1100061 - Gravity Demo Very Slow

Status: NEW

(Core :: Graphics: Canvas2D, defect)

Description

[Sean Stangl [:sstangl]]

The demo at http://www.stephenbalaban.com/wp-content/uploads/2014/11/Gravity.html runs very slowly in Firefox, but quickly in Chrome.

The built-in profiler shows that ~80% of the time is spent in the following function:

>    function transform(transforms, ctx) {
>        ctx.translate(w/2, h/2);
>        ctx.scale(1,-1);
>        var len = transforms.length;
>        for (var i = 0; i < len; ++i) {
>            var m = transforms[i];
>            ctx.save();
>            ctx.transform(m[0], m[3], m[1], m[4], m[2], m[5]);
>        }
>        return ctx;
>    }