ばね パーティクル
package {
import __AS3__.vec.Vector;
import flash.display.Sprite;
import flash.display.StageAlign;
import flash.display.StageScaleMode;
import flash.events.TimerEvent;
import flash.filters.BlurFilter;
import flash.geom.Point;
import flash.utils.Timer;
[SWF(width="512", height="512", backgroundColor="0x000000")]
public class Animation_Particle_Spring extends Sprite
{
private var particles:Vector.<Ball>;
private var numParticles:uint = 50;
private var minDist:Number = 100;
private var springAmount:Number = 0.0025;
private var timer:Timer;
public function Animation_Particle_Spring()
{
stage.scaleMode = StageScaleMode.NO_SCALE;
stage.align = StageAlign.TOP_LEFT;
init();
}
//初期化
private function init():void{
particles = new Vector.<Ball>();
for(var i:uint = 0; i < numParticles; i++){
var size:Number = Math.random() * 10 + 2;
var particle:Ball = new Ball(size, 0xffffff);
particle.filters = [new BlurFilter(2, 2, 5)];
particle.x = Math.random() * stage.stageWidth;
particle.y = Math.random() * stage.stageHeight;
particle.mass = size;
particle.vx = Math.random() * 6 - 3;
particle.vy = Math.random() * 6 - 3;
addChild(particle);
particles.push(particle);
}
timer = new Timer(33);
timer.addEventListener(TimerEvent.TIMER, loop);
timer.start();
}
private function loop(event:TimerEvent):void{
graphics.clear();
for(var i:uint = 0; i < numParticles; i++){
var particle:Ball = particles[i];
particle.x += particle.vx;
particle.y += particle.vy;
if(particle.x > stage.stageWidth){
particle.x = 0;
}
else if(particle.x < 0){
particle.x = stage.stageWidth;
}
if(particle.y > stage.stageHeight){
particle.y = 0;
} else if(particle.y < 0){
particle.y = stage.stageHeight;
}
}
for(i = 0; i < numParticles - 1; i++){
var partA:Ball = particles[i];
for(var j:uint = i + 1; j < numParticles; j++){
var partB:Ball = particles[j];
checkCollision(partA, partB);
spring(partA, partB);
}
}
}
//バネの計算
private function spring(partA:Ball, partB:Ball):void{
var dx:Number = partB.x - partA.x;
var dy:Number = partB.y - partA.y;
var dist:Number = Math.sqrt(dx * dx + dy * dy);
if(dist < minDist){
graphics.lineStyle(1, 0xFFFFFF, 1 - dist / minDist);
graphics.moveTo(partA.x, partA.y);
graphics.lineTo(partB.x, partB.y);
var ax:Number = dx * springAmount;
var ay:Number = dy * springAmount;
partA.vx += ax / partA.mass;
partA.vy += ay / partA.mass;
partB.vx -= ax / partB.mass;
partB.vy -= ay / partB.mass;
}
}
private function checkCollision(ball0:Ball, ball1:Ball):void
{
var dx:Number = ball1.x - ball0.x;
var dy:Number = ball1.y - ball0.y;
var dist:Number = Math.sqrt(dx*dx + dy*dy);
if(dist < ball0.radius + ball1.radius)
{
// 角度とサイン、コサインの計算
var angle:Number = Math.atan2(dy, dx);
var sin:Number = Math.sin(angle);
var cos:Number = Math.cos(angle);
// ball0の位置の回転
var pos0:Point = new Point(0, 0);
// ball1の位置の回転
var pos1:Point = rotate(dx, dy, sin, cos, true);
// ball0の速度の回転
var vel0:Point = rotate(ball0.vx,
ball0.vy,
sin,
cos,
true);
// ball1の速度の回転
var vel1:Point = rotate(ball1.vx,
ball1.vy,
sin,
cos,
true);
// 衝突反応
var vxTotal:Number = vel0.x - vel1.x;
vel0.x = ((ball0.mass - ball1.mass) * vel0.x +
2 * ball1.mass * vel1.x) /
(ball0.mass + ball1.mass);
vel1.x = vxTotal + vel0.x;
// 位置の更新
var absV:Number = Math.abs(vel0.x) + Math.abs(vel1.x);
var overlap:Number = (ball0.radius + ball1.radius)
- Math.abs(pos0.x - pos1.x);
pos0.x += vel0.x / absV * overlap;
pos1.x += vel1.x / absV * overlap;
// 位置の回転
var pos0F:Object = rotate(pos0.x,
pos0.y,
sin,
cos,
false);
var pos1F:Object = rotate(pos1.x,
pos1.y,
sin,
cos,
false);
// 実際の画面位置への調整
ball1.x = ball0.x + pos1F.x;
ball1.y = ball0.y + pos1F.y;
ball0.x = ball0.x + pos0F.x;
ball0.y = ball0.y + pos0F.y;
// 速度の回転
var vel0F:Object = rotate(vel0.x,
vel0.y,
sin,
cos,
false);
var vel1F:Object = rotate(vel1.x,
vel1.y,
sin,
cos,
false);
ball0.vx = vel0F.x;
ball0.vy = vel0F.y;
ball1.vx = vel1F.x;
ball1.vy = vel1F.y;
}
}
private function rotate(x:Number,
y:Number,
sin:Number,
cos:Number,
reverse:Boolean):Point
{
var result:Point = new Point();
if(reverse)
{
result.x = x * cos + y * sin;
result.y = y * cos - x * sin;
}
else
{
result.x = x * cos - y * sin;
result.y = y * cos + x * sin;
}
return result;
}
}
}
import flash.display.Shape;
class Ball extends Shape {
public var radius:Number;
private var color:uint;
public var vx:Number = 0;
public var vy:Number = 0;
public var vz:Number = 0;
public var mass:Number = 1;
public function Ball(radius:Number=40, color:uint=0xff0000) {
this.radius = radius;
this.color = color;
init();
}
public function init():void {
graphics.beginFill(color);
graphics.drawCircle(0, 0, radius);
graphics.endFill();
}
}