diff options
| -rw-r--r-- | examples/rewrite-test.scm | 29 |
1 files changed, 15 insertions, 14 deletions
diff --git a/examples/rewrite-test.scm b/examples/rewrite-test.scm index 311e747..3582174 100644 --- a/examples/rewrite-test.scm +++ b/examples/rewrite-test.scm @@ -1,6 +1,7 @@ (use-modules (srfi srfi-1) (2d color) (2d game) + (2d keyboard) (2d signals) (2d sprite) (2d texture) @@ -11,34 +12,34 @@ (with-window (make-window #:title "FRP is cool" #:resolution (vector2 640 480) #:fullscreen? #f) - + ;; Move when arrow keys are pressed. (define move (make-signal #:init (vector2 320 240) #:transformer (lambda (value old from) - (if (eq? from arrows) - old - (v+ (vscale (signal-ref arrows) 5) - old))) - #:connectors (list arrows (time-every)))) + (v+ (vscale (signal-ref key-arrows) 4) old)) + #:filter (lambda (value old from) + (not (eq? from key-arrows))) + #:connectors (list key-arrows (time-every)))) (define ghost-texture (load-texture "images/ghost.png")) - (define sprite - (make-sprite ghost-texture - #:position move)) + (define ghost (make-sprite ghost-texture #:position move)) (define follower-count 8) + (define followers (list-tabulate follower-count (lambda (i) (make-sprite ghost-texture - #:position (time-delay (* (- follower-count i) 1) move) - #:color (make-color 1 1 1 (/ (1+ i) 16)))))) + ;; Follow ghost with some delay. + #:position (time-delay (* (- follower-count i) 10) move) + ;; Make each ghost more translucent than the last. + #:color (let ((alpha (/ (1+ i) + (* 2 follower-count)))) + (make-color 1 1 1 alpha)))))) - ;; Temporary hack. There shouldn't be side effects like this in - ;; signals. (define quit-on-esc (signal-lift (lambda (down?) (when down? @@ -47,6 +48,6 @@ (define (draw) (for-each draw-sprite followers) - (draw-sprite sprite)) + (draw-sprite ghost)) (run-game #:draw draw)) |