[Wolsh]

function doit():Void{
	var x = _xmouse-bt._x;
	var y = _ymouse-bt._y;
	var angle = 90 + Math.atan2(y, x)/Math.PI*180;
	bt._rotation += (angle - bt.ang);
	bt.ang = angle
	updateAfterEvent ();
}
bt.onPress = function():Void{
	var x = _xmouse-this._x;
	var y = _ymouse-this._y;
	this.ang = 90+Math.atan2(y, x)/Math.PI*180;
	onMouseMove = doit;
};
bt.onRelease = bt.onReleaseOutside = function():Void{
	delete onMouseMove;
};