From aa8a302fcb1e609a311151bc3c9b9bc22fc7a560 Mon Sep 17 00:00:00 2001
From: David Thompson <dthompson2@worcester.edu>
Date: Thu, 23 May 2024 12:06:42 -0400
Subject: [PATCH] Add simple wipe effect for undo.

---
 game.scm                 |  3 ++-
 modules/game/effects.scm | 13 ++++++++++---
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/game.scm b/game.scm
index 4bf4af7..3eaf110 100644
--- a/game.scm
+++ b/game.scm
@@ -108,7 +108,8 @@
     ((snapshot . older-snapshots)
      (set! *actormap* snapshot)
      (set! *snapshots* older-snapshots)
-     (play-sound-effect audio:undo))))
+     (play-sound-effect audio:undo)
+     (show-effect! (make-wipe-effect 0.25)))))
 
 (define (sort lst compare)
   (match lst
diff --git a/modules/game/effects.scm b/modules/game/effects.scm
index 29df590..62dca43 100644
--- a/modules/game/effects.scm
+++ b/modules/game/effects.scm
@@ -16,7 +16,8 @@
             draw-effect
 
             make-fade-out+in-effect
-            make-screen-shake-effect))
+            make-screen-shake-effect
+            make-wipe-effect))
 
 (define (ease:smoothstep t)
   (* t t (- 3 (* 2 t))))
@@ -61,8 +62,8 @@
 (define (make-fade-out+in-effect duration)
   (define (draw context t)
     (if (< t 0.5)
-        (set-global-alpha! context (pk 'alpha-out (* t 2.0)))
-        (set-global-alpha! context (pk 'alpha-in (- 1.0 (* (- t 0.5) 2.0)))))
+        (set-global-alpha! context (* t 2.0))
+        (set-global-alpha! context (- 1.0 (* (- t 0.5) 2.0))))
     (set-fill-color! context "#000000")
     (fill-rect context 0.0 0.0 game-width game-height)
     (set-global-alpha! context 1.0))
@@ -74,3 +75,9 @@
           (y (round (random))))
       (translate! context x y)))
   (make-effect 'pre duration draw))
+
+(define (make-wipe-effect duration)
+  (define (draw context t)
+    (set-fill-color! context "#222034")
+    (fill-rect context 0.0 0.0 (* game-width (- 1.0 t)) game-height))
+  (make-effect 'post duration draw))