Remove dynamic scoping of agendas.

* 2d/agenda.scm: (*global-agenda*, current-agenda, with-agenda): Delete.
  (agenda?, agenda-time): Export.
  (schedule-every, schedule-each): Rename schedule-every to
  schedule-each.
  (schedule-next): Delete.
* 2d/game.scm: (game-agenda): New variable.
  (update): Tick game-agenda.
* 2d/repl.scm: Use new agenda API.
* 2d/sprite.scm: Use new agenda API.
* 2d/time.scm: (time-every, time-each, time-delay): Change signature and
  use new agenda API.
* examples/coroutine.scm: Use new agenda API.
* examples/particles.scm: Use new agenda API.

1 files changed, 3 insertions, 1 deletions

diff --git a/2d/game.scm b/2d/game.scm
index 1594b4a..31780d0 100644
--- a/2d/game.scm
+++ b/2d/game.scm
@@ -32,6 +32,7 @@
   #:use-module (2d window)
   #:export (ticks-per-second
             tick-interval
+            game-agenda
             paused-agenda
             draw-hook
             run-game-loop
@@ -54,6 +55,7 @@
 (define tick-interval (make-parameter 0))
 (define draw-hook (make-hook 2))
 (define accumulator (make-parameter 0))
+(define game-agenda (make-agenda))
 ;; This agenda is only ticked when the game loop is in the paused
 ;; state.  Useful for things like the REPL that should be run even
 ;; though the game is paused.
@@ -86,7 +88,7 @@ many times as `tick-interval` can divide ACCUMULATOR. The return value
 is the unused accumulator time."
   (while (>= (accumulator) (tick-interval))
       (process-events)
-      (tick-agenda! *global-agenda*)
+      (tick-agenda! game-agenda)
       (accumulator (- (accumulator) (tick-interval)))))
 
 (define (alpha)