drawing

var loc:Vector.<Point> = new Vector.<Point>();
var lifts:Vector.<int> = new Vector.<int>();
var index:int = 0;
var resolution:int = 1;
var down:Boolean;
stage.addEventListener(MouseEvent.MOUSE_DOWN, onDown);
stage.addEventListener(MouseEvent.MOUSE_UP, onUp);
stage.addEventListener(KeyboardEvent.KEY_DOWN, onKeyReleased);
addEventListener(Event.ENTER_FRAME, onLoop);
function onKeyReleased(evt:KeyboardEvent):void{
    if (evt.keyCode == Keyboard.RIGHT){
        resolution -= 1;
        if (resolution <1) resolution = 1;
    }else
    if (evt.keyCode == Keyboard.LEFT){
        resolution += 1;
    }
}
function onDown(evt:MouseEvent):void{
    down = true;
    lifts.push(index);
}
function onUp(evt:MouseEvent):void{
    down = false;
}
function onLoop(evt:Event):void {
    if (down){
        loc[index] = new Point(mouseX, mouseY);
        index++;
    }
    graphics.clear();
    graphics.lineStyle(0,0x000000);
    var j:int = 0;
    var lift:int;
    var liftLength:int = lifts.length;
    var lastLoc:int =  loc.length  - 1;
    for (var i:int = 0; i<liftLength; i++){
        j =  lifts[i];
        graphics.moveTo(loc[j].x, loc[j].y);
        if (i <liftLength - 1){
            lift = lifts[i + 1] - 1;
        }else{
            lift = lastLoc;
        }
        while (j <lift){
            j++;
            if (j % resolution == 1 || resolution == 1){
              graphics.lineTo(loc[j].x, loc[j].y);
            }
        }
        graphics.lineTo(loc[j].x, loc[j].y);
    }
}