fglGetFragmentMaterial(3G) OpenGL Reference fglGetFragmentMaterial(3G)NAME
fglGetFragmentMaterialfvSGIX, fglGetFragmentMaterialivSGIX - return
fragment material parameters
FORTRAN SPECIFICATION
SUBROUTINE fglGetFragmentMaterialfvSGIX( INTEGER*4 face,
INTEGER*4 pname,
CHARACTER*8 params )
SUBROUTINE fglGetFragmentMaterialivSGIX( INTEGER*4 face,
INTEGER*4 pname,
CHARACTER*8 params )
PARAMETERS
face Specifies which of the two fragment materials is being queried.
GL_FRONT or GL_BACK are accepted, representing the front and back
fragment materials, respectively.
pname Specifies the fragment material parameter to return. GL_AMBIENT,
GL_DIFFUSE, GL_SPECULAR, GL_EMISSION, GL_SHININESS, and
GL_COLOR_INDEXES are accepted.
params Returns the requested data.
DESCRIPTION
fglGetFragmentMaterial returns in params the value or values of parameter
pname of fragment material face. Six parameters are defined:
GL_AMBIENT params 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)
GL_DIFFUSE params 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],
the corresponding integer return value is
undefined. The initial value is (0.8, 0.8, 0.8,
1.0).
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fglGetFragmentMaterial(3G) OpenGL Reference fglGetFragmentMaterial(3G)
GL_SPECULAR params 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).
GL_EMISSION params 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).
GL_SHININESS params 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.
GL_COLOR_INDEXES params 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.
NOTES
If an error is generated, no change is made to the contents of params.
ERRORS
GL_INVALID_ENUM is generated if face or pname is not an accepted value.
GL_INVALID_OPERATION is generated if fglGetFragmentMaterial is executed
between the execution of fglBegin and the corresponding execution of
fglEnd.
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fglGetFragmentMaterial(3G) OpenGL Reference fglGetFragmentMaterial(3G)MACHINE DEPENDENCIES
The SGIX_fragment_lighting extension is supported only on Octane2 VPro
systems.
SEE ALSO
fglFragmentMaterial
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