universal gravitation

クリックすると惑星が一個増えるかも
各々が各々に判定してるから増やすとどんどん重くなる
３次元座標使ってるのに３次元表示してない

by cpu_t 06 Jan 2010

• Related works: 1
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/**
 * Copyright cpu_t ( http://wonderfl.net/user/cpu_t )
 * MIT License ( http://www.opensource.org/licenses/mit-license.php )
 * Downloaded from: http://wonderfl.net/c/zb4F
 */

// クリックすると惑星が一個増えるかも
// 各々が各々に判定してるから増やすとどんどん重くなる
// ３次元座標使ってるのに３次元表示してない
package {
	import flash.display.Bitmap;
	import flash.display.BitmapData;
    import flash.display.Sprite;
	import flash.events.Event;
	import flash.events.MouseEvent;
	import flash.filters.BlurFilter;
	import flash.geom.Vector3D;
	
	import net.hires.debug.Stats;
	
	[SWF(width = 400, height = 400, backgroundColor = 0xFFFFFF, frameRate = 60)]
    public class PlanetaryMotion extends Sprite {
		
		private const _size:int = stage.stageWidth;
		private var _satellites:Vector.<Satellite>;
		private var _bmpdata:BitmapData;
		private var _blurFilter:BlurFilter;
		
        public function PlanetaryMotion() {
			addEventListener(Event.ADDED_TO_STAGE, init);
        }
		private function init(e:Event):void
		{
			removeEventListener(Event.ADDED_TO_STAGE, init);
			stage.addChild(new Stats());
			
			_satellites = new Vector.<Satellite>;
			
			_bmpdata = new BitmapData(_size, _size, false, 0x000000);
			addChild(new Bitmap(_bmpdata));
			_blurFilter = new BlurFilter(4, 4, 1);
			
			addSatellite(new Satellite(50, new Vector3D(), new Vector3D()));
			addSatellite(new Satellite(1.5, new Vector3D(-90), new Vector3D(0,-3.5)));
			addSatellite(new Satellite(1.5, new Vector3D(-90.5), new Vector3D(0.5,-3.2)));
			addSatellite(new Satellite(2, new Vector3D(0,190), new Vector3D(3.2)));
			
			stage.addEventListener(MouseEvent.MOUSE_DOWN, mouseDownHandler);
			stage.addEventListener(Event.ENTER_FRAME, enterFrameHandler);
		}
		
		private function mouseDownHandler(e:Event):void
		{
			var pt:Vector3D = new Vector3D(mouseX - _size / 2, mouseY - _size / 2, 0);
			var vel:Vector3D = new Vector3D(Math.random() * 6 - 3, Math.random() * 6 - 3, Math.random() * 6 - 3);
			var st:Satellite = new Satellite(Math.random() * 2, pt, vel);
			addSatellite(st);
		}
		
		private function addSatellite(st:Satellite):void
		{
			_satellites.push(st);
		}
		
		private function enterFrameHandler(e:Event):void
		{
			_bmpdata.lock();
			_bmpdata.applyFilter(_bmpdata, _bmpdata.rect, _bmpdata.rect.topLeft, _blurFilter);
			
			var lastsatellites:Vector.<Satellite> = _satellites.concat();
			_satellites = _satellites.filter(function(item:Satellite, index:int, vector:Vector.<Satellite>):Boolean
			{
				if (index != 0) item.update(lastsatellites);
				bdDrawCircle(_bmpdata, _size / 2 + item.point.x, _size / 2 + item.point.y, item.radius, 0xFFFFFF);
				return (item.point.x > -_size && item.point.x < _size && item.point.y > -_size && item.point.y < _size)?true:false;
			}, this);
			
			_bmpdata.unlock();
		}
		
		private function bdDrawCircle(bmpdata:BitmapData, x:Number, y:Number, radius:Number, color:uint):void
		{
			var dx:Number = 0;
			var dy:Number = radius;
			bmpdata.setPixel(int(x + 0.5), int(y + dy + 0.5), color);
			bmpdata.setPixel(int(x + 0.5), int(y - dy + 0.5), color);
			bmpdata.setPixel(int(x + dy + 0.5), int(y + 0.5), color);
			bmpdata.setPixel(int(x - dy + 0.5), int(y + 0.5), color);
			radius *= radius;
			while (dx + 1 < dy) {
				dx++;
				dy = Math.sqrt(radius - dx * dx);
				bmpdata.setPixel(int(x + dx + 0.5), int(y + dy + 0.5), color);
				bmpdata.setPixel(int(x - dx + 0.5), int(y + dy + 0.5), color);
				bmpdata.setPixel(int(x + dx + 0.5), int(y - dy + 0.5), color);
				bmpdata.setPixel(int(x - dx + 0.5), int(y - dy + 0.5), color);
				bmpdata.setPixel(int(x + dy + 0.5), int(y + dx + 0.5), color);
				bmpdata.setPixel(int(x + dy + 0.5), int(y - dx + 0.5), color);
				bmpdata.setPixel(int(x - dy + 0.5), int(y + dx + 0.5), color);
				bmpdata.setPixel(int(x - dy + 0.5), int(y - dx + 0.5), color);
			}
		}
    }
}

import flash.geom.Vector3D;
class Satellite extends Object {
	// Variables
	private var _radius:Number;
	private var _point:Vector3D;
	private var _velocity:Vector3D;
	// Constructor methods
	public function Satellite(radius:Number, point:Vector3D, velocity:Vector3D) {
		_radius = radius;
		_point = point;
		_velocity = velocity;
	}
	// Instance methods
	public function update(satellites:Vector.<Satellite>):void
	{
		const G:Number = 1;
		var r:Number;
		var vec:Vector3D;
		for each(var st:Satellite in satellites) {
			vec = _point.subtract(st.point);
			r = vec.lengthSquared * 500;
			vec.normalize();
			if (r != 0) vec.scaleBy( -G * (_radius*_radius*_radius) * (st.radius*st.radius*st.radius) / r);
			_velocity = _velocity.add(vec);
		}
		_point = _point.add(_velocity);
	}
	// Accessor methods
	public function get radius():Number { return _radius; }
	public function set radius(value:Number):void { _radius = value; }
	public function get point():Vector3D { return _point; }
	public function set point(value:Vector3D):void { _point = value; }
	public function get velocity():Vector3D { return _velocity; }
	public function set velocity(value:Vector3D):void { _velocity = value; }
}