4節リンク機構シミュレーション

/**
 * Copyright Nos_lkSsvOhB ( http://wonderfl.net/user/Nos_lkSsvOhB )
 * MIT License ( http://www.opensource.org/licenses/mit-license.php )
 * Downloaded from: http://wonderfl.net/c/6PAB
 */

package {
    import flash.text.TextField;
    import flash.display.Sprite;
    import flash.events.Event;
    import flash.*;
    public class Linkage extends Sprite {
        private var a:Number=60;
        private var b:Number=140;
        private var c:Number=180;
        private var d:Number=240;
        private var t:Number=10;
        private var theta:Number=0;
        private var xa:Number=100;
        private var ya:Number=280;
        private var xc:Number=340;
        private var yc:Number=280;
        private var xd:Number=100;
        private var yd:Number=280;
        private var bx0:Number;
        private var by0:Number;
        private var bx1:Number;
        private var by1:Number;
        private var link1:Sprite;
        private var link2:Sprite;
        private var link3:Sprite;
        private var link4:Sprite;
        private var trace1:TextField;
        private var al1:Number;
        private var al2:Number;
        private var L:Number;
        private var L2:Number;
        public function Linkage() {
            link4=new Sprite();
            link4.graphics.beginFill(0x9F9F9F);
            link4.graphics.moveTo(-t, -t);
            link4.graphics.lineTo(d+t, -t);
            link4.graphics.lineTo(d+t, t);
            link4.graphics.lineTo(-t, t);
            link4.graphics.lineTo(-t, -t);
            addChild(link4);
            link4.x=xd;
            link4.y=yd;
            link1=new Sprite();
            link1.graphics.beginFill(0x46A099);
            link1.graphics.moveTo(-t, -t);
            link1.graphics.lineTo(a+t, -t);
            link1.graphics.lineTo(a+t, t);
            link1.graphics.lineTo(-t, t);
            link1.graphics.lineTo(-t, -t);
            addChild(link1);
            link1.x=xa;
            link1.y=ya;
            link3=new Sprite();
            link3.graphics.beginFill(0x46A099);
            link3.graphics.moveTo(-t, -t);
            link3.graphics.lineTo(c+t, -t);
            link3.graphics.lineTo(c+t, t);
            link3.graphics.lineTo(-t, t);
            link3.graphics.lineTo(-t, -t);
            addChild(link3);
            link3.x=xc;
            link3.y=yc;
            link2=new Sprite();
            link2.graphics.beginFill(0x48A046);
            link2.graphics.moveTo(-t, -t);
            link2.graphics.lineTo(b+t, -t);
            link2.graphics.lineTo(b+t, t);
            link2.graphics.lineTo(-t, t);
            link2.graphics.lineTo(-t, -t);
            addChild(link2);
            trace1=CreateTF(10,400,300,50);
            addEventListener(Event.ENTER_FRAME,onEnter);
        }
        private function onEnter(event:Event):void {            
            L=Math.sqrt(a*a+d*d-2*a*d*Math.cos(theta));
            L2=a*a+d*d-2*a*d*Math.cos(theta);
            al1=-Math.acos((-a*a+d*d+L2)/(2*d*L));
            al2=-Math.acos((-b*b+c*c+L2)/(2*c*L));
            link1.rotation=theta*180/Math.PI;
            bx0=xa+a*Math.cos(theta);
            by0=ya+a*Math.sin(theta);
            if(by0>=yd){
                al1*=-1;
            }
            bx1=xa+d+c*Math.cos(Math.PI-al1-al2);
            by1=ya+c*Math.sin(Math.PI-al1-al2);
            link2.x=bx0;
            link2.y=by0;
            link2.rotation=Math.atan2(by1-by0,bx1-bx0)*180/Math.PI;
            link3.rotation=(Math.PI-al1-al2)*180/Math.PI;
            if(theta>=2*Math.PI){
                theta=0;
            }else{
                theta+=Math.PI/180*3/2;
            }
//            trace1.text="L="+L+"\nal1="+al1+"\nal2="+al2;
        }
            private function CreateTF(a:Number,b:Number,c:Number,d:Number):TextField{
            var tf:TextField=new TextField();
            tf.x=a;
            tf.y=b;
            tf.width=c;
            tf.height=d;
            tf.background=true;
            tf.border=true;
            addChild(tf);
            return tf
        }

    }
}