HP Workstation zx2000 OpenGL 1.1 Reference for HP-UX 11.x - Page 216

G glGetTexGen params returns the four plane equation coefficients that specify eye linear-coordinate generation. Integer values, when requested, are mapped directly from the internal floating-point representation. The returned values are those maintained in eye coordinates. They are not equal to the values specified using glTexGen, unless the modelview matrix was identity when glTexGen was called. Notes If an error is generated, no change is made to the contents of params. Errors • GL_INVALID_ENUM is generated if coord or pname is not an accepted value. • GL_INVALID_OPERATION is generated if glGetTexGen is executed between the execution of glBegin and the corresponding execution of glEnd. See Also glTexGen 216 Chapter 7