forked from: ルーローの三角形を正方形内で転がしたときの中心→頂点の軌跡

/**
 * Copyright bradsedito ( http://wonderfl.net/user/bradsedito )
 * MIT License ( http://www.opensource.org/licenses/mit-license.php )
 * Downloaded from: http://wonderfl.net/c/AjBq
 */

// forked from keno42's ルーローの三角形を正方形内で転がしたときの中心→頂点の軌跡
package  
{
    import flash.display.Sprite;
    public class Test extends Sprite
    {
        
        public function Test() 
        {
            this.x = 80;
            this.y = 80;
            for ( var i:Number = 0; i < 90; i+= 1 ) {
                var angle:Number = Math.PI * i / 180;
                var r:Number = 400;
                this.graphics.lineStyle(0, 0x00FF00);
                this.graphics.moveTo(0, 0);
                var toX:Number = 0;
                var toY:Number = 0;
                if ( i < 30 ) {
                    toX = 0.5 * r * Math.sqrt(3) - r * Math.cos( angle );
                    toY = - 0.5 * r * Math.sqrt(3) + r * Math.cos( angle - (30 * Math.PI / 180) );
                } else if ( i > 60 ) {
                    toX = - 0.5 * r * Math.sqrt(3) + r * Math.cos( angle - (60 * Math.PI / 180) );
                    toY = 0.5 * r * Math.sqrt(3) - r * Math.cos( angle - (90 * Math.PI / 180) );
                } else {
                    toX = Math.sqrt(3) * r * 0.5 * (2 * Math.sin(angle + (60 * Math.PI / 180)) - 1) - r * Math.cos(angle);
                    toY = Math.sqrt(3) * r * 0.5 * (2 * Math.sin(angle + (30 * Math.PI / 180))  - 1) - r * Math.sin(angle);
                }
                this.graphics.moveTo(toX, toY);
                this.graphics.lineStyle(0, 0x0000FF, 0.2);
                this.graphics.lineTo(toX + r * Math.cos(angle), toY + r * Math.sin(angle));
                
            }
        }
        
    }

}