2 ledger-line-spanner.cc -- implement Ledger_line_spanner
4 source file of the GNU LilyPond music typesetter
6 (c) 2004 Han-Wen Nienhuys <hanwen@xs4all.nl>
13 #include "note-head.hh"
14 #include "staff-symbol-referencer.hh"
15 #include "staff-symbol.hh"
18 #include "group-interface.hh"
19 #include "paper-column.hh"
22 struct Ledger_line_spanner
24 DECLARE_SCHEME_CALLBACK (print, (SCM ));
25 static Stencil brew_ledger_lines (Grob *me,
32 static bool has_interface (Grob*);
37 Ledger_line_spanner::brew_ledger_lines (Grob *staff,
41 Real ledgerlinethickness,
45 int line_count = ((abs (pos) < interspaces)
47 : (abs (pos) - interspaces) / 2);
51 Real blotdiameter = ledgerlinethickness;
53 Interval (-0.5*(ledgerlinethickness),
54 +0.5*(ledgerlinethickness));
55 Stencil proto_ledger_line =
56 Lookup::round_filled_box (Box (x_extent, y_extent), blotdiameter);
58 x_extent[LEFT] += left_shorten;
59 Stencil proto_first_line =
60 Lookup::round_filled_box (Box (x_extent, y_extent), blotdiameter);
62 Direction dir = (Direction)sign (pos);
63 Real offs = (Staff_symbol_referencer::on_staffline (staff, pos))
68 offs += pos * halfspace;
69 for (int i = 0; i < line_count; i++)
71 Stencil ledger_line ((i == 0)
75 ledger_line.translate_axis (-dir * halfspace * i * 2 + offs, Y_AXIS);
76 stencil.add_stencil (ledger_line);
86 Interval ledger_extent_;
87 Interval head_extent_;
91 ledger_extent_.set_empty ();
92 head_extent_.set_empty ();
97 typedef std::map<int, Drul_array<Ledger_request> > Ledger_requests;
101 TODO: ledger share a lot of info. Lots of room to optimize away common
102 use of objects/variables.
104 MAKE_SCHEME_CALLBACK (Ledger_line_spanner,print,1);
106 Ledger_line_spanner::print (SCM smob)
108 Spanner *me = dynamic_cast<Spanner*> (unsmob_grob (smob));
109 Link_array<Grob> heads (Pointer_group_interface__extract_grobs (me, (Grob*)0, "note-heads"));
111 if (heads.is_empty ())
115 Stencil default_ledger;
117 Grob * common[NO_AXES];
119 for (int i = X_AXIS; i < NO_AXES; i++)
122 common[a] = common_refpoint_of_array (heads, me, a);
123 for (int i = heads.size (); i--; )
124 if (Grob * g = unsmob_grob (me->get_property ("accidental-grob")))
125 common[a] = common[a]->common_refpoint (g, a);
128 // find size of note heads.
129 Grob * staff = Staff_symbol_referencer::get_staff_symbol (me);
130 int interspaces = Staff_symbol::line_count (staff)-1;
131 Ledger_requests reqs;
132 Real length_fraction = 0.25;
133 for (int i = heads.size (); i--; )
135 Item *h = dynamic_cast<Item*> (heads[i]);
137 int pos = Staff_symbol_referencer::get_rounded_position (h);
138 if (abs (pos) > interspaces)
140 Interval head_extent = h->extent (common[X_AXIS], X_AXIS);
141 Interval ledger_extent = head_extent;
142 ledger_extent.widen (length_fraction * head_extent.length ());
144 Direction vdir = Direction (sign (pos));
145 int rank = Paper_column::get_rank (h->get_column ());
147 reqs[rank][vdir].ledger_extent_.unite (ledger_extent);
148 reqs[rank][vdir].head_extent_.unite (head_extent);
149 reqs[rank][vdir].position_ =
150 vdir * ((vdir* reqs[rank][vdir].position_) >? (vdir *pos));
154 // determine maximum size for non-colliding ledger.
155 Real gap = robust_scm2double (me->get_property ("gap"), 0.1);
156 Ledger_requests::iterator last (reqs.end ());
157 for (Ledger_requests::iterator i (reqs.begin ());
158 i != reqs.end (); last = i++)
160 if (last == reqs.end ())
168 if (abs (last->second[d].position_) > interspaces
169 && abs (i->second[d].position_) > interspaces)
172 (last->second[d].head_extent_[RIGHT]
173 + i->second[d].head_extent_[LEFT] )/2;
175 Direction which = LEFT;
178 Ledger_request &lr = ((which == LEFT) ? *last : *i).second[d];
180 // due tilt of quarter note-heads
182 (abs (last->second[d].position_) > interspaces + 1
183 && abs (i->second[d].position_) > interspaces + 1);
185 Real limit = (center + (both? which * gap/2 : 0));
186 lr.ledger_extent_.elem_ref (-which)
187 = which * (which * lr.ledger_extent_[-which] >? which * limit);
189 while (flip (&which) != LEFT);
192 while (flip (&d) != DOWN);
195 // create ledgers for note heads
196 Real ledgerlinethickness =
197 Staff_symbol::get_ledger_line_thickness (staff);
198 Real halfspace = Staff_symbol::staff_space (me)/2;
199 for (int i = heads.size (); i--; )
201 Item *h = dynamic_cast<Item*> (heads[i]);
203 int pos = Staff_symbol_referencer::get_rounded_position (h);
204 if (abs (pos) > interspaces + 1)
206 Interval ledger_size = h->extent (common[X_AXIS], X_AXIS);
207 ledger_size.widen (ledger_size.length ()* length_fraction);
209 Interval max_size = reqs[Paper_column::get_rank (h->get_column ())][Direction (sign(pos))].ledger_extent_;
211 ledger_size.intersect (max_size);
212 Real left_shorten =0.0;
213 if (Grob * g = unsmob_grob (h->get_property ("accidental-grob")))
216 linear_combination (Drul_array<Real> (h->extent (common[X_AXIS], X_AXIS)[LEFT],
217 g->extent (common[X_AXIS], X_AXIS)[RIGHT]),
221 left_shorten = (-ledger_size[LEFT] + d) >? 0 ;
224 TODO: shorten 2 ledger lines for the case natural +
230 ledgers.add_stencil (brew_ledger_lines (staff, pos, interspaces,
239 ledgers.translate_axis (-me->relative_coordinate (common[X_AXIS], X_AXIS),
242 return ledgers.smobbed_copy ();
245 ADD_INTERFACE (Ledger_line_spanner,
246 "ledger-line-interface",
247 "This spanner draws the ledger lines of a staff on note heads. ",
248 "note-heads thickness gap length minimum-length")