These are a couple of screen shots of my (now freeware) screensaver called GooMachine. The algorithm is an extension of what we used to call a 'sinus' - calculating a sin wave for every pixel on the screen based on the X coordinate, then feeding that value into another sin wave based on the Y coordinate, etc. (i.e. Function Composition).
The stills may be a little interesting, but the full-screen realtime animated version is pretty impressive (IMHO). Some points of interest:
With # Curves set to 9 on a 1024x768 screen, over 7 million multiplications and MODs, and over 14 million additions are calculated per frame!
The code is reasonably optimized - I get 9 FPS on a HP laptop with a cheesy video card (1024x768x9 waves)
DirectX 3.0 or higher (it's pretty simple stuff)
The source has the ability to play MIDI files along with the eye candy
Has the ability to animate over time (by slowly adding offsets) and by morphing between different curve types (not just sin waves but also with random waves)
Free, with source! (VC++ 6.0)
Be careful with the roughness setting - it can be a little 'rough' at times.
I have yet to make a WinAmp style plug-in, or pipe the output into a height-map viewer, but I'd love to see what anyone else might come up with...
NOTE: This does not work too well as a screen saver since, for some reason, it leaks very small amounts of resources on each run. I tried narrowing the code down to track this down, but found that DX appears to be leaking. I can run this about 250 times on my Athlon 600 box with 256MB ram before I run out of GDI resources.
Editor's note: The demo + source code package is available here: iotd-03-31-2002_goomachine.zip (73k)