Do you know this pattern?

[Zoltan]

I'm sure many of you are familiar with this pattern:

http://www.sparkingspot.com/temp/image344.jpg

I'd like to reproduce it but I don't know its name or how it is generated. The
only thing I remember about it is that it was a popular texture in old demos.

Any clue would be appreciated.

EDIT: I _think_ the algo has something to do with sqrt...

[j83]

I'm sure many of you are familiar with this pattern:

http://www.sparkingspot.com/temp/image344.jpg

I'd like to reproduce it but I don't know its name or how it is generated. The
only thing I remember about it is that it was a popular texture in old demos.

Any clue would be appreciated.

EDIT: I _think_ the algo has something to do with sqrt...

Without knowing the context, perhaps something to do with some form of recursion?

[Zoltan]

Yep, it turned out to be several checkboards (of different size) blended together, much
like this filter: http://www.filterforge.com/filters/2544.html

[saschaherfort]

I remember recreating this by combining two black-to-white-gradients (one on X axis, one od Y axis) with a XOR operation on the bit level of the 8bit-per-channel color values.

For all pixels in the image:

color = gradientX(x,y) xor gradientY(x,y)