2 tie.cc -- implement Tie
4 source file of the GNU LilyPond music typesetter
6 (c) 1997--2000 Han-Wen Nienhuys <hanwen@cs.uu.nl>
12 #include "paper-def.hh"
14 #include "rhythmic-head.hh"
16 #include "paper-column.hh"
18 #include "staff-symbol-referencer.hh"
19 #include "directional-element-interface.hh"
20 #include "molecule.hh"
21 #include "bezier-bow.hh"
25 tie: Connect two noteheads.
29 c4 ~ \clef bass ; c4 or
33 do we have non-horizontal ties then?
38 Tie::set_head (Score_element*me,Direction d, Item * head_l)
40 assert (!head (me,d));
41 index_set_cell (me->get_elt_property ("heads"), d, head_l->self_scm_);
43 dynamic_cast<Spanner*> (me)->set_bound (d, head_l);
44 me->add_dependency (head_l);
48 Tie::set_interface (Score_element*me)
50 me->set_elt_property ("heads", gh_cons (SCM_EOL, SCM_EOL));
51 me->set_interface (ly_symbol2scm ("tie-interface"));
55 Tie::has_interface (Score_element*me)
57 return me->has_interface (ly_symbol2scm ("tie-interface"));
61 Tie::head (Score_element*me, Direction d)
63 SCM c = me->get_elt_property ("heads");
64 c = index_cell (c, d);
66 return unsmob_element (c);
70 Tie::position_f (Score_element*me)
72 Direction d = head (me,LEFT) ? LEFT:RIGHT;
73 return Staff_symbol_referencer::position_f (head (me,d));
78 The direction of the Tie is more complicated (See [Ross] p136 and
79 further), the case of multiple ties is handled by Tie_column.
82 Tie::get_default_dir (Score_element*me)
84 Item * sl = head(me,LEFT) ? Rhythmic_head::stem_l (head (me,LEFT)) :0;
85 Item * sr = head(me,RIGHT) ? Rhythmic_head::stem_l (head (me,RIGHT)) :0;
87 if (sl && Directional_element_interface (sl).get () == UP
88 && sr && Directional_element_interface (sr).get () == UP)
96 Tie::get_control_points (SCM smob)
98 Spanner*me = dynamic_cast<Spanner*> (unsmob_element (smob));
99 Direction headdir = CENTER;
102 else if (head(me,RIGHT))
106 programming_error ("Tie without heads.");
108 return SCM_UNSPECIFIED;
111 if (!Directional_element_interface (me).get ())
112 Directional_element_interface (me).set (Tie::get_default_dir (me));
114 Real staff_space = Staff_symbol_referencer::staff_space (me);
116 Real x_gap_f = me->paper_l ()->get_var ("tie_x_gap");
118 Score_element* commonx = me->common_refpoint (me->get_bound (LEFT), X_AXIS);
119 commonx = me->common_refpoint (me->get_bound (RIGHT), X_AXIS);
121 Score_element* l = me->get_bound (LEFT);
122 Score_element* r = me->get_bound (RIGHT);
123 Real width = r->relative_coordinate (commonx, X_AXIS)
124 + r->extent (X_AXIS)[LEFT]
125 - l->relative_coordinate (commonx, X_AXIS)
126 - l->extent (X_AXIS)[RIGHT]
129 Real left_x = l->extent (X_AXIS)[RIGHT] + x_gap_f;
131 Direction dir = Directional_element_interface (me).get();
133 Real h_inf = me->paper_l ()->get_var ("tie_height_limit_factor") * staff_space;
134 Real r_0 = me->paper_l ()->get_var ("tie_ratio");
137 Bezier b = slur_shape (width, h_inf, r_0);
139 Offset leave_dir = b.control_[1] - b.control_[0];
141 Real dx = (head (me, headdir)->extent (X_AXIS).length () + x_gap_f)/2.0;
142 Real max_gap = leave_dir[Y_AXIS] * dx / leave_dir[X_AXIS];
145 for small ties (t small) we want to start in the Y-center (so dy = 0), for
146 large ties, the tie should appear to come from the center of the
147 head, so dy = max_gap
149 maybe use a different formula?
151 TODO: what if 2 heads have different size.
153 TODO: for small ties, it is better to start over the heads
154 iso. next to the heads.
156 Real t = (width / staff_space - 5.0); // ugh.
157 Real dy = t > 0 ? max_gap * sqr (t / (1 + t)) : 0.0;
159 Real ypos = Tie::position_f (me) * staff_space/2 + dir * dy;
162 todo: prevent ending / staffline collision.
164 todo: tie / stem collision
167 b = slur_shape(width,h_inf, r_0);
169 b.translate (Offset (left_x, ypos));
173 Avoid colliding of the horizontal part with stafflines.
175 should do me for slurs as well.
178 Array<Real> horizontal (b.solve_derivative (Offset (1,0)));
179 if (horizontal.size ())
182 ugh. Doesnt work for non-horizontal curves.
184 Real y = b.curve_point (horizontal[0])[Y_AXIS];
186 Real ry = rint (y/staff_space) * staff_space;
189 if (fabs (y) <= Staff_symbol_referencer::staff_radius (me)
190 && fabs (diff) < me->paper_l ()->get_var ("tie_staffline_clearance"))
192 newy = ry - 0.5 * staff_space * sign (diff) ;
195 Real y0 = b.control_ [0][Y_AXIS];
196 b.control_[2][Y_AXIS] =
197 b.control_[1][Y_AXIS] =
198 (b.control_[1][Y_AXIS] - y0) * ((newy - y0) / (y - y0)) + y0;
201 programming_error ("Tie is nowhere horizontal");
205 SCM controls = SCM_EOL;
207 controls = gh_cons ( ly_offset2scm (b.control_[i]), controls);
211 MAKE_SCHEME_CALLBACK(Tie,set_spacing_rods);
214 TODO: set minimum distances for begin/end of line
217 Tie::set_spacing_rods (SCM smob)
219 Score_element*me = unsmob_element (smob);
220 Spanner*sp = dynamic_cast<Spanner*> (me);
223 r.item_l_drul_ [LEFT]=sp->get_bound (LEFT);
224 r.item_l_drul_ [RIGHT]=sp->get_bound (RIGHT);
227 = gh_scm2double (me->get_elt_property ("minimum-length"))
228 * me->paper_l ()->get_var ("staffspace");
230 return SCM_UNSPECIFIED;
233 MAKE_SCHEME_CALLBACK(Tie,brew_molecule);
235 Tie::brew_molecule (SCM smob)
237 Score_element*me = unsmob_element (smob);
239 SCM cp = me->get_elt_property ("control-points");
242 cp = get_control_points (smob);
243 me->set_elt_property ("control-points", cp);
247 gh_scm2double (me->get_elt_property ("thickness"))
248 * me->paper_l ()->get_var ("stafflinethickness");
252 for (SCM s= cp; s != SCM_EOL; s = gh_cdr (s))
254 b.control_[i] = ly_scm2offset (gh_car (s));
258 Molecule a = me->lookup_l ()->slur (b, Directional_element_interface (me).get () * thick, thick);
260 return a.create_scheme ();