_f_a_c_e Specifies which of the two fragment materials is being queried.
GGGGLLLL____FFFFRRRROOOONNNNTTTT or GGGGLLLL____BBBBAAAACCCCKKKK are accepted, representing the front and back
fragment materials, respectively.
_p_n_a_m_e Specifies the fragment material parameter to return. GGGGLLLL____AAAAMMMMBBBBIIIIEEEENNNNTTTT,
GGGGLLLL____DDDDIIIIFFFFFFFFUUUUSSSSEEEE, GGGGLLLL____SSSSPPPPEEEECCCCUUUULLLLAAAARRRR, GGGGLLLL____EEEEMMMMIIIISSSSSSSSIIIIOOOONNNN, GGGGLLLL____SSSSHHHHIIIINNNNIIIINNNNEEEESSSSSSSS, and
GGGGLLLL____CCCCOOOOLLLLOOOORRRR____IIIINNNNDDDDEEEEXXXXEEEESSSS are accepted.
_p_a_r_a_m_s Returns the requested data.
DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN
ffffggggllllGGGGeeeettttFFFFrrrraaaaggggmmmmeeeennnnttttMMMMaaaatttteeeerrrriiiiaaaallll returns in _p_a_r_a_m_s the value or values of parameter
_p_n_a_m_e of fragment material _f_a_c_e. Six parameters are defined:
GGGGLLLL____AAAAMMMMBBBBIIIIEEEENNNNTTTT _p_a_r_a_m_s returns four integer or floating-point
values representing the ambient reflectance of the
fragment material. Integer values, when requested,
are linearly mapped from the internal floating-
point representation such that 1.0 maps to the most
positive representable integer value, and -1.0 maps
to the most negative representable integer value.
If the internal value is outside the range [-1, 1],
the corresponding integer return value is
undefined. The initial value is (0.2, 0.2, 0.2,
1.0)
GGGGLLLL____DDDDIIIIFFFFFFFFUUUUSSSSEEEE _p_a_r_a_m_s returns four integer or floating-point
values representing the diffuse reflectance of the
fragment material. Integer values, when requested,
are linearly mapped from the internal floating-
point representation such that 1.0 maps to the most
positive representable integer value, and -1.0 maps
to the most negative representable integer value.
If the internal value is outside the range [-1, 1],
GGGGLLLL____SSSSPPPPEEEECCCCUUUULLLLAAAARRRR _p_a_r_a_m_s returns four integer or floating-point
values representing the specular reflectance of the
fragment material. Integer values, when requested,
are linearly mapped from the internal floating-
point representation such that 1.0 maps to the most
positive representable integer value, and -1.0 maps
to the most negative representable integer value.
If the internal value is outside the range [-1, 1],
the corresponding integer return value is
undefined. The initial value is (0, 0, 0, 1).
GGGGLLLL____EEEEMMMMIIIISSSSSSSSIIIIOOOONNNN _p_a_r_a_m_s returns four integer or floating-point
values representing the emitted light intensity of
the fragment material. Integer values, when
requested, are linearly mapped from the internal
floating-point representation such that 1.0 maps to
the most positive representable integer value, and
-1.0 maps to the most negative representable
integer value. If the internal value is outside
the range [-1, 1.0], the corresponding integer
return value is undefined. The initial value is (0,
0, 0, 1).
GGGGLLLL____SSSSHHHHIIIINNNNIIIINNNNEEEESSSSSSSS _p_a_r_a_m_s returns one integer or floating-point value
representing the specular exponent of the fragment
material. Integer values, when requested, are
computed by rounding the internal floating-point
value to the nearest integer value. The initial
value is 0.
GGGGLLLL____CCCCOOOOLLLLOOOORRRR____IIIINNNNDDDDEEEEXXXXEEEESSSS _p_a_r_a_m_s returns three integer or floating-point
values representing the ambient, diffuse, and
specular indices of the fragment material. These
indices are used only for color index lighting.
(All the other parameters are used only for RGBA
lighting.) Integer values, when requested, are
computed by rounding the internal floating-point
values to the nearest integer values.
NNNNOOOOTTTTEEEESSSS
If an error is generated, no change is made to the contents of _p_a_r_a_m_s.
EEEERRRRRRRROOOORRRRSSSS
GGGGLLLL____IIIINNNNVVVVAAAALLLLIIIIDDDD____EEEENNNNUUUUMMMM is generated if _f_a_c_e or _p_n_a_m_e is not an accepted value.
GGGGLLLL____IIIINNNNVVVVAAAALLLLIIIIDDDD____OOOOPPPPEEEERRRRAAAATTTTIIIIOOOONNNN is generated if ffffggggllllGGGGeeeettttFFFFrrrraaaaggggmmmmeeeennnnttttMMMMaaaatttteeeerrrriiiiaaaallll is executed
between the execution of ffffggggllllBBBBeeeeggggiiiinnnn and the corresponding execution of