shader resize fix

source/funkin/backend/system/Main.hx

@@ -116,6 +116,7 @@ class Main extends Sprite
 		#if UPDATE_CHECKING
 		funkin.backend.system.updating.UpdateUtil.init();
 		#end
+		ShaderResizeFix.init();
 		Logs.init();
 		Paths.init();
 		ModsFolder.init();

source/funkin/backend/utils/ShaderResizeFix.hx

@@ -0,0 +1,34 @@
+package funkin.backend.utils;
+
+import openfl.display.Sprite;
+
+class ShaderResizeFix {
+	public static function init() {
+		FlxG.signals.gameResized.add((w:Int, h:Int) -> {fixSpritesShadersSizes();});
+	}
+
+	public inline static function fixSpritesShadersSizes() {
+		fixSpriteShaderSize(Main.instance);
+		if (FlxG.game != null) fixSpriteShaderSize(FlxG.game);
+
+		if (FlxG.cameras == null) return;
+		for (cam in FlxG.cameras.list) {
+			@:privateAccess
+			if (cam != null && (cam._filters != null || cam._filters != []))
+				fixSpriteShaderSize(cam.flashSprite);
+		}	
+	}
+
+	public inline static function fixSpriteShaderSize(sprite:Sprite) // Shout out to Ne_Eo for bringing this to my attention
+	{
+		if (sprite == null) return;
+
+		@:privateAccess {
+			sprite.__cacheBitmap = null;
+			sprite.__cacheBitmapData = null;
+			sprite.__cacheBitmapData2 = null;
+			sprite.__cacheBitmapData3 = null;
+			sprite.__cacheBitmapColorTransform = null;
+		}
+	}
+}