diff options
Diffstat (limited to 'examples/animation.scm')
| -rw-r--r-- | examples/animation.scm | 61 |
1 files changed, 43 insertions, 18 deletions
diff --git a/examples/animation.scm b/examples/animation.scm index 8aaff2e..6afbf34 100644 --- a/examples/animation.scm +++ b/examples/animation.scm @@ -15,12 +15,14 @@ ;;; along with this program. If not, see ;;; <http://www.gnu.org/licenses/>. -(use-modules (sly utils) +(use-modules (srfi srfi-43) + (sly utils) (sly game) (sly window) (sly signal) (sly math) (sly math rect) + ((sly math transform) #:prefix t:) (sly math tween) (sly math vector) (sly render) @@ -33,31 +35,54 @@ (define sprite* (memoize make-sprite)) (define move* (memoize move)) -(define walk-cycle - (let ((tiles (load-tileset "images/princess.png" 64 64))) - (list->vector - (map (lambda (id) - (sprite* (tileset-ref tiles id))) - '(19 20 21 22 23 24 25 26))))) +(define (make-walk-cycle tiles) + (list->vector + (map (lambda (id) + (sprite* (tileset-ref tiles id))) + '(19 20 21 22 23 24 25 26)))) (define position-tween (tween vlerp (compose ease-linear ease-loop) - (vector2 480 240) (vector2 160 240) 120)) + (vector2 640 240) (vector2 0 240) 90)) -(define frame-tween - (let* ((frame-count (vector-length walk-cycle)) - (frame-rate (/ 60 frame-count))) - (tween (compose floor lerp) (compose ease-linear ease-loop) - 0 frame-count (* frame-count frame-rate)))) +(define (make-frame-tween walk-cycle) + (if (vector-empty? walk-cycle) + (const 0) + (let* ((frame-count (vector-length walk-cycle)) + (frame-rate (/ 60 frame-count))) + (tween (compose floor lerp) (compose ease-linear ease-loop) + 0 frame-count (* frame-count frame-rate))))) (define camera (2d-camera #:area (make-rect 0 0 640 480))) +(define (move/interpolate new old renderer) + (lambda (gfx) + (graphics-model-view-excursion gfx + (lambda (gfx) + (let ((v (vlerp old new (graphics-alpha gfx)))) + (graphics-model-view-mul! gfx (t:translate v)) + (renderer gfx)))))) + +(define (render time walk-cycle frame-tween) + (let* ((frame (vector-ref walk-cycle (frame-tween time)))) + (with-camera camera + (move/interpolate (position-tween time) + (position-tween (1- time)) + (render-sprite frame))))) + +(define-signal walk-cycle + (signal-map-maybe make-walk-cycle + (on-start (load-tileset "images/princess.png" 64 64)))) + +(define-signal time (signal-timer)) + +(define-signal frame-tween + (signal-map-maybe make-frame-tween walk-cycle)) + (define-signal scene - (signal-let ((time (signal-timer))) - (let* ((frame (vector-ref walk-cycle (frame-tween time)))) - (with-camera camera - (move* (position-tween time) - (render-sprite frame)))))) + (signal-map (lambda (render) + (or render render-nothing)) + (signal-map-maybe render time walk-cycle frame-tween))) (with-window (make-window #:title "Animation") (run-game-loop scene)) |