- (context-spec-music
- (make-apply-context
- (lambda (context)
- (let* ((time-signature-settings
- (ly:context-property context 'timeSignatureSettings))
- (my-base-length
- (base-length fraction time-signature-settings))
- (my-beat-structure
- (if (null? structure)
- (beat-structure my-base-length
- fraction
- time-signature-settings)
- structure))
- (beaming-exception
- (beam-exceptions fraction time-signature-settings))
- (new-measure-length (ly:make-moment num den)))
- (ly:context-set-property!
- context 'timeSignatureFraction fraction)
- (ly:context-set-property!
- context 'baseMoment (ly:make-moment my-base-length))
- (ly:context-set-property!
- context 'beatStructure my-beat-structure)
- (ly:context-set-property!
- context 'beamExceptions beaming-exception)
- (ly:context-set-property!
- context 'measureLength new-measure-length))))
- 'Timing)
- 'Score))))
+ (context-spec-music
+ (make-apply-context
+ (lambda (context)
+ (let* ((time-signature-settings
+ (ly:context-property context 'timeSignatureSettings))
+ (my-base-length
+ (base-length fraction time-signature-settings))
+ (my-beat-structure
+ (if (null? structure)
+ (beat-structure my-base-length
+ fraction
+ time-signature-settings)
+ structure))
+ (beaming-exception
+ (beam-exceptions fraction time-signature-settings))
+ (new-measure-length (ly:make-moment num den)))
+ (ly:context-set-property!
+ context 'timeSignatureFraction fraction)
+ (ly:context-set-property!
+ context 'baseMoment (ly:make-moment my-base-length))
+ (ly:context-set-property!
+ context 'beatStructure my-beat-structure)
+ (ly:context-set-property!
+ context 'beamExceptions beaming-exception)
+ (ly:context-set-property!
+ context 'measureLength new-measure-length))))
+ 'Timing)
+ 'Score)
+ ;; (make-music 'TimeSignatureEvent music) would always
+ ;; create a Bottom context. So instead, we just send the
+ ;; event to whatever context may be currently active. If
+ ;; that is not contained within an existing context with
+ ;; TimeSignatureEngraver at the time \time is iterated, it
+ ;; will drop through the floor which mostly means that
+ ;; point&click and tweaks are not available for any time
+ ;; signatures engraved due to the Timing property changes
+ ;; but without a \time of its own. This is more a
+ ;; "notification" rather than an "event" (which is always
+ ;; sent to Bottom) but we don't currently have iterators for
+ ;; that.
+ (make-apply-context
+ (lambda (context)
+ (ly:broadcast (ly:context-event-source context)
+ (ly:make-stream-event
+ (ly:make-event-class 'time-signature-event)
+ (ly:music-mutable-properties music))))))))
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; Some MIDI callbacks -- is this a good place for them?
+
+(define-public (breathe::midi-length len context)
+ ;;Shorten by half, or by up to a second, but always by a power of 2
+ (let* ((desired (min (ly:moment-main (seconds->moment 1 context))
+ (* (ly:moment-main len) 1/2)))
+ (scale (inexact->exact (ceiling (/ (log desired) (log 1/2)))))
+ (breath (ly:make-moment (expt 1/2 scale))))
+ (ly:moment-sub (ly:make-moment (ly:moment-main len)) breath)))