A 3D-particle-gravity simulation using OpenGL's transform-feedback feature
making all physics and graphics run on the GPU.

You'll need SDL2 and the corresponding SDL_image on a recent Linux-distribution
and with the right dependencies fulfilled it also compiles and runs under OSX
and Windows (I verified both).

How to compile and run (Linux):
 * make
 * ./glsl-transform-feedback_release 0
 or
 * ./glsl-transform-feedback_debug 0

(Try passing 1 instead of 0 and play around with the gravity sources :)

Compiling under OSX and Windows is a bit more involved. I might update the
branch to compile and run out of the box (assuming build-dependencies are
satisfied) on these platforms too.

Currently hooked up interaction:
 * ESC - quit
 * SPACE - reset simulation and disable any gravity-source
 * LMB-click - place attracting gravity-source
 * LMB-drag - drag attracting gravity-source around in a plane 
 * MMB-click - disable any gravity-source
 * RMB-click - place repelling gravity-source
 * RMB-drag - drag repelling gravity-source

Furthermore you should not bother with this if your system's OpenGL-implement-
ation is < 3.2.

For questions, suggestions, feedback or patches you can reach me via:
 * eMail: [email protected]
 * IRC (FreeNode): #OpenGL, #ubuntu as MacSlow 

There's also a WebGL2/JavaScript-implementation of this available at:
 * https://macslow.org/js/webgl2-transform-feedback.html?cubeSize=100?flag=0