diff options
| -rw-r--r-- | sly/game.scm | 34 |
1 files changed, 20 insertions, 14 deletions
diff --git a/sly/game.scm b/sly/game.scm index 000d1ce..3f00bf3 100644 --- a/sly/game.scm +++ b/sly/game.scm @@ -62,18 +62,21 @@ for the given STACK and error KEY with additional arguments ARGS." (apply display-error (stack-ref stack 0) cep args) (newline cep))) -(define* (start-game-loop cameras +(define* (start-game-loop camera #:optional #:key (frame-rate 60) (tick-rate 60) (max-ticks-per-frame 4)) - "Start the game loop. FRAME-RATE specifies the optimal number of -frames to draw per second. TICK-RATE specifies the optimal game logic -updates per second. Both FRAME-RATE and TICK-RATE are 60 by default. -MAX-TICKS-PER-FRAME is the maximum number of times the game loop will -update game state in a single frame. When this upper bound is reached -due to poor performance, the game will start to slow down instead of -becoming completely unresponsive and possibly crashing." + "Start the game loop. For each frame, render the scene that is +looked upon by CAMERA. CAMERA may be a single camera object, or a +list of cameras for rendering multiple viewports. FRAME-RATE +specifies the optimal number of frames to draw per second. TICK-RATE +specifies the optimal game logic updates per second. Both FRAME-RATE +and TICK-RATE are 60 by default. MAX-TICKS-PER-FRAME is the maximum +number of times the game loop will update game state in a single +frame. When this upper bound is reached due to poor performance, the +game will start to slow down instead of becoming completely +unresponsive and possibly crashing." (let ((tick-interval (interval tick-rate)) (frame-interval (interval frame-rate))) (define (draw dt alpha) @@ -82,8 +85,10 @@ becoming completely unresponsive and possibly crashing." (let ((size (signal-ref window-size))) (gl-viewport 0 0 (vx size) (vy size))) (gl-clear (clear-buffer-mask color-buffer depth-buffer)) - (for-each (cut draw-camera <> alpha) - (signal-ref-maybe cameras)) + (signal-let ((camera camera)) + (if (list? camera) + (for-each (cut draw-camera <> alpha) camera) + (draw-camera camera alpha))) (SDL:gl-swap-buffers)) (define (update lag) @@ -94,10 +99,11 @@ unused accumulator time." (cond ((>= ticks max-ticks-per-frame) lag) ((>= lag tick-interval) - (for-each (cut update-scene-node <>) - (delete-duplicates - (map camera-scene (signal-ref-maybe cameras)) - eq?)) + (signal-let ((camera camera)) + (if (list? camera) + (for-each (cut update-scene-node <>) + (delete-duplicates (map camera-scene camera) eq?)) + (update-scene-node (camera-scene camera)))) (tick-agenda!) (iter (- lag tick-interval) (1+ ticks))) (else |