[chengsun]

Řrřola (a famous demoscene coder [1]) found a far better constant than the original (a 2.7-fold accuracy improvement) by using an optimisation algorithm over all three constants present in the original inverse square hack.

His algorithm and the result (along with a plot of relative error) can be found on his blog [2].

[1]: See, for example, this 256-byte raycaster https://www.youtube.com/watch?v=R35UuntQQF8

[2]: http://rrrola.wz.cz/inv_sqrt.html

[soravux]

This is really interesting. I'll be sure to include these references in my next blog post on the subject. The goal of the post was to find the equation from scratch, though. As it can be seen, the constant optimization was less the spotlight of the post.

[zo1]

Not to mention your blog engine/site is broken. Please fix the fact that we can't click on the right scrollbar due to your fancy shmancy javascript side menu.

Put it on the left hand side, or don't overlay it over the scrollbar.

Damn #hipstercoders

[nitrogen]

The placement of any site elements on top of the scrollbar is indeed annoying. Is that a Blogspot thing, or is it due to a customization?

[masklinn]

It's blogspots "Dynamic Views". Complete dreck. I can only assume it's the default when you create a blog nowadays as I have no idea why anybody (least of all developers) would opt into that crap.

[coldpie]

Someone at blogspot needs a smack on the head. The site takes several seconds to load, which is absolutely ludicrous for displaying plain text, and when it finally does it's unusable as you've noted.

[Sprint]

It's a sadly commonly used theme that also does not display anything at all if you don't enable Javascript.

[soravux]

Everything is on default from Blogspot. I only put the Gist source code displayer and the LaTeX math javascript. If anyone is offering a new design, I would gladly take it... As long as I can concentrate on the content and not the container.

[xellisx]

Has anyone gone in an plugged this into the Quake III / IOQuake 3 source and see if it's make a difference? Speed or better looking geometry?

[jheriko]

its not faster and the accuracy improvement is more of a curiosity than of real value.

infact on modern desktop/console hardware invsqrt hack is really bad. it causes type aliasing which is 'expensive' in native software terms. the x86(-64) chips underlying them all now has a dedicated instruction for this, as do the PPCs that came in the generation before... still of value on ARM though which is becoming more and more important.