Gacela as Guile modules.

[gacela.git] / src / widgets / timer.scm

diff --git a/src/widgets/timer.scm b/src/widgets/timer.scm
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+;;; Gacela, a GNU Guile extension for fast games development
+;;; Copyright (C) 2009 by Javier Sancho Fernandez <jsf at jsancho dot org>
+;;;
+;;; This program is free software: you can redistribute it and/or modify
+;;; it under the terms of the GNU General Public License as published by
+;;; the Free Software Foundation, either version 3 of the License, or
+;;; (at your option) any later version.
+;;;
+;;; This program is distributed in the hope that it will be useful,
+;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;;; GNU General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU General Public License
+;;; along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+
+(define-module (gacela widgets timer)
+  #:use-module (gacela sdl)
+  #:export (make-timer
+           start-timer
+           stop-timer
+           get-time
+           get-state
+           pause-timer
+           resume-timer))
+
+
+(define (make-timer)
+  (let ((start 0) (paused 0) (state 'stopped))
+    (lambda (op)
+      (case op
+       ((start-timer)
+        (set! start (SDL_GetTicks))
+        (set! state 'running))
+
+       ((stop-timer)
+        (set! state 'stopped))
+
+       ((get-time)
+        (cond ((eq? state 'stopped) 0)
+              ((eq? state 'paused) paused)
+              (else (- (SDL_GetTicks) start))))
+
+       ((get-state)
+        state)
+
+       ((pause-timer)
+        (cond ((eq? state 'running)
+               (set! paused (- (SDL_GetTicks) start))
+               (set! state 'paused))))
+
+       ((resume-timer)
+        (cond ((eq? state 'paused)
+               (set! start (- (SDL_GetTicks) paused))
+               (set! state 'running))))))))
+
+(define (start-timer timer)
+  (timer 'start-timer))
+
+(define (stop-timer timer)
+  (timer 'stop-timer))
+
+(define (get-time timer)
+  (timer 'get-time))
+
+(define (get-state timer)
+  (timer 'get-state))
+
+(define (pause-timer timer)
+  (timer 'pause-timer))
+
+(define (resume-timer timer)
+  (timer 'resume-timer))