Enrich entities pipelining to provide scene context to processors

1 files changed, 14 insertions, 11 deletions

diff --git a/engine.scm b/engine.scm
index 95d33b9..faa0909 100644
--- a/engine.scm
+++ b/engine.scm
@@ -7,6 +7,7 @@
         (prefix sdl2-ttf "ttf:")
         (prefix sdl2-image "img:")
         (srfi 69)
+	(only srfi-197 chain)
         defstruct
         downstroke-world
         downstroke-input
@@ -49,17 +50,19 @@
 (define (default-engine-update game dt)
   (let ((scene (game-scene game)))
     (when scene
-      (let* ((scene (scene-map-entities scene (cut step-tweens <> scene dt)))
-             (scene (scene-map-entities scene (cut apply-acceleration <> scene dt)))
-             (scene (scene-map-entities scene (cut apply-gravity <> scene dt)))
-             (scene (scene-map-entities scene (cut apply-velocity-x <> scene dt)))
-             (scene (scene-map-entities scene (cut resolve-tile-collisions-x <> scene dt)))
-             (scene (scene-map-entities scene (cut apply-velocity-y <> scene dt)))
-             (scene (scene-map-entities scene (cut resolve-tile-collisions-y <> scene dt)))
-             (scene (scene-map-entities scene (cut detect-on-solid <> scene dt)))
-             (scene (scene-transform-entities scene resolve-entity-collisions))
-             (scene (scene-transform-entities scene sync-groups)))
-        (game-scene-set! game scene)))))
+      (game-scene-set!
+       game
+       (chain scene
+	      (scene-map-entities _ (cut step-tweens <> <> dt))
+	      (scene-map-entities _ (cut apply-acceleration <> <> dt))
+	      (scene-map-entities _ (cut apply-gravity <> <> dt))
+	      (scene-map-entities _ (cut apply-velocity-x <> <> dt))
+	      (scene-map-entities _ (cut resolve-tile-collisions-x <> <> dt))
+	      (scene-map-entities _ (cut apply-velocity-y <> <> dt))
+	      (scene-map-entities _ (cut resolve-tile-collisions-y <> <> dt))
+	      (scene-map-entities _ (cut detect-on-solid <> <> dt))
+	      (scene-transform-entities _ resolve-entity-collisions)
+	      (scene-transform-entities _ sync-groups))))))
 
 (define (make-game #!key
     (title "Downstroke Game")