(set-game-properties! #:title "Gacela Asteroids")
-(define max-x (/ (cdr (assoc 'width (get-game-properties))) 2))
+(define max-x (/ (assoc-ref (get-game-properties) 'width) 2))
(define min-x (- max-x))
-(define max-y (/ (cdr (assoc 'height (get-game-properties))) 2))
+(define max-y (/ (assoc-ref (get-game-properties) 'height) 2))
(define min-y (- max-y))
(define draw-asteroid
(let ((asteroid (load-texture "Asteroid.png")))
(lambda (a)
(to-origin)
- (translate (car a) (cadr a))
+ (translate (assoc-ref a 'x) (assoc-ref a 'y))
+ (rotate (assoc-ref a 'angle))
(draw-texture asteroid))))
(define (move-asteroid a)
- (let* ((x (car a)) (y (cadr a))
- (vx (caddr a)) (vy (cadddr a))
- (nx (+ x vx)) (ny (+ y vy)))
- (cond ((> nx max-x) (set! vx -1))
- ((< nx min-x) (set! vx 1)))
- (cond ((> ny max-y) (set! vy -1))
- ((< ny min-y) (set! vy 1)))
- (list (+ x vx) (+ y vy) vx vy)))
+ (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 (car s) (cadr s))
- (rotate (caddr s))
- (draw-texture ship1))))
+ (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 (car s)) (y (cadr s))
- (angle (caddr s))
- (vx (cadddr s)) (vy (cadddr (cdr 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) (set! y (+ y 3))))
- (list x y angle vx vy)))
+ (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))))
+ (else
+ #f)))
+
+(define (draw-shot sh)
+ (to-origin)
+ (translate (assoc-ref sh 'x) (assoc-ref sh 'y))
+ (rotate (assoc-ref sh 'angle))
+ (draw-line 10))
+
+(define (move-shots shots)
+ (cond ((null? shots) '())
+ (else
+ (let* ((sh (car shots))
+ (x (assoc-ref sh 'x)) (y (assoc-ref sh 'y))
+ (angle (assoc-ref sh 'angle))
+ (r (degrees-to-radians (- angle))))
+ (set! x (+ x (* 10 (sin r))))
+ (set! y (+ y (* 10 (cos r))))
+ (cond ((and (<= x max-x)
+ (>= x min-x)
+ (<= y max-y)
+ (>= y min-y))
+ (cons `((x . ,x) (y . ,y) (angle . ,angle))
+ (move-shots (cdr shots))))
+ (else
+ (move-shots (cdr shots))))))))
+
+(define (make-asteroids n)
+ (define (xy n r)
+ (let ((n2 (- (random (* n 2)) n)))
+ (cond ((and (< n2 r) (>= n2 0)) r)
+ ((and (> n2 (- r)) (< n2 0)) (- r))
+ (else n2))))
+
+ (cond ((= n 0) '())
+ (else
+ (cons `((x . ,(xy max-x 20)) (y . ,(xy max-y 20)) (angle . 0) (vx . 1) (vy . 1) (size . 95))
+ (make-asteroids (- n 1))))))
+
+(define (killed-ship? s a)
+ (cond ((null? a) #f)
+ (else
+ (or (< (sqrt (+ (expt (- (assoc-ref s 'x) (assoc-ref (car a) 'x)) 2)
+ (expt (- (assoc-ref s 'y) (assoc-ref (car a) 'y)) 2)))
+ (assoc-ref (car a) 'size))
+ (killed-ship? s (cdr a))))))
+
+(let ((asteroids #f) (ship #f) (shots #f))
+ (define (new-game n)
+ (set! asteroids (make-asteroids n))
+ (set! ship '((x . 0) (y . 0) (angle . 0) (moving . #f)))
+ (set! shots '()))
+
+ (new-game 2)
-(let ((asteroids '((100 100 1 1) (-100 -100 -1 1)))
- (ship '(0 0 0 0 0)))
(run-game
+ (cond ((killed-ship? ship asteroids)
+ (new-game 2)))
(set! asteroids (map move-asteroid asteroids))
(set! ship (move-ship ship))
+ (let ((shot (ship-shot ship)))
+ (cond (shot
+ (set! shots (cons shot shots)))))
+ (set! shots (move-shots shots))
(for-each draw-asteroid asteroids)
+ (for-each draw-shot shots)
(draw-ship ship)))