Hi, I've been working on this little shadow engine for the Nspire the last 2 days:
It dynamically calculates and renders the shadows of a variable number of objects, relative to the position of the light source and draws their illuminated sides.
With 6 objects, it runs smoothly with 12-16 frames per second on the handheld.


Controls:
- click to enable/disable mouse control
- press m to change the render mode
- press r to enable/disable the illuminated rims
- in the upper left corner, there's a little fps counter


Note: There are some bugs, if objects are too close to each other or if the light source is too close to an object (but I didn't encounter a crash yet)


I made this engine just for fun, I don't think I'll do something with it or improve it soon; so you can do anything you want with it (but giving credit would be nice )

Looks super nice

Blinded by the Dark Nspire port soon? http://www.ticalc.org/archives/files/fileinfo/226/22637.html

This looks pretty nice. I wonder how fast is it on a real calc?

Seems quite nice. I bet it might be slower on 3.1, but thankfully, 3.6 can run Ndless so many people have switched. 14 FPS seems pretty fine IMHO (and higher would be problematic on the Click/Touchpad models anyway since motion blur would be too intense)

@Jens :
I only quickly went through the code, but I believe that it can still be optimized. (Making math stuff in on.timer local, not redefining the gc-using function inside each on.paint call, etc.)
I'll go through it more in depth when I have some time, though, these days are pretty busy for me....