Im confused as to whats the real signature for this function the GLee header has this for glStencilFuncSeparate, which im using typedef void (APIENTRYP PFNGLSTENCILFUNCSEPARATEPROC) (GLenum frontfunc, GLenum backfunc, GLint ref, GLuint mask); and this for ATI version which ive read the 2.0 is based off typedef void (APIENTRYP PFNGLSTENCILFUNCSEPARATEATIPROC) (GLenum frontfunc, GLenum backfunc, GLint ref, GLuint mask); but the opengl.org sdk doc here (http://www.opengl.org/sdk/docs/man/xhtml/glStencilFuncSeparate.xml) has this void glStencilFuncSeparate (GLenum face, GLenum func, GLint ref, GLuint mask); I have the two pass shadow volume rendering working, but im getting strange results when doing them together. I just want to make sure I have this straight, is GLee right? I read a post on opengl.org that the spec is wrong, has anyone used this successfully and which one was it? To confuse things more the book More OpenGL Game Programming lists the gl sdk doc version (GLenum face, GLenum func, ...) seemingly for GL2 and ATi...