3D Circular Ring

talk open source
1

In this experiment I wanted to work out the best method for finding the depth at which to move movieclips to as they rotate.

I did it on the second attempt, too, after starting from scratch. Here is the result:

The code in action

var x:Number = 275;
var y:Number = 200;

var h:Number = 0;
var w:Number = 300;

var c:Array = [];
var cCount:Number = 1;

var theta:Number = 0;

function init() {	
	for (var i:Number =0; i < cCount; i++) {
		var circle:MovieClip = _root.attachMovie("circle", "circle_"+i, i, {
			 _x: x + w/2*Math.sin(Math.PI*2*i/cCount),
			 _y: y + h/2*Math.cos(Math.PI*2*i/cCount)
			 });
		c.push(circle);
		
		var col:Color = new Color(circle);
		var o = {
			r: 255*(2*Math.abs(i-cCount/2)/cCount),
			g: 100+155*(2*Math.abs(i-cCount/2)/cCount),
			b: 100
		};
		col.setRGB((o.r<<16)+(o.g<<8)+o.b);
	}
}

function onEnterFrame() {
	theta += 0.02 *Math.PI*(_root._xmouse-Stage.width/2)/Stage.width;
	theta = (theta-Math.PI)%(2*Math.PI)+Math.PI;
	theta = (theta+Math.PI)%(2*Math.PI)-Math.PI;
	
	h = (_root._ymouse - Stage.height/2)*0.4;
	
	for (var i in c) {
		var circle = c*;
		
		var t:Number = Math.PI*2*i/cCount + theta;
		t = (t-Math.PI)%(2*Math.PI)+Math.PI;
		t = (t+Math.PI)%(2*Math.PI)-Math.PI;
		
		circle._x = x+w/2*Math.sin(t);
		circle._y = y+h/2*Math.cos(t);
		
		circle._xscale = circle._yscale = 70+30*Math.cos(t);
		circle._xscale *= Math.cos(t);
		
		t = 1 - Math.abs(t)/Math.PI;
		circle.swapDepths(Math.round(t*2*cCount));
	}
}

Mouse.addListener(this);
this.onMouseWheel = function(d) {
	while (c.length > 0) c.pop().removeMovieClip();
	cCount = Math.max(cCount+d, 1);
	init();
}
Key.addListener(this);
this.onKeyDown = function() {
	if (Key.getCode() == Key.UP)
		this.onMouseWheel(1);
	else if (Key.getCode() == Key.DOWN)
		this.onMouseWheel(-1);
}

init();