glGetTexGen returns in params selected parameters of a texture coordinate generation function that was specified using glTexGen. coord names one of the (s, t, r, q) texture coordinates, using the symbolic constant GL_S, GL_T, GL_R, or GL_Q.pname specifies one of three symbolic names:
GL_TEXTURE_GEN_MODE
params returns the single-valued texture generation function, a symbolic constant. The initial value is GL_EYE_LINEAR.
GL_OBJECT_PLANE
params returns the four plane equation coefficients that specify object linear-coordinate generation. Integer values, when requested, are mapped directly from the internal floating-point representation.
GL_EYE_PLANE
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.