(Actionscript) Wave-like animation on objects

Question

I have different cards, I need to reveal them in a wave like form, i.e. the cards open and close at different timings sequentially and systematically such that they form a wave.

I have the cards in an array alr. How do I implement this animation in the most efficient way? Thx!

Answer 1

You should get comfortable using Math.sin() and Math.cos(). Look into simple trig functions and memorize converting radians and degrees. There are many cool and interesting tricks you can re-use in different contexts once you have a good grasp on these concepts. The following snippet demonstrates how to move an object with "a wave like form". It may not be exactly what you are looking for but it should help you get where you trying to go. It is written in the AS3 using the CS4 IDE.

var n:Number = 0;
var ball:MovieClip = new MovieClip();
ball.graphics.beginFill( 0xFFCC00, 1 );
ball.graphics.drawCircle( 0, 0, 15 );
addChild( ball );

ball.x = stage.stageWidth;
ball.y = stage.stageHeight * .5;

var prev:Point = new Point(ball.x, ball.y);

addEventListener( Event.ENTER_FRAME, onEnterFrameHanlder );

function onEnterFrameHanlder( event:Event ):void
{
    n+=3;
    ball.x = Math.cos( n * .25 * Math.PI/180 ) * ( stage.stageWidth * .5 ) + ( stage.stageWidth * .5 );
    ball.y = Math.sin( n * Math.PI/180 ) * ( stage.stageHeight * .5 ) + ( stage.stageHeight * .5 );

    graphics.lineStyle( 1, 0xFFCC00 );
    graphics.moveTo( ball.x, ball.y );
    graphics.lineTo( prev.x, prev.y );

    prev.x = ball.x;
    prev.y = ball.y;
}

Answer 2

presuming what you are meaning is a stadium "wave" effect, try to define an array with an offset, this will depend if you are using a tweening engine etc or if you are using another function.

The Timer class for example will do you well in this one:

private var t:Timer = new Timer(100, 0);
    private var index:int = 0;
    t.addEventListener(TimerEvent.TIMER, ping);
    t.start();

    private function ping(ev:TimerEvent) {
        if(index < waveArray.length){
            waveArray[index].startAnimation(); //If animated by object
            startAnimation(waveArray[index]); //If animated by container
            index ++;
        }
        else {
            t.stop();
            endAnimation(); //All cards have animated
        }
    }