blue fade shader

source/funkin/graphics/shaders/BlueFade.hx

@@ -0,0 +1,51 @@
+package funkin.graphics.shaders;
+
+import flixel.system.FlxAssets.FlxShader;
+import flixel.tweens.FlxEase;
+import flixel.tweens.FlxTween;
+
+class BlueFade extends FlxShader
+{
+  public var fadeVal(default, set):Float;
+
+  function set_fadeVal(val:Float):Float
+  {
+    fadeAmt.value = [val];
+    fadeVal = val;
+    // trace(fadeVal);
+
+    return val;
+  }
+
+  public function fade(startAmt:Float = 0, targetAmt:Float = 1, duration:Float, _options:TweenOptions):Void
+  {
+    fadeVal = startAmt;
+    FlxTween.tween(this, {fadeVal: targetAmt}, duration, _options);
+  }
+
+  @:glFragmentSource('
+       #pragma header
+
+        // Value from (0, 1)
+        uniform float fadeAmt;
+
+        // fade the image to blue as it fades to black
+
+        void main()
+        {
+          vec4 tex = flixel_texture2D(bitmap, openfl_TextureCoordv);
+
+          vec4 finalColor = mix(vec4(vec4(0.0, 0.0, tex.b, tex.a) * fadeAmt), vec4(tex * fadeAmt), fadeAmt);
+
+          // Output to screen
+          gl_FragColor = finalColor;
+        }
+
+    ')
+  public function new()
+  {
+    super();
+
+    this.fadeVal = 1;
+  }
+}