For those who are curious about how to do projective texturing in
Jitter, I've uploaded a sample patch and Cg shader for doing
projective texturing with Phong shading. I'm using the jit.gl.texture
@bordercolor attribute in the patch, so if you don't have the latest
beta when a bug related to bordercolor was fixed, some of the colors
might look funky.
The key to doing projetive texturing is using OpenGL's matrix loading
and multiplication functions to calculate the coordinate transform of
the scene from the light's point of view. This is applied to the
texture coordinates so that they seem to project from that location.
The texture transform matrix also needs the model to world transform
of the object the shader is operating on, so that matrix is passed in
as another variable.