summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--2d/game-loop.scm76
-rw-r--r--2d/game.scm5
2 files changed, 59 insertions, 22 deletions
diff --git a/2d/game-loop.scm b/2d/game-loop.scm
index aeb8889..37e8036 100644
--- a/2d/game-loop.scm
+++ b/2d/game-loop.scm
@@ -35,6 +35,9 @@
#:use-module (2d mvars)
#:use-module (2d window)
#:export (current-fps
+ push-scene
+ replace-scene
+ pop-scene
run-game
quit-game-loop!))
@@ -50,9 +53,7 @@
;;;
(define game-fps 0)
-(define game-running #f)
-(define game-scene #f)
-(define game-next-scene #f)
+(define running #f)
;;;
;;; Event Handling
@@ -69,28 +70,28 @@
"Calls the relevant callback for the event."
(case (SDL:event:type e)
((active)
- (scene-trigger game-scene 'active))
+ (scene-trigger current-scene 'active))
((video-resize)
- (scene-trigger game-scene
+ (scene-trigger current-scene
'resize
(SDL:event:resize:w e)
(SDL:event:resize:h e)))
((quit)
- (scene-trigger game-scene 'quit))
+ (scene-trigger current-scene 'quit))
((key-down)
- (scene-trigger game-scene
+ (scene-trigger current-scene
'key-down
(SDL:event:key:keysym:sym e)
(SDL:event:key:keysym:mod e)
(SDL:event:key:keysym:unicode e)))
((key-up)
- (scene-trigger game-scene
+ (scene-trigger current-scene
'key-up
(SDL:event:key:keysym:sym e)
(SDL:event:key:keysym:mod e)
(SDL:event:key:keysym:unicode e)))
((mouse-motion)
- (scene-trigger game-scene
+ (scene-trigger current-scene
'mouse-motion
(SDL:event:motion:state e)
(SDL:event:motion:x e)
@@ -98,13 +99,13 @@
(SDL:event:motion:xrel e)
(SDL:event:motion:yrel e)))
((mouse-button-down)
- (scene-trigger game-scene
+ (scene-trigger current-scene
'mouse-press
(SDL:event:button:button e)
(SDL:event:button:x e)
(SDL:event:button:y e)))
((mouse-button-up)
- (scene-trigger game-scene
+ (scene-trigger current-scene
'mouse-click
(SDL:event:button:button e)
(SDL:event:button:x e)
@@ -143,7 +144,7 @@
(set-gl-matrix-mode (matrix-mode modelview))
(gl-load-identity)
(gl-clear (clear-buffer-mask color-buffer depth-buffer))
- (scene-draw game-scene)
+ (scene-draw current-scene)
(SDL:gl-swap-buffers))
(define (update accumulator)
@@ -152,7 +153,7 @@ many times as tick-interval can divide accumulator. The return value
is the unused accumulator time."
(if (>= accumulator tick-interval)
(begin
- (scene-update game-scene)
+ (scene-update current-scene)
(update-agenda)
(update (- accumulator tick-interval)))
accumulator))
@@ -190,11 +191,43 @@ INPUT, OUTPUT, and ERROR ports."
;;; Scene management
;;;
-(define (set-game-scene scene)
- (when game-scene
- (scene-trigger game-scene 'stop))
+(define scenes '())
+(define current-scene #f)
+(define next-scene #f)
+
+(define (push-scene scene)
+ "Pause the current scene and start SCENE upon next game tick."
+ (set! scenes (cons scene scenes))
+ (set! next-scene scene))
+
+(define (replace-scene scene)
+ (set! scenes (cons scene (cdr scenes)))
+ (set! next-scene scene))
+
+(define (pop-scene)
+ "Exit the current scene and resume the previous scene. If there is
+no previous scene, the game loop will terminate."
+ (if (null? scenes)
+ (quit-game-loop!)
+ (begin
+ (set! next-scene (car scenes))
+ (set! scenes (cdr scenes)))))
+
+(define (switch-scenes-maybe)
+ "Switch scenes if the current scene is not the scene at the top of
+the stack."
+ (when next-scene
+ (scene-trigger current-scene 'stop)
+ (set-current-scene next-scene)
+ (set! next-scene #f)))
+
+(define (set-current-scene scene)
(scene-trigger scene 'start)
- (set! game-scene scene))
+ (set! current-scene scene))
+
+(define (set-initial-scene scene)
+ (set! scenes (list scene))
+ (set-current-scene scene))
;;;
;;; Game Loop
@@ -202,7 +235,7 @@ INPUT, OUTPUT, and ERROR ports."
(define (game-loop last-time next-time accumulator)
"Runs input, render, and update hooks."
- (when game-running
+ (when running
(handle-events)
(let* ((time (SDL:get-ticks))
(dt (- time last-time))
@@ -210,6 +243,7 @@ INPUT, OUTPUT, and ERROR ports."
(remainder (update accumulator)))
(run-repl)
(render)
+ (switch-scenes-maybe)
(accumulate-fps! dt)
(SDL:delay (time-left (SDL:get-ticks) next-time))
(game-loop time
@@ -221,8 +255,8 @@ INPUT, OUTPUT, and ERROR ports."
(open-window (game-title game)
(game-resolution game)
(game-fullscreen? game))
- (set! game-running #t)
- (set-game-scene ((game-first-scene game)))
+ (set! running #t)
+ (set-initial-scene ((game-first-scene game)))
(spawn-server)
(agenda-schedule show-fps)
(let ((time (SDL:get-ticks)))
@@ -232,4 +266,4 @@ INPUT, OUTPUT, and ERROR ports."
(define (quit-game-loop!)
"Tell the game loop to finish up the current frame and then
terminate."
- (set! game-running #f))
+ (set! running #f))
diff --git a/2d/game.scm b/2d/game.scm
index c7fa02f..af3bf7a 100644
--- a/2d/game.scm
+++ b/2d/game.scm
@@ -69,7 +69,10 @@ creates a new scene."
scene-state
scene-trigger
scene-update
- scene-draw)
+ scene-draw
+ push-scene
+ replace-scene
+ pop-scene)
(export make-scene
define-scene