aid for counting repeated measures. There is no requirement that the
affected measures be repeated, however. The user delimits the area to
receive a count with @code{\\startMeasureCount} and
-@code{\\stopMeasureCount}.
-
-Each element of a count is a spanner, and a count is thus a series of
-spanners. Each spanner is bounded by the first @code{CommandColumn} of
-successive measures, and boundaries are shared by adjoining spanners."
+@code{\\stopMeasureCount}."
(let ((count-spanner '()) ; a single element of the count
(go? #f) ; is the count in progress?
(stop? #f) ; do we end the count?
(last-measure-seen 0)
- (new-measure? #f)
(elapsed 0))
(make-engraver
- (listeners ((measure-counter-event engraver event)
- (set! last-measure-seen (ly:context-property context 'currentBarNumber))
- (set! new-measure? #t)
+ (listeners
+ ((measure-counter-event engraver event)
(cond
((and (= START (ly:event-property event 'span-direction))
go?)
- (begin
- (set! stop? #t)
- (ly:input-warning
- (ly:event-property event 'origin)
- "count not ended before another begun")))
+ (set! stop? #t)
+ (ly:input-warning
+ (ly:event-property event 'origin)
+ "count not ended before another begun"))
((= START (ly:event-property event 'span-direction))
- (set! go? #t))
+ (set! go? #t)
+ ;; initialize one less so first measure receives a count spanner
+ (set! last-measure-seen
+ (1- (ly:context-property context 'currentBarNumber))))
((= STOP (ly:event-property event 'span-direction))
- (begin
- (set! stop? #t)
- (set! go? #f))))))
+ (set! stop? #t)
+ (set! go? #f)))))
- ((process-music trans)
- (let ((col (ly:context-property context 'currentCommandColumn))
- (now (ly:context-property context 'measurePosition))
- (current-bar (ly:context-property context 'currentBarNumber)))
- ;; If the counter has been started, make sure we're in a new bar
- ;; before finishing a count-spanner and starting a new one.
- ;; Since we consider all CommandColumns encountered, we need this
- ;; check so that a count-spanner is not created for each pair.
- (if (and (ly:grob? count-spanner)
- (> current-bar last-measure-seen))
- (set! new-measure? #t))
- (if new-measure?
- (begin
- ;; Check if we have the first column of the measure.
- ;; The possibility of initial grace notes is considered.
- (if (moment<=? now ZERO-MOMENT)
- (begin
- ;; If we have the first column, finish the previous
- ;; counter-spanner (if there is one).
- (if (ly:grob? count-spanner)
- (begin
- (ly:spanner-set-bound! count-spanner RIGHT col)
- (ly:pointer-group-interface::add-grob count-spanner 'columns col)
- (ly:engraver-announce-end-grob trans count-spanner col)
- (set! count-spanner '())))
- ;; if count is over, reset variables
- (if stop?
- (begin
- (set! elapsed 0)
- (set! stop? #f)))
- ;; if count is in progress, begin a counter object
- (if go?
- (let* ((c (ly:engraver-make-grob trans 'MeasureCounter col))
- (counter (ly:grob-property c 'count-from)))
- (ly:spanner-set-bound! c LEFT col)
- (ly:pointer-group-interface::add-grob c 'columns col)
- (set! (ly:grob-property c 'count-from) (+ counter elapsed))
- (set! count-spanner c)
- (set! elapsed (1+ elapsed))))
- (set! new-measure? #f)))))
- (set! last-measure-seen current-bar)))
+ ((process-music trans)
+ (let ((col (ly:context-property context 'currentCommandColumn))
+ (now (ly:context-property context 'measurePosition))
+ (current-bar (ly:context-property context 'currentBarNumber)))
+ ;; Each measure of a count receives a new spanner, which is bounded
+ ;; by the first "command column" of that measure and the following one.
+ ;; The possibility of initial grace notes (negative measure position)
+ ;; is considered.
+ (if (and (> current-bar last-measure-seen)
+ (moment<=? now ZERO-MOMENT))
+ (begin
+ ;; Finish the previous count-spanner if there is one.
+ (if (ly:grob? count-spanner)
+ (begin
+ (ly:spanner-set-bound! count-spanner RIGHT col)
+ (ly:pointer-group-interface::add-grob count-spanner 'columns col)
+ (ly:engraver-announce-end-grob trans count-spanner col)
+ (set! count-spanner '())))
+ ;; If count is over, reset variables.
+ (if stop?
+ (begin
+ (set! elapsed 0)
+ (set! stop? #f)))
+ ;; If count is in progress, begin a count-spanner.
+ (if go?
+ (let* ((c (ly:engraver-make-grob trans 'MeasureCounter col))
+ (counter (ly:grob-property c 'count-from)))
+ (ly:spanner-set-bound! c LEFT col)
+ (ly:pointer-group-interface::add-grob c 'columns col)
+ (set! (ly:grob-property c 'count-from) (+ counter elapsed))
+ (set! count-spanner c)
+ (set! elapsed (1+ elapsed))))))
+ (set! last-measure-seen current-bar)))
- ((finalize trans)
- (if go?
- (begin
- (set! go? #f)
- (ly:grob-suicide! count-spanner)
- (set! count-spanner '())
- (ly:warning "measure count left unfinished")))))))
+ ((finalize trans)
+ (if go?
+ (begin
+ (set! go? #f)
+ (ly:grob-suicide! count-spanner)
+ (set! count-spanner '())
+ (ly:warning "measure count left unfinished")))))))
projects / lilypond.git / blobdiff