2 ambitus-engraver.cc -- implement Ambitus_engraver
4 source file of the GNU LilyPond music typesetter
6 (C) 2002 Juergen Reuter <reuter@ipd.uka.de>
11 #include "note-head.hh"
12 #include "staff-symbol-referencer.hh"
13 #include "musical-request.hh"
17 * This class implements an engraver for ambitus grobs.
19 * TODO: There are quite some conceptional issues left open:
21 * - Many publishers put ambitus _before_ the first occurrence of a
22 * clef. Hence, formally the pitches are undefined in this case. Of
23 * course, one could always silently assume that ambitus pitches refer
24 * to the first occurrence of a clef. Or should we, by default, put
25 * the ambitus always after the first clef, if any?
27 * - Enharmonically equal pitches: Assume piece contains once a "gis",
28 * another time an "aes" as highest pitch. Which one should be
29 * selected for the ambitus grob? The "aes", because it is
30 * musically/notationally "higher" than "gis"? Or "gis", because (if
31 * using pure temperament) it has a slightly higher frequency? Or
32 * that pitch that come closer to the key signature? But there may be
33 * key signature changes in the piece...
35 * - Multiple voices in single staff: Assume a vocal piece of music,
36 * where the soprano voice and the alto voice are put into the same
37 * staff (this is generally a bad idea, but unfortunately common
38 * practice). Then, there probably should be two ambitus grobs, one
39 * for each voice. But how can you see which ambitus grob refers to
40 * which voice? Most probably you can guess it from the fact that the
41 * ambitus of the alto voice typically lies in a lower range than that
42 * of the soprano voice, but this is just a heuristic rather than a
43 * generally valid rule. In the case of only two voices, using stems
44 * in the ambitus grob might help, but probably looks quite ugly.
46 * - If a piece consists of several loosely coupled sections, should
47 * there be multiple ambitus grobs allowed, one for each section?
48 * Then there probably should be some "\ambitus" request added to
49 * mudela, stating where an ambitus grob should be placed. This
50 * ambitus grob should then represent the ambitus in the range of time
51 * between this "\ambitus" request and the next one (or the end of the
52 * piece, if there is no more such request). To be compliant with the
53 * current implementation, we might implicitly assume an "\ambitus"
54 * request at the beginning of the piece, but then the question where
55 * to put this first ambitus grob (before/after the clef?) becomes
58 * - Incipits of transcribed music may need special treatment for
59 * ambitus, since, for readability, the ambitus most probably should
60 * not refer to the ancient clefs of the incipit, but rather to the
61 * clefs used in the transcribed parts.
63 class Ambitus_engraver : public Engraver
66 TRANSLATOR_DECLARATIONS(Ambitus_engraver);
67 virtual void start_translation_timestep ();
68 virtual void acknowledge_grob (Grob_info);
69 virtual void create_grobs ();
70 virtual void stop_translation_timestep ();
73 void create_ambitus ();
76 Pitch pitch_min, pitch_max;
79 Ambitus_engraver::Ambitus_engraver ()
81 ambitus_p_ = 0; isActive = 0;
83 // (pitch_min > pitch_max) means that pitches are not yet
85 pitch_min = Pitch (0, 0, +1);
86 pitch_max = Pitch (0, 0, -1);
90 Ambitus_engraver::stop_translation_timestep ()
95 if (ambitus_p_ && isActive)
97 SCM key_signature = get_property ("keySignature");
98 ambitus_p_->set_grob_property ("keySignature", key_signature);
99 typeset_grob (ambitus_p_);
106 Ambitus_engraver::start_translation_timestep ()
114 Ambitus_engraver::create_grobs ()
122 Ambitus_engraver::acknowledge_grob (Grob_info info)
129 Item *item = dynamic_cast <Item *>(info.grob_l_);
132 if (Note_head::has_interface (info.grob_l_))
134 Note_req *nr = dynamic_cast<Note_req*> (info.music_cause ());
137 Pitch pitch = *unsmob_pitch (nr->get_mus_property ("pitch"));
138 if (Pitch::compare (pitch_min, pitch_max) > 0) // already init'd?
140 // not yet init'd; use current pitch to init min/max
143 ambitus_p_->set_grob_property ("pitch-min",
144 pitch_min.smobbed_copy ());
145 ambitus_p_->set_grob_property ("pitch-max",
146 pitch_max.smobbed_copy ());
148 else if (Pitch::compare (pitch, pitch_max) > 0) // new max?
151 ambitus_p_->set_grob_property ("pitch-max",
152 pitch_max.smobbed_copy ());
154 else if (Pitch::compare (pitch, pitch_min) < 0) // new min?
157 ambitus_p_->set_grob_property ("pitch-min",
158 pitch_min.smobbed_copy ());
166 Ambitus_engraver::create_ambitus ()
168 SCM basicProperties = get_property ("Ambitus");
169 SCM c0 = get_property ("centralCPosition");
170 ambitus_p_ = new Item (basicProperties); isActive = 1;
171 ambitus_p_->set_grob_property ("centralCPosition", c0);
172 announce_grob (ambitus_p_, SCM_EOL);
175 ENTER_DESCRIPTION(Ambitus_engraver,
177 /* creats*/ "Ambitus",
178 /* acks */ "note-head-interface",