COLLISION BALLS
Main
メインクラス.
/**
* Copyright kazy ( http://wonderfl.net/user/kazy )
* MIT License ( http://www.opensource.org/licenses/mit-license.php )
* Downloaded from: http://wonderfl.net/c/vWM7
*/
package
{
import flash.display.Sprite;
import flash.events.Event;
import flash.geom.Point;
/**
* Main
* メインクラス.
*/
public class Main extends Sprite
{
private var balls:Array;
private var numBalls:uint = 8;
private var bounce:Number = -1.0;
/**
* コンストラクタ.
*/
public function Main()
{
init();
}
/**
* 初期設定.
*/
private function init():void
{
balls = new Array();
//numBallsの数だけボール生成
for(var i:uint = 0; i < numBalls; i++)
{
var radius:Number = Math.random() * 20 + 20;
var ball:Ball = new Ball(radius);
ball.mass = radius;
ball.x = i * 100
ball.y = i * 50;
ball.vx = Math.random() * 10 - 5;
ball.vy = Math.random() * 10 - 5;
addChild(ball);
balls.push(ball);
}
addEventListener(Event.ENTER_FRAME, onEnterFrame);
}
/**
* onEnterFrame.
*/
private function onEnterFrame(event:Event):void
{
for(var i:uint = 0; i < numBalls; i++)
{
var ball:Ball = balls[i];
//加速
ball.x += ball.vx;
ball.y += ball.vy;
//壁の接触判定
checkWalls(ball);
}
for(i = 0; i < numBalls - 1; i++)
{
var ballA:Ball = balls[i];
for(var j:Number = i + 1; j < numBalls; j++)
{
var ballB:Ball = balls[j];
//衝突判定
checkCollision(ballA, ballB);
}
}
}
/**
* 壁の接触判定.
* @param ball 判定するボール
*/
private function checkWalls(ball:Ball):void
{
if(ball.x + ball.radius > stage.stageWidth)
{
ball.x = stage.stageWidth - ball.radius;
ball.vx *= bounce;
}
else if(ball.x - ball.radius < 0)
{
ball.x = ball.radius;
ball.vx *= bounce;
}
if(ball.y + ball.radius > stage.stageHeight)
{
ball.y = stage.stageHeight - ball.radius;
ball.vy *= bounce;
}
else if(ball.y - ball.radius < 0)
{
ball.y = ball.radius;
ball.vy *= bounce;
}
}
/**
* 衝突判定.
* @param ball0 ボール0
* @param ball1 ボール1
*/
private function checkCollision(ball0:Ball, ball1:Ball):void
{
var dx:Number = ball1.x - ball0.x;
var dy:Number = ball1.y - ball0.y;
//ボール間の距離
var dist:Number = Math.sqrt(dx * dx + dy * dy);
//ボールの半径の合計より、ボール間の距離が短かったら
if(dist < ball0.radius + ball1.radius)
{
// 角度
var angle:Number = Math.atan2(dy, dx);
//sin
var sin:Number = Math.sin(angle);
//cos
var cos:Number = Math.cos(angle);
// rotate ball0's position
var pos0:Point = new Point(0, 0);
// 座標を回転
var pos1:Point = rotate(dx, dy, sin, cos, true);
var vel0:Point = rotate(ball0.vx,
ball0.vy,
sin,
cos,
true);
// 加速ベクトルを回転
var vel1:Point = rotate(ball1.vx,
ball1.vy,
sin,
cos,
true);
//
var vxTotal:Number = vel0.x - vel1.x
//運動量保存の法則
vel0.x = ((ball0.mass - ball1.mass) * vel0.x +
2 * ball1.mass * vel1.x) /
(ball0.mass + ball1.mass);
vel1.x = vxTotal + vel0.x;
// 座標をボールに適応
pos0.x += vel0.x;
pos1.x += vel1.x;
// 回転座標を戻す
var pos0F:Object = rotate(pos0.x,
pos0.y,
sin,
cos,
false);
var pos1F:Object = rotate(pos1.x,
pos1.y,
sin,
cos,
false);
// 正規の座標に適応
ball1.x = ball0.x + pos1F.x;
ball1.y = ball0.y + pos1F.y;
ball0.x = ball0.x + pos0F.x;
ball0.y = ball0.y + pos0F.y;
// // 回転加速度ベクトルを戻す
var vel0F:Object = rotate(vel0.x,
vel0.y,
sin,
cos,
false);
var vel1F:Object = rotate(vel1.x,
vel1.y,
sin,
cos,
false);
// 正規の加速度に適応
ball0.vx = vel0F.x;
ball0.vy = vel0F.y;
ball1.vx = vel1F.x;
ball1.vy = vel1F.y;
}
}
/**
* 回転座標を返す.
* @param x x座標
* @param y y座標
* @param sin sin
* @param cos cos
* @param reverse 負の角度
*/
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;
}
}
}
/**
* Ball
* ボール生成クラス.
*/
class Ball extends flash.display.Sprite {
public var radius:Number;
private var color:uint;
public var vx:Number = 0;
public var vy:Number = 0;
public var mass:Number = 1;
/**
* コンストラクタ.
*/
public function Ball(radius:Number=40, color:uint=0x990033) {
this.radius = radius;
this.color = color;
init();
}
/**
* 初期化.
*/
public function init():void {
graphics.beginFill(color);
graphics.drawCircle(0, 0, radius);
graphics.endFill();
}
}