diff options
| author | Thomas White <taw@physics.org> | 2021-05-10 20:54:53 +0200 |
|---|---|---|
| committer | Thomas White <taw@physics.org> | 2021-05-10 20:56:02 +0200 |
| commit | 1fa25deedd48440dd17521f5e7d41a3e69bd3743 (patch) | |
| tree | 6c1a7820c0fcf9c74253d2e3a28c6c8a78e538a5 | |
| parent | 0acf5d8958fae9ef959b9bae4917c656081189ef (diff) | |
Run cues as single atomic operations
This avoids a potential situation where one parameter of a fixture is
reconfigured before another, which could (in theory) lead to flickering
of lights.
| -rw-r--r-- | guile/starlet/playback.scm | 11 | ||||
| -rw-r--r-- | guile/starlet/state.scm | 20 |
2 files changed, 26 insertions, 5 deletions
diff --git a/guile/starlet/playback.scm b/guile/starlet/playback.scm index c09e69b..f9f621f 100644 --- a/guile/starlet/playback.scm +++ b/guile/starlet/playback.scm @@ -522,7 +522,8 @@ (let ((this-cue-state (calculate-tracking (get-playback-cue-list pb) cue-index)) (next-cue-state (calculate-tracking (get-playback-cue-list pb) (+ cue-index 1))) (the-cue (vector-ref (get-playback-cue-list pb) cue-index)) - (tnow (hirestime))) + (tnow (hirestime)) + (overlay-state (make-empty-state))) (for-each (lambda (fix-attr) @@ -537,7 +538,7 @@ (if (intensity? attr) ;; Intensity attribute - (set-in-state! pb fix attr + (set-in-state! overlay-state fix attr (make-intensity-fade start-val target-val fade-times @@ -558,7 +559,7 @@ (fade-start-time (+ tnow (get-fade-attr-delay fade-times))) (preset-start-time (+ tnow (calc-preset-start-time fix the-cue)))) - (set-in-state! pb fix attr + (set-in-state! overlay-state fix attr (make-fade-func start-val target-val preset-val @@ -570,7 +571,9 @@ ;; Add the next cue to list of states to look at, only if it exists) (if next-cue-state (fix-attrs-involved pb this-cue-state next-cue-state) - (fix-attrs-involved pb this-cue-state))))) + (fix-attrs-involved pb this-cue-state))) + + (atomically-overlay-state! pb overlay-state))) (define (print-playback pb) diff --git a/guile/starlet/state.scm b/guile/starlet/state.scm index 13888e8..a889d0c 100644 --- a/guile/starlet/state.scm +++ b/guile/starlet/state.scm @@ -48,7 +48,8 @@ blackout sel selection-hook - value->number)) + value->number + atomically-overlay-state!)) ;; A "state" is an atomically-updating container for an immutable @@ -231,6 +232,23 @@ pre-existing contents." (state-for-each at state)) +(define (atomically-overlay-state! state newbits) + "Apply 'newbits' within 'state', as a single atomic operation." + (let* ((old-ht (atomic-box-ref (get-ht-box state))) + (new-ht (copy-hash-table old-ht))) + (state-for-each (lambda (fix attr val) + (hash-set! new-ht + (cons fix attr) + val)) + newbits) + (unless (eq? (atomic-box-compare-and-swap! + (get-ht-box state) + old-ht + new-ht) + old-ht) + (atomically-overlay-state! state newbits)))) ;; Try again + + (define current-state (make-parameter programmer-state)) |