Refactor update pipelines

1 files changed, 15 insertions, 22 deletions

diff --git a/physics.scm b/physics.scm
index 24ded09..773d922 100644
--- a/physics.scm
+++ b/physics.scm
@@ -1,5 +1,5 @@
 (module downstroke-physics
-    (scene-resolve-collisions resolve-entity-collisions resolve-pair
+    (resolve-entity-collisions resolve-pair
      aabb-overlap? push-apart push-along-axis aabb-overlap-on-axis
      entity-center-on-axis push-entity axis->velocity axis->dimension
      index-pairs list-set apply-jump detect-on-solid
@@ -33,17 +33,15 @@
 
   ;; Consume #:ay into #:vy and clear it (one-shot acceleration)
   (define-pipeline (apply-acceleration acceleration) (entity)
-    (if (not (entity-ref entity #:gravity? #f))
-        entity
-        (let ((ay (entity-ref entity #:ay 0))
-              (vy (entity-ref entity #:vy 0)))
-          (entity-set (entity-set entity #:vy (+ vy ay)) #:ay 0))))
+      guard: (entity-ref entity #:gravity? #f)
+    (let ((ay (entity-ref entity #:ay 0))
+          (vy (entity-ref entity #:vy 0)))
+      (entity-set (entity-set entity #:vy (+ vy ay)) #:ay 0)))
 
   ;; Apply gravity to an entity if it has gravity enabled
   (define-pipeline (apply-gravity gravity) (entity)
-    (if (entity-ref entity #:gravity? #f)
-        (entity-set entity #:vy (+ (entity-ref entity #:vy) *gravity*))
-        entity))
+      guard: (entity-ref entity #:gravity? #f)
+    (entity-set entity #:vy (+ (entity-ref entity #:vy) *gravity*)))
 
   ;; Update entity's x by its vx velocity
   (define-pipeline (apply-velocity-x velocity-x) (entity)
@@ -179,18 +177,16 @@
 
   (define-pipeline (detect-on-solid on-solid)
       (entity tilemap #!optional (other-entities #f))
-    (if (not (entity-ref entity #:gravity? #f))
-        entity
-        (let* ((on-tile?   (and tilemap (tile-ground-below? entity tilemap)))
-               (on-entity? (and other-entities
-                                (entity-solid-support-below? entity other-entities))))
-          (entity-set entity #:on-ground? (or on-tile? on-entity?)))))
+      guard: (entity-ref entity #:gravity? #f)
+    (let* ((on-tile?   (and tilemap (tile-ground-below? entity tilemap)))
+           (on-entity? (and other-entities
+                            (entity-solid-support-below? entity other-entities))))
+      (entity-set entity #:on-ground? (or on-tile? on-entity?))))
 
   ;; Set vertical acceleration for jump (consumed next frame by apply-acceleration)
   (define-pipeline (apply-jump jump) (entity jump-pressed?)
-    (if (and jump-pressed? (entity-ref entity #:on-ground? #f))
-        (entity-set entity #:ay (- (entity-ref entity #:jump-force *jump-force*)))
-        entity))
+      guard: (and jump-pressed? (entity-ref entity #:on-ground? #f))
+    (entity-set entity #:ay (- (entity-ref entity #:jump-force *jump-force*))))
 
   ;; Replace element at idx in lst with val
   (define (list-set lst idx val)
@@ -318,7 +314,4 @@
           entities
           (index-pairs (length entities))))
 
-  ;; Returns a new scene with entity-entity collisions resolved.
-  (define (scene-resolve-collisions scene)
-    (update-scene scene
-      entities: (resolve-entity-collisions (scene-entities scene)))))
+)