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authorDavid Thompson <dthompson2@worcester.edu>2014-01-07 21:51:30 -0500
committerDavid Thompson <dthompson2@worcester.edu>2014-01-07 21:51:30 -0500
commit4e307506829a3f710f40a58f4fe07b758e3636cc (patch)
tree1aca3b8dc0c77be8b377031e7280b4575c28c613
parentb830d683cd4ecd7953a6b2b6ad455f1ee7ab5472 (diff)
Make tick-interval a parameter.
* 2d/game.scm (run-game-loop): Compute tick-interval. (update, update-and-render, tick): Use tick-interval parameter.
-rw-r--r--2d/game.scm24
1 files changed, 13 insertions, 11 deletions
diff --git a/2d/game.scm b/2d/game.scm
index 3e1f982..da4e0b8 100644
--- a/2d/game.scm
+++ b/2d/game.scm
@@ -34,7 +34,9 @@
#:use-module (2d repl repl)
#:use-module (2d signals)
#:use-module (2d vector2)
- #:export (draw-hook
+ #:export (ticks-per-second
+ tick-interval
+ draw-hook
run-game-loop
quit-game
pause-game
@@ -53,17 +55,17 @@
;; * running
;; * paused
(define %state 'stopped)
-;; TODO: Make this configurable
(define ticks-per-second 60)
-(define tick-interval (floor (/ 1000 ticks-per-second)))
+(define tick-interval (make-parameter 0))
(define draw-hook (make-hook))
(define (run-game-loop)
"Start the game loop."
- (set! %state 'running)
- (resume-game)
- (spawn-server)
- (game-loop (SDL:get-ticks) 0))
+ (parameterize ((tick-interval (floor (/ 1000 ticks-per-second))))
+ (set! %state 'running)
+ (resume-game)
+ (spawn-server)
+ (game-loop (SDL:get-ticks) 0)))
(define (draw dt alpha)
"Render a frame."
@@ -78,17 +80,17 @@
"Call the update callback. The update callback will be called as
many times as `tick-interval` can divide ACCUMULATOR. The return value
is the unused accumulator time."
- (if (>= accumulator tick-interval)
+ (if (>= accumulator (tick-interval))
(begin
(handle-events)
(tick-agenda!)
- (update (- accumulator tick-interval)))
+ (update (- accumulator (tick-interval))))
accumulator))
(define (update-and-render dt accumulator)
(let ((remainder (update accumulator)))
(run-repl)
- (draw dt (/ remainder tick-interval))
+ (draw dt (/ remainder (tick-interval)))
remainder))
(define (tick dt accumulator)
@@ -96,7 +98,7 @@ is the unused accumulator time."
(if (game-paused?)
(begin
(run-repl)
- (SDL:delay tick-interval)
+ (SDL:delay (tick-interval))
accumulator)
(catch #t
(lambda ()