node-2d: Add <animation> class.

Now each sprite animation can have its own frame duration.

1 files changed, 13 insertions, 6 deletions

diff --git a/starling/node-2d.scm b/starling/node-2d.scm
index c71d4e8..df434f8 100644
--- a/starling/node-2d.scm
+++ b/starling/node-2d.scm
@@ -88,6 +88,10 @@
             atlas
             index
 
+            <animation>
+            frames
+            frame-duration
+
             <animated-sprite>
             animations
             frame-duration
@@ -522,11 +526,13 @@
 ;;; Animated Sprite
 ;;;
 
+(define-class <animation> ()
+  (frames #:getter frames #:init-keyword #:frames)
+  (frame-duration #:getter frame-duration #:init-keyword #:frame-duration
+                  #:init-form 250))
+
 (define-class <animated-sprite> (<atlas-sprite>)
   (animations #:accessor animations #:init-keyword #:animations)
-  (frame-duration #:accessor frame-duration
-                  #:init-keyword #:frame-duration
-                  #:init-form 500)
   (current-animation #:accessor current-animation
                      #:init-keyword #:default-animation
                      #:init-form 'default)
@@ -537,10 +543,11 @@
 
 (define-method (update (sprite <animated-sprite>) dt)
   (let* ((anim (assq-ref (animations sprite) (current-animation sprite)))
-         (frame-duration (frame-duration sprite))
-         (anim-duration (* frame-duration (vector-length anim)))
+         (frame-duration (frame-duration anim))
+         (frames (frames anim))
+         (anim-duration (* frame-duration (vector-length frames)))
          (time (modulo (- (elapsed-time) (start-time sprite)) anim-duration))
-         (frame (vector-ref anim (floor (/ time frame-duration)))))
+         (frame (vector-ref frames (floor (/ time frame-duration)))))
     (set! (index sprite) frame)
     (next-method)))