Added ReverseInput and ReverseOutput to Easings

CHANGELOG.md

@@ -14,6 +14,7 @@ Additions
 - Added consuming variants of IsPressed methods to InputHandler and Keybind
 - Added SpriteBatchContext struct and extensions
 - Added InputHandler.InvertPressBehavior
+- Added ReverseInput and ReverseOutput to Easings
 
 ### MLEM.Ui
 Additions

MLEM/Misc/Easings.cs

@@ -114,6 +114,24 @@ namespace MLEM.Misc {
             return p => easing(p) * (max - min) + min;
         }
 
+        /// <summary>
+        /// Reverses the input of an easing function, which is usually between 0 and 1, to be passed into the easing function as if it were between 1 and 0.
+        /// </summary>
+        /// <param name="easing">The easing function whose output to reverse.</param>
+        /// <returns>The reversed easing function.</returns>
+        public static Easing ReverseInput(this Easing easing) {
+            return p => easing(1 - p);
+        }
+
+        /// <summary>
+        /// Reverses the output of an easing function, which is usually between 0 and 1, to return as if it were between 1 and 0.
+        /// </summary>
+        /// <param name="easing">The easing function whose input to reverse.</param>
+        /// <returns>The reversed easing function.</returns>
+        public static Easing ReverseOutput(this Easing easing) {
+            return p => 1 - easing(p);
+        }
+
         /// <summary>
         /// Causes the easing functino to play fully, and then play fully in reverse, in the span between an input of 0 and 1.
         /// In some places, this behavior is also called "auto-reversing".