import flash.geom.Point
import flash.events.Event
import flash.display.Bitmap
import flash.display.BitmapData
import flash.filters.BitmapFilter
import flash.filters.DisplacementMapFilter
import flash.filters.DisplacementMapFilterMode

// Setup our perlin noise map BitmapData and noise seed
var bmd:BitmapData 	= new BitmapData(250,250);
var seed:Number 	= Math.floor(Math.random()*int.MAX_VALUE);
var speed:Number 	= .5;
var t:Number 		= 0;

// Add the noise map to the stage
var map:Bitmap = Bitmap(addChild(new Bitmap(bmd)));
map.x = map.width;

// WaterfallPic is an image with library linkage class 'WaterfallPic'
var image:Bitmap = Bitmap(addChild(new Bitmap(new WaterfallPic(0,0))));

// Set the enterFrame event to call the 'update' function
addEventListener(Event.ENTER_FRAME,update);

// Redraws the noise map and main image
function update (e:Event):void {
	// The value 't' governs positions of the offset mapping points
	t += speed;
	// Create an array of points that offset our 4 noise map octaves
	var pointsArray:Array = [new Point(-t,t/2),new Point(t/2,-t),new Point(t,t),new Point(t,0),new Point(0,-t)];
	// Create perlin noise with the same seed, but the new offsets
	bmd.perlinNoise(100, 100, 4, seed, true, false, 1, true, pointsArray);
	// Apply this as a DisplacementMapFilter for our waterfall image
	image.filters = [getBitmapFilter(bmd)];
}

// Returns a DisplacementMapFilter from the given BitmapData
function getBitmapFilter(mapBitmap:BitmapData):BitmapFilter {
    return new DisplacementMapFilter(mapBitmap, new Point(0,0), 1, 1, 25, 25, "wrap", 0, 0);
}