2 coherent-ligature-engraver.cc -- implement Coherent_ligature_engraver
4 source file of the GNU LilyPond music typesetter
6 (c) 2003--2005 Juergen Reuter <reuter@ipd.uka.de>
9 #include "coherent-ligature-engraver.hh"
12 #include "staff-symbol-referencer.hh"
14 #include "paper-column.hh"
16 #include "pointer-group-interface.hh"
19 * This abstract class serves as common superclass for all ligature
20 * engravers thet produce a single connected graphical object of fixed
21 * width, consisting of noteheads and other primitives (see class
22 * Ligature_engraver for more information on the interaction between
23 * this class and its superclass). In particular, it cares for the
26 * - provide a function for putting all grobs of the ligature into a
27 * single paper column,
29 * - delegate actual creation of ligature to concrete subclass,
31 * - collect all accidentals that occur within the ligature and put
32 * them at the left side of the ligature (TODO; see function
33 * collect_accidentals ()),
35 * - collapse superflous space after each ligature (TODO).
37 * Concrete subclasses must implement function build_ligature (Spanner
38 * *, Array<Grob_info>). This function is responsible for actually
39 * building the ligature by transforming the array of noteheads.
41 * Currently, there are two subclasses: Gregorian_ligature_engraver
42 * for Gregorian chant notation (also known as plain song or cantus
43 * planus) and Mensural_ligature_engraver for white mensural notation.
44 * Subclasses for other music notation styles such as modal notation
45 * or ars nova notation may eventually be added.
49 * TODO: local accidentals: collect accidentals that occur within a
50 * ligature and put them before the ligature. If an accidental
51 * changes within a ligature, print a warning (user error) and ignore
52 * any further accidental for that pitch within that ligature
53 * (actually, in such a case, the user should split the ligature into
54 * two separate ligatures). Similarly, any object that, in ordinary
55 * notation, may be put to the left or to the right of a note-head,
56 * should be collected and put before or after the ligature.
58 * TODO: make spacing more robust: do not screw up spacing if user
59 * erroneously puts rest in ligature.
61 * TODO: for each ligature, add Rod that represents the total length
62 * of the ligature (to preemptively avoid collision with adjacent
63 * notes); or maybe just additionally create a
64 * mensural/vaticana/whatever-ligature grob (e.g. via
65 * Mensural_ligature::print (SCM)) that just consists of a
66 * bounding box around all primitives of the ligature.
68 * TODO: Maybe move functions fold_up_primitives () and
69 * join_primitives () from subclasses to here? N.B. it is not
70 * appropriate to put these into Ligature_engraver, since, for
71 * example, Ligature_bracket_engraver does not share any of this code.
75 * TODO: Let superflous space after each ligature collapse. The
76 * following code should help in doing so (though it does not yet
77 * fully work). Just put the following code into
78 * Spacing_spanner::do_measure (). I put it temporarily here as memo
79 * until it really works and I also get Han-Wen's/Jan's permission to
80 * add it to the spacing spanner code.
82 #if 0 /* experimental code to collapse spacing after ligature */
83 SCM incr_scm = lc->get_property ("forced-spacing");
84 if (incr_scm != SCM_EOL) /* (Paper_column::is_musical (l)) */
86 me->warning (_f ("gotcha: ptr=%ul", lc));//debug
87 ly_display_scm (lc->self_scm ());
89 if (incr_scm != SCM_EOL)
91 distance = scm_to_double (incr_scm);
95 me->warning (_ ("distance undefined, assuming 0.1"));
98 me->warning (_f ("distance=%f", distance));//debug
99 Real inverse_strength = 1.0;
100 Spaceable_grob::add_spring (lc, rc, distance, inverse_strength);
101 if (Item *rb = r->find_prebroken_piece (LEFT))
102 Spaceable_grob::add_spring (lc, rb, distance, inverse_strength);
109 * TODO: move this function to class Item?
112 Coherent_ligature_engraver::get_set_column (Item *item, Paper_column *column)
114 Item *parent = dynamic_cast<Item *> (item->get_parent (X_AXIS));
117 programming_error ("failed tweaking paper column in ligature");
121 String name = parent->name ();
122 if (!String::compare (name, "PaperColumn"))
124 // Change column not only for targeted item (NoteColumn), but
125 // also for all associated grobs (NoteSpacing, SeparationItem).
126 Grob *sl = Staff_symbol_referencer::get_staff_symbol (item);
128 extract_item_set (parent, "elements", elements);
130 for (int i = elements.size (); i--;)
132 Item *sibling = elements[i];
134 && (Staff_symbol_referencer::get_staff_symbol (sibling) == sl))
136 #if 0 /* experimental code to collapse spacing after ligature */
137 Grob *sibling_parent = sibling->get_parent (X_AXIS);
138 sibling_parent->warning (_f ("Coherent_ligature_engraver: "
139 "setting `spacing-increment="
140 "0.01': ptr=%ul", parent));
141 sibling_parent->set_property ("forced-spacing",
142 scm_from_double (0.01));
144 sibling->set_parent (column, X_AXIS);
150 get_set_column (parent, column);
155 * TODO: This function should collect all accidentals that occur
156 * within the ligature (by scanning through the primitives array) and
157 * place all of them at the left of the ligature. If there is an
158 * alteration within the ligature (e.g. an "f" followed by a "fis"
159 * somewhere later in the ligature), issue a warning (and maybe create
160 * an additional natural symbol to explicitly make clear that there is
161 * an "f" first?). The warning should suggest the user to break the
162 * ligature into two or more smaller ligatures such that no alteration
163 * occurs within the broken ligatures any more.
166 Coherent_ligature_engraver::collect_accidentals (Spanner *, Array<Grob_info>)
172 compute_delta_pitches (Array<Grob_info> primitives)
176 Item *prev_primitive = 0, *primitive = 0;
177 for (int i = 0; i < primitives.size (); i++)
179 primitive = dynamic_cast<Item *> (primitives[i].grob ());
180 Music *music_cause = primitives[i].music_cause ();
182 = unsmob_pitch (music_cause->get_property ("pitch"))->steps ();
185 delta_pitch = pitch - prev_pitch;
186 prev_primitive->set_property ("delta-pitch",
187 scm_from_int (delta_pitch));
190 prev_primitive = primitive;
192 primitive->set_property ("delta-pitch", scm_from_int (0));
196 Coherent_ligature_engraver::typeset_ligature (Spanner *ligature,
197 Array<Grob_info> primitives)
199 // compute some commonly needed context info stored as grob
201 compute_delta_pitches (primitives);
203 // prepare ligature for typesetting
204 build_ligature (ligature, primitives);
205 collect_accidentals (ligature, primitives);
208 // no ADD_ACKNOWLEDGER / ADD_ACKNOWLEDGER / ADD_TRANSLATOR macro calls
209 // since this class is abstract