-(define draw-asteroid
- (let ((asteroid (load-texture "Asteroid.png")))
- (lambda (a)
- (to-origin)
- (translate (assoc-ref a 'x) (assoc-ref a 'y))
- (rotate (assoc-ref a 'angle))
- (draw-texture asteroid))))
-
-(define (move-asteroid a)
- (let* ((x (assoc-ref a 'x)) (y (assoc-ref a 'y))
- (angle (assoc-ref a 'angle))
- (vx (assoc-ref a 'vx)) (vy (assoc-ref a 'vy)))
- (set! x (+ x vx))
- (set! y (+ y vy))
- (cond ((> x max-x) (set! vx -1))
- ((< x min-x) (set! vx 1)))
- (cond ((> y max-y) (set! vy -1))
- ((< y min-y) (set! vy 1)))
-
- (assoc-multiple-set! a 'x x 'y y 'angle (+ angle 1) 'vx vx 'vy vy)))
-
-(define draw-ship
- (let ((ship1 (load-texture "Ship1.png"))
- (ship2 (load-texture "Ship2.png")))
- (lambda (s)
- (to-origin)
- (translate (assoc-ref s 'x) (assoc-ref s 'y))
- (rotate (assoc-ref s 'angle))
- (let ((ship (if (assoc-ref s 'moving) ship2 ship1)))
- (draw-texture ship)))))
-
-(define (move-ship s)
- (let ((x (assoc-ref s 'x)) (y (assoc-ref s 'y))
- (angle (assoc-ref s 'angle))
- (moving (assoc-ref s 'moving)))
- (cond ((key? 'left) (set! angle (+ angle 5)))
- ((key? 'right) (set! angle (- angle 5))))
- (cond ((key? 'up)
- (let ((r (degrees-to-radians (- angle))))
- (set! x (+ x (* 4 (sin r))))
- (set! y (+ y (* 4 (cos r)))))
- (cond ((> x max-x) (set! x min-x))
- ((< x min-x) (set! x max-x)))
- (cond ((> y max-y) (set! y min-y))
- ((< y min-y) (set! y max-y)))
- (set! moving #t))
- (else
- (set! moving #f)))
-
- (assoc-multiple-set! s 'x x 'y y 'angle angle 'moving moving)))
-
-(define (ship-shot s)
- (cond ((key-pressed? 'space)
- `((x . ,(assoc-ref s 'x)) (y . ,(assoc-ref s 'y)) (angle . ,(assoc-ref s 'angle))))
+
+;;; Asteroids
+
+(define-checking-mobs (asteroid-shots x y size) (shot (sx x) (sy y))
+ (if (< (distance-between-points (list sx sy) (list x y)) size) 1 0))
+
+(define (asteroid-killed? x y size)
+ (> (apply + (asteroid-shots x y size)) 0))
+
+(define-mob (asteroid
+ (image (load-texture "Asteroid.png"))
+ (x 0) (y 0) (angle 0) (dir 0) (size 100))
+ (cond ((asteroid-killed? x y size)
+ (kill-me))