GL_SGIX_fog_texture
http://www.opengl.org/registry/specs/gl/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)