Window clear color and create window after tests

engine/core.scm

@@ -5,6 +5,7 @@
 	(chicken sort)
 	raylib
 	(srfi 1)
+	(srfi 4)
 	(srfi 69)
 	(srfi 99)
 	(srfi 113)
@@ -326,18 +327,7 @@
 	#f)))
 
 ;; Frame generation and game loop
-(export resolve-queues next-frame)
-
-;; Resolve the entity and system queues. This is exported which allows breaking iteration
-(define (resolve-queues)
-  (resolve-entity-queue)
-  (resolve-system-queue))
-
-;; Generate the next frame, for use in the main game loop
-(define (next-frame)
-  (resolve-queues)
-  (with-drawing
-   execute-systems))
+(export resolve-queues next-frame *clear-color*)
 
 ;; Utility function for guarding parameter values
 (define (guarded-parameter default predicate)
@@ -346,6 +336,22 @@
 				val
 				default))))
 
+;; Resolve the entity and system queues. This is exported which allows breaking iteration
+(define (resolve-queues)
+  (resolve-entity-queue)
+  (resolve-system-queue))
+
+;; Clear color
+(define *clear-color* (guarded-parameter RAYWHITE u8vector?))
+
+;; Generate the next frame, for use in the main game loop
+(define (next-frame)
+  (resolve-queues)
+  (with-drawing
+   (lambda ()
+     (clear-background (*clear-color*))
+     (execute-systems))))
+
 ;; Window creation
 (export *window-size* *window-title* create-window)
 

test/engine.scm

@@ -82,4 +82,6 @@
 
 (check (point-x (pop-event 'foo 'bar)) => 1) ;; Event is popped
 (check (hash-table-size (fetch-event-bus 'foo)) => 0) ;; Event is removed exists
+
+(create-window)
 )