javascripthtmlcanvascreatejs

Adobe Animate CC Canvas mouse actions on the stage are laggy and intermittent

In Adobe Animate CC HTML5 Canvas (createJS), I'm trying to do something very simple, to trigger an animated rollover when the entire stage of an ad is moused over, and to trigger an animated rollout when the mouse leaves the stage. It should be very simple, but it's not. Using mouseenter and mouseleave on the stage is laggy and only works intermittently. It's the same with mouseover and mouseout.

Here's the code that's laggy and intermittent:

stage.addEventListener("mouseenter", fl_MouseOverHandler.bind(this));
stage.addEventListener("mouseleave", fl_MouseOutHandler.bind(this));

function fl_MouseOverHandler(){
    this.btnOverAnim.gotoAndPlay("on");
}

function fl_MouseOutHandler(){
    this.btnOverAnim.gotoAndPlay("off");
}

I also tried mouseover and mouseout on a button the entire size of the stage and I got the same issue. (Also doing it this way doesn't work at all from inside a frame, and the ad is served inside a frame). I put the var frequency way up to 90 to see if that would help with the lagging, it didn't.

This was the simple mouseover / mouseout code I tried:

var frequency = 90;
stage.enableMouseOver(frequency);

this.bgCta.addEventListener("mouseover", fl_MouseOverHandler.bind(this));
this.bgCta.addEventListener("mouseout", fl_MouseOutHandler.bind(this));

On the createJS website it says "You can monitor whether the pointer is over the canvas by using stage.mouseInBounds AND the mouseleave / mouseenter events." So I'm wondering if using stage.mouseInBounds will help (but I can't find an example anywhere of how to use it). But I actually don't think it'll help because I think this whole problem is about createJS not reading where the mouse is fast enough.

Does anyone know how to fix this lagginess and intermittent firing? A work around? Why does createJS not just monitor the mouse events constantly like pure js?

Also mouseenter and mouseleave on the stage in createJS do not work on tablets or mobile and that's a problem, so it would be better to do this with mouseover and mouseout on a button the entire size of the stage. I did try using mouseover and mouseout and having 3 pixels space around the button between the edge of the button and the edge of the ad banner, this helped, but it was still firing intermittently.

Your thoughts and ideas please.

Solution

  • Mouseover checks are expensive. A canvas is essentially just a bitmap, so EaselJS can't use mouse events from the browser (you just get one for the entire canvas). Instead, mouseover in EaselJS requires every element to be drawn to a 1x1 pixel canvas, and then checked for fill. This gives pixel-perfect detection, but is costly if you are either checking a lot of content, or checking too often.

    Reduce your frequency: It looks like you have set the frequency to 90. This is really high (11 ms between checks, which is basically trying to achieve 90 fps). The default is 10, which is slower than a good framerate, but fast enough to feel responsive. You can probably bring it down to 20 or so to give you a peppy check without it being unnecessarily high.

    Modify interactivity: Another thing you can do is filter out exactly what gets checked. By default, all display objects get checked -- but you can reduce this by turning off mouseEnabled on anything you don't care about (omitting them from the check), and turning off mouseChildren on containers that you want to treat as a single object (so something like a complex button is drawn once, instead of all its contents being drawn individually).

    // Example
myBackground.mouseEnabled = false;
myButton.mouseChildren = false;

    Hope that helps!