Engine sound and code clean-up

1 files changed, 13 insertions, 4 deletions

diff --git a/turbo/vehicles.scm b/turbo/vehicles.scm
index 62b6a02..68d6ced 100644
--- a/turbo/vehicles.scm
+++ b/turbo/vehicles.scm
@@ -12,12 +12,14 @@
 	    vehicle-position
 	    vehicle-speed
 	    vehicle-active?
+	    vehicle-inactive?
 	    set-vehicle-position!
 	    set-vehicle-speed!
 	    set-vehicle-active!
 	    vehicle-hitbox
 	    vehicle-safety-distance?
-	    vehicle-speed-diff))
+	    vehicle-speed-diff
+	    vehicle-move!))
 
 (define vehicle-height 45)
 (define vehicle-length 100)
@@ -44,9 +46,16 @@
 (define (vehicle-safety-distance? vehicle1 vehicle2)
   (let ((vehicle1-x (vec2-x (vehicle-position vehicle1)))
 	(vehicle2-x (vec2-x (vehicle-position vehicle2))))
-    (> vehicle2-x
-       (+ (* 3 vehicle-length)
-	  vehicle1-x))))
+    (> (abs (- vehicle2-x vehicle1-x))
+       (+ (* 3 vehicle-length)))))
 
 (define (vehicle-speed-diff vehicle1 vehicle2)
   (abs (- (vehicle-speed vehicle1) (vehicle-speed vehicle2))))
+
+(define (vehicle-move! vehicle translation)
+  (set-vehicle-position!
+   vehicle
+   (vec2+ (vehicle-position vehicle) translation)))
+
+(define (vehicle-inactive? vehicle)
+  (not (vehicle-active? vehicle)))