Added Camera.alpha property

Author: photonstorm

src/cameras/2d/Camera.js

@@ -313,6 +313,16 @@ var Camera = new Class({
          */
         this.backgroundColor = ValueToColor('rgba(0,0,0,0)');
 
+        /**
+         * The Camera alpha value.
+         *
+         * @name Phaser.Cameras.Scene2D.Camera#alpha
+         * @type {number}
+         * @default 1
+         * @since 3.11.0
+         */
+        this.alpha = 1;
+
         /**
          * The Camera Fade effect handler.
          * To fade this camera see the `Camera.fade` methods.
@@ -1317,10 +1327,23 @@ var Camera = new Class({
     },
 
     /**
-     * Set the world bounds for this Camera.
-     *
-     * A Camera bounds controls where the camera can scroll to within the world. It does not limit
-     * rendering of the camera, or placement of the viewport within your game.
+     * Set the bounds of the Camera. The bounds are an axis-aligned rectangle.
+     * 
+     * The Camera bounds controls where the Camera can scroll to, stopping it from scrolling off the
+     * edges and into blank space. It does not limit the placement of Game Objects, or where
+     * the Camera viewport can be positioned.
+     * 
+     * Temporarily disable the bounds by changing the boolean `Camera.useBounds`.
+     * 
+     * Clear the bounds entirely by calling `Camera.removeBounds`.
+     * 
+     * If you set bounds that are smaller than the viewport it will stop the Camera from being
+     * able to scroll. The bounds can be positioned where-ever you wish. By default they are from
+     * 0x0 to the canvas width x height. This means that the coordinate 0x0 is the top left of
+     * the Camera bounds. However, you can position them anywhere. So if you wanted a game world
+     * that was 2048x2048 in size, with 0x0 being the center of it, you can set the bounds x/y
+     * to be -1024, -1024, with a width and height of 2048. Depending on your game you may find
+     * it easier for 0x0 to be the top-left of the bounds, or you may wish 0x0 to be the middle.
      *
      * @method Phaser.Cameras.Scene2D.Camera#setBounds
      * @since 3.0.0
@@ -1343,6 +1366,11 @@ var Camera = new Class({
         {
             this.centerToBounds();
         }
+        else
+        {
+            this.scrollX = this.clampX(this.scrollX);
+            this.scrollY = this.clampY(this.scrollY);
+        }
 
         return this;
     },