2 ambitus-engraver.cc -- implement Ambitus_engraver
4 source file of the GNU LilyPond music typesetter
6 (c) 2002--2003 Juergen Reuter <reuter@ipd.uka.de>
11 #include "note-head.hh"
12 #include "staff-symbol-referencer.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" event 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" event and the next one (or the end of the
52 * piece, if there is no more such event). To be compliant with the
53 * current implementation, we might implicitly assume an "\ambitus"
54 * event 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 process_music ();
68 virtual void acknowledge_grob (Grob_info
);
69 virtual void stop_translation_timestep ();
70 virtual void finalize ();
73 void create_ambitus ();
75 int/*bool*/ is_typeset
;
76 Pitch pitch_min
, pitch_max
;
79 Ambitus_engraver::Ambitus_engraver ()
85 * (pitch_min > pitch_max) means that pitches are not yet
88 pitch_min
= Pitch (0, 0, SHARP
);
89 pitch_max
= Pitch (0, 0, FLAT
);
93 Ambitus_engraver::process_music ()
96 * Ensure that ambitus is created in the very first timestep (on
97 * which lily does not call start_translation_timestep ()).
98 * Otherwise, if a voice begins with a rest, the ambitus grob will
99 * be placed after the rest.
107 Ambitus_engraver::stop_translation_timestep ()
109 if (ambitus_
&& !is_typeset
)
112 * Evaluate centralCPosition not until now, since otherwise we
113 * may then oversee a clef that is defined in a staff context if
114 * we are in a voice context; centralCPosition would then be
117 SCM c0
= get_property ("centralCPosition");
118 ambitus_
->set_grob_property ("c0-position", c0
);
121 * Similar for keySignature.
123 SCM key_signature
= get_property ("keySignature");
124 ambitus_
->set_grob_property ("accidentals", key_signature
);
126 typeset_grob (ambitus_
);
132 Ambitus_engraver::acknowledge_grob (Grob_info info
)
134 Item
*item
= dynamic_cast <Item
*>(info
.grob_
);
137 if (Note_head::has_interface (info
.grob_
))
139 Music
*nr
= info
.music_cause ();
140 if (nr
&& nr
->is_mus_type ("note-event"))
142 Pitch pitch
= *unsmob_pitch (nr
->get_mus_property ("pitch"));
143 if (Pitch::compare (pitch_min
, pitch_max
) > 0) // already init'd?
145 // not yet init'd; use current pitch to init min/max
149 else if (Pitch::compare (pitch
, pitch_max
) > 0) // new max?
153 else if (Pitch::compare (pitch
, pitch_min
) < 0) // new min?
163 Ambitus_engraver::create_ambitus ()
165 SCM basicProperties
= get_property ("Ambitus");
166 ambitus_
= new Item (basicProperties
); is_typeset
= 0;
167 announce_grob (ambitus_
, SCM_EOL
);
171 Ambitus_engraver::finalize ()
175 if (Pitch::compare (pitch_min
, pitch_max
) <= 0)
177 ambitus_
->set_grob_property ("pitch-min",
178 pitch_min
.smobbed_copy ());
179 ambitus_
->set_grob_property ("pitch-max",
180 pitch_max
.smobbed_copy ());
182 else // have not seen any pitch, so forget about the ambitus
185 * Do not print a warning on empty ambitus range, since this
186 * most probably arises from an empty voice, such as shared
187 * global timesig/clef definitions.
190 ambitus_
->warning("empty ambitus range [ignored]");
197 ENTER_DESCRIPTION(Ambitus_engraver
,
199 /* creats*/ "Ambitus",
201 /* acks */ "note-head-interface",