
 175     0,
 176     spanner->get_bound (RIGHT)
 177   };
 178
 179   Item** bound = bound_drul + 1;
 180
 181   Grob *common[] = { 0, 0 };
 182   for (Axis a = X_AXIS;  a < NO_AXES; a = Axis (a + 1))
 183     {
 184       common[a] = bound[LEFT]->common_refpoint (bound[RIGHT], a);
 185
 186       if (!common[a])
 187         return SCM_EOL;
 188     }
 189
 190   Real gap = gh_scm2double (me->get_grob_property ("gap"));
 191   Real dist; /*distance between points */
 192
 193   Offset ofxy (gap, 0); /*offset from start point to start of line*/
 194   Offset dxy ;
 195   Offset my_off;
 196   Offset his_off;
 197
 198
 199   if (bound[LEFT]->break_status_dir () || bound[RIGHT]->break_status_dir ())
 200     /* across line break */
 201     {
 202       Direction broken = bound[LEFT]->break_status_dir () ? LEFT : RIGHT;
 203
 204       dxy[X_AXIS] = bound[RIGHT]->extent (common[X_AXIS], X_AXIS)[LEFT]
 205         - bound[LEFT]->extent (common[X_AXIS], X_AXIS)[RIGHT];
 206
 207       dxy += broken_trend_offset (me, broken);
 208       dxy[X_AXIS] -= 1 * gap;
 209
 210       my_off = Offset (0,
 211                        me->relative_coordinate (common[Y_AXIS], Y_AXIS));
 212
 213       his_off = Offset (0,
 214                         bound[-broken]->relative_coordinate (common[Y_AXIS],
 215                                                              Y_AXIS));
 216
 217       if (broken == LEFT)
 218         {
 219           my_off[Y_AXIS] += dxy[Y_AXIS];
 220         }
 221     }
 222   else
 223     {
 224       Real off = gap + ((bound[LEFT]->extent (bound[LEFT], X_AXIS).length ()*3)/4); // distance from center to start of line
 225       dxy[X_AXIS] = bound[RIGHT]->extent (common[X_AXIS], X_AXIS).center ()
 226         - bound[LEFT]->extent (common[X_AXIS], X_AXIS).center ();
 227       dxy[Y_AXIS] = bound[RIGHT]->extent (common[Y_AXIS], Y_AXIS).center ()
 228         - bound[LEFT]->extent (common[Y_AXIS], Y_AXIS).center ();
 229
 230       dist = sqrt (dxy[X_AXIS]*dxy[X_AXIS]+dxy[Y_AXIS]*dxy[Y_AXIS]);
 231       ofxy = dxy* (off/dist);
 232       dxy -= 2*ofxy;
 233
 234       my_off = Offset (me->relative_coordinate (common[X_AXIS], X_AXIS),
 235                        me->relative_coordinate (common[Y_AXIS], Y_AXIS));
 236
 237       his_off = Offset (bound[LEFT]->relative_coordinate (common[X_AXIS],
 238                                                           X_AXIS),
 239                         bound[LEFT]->relative_coordinate (common[Y_AXIS],
 240                                                           Y_AXIS));
 241
 242       }
 243
 244   Molecule line = line_molecule (me, dxy[X_AXIS], dxy[Y_AXIS]);
 245   line.translate_axis (bound[LEFT]->extent (bound[LEFT],
 246                                             X_AXIS).length ()/2, X_AXIS);
 247   line.translate (ofxy - my_off + his_off);
 248   return line.smobbed_copy ();
 249 }
 250
 251