2 ledger-line-spanner.cc -- implement Ledger_line_spanner
4 source file of the GNU LilyPond music typesetter
6 (c) 2004--2005 Han-Wen Nienhuys <hanwen@xs4all.nl>
12 #include "note-head.hh"
13 #include "staff-symbol-referencer.hh"
14 #include "staff-symbol.hh"
17 #include "group-interface.hh"
18 #include "paper-column.hh"
20 struct Ledger_line_spanner
22 DECLARE_SCHEME_CALLBACK (print, (SCM));
23 DECLARE_SCHEME_CALLBACK (set_spacing_rods, (SCM));
24 static Stencil brew_ledger_lines (Grob *me,
31 static bool has_interface (Grob *);
35 Ledger_line_spanner::brew_ledger_lines (Grob *staff,
39 Real ledgerlinethickness,
43 int line_count = ((abs (pos) < interspaces)
45 : (abs (pos) - interspaces) / 2);
49 Real blotdiameter = ledgerlinethickness;
51 = Interval (-0.5* (ledgerlinethickness),
52 +0.5* (ledgerlinethickness));
53 Stencil proto_ledger_line
54 = Lookup::round_filled_box (Box (x_extent, y_extent), blotdiameter);
56 x_extent[LEFT] += left_shorten;
57 Stencil proto_first_line
58 = Lookup::round_filled_box (Box (x_extent, y_extent), blotdiameter);
60 Direction dir = (Direction)sign (pos);
61 Real offs = (Staff_symbol_referencer::on_staffline (staff, pos))
65 offs += pos * halfspace;
66 for (int i = 0; i < line_count; i++)
68 Stencil ledger_line ((i == 0)
71 ledger_line.translate_axis (-dir * halfspace * i * 2 + offs, Y_AXIS);
72 stencil.add_stencil (ledger_line);
81 set_rods (Drul_array<Interval> const ¤t_extents,
82 Drul_array<Interval> const &previous_extents,
84 Item *previous_column,
85 Real min_length_fraction)
90 if (!current_extents[d].is_empty ()
91 && !previous_extents[d].is_empty ())
93 Real total_head_length = previous_extents[d].length ()
94 + current_extents[d].length ();
97 rod.distance_ = total_head_length
98 * (3/2 * min_length_fraction)
100 we go from right to left.
102 - previous_extents[d][LEFT]
103 + current_extents[d][RIGHT];
105 rod.item_drul_[LEFT] = current_column;
106 rod.item_drul_[RIGHT] = previous_column;
111 while (flip (&d) != DOWN);
115 MAKE_SCHEME_CALLBACK (Ledger_line_spanner, set_spacing_rods, 1);
117 Ledger_line_spanner::set_spacing_rods (SCM smob)
119 Spanner *me = dynamic_cast<Spanner *> (unsmob_grob (smob));
121 // find size of note heads.
122 Grob *staff = Staff_symbol_referencer::get_staff_symbol (me);
126 SCM heads = me->get_property ("note-heads");
129 Real min_length_fraction
130 = robust_scm2double (me->get_property ("minimum-length-fraction"), 0.15);
133 Drul_array<Interval> current_extents;
134 Drul_array<Interval> previous_extents;
135 Item *previous_column = 0;
136 Item *current_column = 0;
139 Run through heads using a loop. Since Legder_line_spanner can
140 contain a lot of noteheads, superlinear performance is too slow.
142 int interspaces = Staff_symbol::line_count (staff) - 1;
143 for (SCM hp = heads; scm_is_pair (hp); hp = scm_cdr (hp))
145 Item *h = dynamic_cast<Item *> (unsmob_grob (scm_car (hp)));
147 int pos = Staff_symbol_referencer::get_rounded_position (h);
148 if (abs (pos) <= interspaces)
151 Item *column = h->get_column ();
152 if (current_column != column)
154 set_rods (current_extents, previous_extents,
155 current_column, previous_column,
156 min_length_fraction);
158 previous_column = current_column;
159 current_column = column;
160 previous_extents = current_extents;
162 current_extents[DOWN].set_empty();
163 current_extents[UP].set_empty();
167 Interval head_extent = h->extent (column, X_AXIS);
168 Direction vdir = Direction (sign (pos));
172 current_extents[vdir].unite (head_extent);
175 if (previous_column && current_column)
176 set_rods (current_extents, previous_extents,
177 current_column, previous_column,
178 min_length_fraction);
182 return SCM_UNSPECIFIED;
185 struct Ledger_request
187 Interval ledger_extent_;
188 Interval head_extent_;
193 ledger_extent_.set_empty ();
194 head_extent_.set_empty ();
199 typedef std::map < int, Drul_array<Ledger_request> > Ledger_requests;
202 TODO: ledger share a lot of info. Lots of room to optimize away
203 common use of objects/variables.
206 MAKE_SCHEME_CALLBACK (Ledger_line_spanner, print, 1);
208 Ledger_line_spanner::print (SCM smob)
210 Spanner *me = dynamic_cast<Spanner *> (unsmob_grob (smob));
211 Link_array<Grob> heads (extract_grob_array (me, ly_symbol2scm ("note-heads")));
213 if (heads.is_empty ())
216 // find size of note heads.
217 Grob *staff = Staff_symbol_referencer::get_staff_symbol (me);
222 = robust_scm2double (me->get_property ("length-fraction"), 0.25);
225 Stencil default_ledger;
227 Grob *common[NO_AXES];
229 for (int i = X_AXIS; i < NO_AXES; i++)
232 common[a] = common_refpoint_of_array (heads, me, a);
233 for (int i = heads.size (); i--;)
234 if (Grob *g = unsmob_grob (me->get_property ("accidental-grob")))
235 common[a] = common[a]->common_refpoint (g, a);
238 int interspaces = Staff_symbol::line_count (staff) - 1;
239 Ledger_requests reqs;
240 for (int i = heads.size (); i--;)
242 Item *h = dynamic_cast<Item *> (heads[i]);
244 int pos = Staff_symbol_referencer::get_rounded_position (h);
246 && abs (pos) > interspaces)
248 Interval head_extent = h->extent (common[X_AXIS], X_AXIS);
249 Interval ledger_extent = head_extent;
250 ledger_extent.widen (length_fraction * head_extent.length ());
252 Direction vdir = Direction (sign (pos));
253 int rank = Paper_column::get_rank (h->get_column ());
255 reqs[rank][vdir].ledger_extent_.unite (ledger_extent);
256 reqs[rank][vdir].head_extent_.unite (head_extent);
257 reqs[rank][vdir].position_
258 = vdir * ((vdir* reqs[rank][vdir].position_) >? (vdir *pos));
262 // determine maximum size for non-colliding ledger.
263 Real gap = robust_scm2double (me->get_property ("gap"), 0.1);
264 Ledger_requests::iterator last (reqs.end ());
265 for (Ledger_requests::iterator i (reqs.begin ());
266 i != reqs.end (); last = i++)
268 if (last == reqs.end ())
276 if (abs (last->second[d].position_) > interspaces
277 && abs (i->second[d].position_) > interspaces)
280 = (last->second[d].head_extent_[RIGHT]
281 + i->second[d].head_extent_[LEFT]) / 2;
283 Direction which = LEFT;
286 Ledger_request &lr = ((which == LEFT) ? *last : *i).second[d];
288 // due tilt of quarter note-heads
290 = (abs (last->second[d].position_) > interspaces + 1
291 && abs (i->second[d].position_) > interspaces + 1);
293 Real limit = (center + (both? which * gap / 2 : 0));
294 lr.ledger_extent_.elem_ref (-which)
295 = which * (which * lr.ledger_extent_[-which] >? which * limit);
297 while (flip (&which) != LEFT);
300 while (flip (&d) != DOWN);
303 // create ledgers for note heads
304 Real ledgerlinethickness
305 = Staff_symbol::get_ledger_line_thickness (staff);
306 Real halfspace = Staff_symbol::staff_space (staff) / 2;
307 for (int i = heads.size (); i--;)
309 Item *h = dynamic_cast<Item *> (heads[i]);
311 int pos = Staff_symbol_referencer::get_rounded_position (h);
312 if (abs (pos) > interspaces + 1)
314 Interval head_size = h->extent (common[X_AXIS], X_AXIS);
315 Interval ledger_size = head_size;
316 ledger_size.widen (ledger_size.length ()* length_fraction);
318 Interval max_size = reqs[Paper_column::get_rank (h->get_column ())][Direction (sign (pos))].ledger_extent_;
320 ledger_size.intersect (max_size);
321 Real left_shorten = 0.0;
322 if (Grob *g = unsmob_grob (h->get_property ("accidental-grob")))
324 Interval accidental_size = g->extent (common[X_AXIS], X_AXIS);
326 = linear_combination (Drul_array<Real> (accidental_size[RIGHT],
330 left_shorten = (-ledger_size[LEFT] + d) >? 0;
333 TODO: shorten 2 ledger lines for the case natural +
339 ledgers.add_stencil (brew_ledger_lines (staff, pos, interspaces,
347 ledgers.translate_axis (-me->relative_coordinate (common[X_AXIS], X_AXIS),
350 return ledgers.smobbed_copy ();
353 ADD_INTERFACE (Ledger_line_spanner,
354 "ledger-line-interface",
355 "This spanner draws the ledger lines of a staff, for note heads that stick out. ",
356 "note-heads thickness minimum-length-fraction length-fraction gap");
358 struct Ledgered_interface
360 static bool has_interface (Grob *);
363 ADD_INTERFACE (Ledgered_interface,
364 "ledgered-interface",
365 "Objects that need ledger lines.",