//First let's configure the sliders.
angleSpeedSlider.value = 10;
angleSpeedSlider.minimum = 1;
angleSpeedSlider.maximum = 30;

zSpeedSlider.value = 7;
zSpeedSlider.minimum = 1;
zSpeedSlider.maximum = 20;

radiusSlider.value = 7;
radiusSlider.minimum = 1;
radiusSlider.maximum = 20;

//The maximum depth
const MAXIMUM_Z:Number = 450;

//The number of the boxes
const NUMBER_OF_BOXES:Number = 14;

//Create an array that will contain all the boxes
var boxes:Array = new Array();

//Set the focal length
var focalLength:Number = 300;

//Set the vanishing point
var vanishingPointX:Number = stage.stageWidth / 2;
var vanishingPointY:Number = 20;

//The 3D floor for the boxes
var floor:Number = 80;

//The starting depth
var startingDepth:Number = MAXIMUM_Z;

//The z distance between two boxes
var zDistance:Number = 50;

//The depth speed (how fast the boxes are moving towards you)
var zSpeed:Number = -(zSpeedSlider.value);

//We assign a different starting angle for each box (we increment this later on)
var angle:Number = 0;

//Angle difference between the boxes
var angleDifference:Number = 0.3;

//How fast the angle changes
var angleSpeed:Number = angleSpeedSlider.value * 0.01;

//The radius for the boxes
var radius:Number = radiusSlider.value * 10;

//This loop creates and positions the boxes (starting from the box furthest away)
for (var i=0; i < NUMBER_OF_BOXES; i++) {

	//Create a new box
	var box:MyBox = new MyBox();

	//Calculate the 3D x position (we will do a sine wave)
	box.xpos3D = Math.sin(angle) * radius;

	//Save the angle information for the box
	box.currentAngle = angle;

	//Increase the starting angle for the next box
	angle += angleDifference;

	//3D y position is the same for all the boxes
	box.ypos3D=floor;

	//Assign a z value for the box (the greater the z, the further away the box is)
	box.zpos3D=startingDepth;

	//Update the starting depth for the next box
	startingDepth-=zDistance;

	//Calculate the scale ratio for the box
	var scaleRatio = focalLength/(focalLength + box.zpos3D);

	//Scale the box according to the scale ratio
	box.scaleX=box.scaleY=scaleRatio;

	//Position the box on to the stage (from 3D to 2D coordinates)
	box.x=vanishingPointX+box.xpos3D*scaleRatio;
	box.y=vanishingPointY+box.ypos3D*scaleRatio;

	//Push the box to the array
	boxes.push(box);

	//Add the box on to the stage
	addChild(box);
}

//We use ENTER_FRAME for the animation
addEventListener(Event.ENTER_FRAME, enterFrameHandler);

//This function is called in each frame
function enterFrameHandler(e:Event):void {

	//First, let's get the dynamic speeds from our sliders
	angleSpeed=angleSpeedSlider.value*0.01;
	zSpeed = -(zSpeedSlider.value);
	radius = radiusSlider.value * 10;

	//Loop through the array of boxes
	for (var i=0; i < NUMBER_OF_BOXES; i++) {

		//Save the box to a local variable
		var box:MyBox = (MyBox)(boxes[i]);

		//Update the z position of the box
		box.zpos3D+=zSpeed;

		//Update the current angle of the box
		box.currentAngle+=angleSpeed;

		//If zpos3D <= -focalLength, we end up with a negative scaleRatio (or we are dividing by zero).
		//At this point, we know that the object has already passed "us".
		//Therefore, we put the box behind the last box of the line.
		if (box.zpos3D<=- focalLength) {

			//Save the last box to a local variable
			//The last box of the line is always first in the array,
			//because of the sortZ() function.
			var lastBox:MyBox = (MyBox)(boxes[0]);

			//Position the box behind the last box
			box.zpos3D=lastBox.zpos3D+zDistance;

			//Get the new angle for the box (same as the last box's, minus the angle difference).
			//This way the box wave stays uniform.
			box.currentAngle=lastBox.currentAngle-angleDifference;
		}

		//Calculate the new 3D x position
		box.xpos3D=Math.sin(box.currentAngle)*radius;

		//Calculate a scale ratio for the box
		var scaleRatio = focalLength/(focalLength + box.zpos3D);

		//Scale the box according to the scale ratio
		box.scaleX=box.scaleY=scaleRatio;

		//Set an alpha according to the scale ratio
		box.alpha=scaleRatio-0.5;

		//Position the box on to the stage (from 3D to 2D coordinates)
		box.x=vanishingPointX+box.xpos3D*scaleRatio;
		box.y=vanishingPointY+box.ypos3D*scaleRatio;
	}

	//Sort the boxes according to depth
	sortZ();
}

//This function sorts the boxes so they overlap correctly
function sortZ():void {

	//Sort the array so that the box which has the highest
	//z position (= furthest away) is first in the array
	boxes.sortOn("zpos3D", Array.NUMERIC | Array.DESCENDING);

	//Set new child indexes for the boxes
	for (var i:uint = 0; i < NUMBER_OF_BOXES; i++) {
		setChildIndex(boxes[i], i);
	}
}