Seeing Stars

James Bowman

Introduction

I was inspired to write this short program after seeing the Rival Lights screensaver. It works very well on consumer 3D hardware; drawing only 100 textured quads per frame, it easily runs at 60Hz.

It works like this:

• Transform the stars (about 100 points), and use GL_FEEDBACK to find their positions in screen coordinates. This stage does no actual drawing.
• Switch to identity transform matrices, and draw a textured quad ("sprite") for every star, with the appropriate blending, texture, color.

stars.c source (distributed under the terms of the GNU General Public License).

(If you want to compile it, you'll also need GLUT).