// forked from sake's らせん階段を上ります。
/*
     らせん階段を上ります。
      定数kの値でジャンプする高さを変更できます。
*/
package
{
	import flash.display.Graphics;
	import flash.display.Sprite;
	import flash.display.StageQuality;
	import flash.events.Event;
	import flash.geom.Matrix3D;

[SWF(width="465", height="465", backgroundColor="0xFFFFFF", frameRate="30")]

public class spiral extends Sprite
	{
		private var container:Sprite;
		private var cube:Sprite;
		private var nn:int;
		private var xx:Number;
		private var ss:Number;

// ジャンプする度合いを決める定数
		private const k:Number=10;

public function spiral()
		{
			container=new Sprite();
			container.x=465 / 2;
			container.y=465 / 2;
			addChild(container);
			container.scaleX=container.scaleY=container.scaleZ=0.15;
			nn=xx=ss=0;

cube=new Sprite;
			container.addChild(cube);
			cube.name="sp" + nn.toString();
			nn++;

var sp0:Sprite=new Sprite();
			draw(sp0.graphics);
			sp0.rotationY=90;
			sp0.x=50;
			cube.addChild(sp0);
			sp0.name="plane0";

var sp1:Sprite=new Sprite();
			draw(sp1.graphics);
			sp1.rotationY=-90;
			sp1.x=-50;
			cube.addChild(sp1);
			sp1.name="plane1";

var sp2:Sprite=new Sprite();
			draw(sp2.graphics);
			sp2.rotationX=-90;
			sp2.y=-50;
			cube.addChild(sp2);
			sp2.name="plane2";

var sp3:Sprite=new Sprite();
			draw(sp3.graphics);
			sp3.rotationX=90;
			sp3.y=50;
			cube.addChild(sp3);
			sp3.name="plane3";

var sp4:Sprite=new Sprite();
			draw(sp4.graphics);
			sp4.z=-50;
			cube.addChild(sp4);
			sp4.name="plane4";

var sp5:Sprite=new Sprite();
			draw(sp5.graphics);
			sp5.z=50;
			cube.addChild(sp5);
			sp5.name="plane5";

var h:int=-50;
			var s:Number=0;
			for(var i:int=0; i < 140; i++)
			{
				var sp6:Sprite=new Sprite;
				sp6.graphics.beginFill(0x00FF00, 0.3);
				sp6.graphics.drawRect(-50, -50, 100, 100);
				sp6.graphics.endFill();
				container.addChild(sp6);
				sp6.name="sp" + nn.toString();
				nn++;
				sp6.rotationX=90;
				sp6.y=-h;
				h+=10;
				sp6.x=1.1 * s * Math.cos(s * Math.PI / 180);
				sp6.z=1.1 * s * Math.sin(s * Math.PI / 180);
				s+=20;
			}

container.rotationX=50;
			container.rotationY=40;

addEventListener(Event.ENTER_FRAME, onFrame);
		}

private function draw(g:Graphics):void
		{
			g.beginFill(0xFFFFFF * Math.random(), 0.7);
			g.drawRect(-50, -50, 100, 100);
			g.endFill();
		}

private function onFrame(e:Event):void
		{
			cube.z=1.1 * ss * Math.sin(ss * Math.PI / 180);
			cube.x=1.1 * ss * Math.cos(ss * Math.PI / 180);
			cube.y=-10 * (-1 * (2 * k - 1 + 2 * Math.sqrt(k * k - k)) * (xx - k + Math.sqrt(k * k - k) - Math.floor(xx)) * (xx - k + Math.sqrt(k * k - k) - Math.floor(xx)) + k + Math.floor(xx));

xx+=0.05;
			ss+=1;

var array:Array=[];
			for(var i:int=0; i < 6; i++)
			{
				var sp:Sprite=cube.getChildByName("plane" + i.toString())as Sprite;
				var mat:Matrix3D=sp.transform.getRelativeMatrix3D(this);
				array.push({sp:sp, z:mat.position.z});
			}
			array.sortOn("z", Array.NUMERIC | Array.DESCENDING);
			for(var i:int=0; i < 6; i++)
			{
				var sp:Sprite=array[i].sp as Sprite;
				cube.setChildIndex(sp, i);
			}

array=[];
			for(var i:int=0; i < nn; i++)
			{
				var sp:Sprite=container.getChildByName("sp" + i.toString())as Sprite;
				var mat:Matrix3D=sp.transform.getRelativeMatrix3D(this);
				array.push({sp:sp, z:mat.position.z});
			}
			array.sortOn("z", Array.NUMERIC | Array.DESCENDING);
			for(var i:int=0; i < nn; i++)
			{
				var sp:Sprite=array[i].sp as Sprite;
				container.setChildIndex(sp, i);
			}
		}
	}
}

forked from: らせん階段を上ります。