2 coherent-ligature-engraver.cc -- implement Coherent_ligature_engraver
4 source file of the GNU LilyPond music typesetter
6 (c) 2003--2006 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 * *, vector<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.
76 * TODO: move this function to class Item?
79 Coherent_ligature_engraver::get_set_column (Item *item, Paper_column *column)
81 Item *parent = dynamic_cast<Item *> (item->get_parent (X_AXIS));
84 programming_error ("failed tweaking paper column in ligature");
88 string name = parent->name ();
89 if (name != "PaperColumn")
91 // Change column not only for targeted item (NoteColumn), but
92 // also for all associated grobs (NoteSpacing, SeparationItem).
93 Grob *sl = Staff_symbol_referencer::get_staff_symbol (item);
95 extract_item_set (parent, "elements", elements);
97 for (vsize i = elements.size (); i--;)
99 Item *sibling = elements[i];
101 && (Staff_symbol_referencer::get_staff_symbol (sibling) == sl))
103 #if 0 /* experimental code to collapse spacing after ligature */
104 Grob *sibling_parent = sibling->get_parent (X_AXIS);
105 sibling_parent->warning (_f ("Coherent_ligature_engraver: "
106 "setting `spacing-increment="
107 "0.01': ptr=%ul", parent));
108 sibling_parent->set_property ("forced-spacing",
109 scm_from_double (0.01));
111 sibling->set_parent (column, X_AXIS);
116 get_set_column (parent, column);
120 * TODO: This function should collect all accidentals that occur
121 * within the ligature (by scanning through the primitives array) and
122 * place all of them at the left of the ligature. If there is an
123 * alteration within the ligature (e.g. an "f" followed by a "fis"
124 * somewhere later in the ligature), issue a warning (and maybe create
125 * an additional natural symbol to explicitly make clear that there is
126 * an "f" first?). The warning should suggest the user to break the
127 * ligature into two or more smaller ligatures such that no alteration
128 * occurs within the broken ligatures any more.
131 Coherent_ligature_engraver::collect_accidentals (Spanner *, vector<Grob_info>)
137 compute_delta_pitches (vector<Grob_info> primitives)
141 Item *prev_primitive = 0, *primitive = 0;
142 for (vsize i = 0; i < primitives.size (); i++)
144 primitive = dynamic_cast<Item *> (primitives[i].grob ());
145 Music *music_cause = primitives[i].music_cause ();
147 = unsmob_pitch (music_cause->get_property ("pitch"))->steps ();
150 delta_pitch = pitch - prev_pitch;
151 prev_primitive->set_property ("delta-position",
152 scm_from_int (delta_pitch));
155 prev_primitive = primitive;
157 primitive->set_property ("delta-position", scm_from_int (0));
161 Coherent_ligature_engraver::typeset_ligature (Spanner *ligature,
162 vector<Grob_info> primitives)
164 // compute some commonly needed context info stored as grob
166 compute_delta_pitches (primitives);
168 // prepare ligature for typesetting
169 build_ligature (ligature, primitives);
170 collect_accidentals (ligature, primitives);
173 // no ADD_ACKNOWLEDGER / ADD_ACKNOWLEDGER / ADD_TRANSLATOR macro calls
174 // since this class is abstract