问如何在波浪运动中移动html5 (createjs)中的对象

EN

    function handleComplete() {
    exportRoot = new lib.PlatypusGame();
    exportRoot.removeChild(exportRoot.platypus);

    stage = new Stage(canvas);
    stage.addChild(exportRoot);

    Touch.enable(stage);

    Ticker.setFPS(20);
    // add the listener to window, so we can do some work before updating the stage:
    Ticker.addListener(window);
}

function tick() {
    if (platypii.length < 1 || Math.random() < 0.01 && platypii.length < 5) {
        var platypus = new lib.Platypus();
        platypus.scaleX = platypus.scaleY = Math.random()*0.3+0.3;
        platypus.x = 800;
        // nominalBounds holds the dimensions of the first frame of the symbol at export time.
        platypus.y = Math.random()*(400-platypus.scaleY*platypus.nominalBounds.height);
        platypus.velX = (1+platypus.scaleX)*-6;
        platypus.velY = 0;
        // we only want to know about clicks on the balloon, not the whole platypus:
        platypus.platypusIdle.balloon.onClick = handleBalloonClick;
        platypus.onPopped = handleBalloonPopped;

        platypii.push(platypus);
        exportRoot.addChild(platypus);
    }

    // go in reverse to make it easier to splice items from the array
    for (var i=platypii.length-1; i>=0; i--) {
        platypus = platypii[i];

        // add gravity to the Y velocity if it's falling:
        if (platypus.falling) { platypus.velY += 3; }
        platypus.x += platypus.velX;
        platypus.y += platypus.velY;

        if (platypus.x < -platypus.nominalBounds.width*platypus.scaleX || platypus.y > 400) {
            platypii.splice(i,1);
            exportRoot.removeChild(platypus);
            // add +100 points if it fell or -500 if it escaped
            updateScore(platypus.y > 400 ? 100 : -500);
        }
    }

    stage.update();
}