Swapped to gl.KEEP for further testing

Author: photonstorm

src/display/mask/GeometryMask.js

@@ -53,7 +53,7 @@ var GeometryMask = new Class({
      * @method Phaser.Display.Masks.GeometryMask#preRenderWebGL
      * @since 3.0.0
      *
-     * @param {(Phaser.Renderer.Canvas.CanvasRenderer|Phaser.Renderer.WebGL.WebGLRenderer)} renderer - [description]
+     * @param {Phaser.Renderer.WebGL.WebGLRenderer} renderer - [description]
      * @param {Phaser.GameObjects.GameObject} mask - [description]
      * @param {Phaser.Cameras.Scene2D.Camera} camera - [description]
      */
@@ -79,7 +79,7 @@ var GeometryMask = new Class({
         // Use stencil buffer to affect next rendering object
         gl.colorMask(true, true, true, true);
         gl.stencilFunc(gl.EQUAL, 1, 1);
-        gl.stencilOp(gl.INVERT, gl.INVERT, gl.INVERT);
+        gl.stencilOp(gl.KEEP, gl.KEEP, gl.KEEP);
     },
 
     /**
@@ -88,7 +88,7 @@ var GeometryMask = new Class({
      * @method Phaser.Display.Masks.GeometryMask#postRenderWebGL
      * @since 3.0.0
      *
-     * @param {(Phaser.Renderer.Canvas.CanvasRenderer|Phaser.Renderer.WebGL.WebGLRenderer)} renderer - [description]
+     * @param {Phaser.Renderer.WebGL.WebGLRenderer} renderer - [description]
      */
     postRenderWebGL: function (renderer)
     {
@@ -105,7 +105,7 @@ var GeometryMask = new Class({
      * @method Phaser.Display.Masks.GeometryMask#preRenderCanvas
      * @since 3.0.0
      *
-     * @param {(Phaser.Renderer.Canvas.CanvasRenderer|Phaser.Renderer.WebGL.WebGLRenderer)} renderer - [description]
+     * @param {Phaser.Renderer.Canvas.CanvasRenderer} renderer - [description]
      * @param {Phaser.GameObjects.GameObject} mask - [description]
      * @param {Phaser.Cameras.Scene2D.Camera} camera - [description]
      */
@@ -126,7 +126,7 @@ var GeometryMask = new Class({
      * @method Phaser.Display.Masks.GeometryMask#postRenderCanvas
      * @since 3.0.0
      *
-     * @param {(Phaser.Renderer.Canvas.CanvasRenderer|Phaser.Renderer.WebGL.WebGLRenderer)} renderer - [description]
+     * @param {Phaser.Renderer.Canvas.CanvasRenderer} renderer - [description]
      */
     postRenderCanvas: function (renderer)
     {