GL_SGIX_fog_texture http://www.opengl.org/registry/specs/SGIX/fog_texture.txt GL_SGIX_fog_texture GL_TEXTURE_FOG_SGIX 0 GL_FOG_PATCHY_FACTOR_SGIX 0 GL_FRAGMENT_FOG_SGIX 0 void glTextureFogSGIX (GLenum pname)