How to do halos

I have repeatedly seen very cool halo effects done in recent games like Enigma, GLTron, Homeworld.
My question is, how do you do it? Use a semi-transparent texture with billboarding, perhaps?

And while we’re at it, how do you to mouse input under the WINAPI?


You can make a halo this way:

  1. Render the object and write to the stencil buffer. This is the normal object.
  2. Render the object again but scale so it will be bigger than the original. Use the stencil buffer to mask. This is your halo so do some fancy blending and effects.

Lesson23 from NeHe is doing mouse input using WINAPI.