Limit and display car speed

1 files changed, 14 insertions, 10 deletions

diff --git a/turbo.scm b/turbo.scm
index 3c5b194..367b03c 100644
--- a/turbo.scm
+++ b/turbo.scm
@@ -1,7 +1,8 @@
 (use-modules (chickadee graphics sprite)
 	     (chickadee)
 	     (chickadee graphics viewport)
-	     (ice-9 pretty-print))
+	     (ice-9 pretty-print)
+	     (ice-9 format))
 
 (define lane-height 65)
 (define lane-length 200)
@@ -38,10 +39,11 @@
 (define selected-car (texture-atlas-ref vehicles 0))
 
 (define car-pos-x 0.0)
-(define car-speed 4.0)
-(define car-steering 4.0)
+(define car-steering-speed 4.0)
 (define player-velocity (vec2 0 0))
-(define road-velocity 4)
+(define road-min-speed 4)
+(define road-max-speed 20)
+(define road-speed road-min-speed)
 (define road-position 0)
 
 (define player-position
@@ -51,11 +53,13 @@
 
 (define (draw alpha)
   (set! road-position (if (< road-position (* lane-length -1))
-			  (- (+ road-position lane-length) road-velocity)
-			  (- road-position road-velocity)))
+			  (- (+ road-position lane-length) road-speed)
+			  (- road-position road-speed)))
   (draw-road road-position road-start-y 5)
 
   (draw-text "Turbo Racers!" (vec2 260.0 (- (window-height (current-window)) 25)))
+  (draw-text (format #f "Speed: ~smph" (* road-speed 5))
+	     (vec2 450.0 20.0))
 
   (set! player-position (vec2+ player-position player-velocity))
 
@@ -63,13 +67,13 @@
 
 (define (key-press key modifiers repeat?)
   (if (eq? key 'w)
-      (set! player-velocity (vec2 0 car-steering)))
+      (set! player-velocity (vec2 0 car-steering-speed)))
   (if (eq? key 's)
-      (set! player-velocity (vec2 0 (* car-steering -1))))
+      (set! player-velocity (vec2 0 (* car-steering-speed -1))))
   (if (eq? key 'a)
-      (set! road-velocity (- road-velocity 1)))
+      (set! road-speed (max (- road-speed 1) road-min-speed)))
   (if (eq? key 'd)
-      (set! road-velocity (+ road-velocity 1)))
+      (set! road-speed (min (+ road-speed 1) road-max-speed)))
   )
 
 (define (key-release key modifiers)