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authorDavid Thompson <dthompson@member.fsf.org>2013-09-14 09:57:15 -0400
committerDavid Thompson <dthompson@member.fsf.org>2013-09-14 09:57:15 -0400
commitb4e0256eec659e31f3839e4281c2ce679264fe75 (patch)
tree84a964218ccd2b9f2eb9a812a5ef8fee850102a3
parentcba91570c627522ef948a68809448aba0d5e8234 (diff)
Switch back to a simpler method for FPS calculation.
-rw-r--r--2d/game-loop.scm60
1 files changed, 21 insertions, 39 deletions
diff --git a/2d/game-loop.scm b/2d/game-loop.scm
index eb8aa8b..6d32bcb 100644
--- a/2d/game-loop.scm
+++ b/2d/game-loop.scm
@@ -116,40 +116,37 @@
;;;
(define accumulate-fps!
- (let* ((frame-time 0)
- (alpha 1/5)
- (inverse-alpha (- 1 alpha)))
+ (let* ((elapsed-time 0)
+ (fps 0))
(lambda (dt)
- "Computes a weighted average FPS."
- (set! frame-time (+ (* alpha dt) (* inverse-alpha frame-time)))
- (unless (zero? frame-time)
- (set! game-fps (/ 1000 frame-time))))))
+ "Increments. Resets to 0 every second."
+ (let ((new-time (+ elapsed-time dt))
+ (new-fps (1+ fps)))
+ (if (>= new-time 1000)
+ (begin
+ (set! game-fps new-fps)
+ (set! fps 0)
+ (set! elapsed-time 0))
+ (begin
+ (set! fps new-fps)
+ (set! elapsed-time new-time)))))))
(define (current-fps)
"Returns the current FPS value."
game-fps)
-(codefine (show-fps)
- "Display the current FPS every second."
- (wait 60)
- (pk 'FPS (floor game-fps))
- (pk 'Updates *updates*)
- (set! *updates* 0)
- (show-fps))
-
;;;
;;; Update and Render
;;;
-(define (render)
+(define (render dt)
"Renders a frame."
(set-gl-matrix-mode (matrix-mode modelview))
(gl-load-identity)
(gl-clear (clear-buffer-mask color-buffer depth-buffer))
(scene-draw current-scene)
- (SDL:gl-swap-buffers))
-
-(define *updates* 0)
+ (SDL:gl-swap-buffers)
+ (accumulate-fps! dt))
(define (update accumulator)
"Call the update callback. The update callback will be called as
@@ -157,13 +154,10 @@ many times as tick-interval can divide accumulator. The return value
is the unused accumulator time."
(if (>= accumulator tick-interval)
(begin
- (set! *updates* (1+ *updates*))
(handle-events)
(update-agenda)
- ;; (scene-update current-scene)
- ;; (update (- accumulator tick-interval))
- (- accumulator tick-interval)
- )
+ (scene-update current-scene)
+ (update (- accumulator tick-interval)))
accumulator))
;;;
@@ -236,26 +230,15 @@ the stack."
;;; Game Loop
;;;
-;; (define (time-left current-time next-time)
-;; "Calculate the delta between NEXT-TIME and CURRENT-TIME. If
-;; NEXT-TIME is less than CURRENT-TIME, 0 is returned."
-;; (max (floor (- next-time current-time)) 0))
-
-;; (define (frame-sleep time)
-;; (unless (zero? time)
-;; (SDL:delay time)))
-
(define (game-loop last-time accumulator)
"Runs input, render, and update hooks."
(when running
(let* ((current-time (SDL:get-ticks))
(dt (- current-time last-time))
(remainder (update (+ accumulator dt))))
- ;; (run-repl)
- ;; (render)
- (accumulate-fps! dt)
+ (run-repl)
+ (render dt)
(switch-scenes-maybe)
- ;; (frame-sleep (time-left (SDL:get-ticks) next-time))
(game-loop current-time
remainder))))
@@ -266,8 +249,7 @@ the stack."
(game-fullscreen? game))
(set! running #t)
(set-initial-scene ((game-first-scene game)))
- ;; (spawn-server)
- (agenda-schedule show-fps)
+ (spawn-server)
(game-loop (SDL:get-ticks) 0)
(close-window))