Pixel rounding

Well not really a bug, but I didn't know where to post it and I want this to catch someone's attention badly, so Ashley :)

I did some experiments with mobile exports as you may know already and it came to me, that doing pixel rounding the way it's done in the runtime by Math.round(x) is the slowest way available to round a number.

Done some research and it seems that you can achieve double the speed by rounding using something called a Hack rounding with bitwise or:

rounded = (0.5 + somenum) | 0;

if (this.runtime.pixel_rounding) ... Math.round

How much of a performance boost could you measure?

I'd have thought it was negligable, since doing something like drawing a sprite probably takes 1000 times longer than the call to Round().

around 2 fps gain. not much but still... :)

OK, well every little helps on mobile, so I've used the (x + 0.5) | 0 form in the next build. It won't be changelogged though since it's a really small change.

well no problem for me it's not changelogged :) thanks and cheers!