1 \input texinfo @c -*-texinfo-*- vim:tw=72
2 @setfilename regression-test.info
3 @settitle LilyPond Regression test
7 @author Han-Wen Nienhuys and Jan Nieuwenhuizen
8 @title LilyPond Regression test
15 This document tries give an brief overview of LilyPond features. When
16 the text correspond with the shown notation, we consider LilyPond
17 Officially BugFree (tm). This document is intended for finding bugs,
18 and documenting bugfixes.
20 @section Notes and rests
22 Rests. Note that the dot of 8th, 16th and 32nd rests rest should be
23 next to the top of the rest. All rests except the whole rest are
24 centered on the middle staff line.
28 Note head shapes are settable. The stem endings should be adjusted
29 per note head. If you want different note head styles on one stem,
30 you must create a special context called Thread.
32 Harmonic notes have a different shape and different
33 dimensions. Nevertheless, noteheads in both styles can be combined, on
34 either up or down stems.
36 @mudelafile{noteheadstyle.ly}
38 Noteheads can have dots, and rests can too. Augmentation dots should
39 never be printed on a staff line, but rather be shifted vertically. They
40 should go up, but in case of multiple parts, the down stems have down
41 shifted dots. (Wanske p. 186) In case of chords, all dots should be in
42 a column. The dots go along as rests are shifted to avoid collisions.
46 Multiple measure rests do not collide with barlines and clefs. They
47 are not expanded when you set @code{Score.skipBars}. Although the
48 multi-measure-rest is a Spanner, minimum distances are set to keep it
49 colliding from barlines.
51 @mudelafile{multi-measure-rest.ly}
53 If @code{Score.skipBars} is set,
54 the signs for four, two, and one measure rest are combined to
55 produce the graphical representation of rests for up to 10 bars.
56 The number of bars will be written above the sign.
58 @mudelafile{mm-rests2.ly}
60 A sharp sign after a double sharp sign, as well as a flat sign
61 after a double flat sign is automatically prepended with a
64 @mudelafile{double-single-acc.ly}
68 Stem tremolos or rolls are tremolo signs that look like beam segments
69 crossing stems. If the stem is in a beam, the tremolo must be parallel
70 to the beam. If the stem is invisible (eg. on a whole note), the
71 tremolo must be centered on the note.
73 @mudelafile{stem-tremolo.ly}
75 Chord tremolos look like beams, but are a kind of repeat symbol.
76 To avoid confusion, chord tremolo beams do not reach the stems, but
77 leave a gap. Chord tremolo beams on half notes are not ambiguous,
78 as half notes cannot appear in a regular beam, and should reach the
81 @mudelafile{chord-tremolo.ly}
83 Beams, stems and noteheads often have communication troubles, since
84 the two systems for y dimensions (1 unit = staffspace, 1 unit = 1
87 Stems, beams, ties and slurs should behave similarly, when placed
88 on the middle staff line. Of course stem-direction is down for high
89 notes, and up for low notes.
91 @mudelafile{stem-direction.ly}
93 Similarly, if @code{stem_default_neutral_direction} is set to @code{-1}.
95 @mudelafile{stem-direction-down.ly}
99 The staccato dot (and all scripts with follow-into-staff set), must
100 not be on staff lines.
102 @mudelafile{staccato-pos.ly}
106 Chord names are generated from a list pitches, and are customisable
107 from guile. For some unlogical names, guile customisation is used
110 @mudelafile{chord-names.ly}
114 Grace notes are typeset as an encapsulated piece of music. You can
115 have beams, notes, chords, stems etc. within a @code{\grace} section.
116 Slurs that start within a grace section, but aren't ended are attached
117 to the next normal note. Grace notes have zero duration. If there
118 are tuplets, the grace notes won't be under the brace. Grace notes
119 can have accidentals, but they are (currently) spaced at a fixed
120 distance. Grace notes (of course) come before the accidentals of the
121 main note. Grace notes can also be positioned after the main note.
123 Grace notes without beams should have a slash, if @code{flagStyle} is
124 not set. Main note scripts don't end up on the grace note.
126 @mudelafile{grace.ly}
129 @section Beams, slurs and other spanners
131 Beaming is generated automatically. Beams may cross bar lines. In that
132 case, line breaks are forbidden. Yet clef and key signatures are
133 hidden just as with breakable bar lines.
135 @mudelafile{beaming.ly}
137 Beams should behave reasonably well, even under extreme circumstances.
138 Stems may be short, but noteheads should never touch the beam.
140 @mudelafile{beam-extreme.ly}
142 Beams should always reach the middle staff line. The second beam
143 counting from the note head side, should never be lower than the
144 second staff line. This does not hold for grace note beams.
145 Override with @code{noStemExtend}.
147 @mudelafile{beam-position.ly}
149 Slurs should look nice and symmetric. The curvature may increase
150 only to avoid noteheads, and as little as possible.
152 @mudelafile{slur-symmetry.ly}
153 @mudelafile{slur-symmetry-1.ly}
155 Ties are strictly horizontal. They are placed in between note heads.
156 The horizontal middle should not overlap with a staffline.
160 When tieing chords, the outer slurs point outwards, the inner slurs
161 point away from the center of the staff. Override with
162 @code{tieVerticalDirection}.
164 @mudelafile{tie-chord.ly}
166 When tieing notes with accidentals across a bar boundary, the accidental
167 must not be drawn on the note in the new bar. Instead, the next note of
168 the same pitch in this bar should always show the accidental (even if
169 it's natural). Slurring a accidentaled note to a natural one across bar
170 boundaries should be explicit.
172 Pitches can be verified by printing them with the @code{NoteNames} context.
174 @mudelafile{tie-accidental.ly}
176 Beams can be typeset over fixed distance aligned staffs, beam
177 beautification doesn't really work, but knees do. Beams should be
178 behave well, wherever the switching point is.
180 @mudelafile{beam-cross-staff.ly}
182 The same goes for slurs. They behave decently when broken across
185 @mudelafile{slur-cross-staff.ly}
187 Tuplets are indicated by a bracket with a number. There should be no
188 bracket if there is one beam that matches the length of the tuplet.
189 The bracket does not interfere with the stafflines, and the number is
190 centered in the gap in the bracket.
194 @section Property details
196 More specific settings take precendence over less specific settings. The
197 second slur has slurDirection set to down, overriding the stemup setting.
199 @mudelafile{generic-property-override.ly}
203 LilyPond has three modes for repeats: folded, unfolded and
204 semi-unfolded. Unfolded repeats are fully written out. Semi unfolded
205 repeats have the body written and all alternatives sequentially.
206 Folded repeats have the body written and all alternatives
207 simultaneo.ly. If the number of alternatives is larger than the
208 repeat count, the excess alternatives are ignored. If the number of
209 alternatives is smaller, the first alternative is multiplied to get to
210 the number of repeats.
214 @mudelafile{repeat-unfold.ly}
216 Volta (Semi folded) behavior. Voltas can start on non-barline moments.
217 If they don't barlines should still be shown.
219 @mudelafile{repeat-volta.ly}
221 Folded. This doesn't make sense without alternatives, but it works.
223 @mudelafile{repeat-fold.ly}
225 Across linebreaks, the left edge of a first and second alternative
226 bracket should be equal
228 @mudelafile{repeat-line-break.ly}
234 Lyrics can be set to a melody automatically. Excess lyrics will be
235 dumped. Lyrics will not be set over rests. You can have melismata
236 either by setting a property melismaBusy, or by setting
237 automaticMelismas (which will set melismas during slurs and ties). If
238 you want a different order than first Music, then Lyrics, you must
239 precook a chord of staffs/lyrics and label those. Of course
240 @code{\rhythm} ignores any other rhythms in the piece. Hyphens and
241 extenders do not assume anything about lyric lengths, so they continue
244 @mudelafile{lyric-combine.ly}
246 @section Multiple notes
248 Rests should not collide with beams, stems and noteheads. Rests may
249 be under beams. Rests should be move by integral number of spaces
250 inside the staff, and by half spaces outside. Notice that the half
251 and whole rests just outside the staff get ledger lines in different
254 @mudelafile{rest-collision.ly}
256 Normal collisions. We have support for polyphony, where the
257 middle voices are horizontally shifted.
259 @mudelafile{collisions.ly}
261 The number of stafflines of a staff can be set with the property
262 numberOfStaffLines. Ledger lines both on note heads and rests are
263 adjusted. Barlines also are adjusted.
266 @mudelafile{number-staff-lines.ly}
270 In a limited number of cases, LilyPond corrects for optical spacing
271 effects. In this example, space for opposite pointed stems is adjusted
273 @mudelafile{stem-spacing.ly}
275 If there are accidentals in the music, we add space, but the space
276 between note and accidentals is less than between the notes with the
277 same value. Clef changes also get extra space, but not as much as
281 Even if a line is very tightly spaced, there will still be room
282 between prefatory matter and the following notes. The space after the
283 prefatory is very rigid. In contrast, the space before the barline
284 must stretch like the space within the measure.
288 @mudelafile{spacing-tight.ly}
292 @mudelafile{spacing-natural.ly}
296 @mudelafile{spacing-loose.ly}
298 Adding a @code{Bar_engraver} to the LyricsVoice context makes sure that
299 lyrics don't collide with barlines.
301 @mudelafile{lyrics-bar.ly}
303 @section Global stuff
305 Breaks can be encouraged and discouraged using @code{\break} and
306 @code{\nobreak}. They are abbrevs for @code{\penalty} commands.
308 @mudelafile{break.ly}
311 Markings that are attached to (invisible) barlines are
312 delicate: the are attached to the rest of the score without the score
313 knowing it. Consequently, they fall over often.
315 @mudelafile{bar-scripts.ly}
317 Staff margins are also markings attached to barlines. They should be
318 left of the staff, and be centered vertically wrt the staff. They may
319 be on normal staffs, but also on compound staffs, like the PianoStaff
321 @mudelafile{staff-margin.ly}
323 Breathing signs, also used for phrasing, do normally not influence
324 global spacing -- only if space gets tight, notes are shifted to make
325 room for the breathing sign. Breathing signs break beams running
326 through their voice. In the following example, the notes in the first
327 two measures all have the same distance from each other:
329 @mudelafile{breathing-sign.ly}
331 Fonts are available in a default set of sizes: 11, 13, 16, 20, 23 and
332 26pt staffheight. Sizes of the text fonts and symbol fonts are made
333 to match the staff dimensions.
335 @mudelafile[nofly]{size11.ly}
337 @mudelafile[nofly]{size13.ly}
339 @mudelafile[nofly]{size16.ly}
341 @mudelafile[nofly]{size20.ly}
343 @mudelafile[nofly]{size23.ly}
345 @mudelafile[nofly]{size26.ly}
348 @section Clefs and Time Signatures
350 The transparent clef should not occupy any space and with style
351 @code{fullSizeChanges}, the changing clef should be typeset in full
352 size. For octaviated clefs, the ``8'' should appear closely above or
353 below the clef respectively. The ``8'' is processed in a convoluted
354 way, so this is fragile as well.
356 @mudelafile{clefs.ly}
359 Key signatures appear on key changes. They may also
360 appear without barlines. The restoration accidentals are not printed at
361 the start of the line. If @code{createKeyOnClefChange} is set, they're
362 also created on a clef change.
367 @c the input file is too long and does not test for specific bugs
369 By default, time signatures are written with two numbers. With style
370 ``C'', 4/4 and 2/2 are written with their corresponding symbols and
371 with style ``old'', 2/2, 3/2, 2/4, 3/4, 4/4, 6/4, 9/4, 4/8, 6/8 and
372 9/8 are typeset with symbols, all other signatures retain the default
373 layout. The style ``1'', gives single number signatures for all
376 \mu delafile{time.ly}
381 @section Hacks and Features
383 As a last resort, the placement of items can be adjusted manually, by
384 setting the @code{extra-offset} of an output object.
386 @mudelafile{generic-output-property.ly}