very nice buddhi

ker2x:
I can't guarantee that I still have all the formulae but if you want to know any specific of them I can try to find it

Are you using a fixed grid approach or a random grid one to render your results?
In both cases, multithreating should be somewhat easy to implement: for the random case, just start an additional rekursion per thread and for the fixed grid maybe render per quadrant or make it so the cores cycle through the points.

Just some thoughts...
I choose random point.
You can find the the source code in *.pb file
Even if you don't know purebasic, it's very easy to understand

The problem with multithread :
- With a standard mandelbrot rendering, computing one point write one pixel.
- With buddhabrot, computing one point write on the whole image.
- with millions of point written per seconds, the problem will spend all its time to wait for mutex. Unless i accept some consistancy problem... the effect could be negligible.
For now, i'm playing with rewriting fractal rendering in x64 asm with SSE2&3 instruction. Big speed improvement.
I started to rewrite the buddhabrot renderer in asm with SSE