Start extracting code into modules

2 files changed, 61 insertions, 41 deletions

diff --git a/turbo.scm b/turbo.scm
index 9e16e1f..3497124 100644
--- a/turbo.scm
+++ b/turbo.scm
@@ -4,7 +4,7 @@
 	     (chickadee audio)
 	     (ice-9 pretty-print)
 	     (ice-9 format)
-	     (srfi srfi-9))
+	     (turbo vehicles))
 
 ;;;; Constants and variables
 
@@ -23,9 +23,6 @@
 (define grass (load-image "grass.png"))
 (define grass-height 96)
 
-(define vehicle-height 45)
-(define vehicle-length 100)
-(define vehicle-steering-speed 4.0)
 (define vehicles-sprites (load-tileset "vehicles.png" vehicle-length vehicle-height))
 
 (define player-car (texture-atlas-ref vehicles-sprites 0))
@@ -35,22 +32,10 @@
 (define player-speed (+ player-min-speed 1))
 (define player-rotation 0)
 
-(define red-van (texture-atlas-ref vehicles-sprites 1))
-(define red-van-initial-speed 4)
-(define red-van-speed red-van-initial-speed)
-
 (define music-play? #f)
 (define music-res (load-audio "music.ogg"))
 (define music (make-source #:audio music-res #:loop? #t))
 
-(define-record-type <vehicle>
-  (make-vehicle id sprite position speed active?)
-  vechicle?
-  (id vehicle-id)
-  (sprite vehicle-sprite)
-  (position vehicle-position set-vehicle-position!)
-  (speed vehicle-speed set-vehicle-speed!)
-  (active? vehicle-active? set-vehicle-active!))
 
 (define (calculate-vehicle-position lane)
   (vec2 (window-width (current-window))
@@ -58,15 +43,17 @@
 	    (* 65 (- lane 1))
 	   (/ (- lane-height vehicle-height) 2))))
 
-(define (make-inactive-vehicle id tile)
-  (make-vehicle id tile (calculate-vehicle-position (+ 1 (random 5))) 4 #f))
+(define (random-lane-start-pos)
+  (calculate-vehicle-position (+ 1 (random road-num-lanes))))
 
 (define (make-vehicle-list vehicle-list tile-ref)
   (if (< tile-ref (texture-atlas-size vehicles-sprites))
       (cons (make-inactive-vehicle (* 2 tile-ref)
-				   (texture-atlas-ref vehicles-sprites tile-ref))
+				   (texture-atlas-ref vehicles-sprites tile-ref)
+				   (random-lane-start-pos))
 	    (cons (make-inactive-vehicle (+ 1 (* 2 tile-ref))
-					 (texture-atlas-ref vehicles-sprites tile-ref))
+					 (texture-atlas-ref vehicles-sprites tile-ref)
+					 (random-lane-start-pos))
 		  (make-vehicle-list vehicle-list (+ tile-ref 1))))
       vehicle-list))
 
@@ -74,13 +61,6 @@
 
 (define game-over #f)
 
-(define (vehicle-safety-distance? vehicle1 vehicle2)
-  (let ((vehicle1-x (vec2-x (vehicle-position vehicle1)))
-	(vehicle2-x (vec2-x (vehicle-position vehicle2))))
-    (> vehicle2-x
-       (+ (* 2 vehicle-length)
-	  vehicle1-x))))
-
 (define (vehicle-has-spawn-space? vehicle)
   (let loop ((vehicles vehicles))
     (let ((other-vehicle (car vehicles))
@@ -149,9 +129,6 @@
       (off-road-player-top)
       (off-road-player-bottom)))
 
-(define (vehicle-hitbox vehicle-pos)
-  (rect (vec2-x vehicle-pos) (vec2-y vehicle-pos) vehicle-length vehicle-height))
-
 (define (player-collides?)
   (let ((player-hitbox (vehicle-hitbox player-position)))
     (let loop ((vehicles vehicles))
@@ -236,17 +213,17 @@
   
 
 (define (key-press key modifiers repeat?)
-  (if (eq? key 'w)
-      (set! player-velocity (vec2 0 vehicle-steering-speed)))
-  (if (eq? key 's)
-      (set! player-velocity (vec2 0 (* vehicle-steering-speed -1))))
-  (if (eq? key 'a)
-      (set! player-speed (max (- player-speed 1) player-min-speed)))
-  (if (eq? key 'd)
-      (set! player-speed (min (+ player-speed 1) player-max-speed)))
-  (if (eq? key 'escape)
-      (abort-game))
-  )
+  (cond
+   ((eq? key 'w)
+    (set! player-velocity (vec2 0 vehicle-steering-speed)))
+   ((eq? key 's)
+    (set! player-velocity (vec2 0 (* vehicle-steering-speed -1))))
+   ((eq? key 'a)
+       (set! player-speed (max (- player-speed 1) player-min-speed)))
+   ((eq? key 'd)
+       (set! player-speed (min (+ player-speed 1) player-max-speed)))
+   ((eq? key 'escape)
+       (abort-game))))
 
 (define (key-release key modifiers)
   (if (or (eq? key 'w) (eq? key 's))
diff --git a/turbo/vehicles.scm b/turbo/vehicles.scm
new file mode 100644
index 0000000..618d808
--- /dev/null
+++ b/turbo/vehicles.scm
@@ -0,0 +1,43 @@
+(define-module (turbo vehicles)
+  #:use-module (srfi srfi-9)
+  #:export (make-vehicle
+	    make-inactive-vehicle
+	    vehicle-height
+	    vehicle-length
+	    vehicle-steering-speed
+	    vehicle-id
+	    vehicle-sprite
+	    vehicle-position
+	    vehicle-speed
+	    vehicle-active?
+	    set-vehicle-position!
+	    set-vehicle-speed!
+	    set-vehicle-active!
+	    vehicle-hitbox
+	    vehicle-safety-distance?))
+
+(define vehicle-height 45)
+(define vehicle-length 100)
+(define vehicle-steering-speed 4.0)
+
+(define-record-type <vehicle>
+  (make-vehicle id sprite position speed active?)
+  vechicle?
+  (id vehicle-id)
+  (sprite vehicle-sprite)
+  (position vehicle-position set-vehicle-position!)
+  (speed vehicle-speed set-vehicle-speed!)
+  (active? vehicle-active? set-vehicle-active!))
+
+(define (make-inactive-vehicle id tile initial-position)
+  (make-vehicle id tile initial-position 4 #f))
+
+(define (vehicle-hitbox vehicle-pos)
+  (rect (vec2-x vehicle-pos) (vec2-y vehicle-pos) vehicle-length vehicle-height))
+
+(define (vehicle-safety-distance? vehicle1 vehicle2)
+  (let ((vehicle1-x (vec2-x (vehicle-position vehicle1)))
+	(vehicle2-x (vec2-x (vehicle-position vehicle2))))
+    (> vehicle2-x
+       (+ (* 2 vehicle-length)
+	  vehicle1-x))))