package { import flash.display.MovieClip; import flash.display.Sprite; import flash.events.Event; [SWF(width = "465", height = "465", backgroundColor = "0xFFFFFF", frameRate = "24")] /** * なんか長くなり過ぎたな、、、。 * @author naoto koshikawa */ public class PhysicalSomething3 extends MovieClip { // _____________________________________________________ Property /** particle count */ private static const PARTICLE_COUNT:uint = 10; /** particle min size */ private static const PARTICLE_SIZE_MIN:uint = 15; /** particle max size */ private static const PARTICLE_SIZE_MAX:uint = 30; /** particle list */ private var _particles:Array; /** for index */ private var _i:uint; private var _j:uint; // _____________________________________________________ Method /** * constructor */ public function PhysicalSomething3() { _particles = []; Physics.init(stage); createParticles(); addEventListener(Event.ENTER_FRAME, enterFrameListener); } /** * create particles */ private function createParticles():void { for (var i:uint = 0; i < PARTICLE_COUNT; i++) { var size:Number = Math.floor(Math.random() * (PARTICLE_SIZE_MAX - PARTICLE_SIZE_MIN + 1 )) + PARTICLE_SIZE_MIN; var particle:MovieClip = new Particle(size); Physics.base.addChild(particle); var position:Object = Physics.getRandomPosition(particle); particle.alpha = 0.7; particle.x = position.x; particle.y = position.y; _particles.push(particle); } } // _____________________________________________________ Listener /** * Event.ENTER_FRAME event listener * @param event */ private function enterFrameListener(event:Event):void { for (_i = 0; _i < _particles.length - 1; _i++) { for (_j = _i + 1; _j < _particles.length; _j++) { var dx:Number = _particles[_j].x - _particles[_i].x; var dy:Number = _particles[_j].y - _particles[_i].y; var dist:Number = Math.sqrt(dx * dx + dy * dy); var collisionDist:Number = _particles[_j].size + _particles[_i].size; if (dist < collisionDist) { var radian:Number = Math.atan2(dy, dx); _particles[_i].ax = -((_particles[_i].x + Math.cos(radian) * collisionDist) - _particles[_j].x) * Physics.SPRING; _particles[_i].ay = -((_particles[_i].y + Math.sin(radian) * collisionDist) - _particles[_j].y) * Physics.SPRING; _particles[_j].ax = ((_particles[_i].x + Math.cos(radian) * collisionDist) - _particles[_j].x) * Physics.SPRING; _particles[_j].ay = ((_particles[_i].y + Math.sin(radian) * collisionDist) - _particles[_j].y) * Physics.SPRING; } } } for (_i = 0; _i < _particles.length; _i++) { _particles[_i].x += _particles[_i].vx * Physics.t + 0.5 * _particles[_i].ax * Physics.t * Physics.t; _particles[_i].y += _particles[_i].vy * Physics.t + 0.5 * _particles[_i].ay * Physics.t * Physics.t; _particles[_i].vx += _particles[_i].ax * Physics.t; _particles[_i].vy += _particles[_i].ay * Physics.t; // bound horizontally if (Physics.right < _particles[_i].x + _particles[_i].width / 2) { _particles[_i].vx *= Physics.BOUNCE; _particles[_i].x = Physics.right - _particles[_i].width / 2; } else if (_particles[_i].x - _particles[_i].width / 2 < Physics.left) { _particles[_i].vx *= Physics.BOUNCE; _particles[_i].x = Physics.left + _particles[_i].width / 2; } // bound vertically if (Physics.bottom < _particles[_i].y + _particles[_i].height / 2) { _particles[_i].vy *= Physics.BOUNCE; _particles[_i].y = Physics.bottom - _particles[_i].height / 2; } else if (_particles[_i].y - _particles[_i].height / 2 < Physics.top) { _particles[_i].vy *= Physics.BOUNCE; _particles[_i].y = Physics.top + _particles[_i].height / 2; } _particles[_i].ax = 0; _particles[_i].ay = 0; } } } } import flash.display.BitmapData; import flash.display.DisplayObject; import flash.display.DisplayObjectContainer; import flash.display.Shape; import flash.display.Sprite; import flash.display.Stage; import flash.events.Event; import flash.utils.getTimer; class Physics { // _____________________________________________________ Property /** gravity accerator */ internal static const GRAVITY:Number = 980; /** firiction */ internal static const FRICTIION:Number = 0.0; /** bounce */ internal static const BOUNCE:Number = -0.9; /** spring */ internal static const SPRING:Number = 30; /** boundary of top position */ private static var _top:Number; public static function get top():Number { if (!_init) throwError(); return _top; } /** boundary of left postion */ private static var _left:Number; public static function get left():Number { if (!_init) throwError(); return _left; } /** boundary of bottom position */ private static var _bottom:Number; public static function get bottom():Number { if (!_init) throwError(); return _bottom; } /** boundary of right postion */ private static var _right:Number; public static function get right():Number { if (!_init) throwError(); return _right; } /** initialized flag */ private static var _init:Boolean; /** real stage */ private static var _stage:Stage; /** virtual stage */ private static var _base:Sprite; public static function get base():Sprite { if (!_init) throwError(); return _base; } /** time */ private static var _prevtime:Number; private static var _t:Number; public static function get t():Number { if (!_init) throwError(); return _t; } // _____________________________________________________ Method /** * init */ public static function init(stage:Stage):void { _stage = stage; _prevtime = flash.utils.getTimer(); createBase(); _init = true; } /** * get random poisition * @param target target object whicth you wanna get random position * @param parent target.parent * @return */ public static function getRandomPosition(target:DisplayObject, parent:DisplayObjectContainer=null):Object { if (!_init) throwError(); if (!parent) parent = _base; var position:Object = { x:0, y:0 }; position.x = Math.random() * (parent.width - target.width) + target.width / 2 - parent.x; position.y = Math.random() * (parent.height - target.height) + target.width / 2 - parent.y; return position; } /** * throw error */ private static function throwError():void { throw(new Error("please invoke Physics.init, first")); } /** * create base object */ private static function createBase():void { _base = new Sprite(); _base.x = _stage.stageWidth / 2; _base.y = _stage.stageHeight / 2; var dotData:BitmapData = new BitmapData(2, 2, true, 0x00000000); dotData.setPixel32(0, 0, 0x33000000 | 0x00FFFFFF * Math.random()); var dot:Shape = new Shape(); dot.graphics.beginBitmapFill(dotData); dot.graphics.drawRect(-_base.x, -_base.y, _stage.stageWidth, _stage.stageHeight); _base.addChild(dot); _stage.addChild(_base); _top = -_base.height/2; _left = - _base.width/2 ; _bottom = _base.height / 2; _right = _base.width / 2; _base.addEventListener(Event.ENTER_FRAME, enterFrameListener, false, int.MIN_VALUE, true); } // _____________________________________________________ Listener /** * Event.ENTER_FRAME event listener * @param event */ private static function enterFrameListener(event:Event):void { _t = (getTimer() - _prevtime) / 1000; _prevtime = getTimer(); } } import flash.display.Graphics; import flash.display.MovieClip; class Particle extends MovieClip { // _____________________________________________________ Property public var vx:Number = 0; public var vy:Number = 0; public var ax:Number = 0; public var ay:Number = 0; public var size:Number; // _____________________________________________________ Method /** * constructor */ public function Particle(size:Number=20):void { this.size = size; var gr:Graphics = graphics; gr.beginFill(0xEEEEEE * Math.random(), 0.9); gr.drawCircle(0, 0, size); var radian:Number = Math.random() * Math.PI * 2; var radius:Number = Math.random() * size * 10 + 30; // temporary action ... vx = Math.cos(radian) * radius; vy = Math.sin(radian) * radius; } }