From e99551161b1199fcd068dce0f7b0fd2f3927e771 Mon Sep 17 00:00:00 2001
From: jsancho <devnull@localhost>
Date: Fri, 26 Aug 2011 17:34:06 +0000
Subject: [PATCH]

---
 games/asteroids/Ship2.png     | Bin 406 -> 403 bytes
 games/asteroids/asteroids.scm |  49 ++++++++++++++++++++++++----------
 src/gacela_misc.scm           |  11 ++++++++
 3 files changed, 46 insertions(+), 14 deletions(-)

diff --git a/games/asteroids/Ship2.png b/games/asteroids/Ship2.png
index 2a360963d32226f52cc4978873d3628e74bafacd..87189e6ca0aaa39ef57b677e68edcd3649f0033c 100644
GIT binary patch
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delta 320
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diff --git a/games/asteroids/asteroids.scm b/games/asteroids/asteroids.scm
index 6d477e5..283333f 100644
--- a/games/asteroids/asteroids.scm
+++ b/games/asteroids/asteroids.scm
@@ -1,8 +1,8 @@
 (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
@@ -10,38 +10,59 @@
     (lambda (a)
       (to-origin)
       (translate (car a) (cadr a))
+      (rotate (caddr a))
       (draw-texture asteroid))))
 
 (define (move-asteroid a)
   (let* ((x (car a)) (y (cadr a))
-	 (vx (caddr a)) (vy (cadddr a))
+	 (angle (caddr a))
+	 (vx (cadddr a)) (vy (cadddr (cdr 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)))
+    (set! angle (+ angle 1))
+    (list (+ x vx) (+ y vy) angle vx 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)))))
+	   (set! moving #t))
+	  (else
+	   (set! moving #f)))
+    `((x . ,x) (y . ,y) (angle . ,angle) (moving . ,moving))))
 
-(let ((asteroids '((100 100 1 1) (-100 -100 -1 1)))
-      (ship '(0 0 0 0 0)))
+(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 (list (xy max-x 20) (xy max-y 20) 0 1 1) (make-asteroids (- n 1))))))
+
+(let ((asteroids (make-asteroids 2))
+      (ship '((x . 0) (y . 0) (angle . 0) (moving . #f))))
   (run-game
    (set! asteroids (map move-asteroid asteroids))
    (set! ship (move-ship ship))
diff --git a/src/gacela_misc.scm b/src/gacela_misc.scm
index 42c8841..9dc10aa 100644
--- a/src/gacela_misc.scm
+++ b/src/gacela_misc.scm
@@ -21,6 +21,11 @@
 (use-modules (srfi srfi-1))
 
 
+;;; Constants
+
+(define *pi* (* (asin 1) 2))
+
+
 ;;; Functions
 
 (define (nearest-power-of-two n)
@@ -29,6 +34,12 @@
 	  (else (power (* p 2) n))))
   (power 1 n))
 
+(define (degrees-to-radians angle)
+  (/ (* angle *pi*) 180))
+
+(define (radians-to-degrees angle)
+  (/ (* angle 180) *pi*))
+
 (define-macro (pushnew elem list)
   `(cond ((not (find (lambda (e) (eq? e ,elem)) ,list))
 	  (set! ,list (cons ,elem ,list)))))
-- 
2.39.2