Is it possible to have an hdri environment map in OpenGL as oppose to the cube map?
Have a read of http://www.smetz.fr/wp-content/uploads/2007/01/hdr\_opengl.pdf
Be aware that some opengl platforms limit the size of textures, hell if you end up doing opengles coding the limits can be nasty.
I know one device that only supports 256 pixels, anything bigger is truncated.
oh! so it's more complicated than I thought! Thanks for the paper, I'll study it.