GLGETMATERIAL(3G) GLGETMATERIAL(3G)
NAME
glGetaterialfv,, glGetaterialiv - return material parameters
C SPECIFICATION
void glGetaterialfv( GLenum face,
GLenum pname,
GLfloat *params )
void glGetaterialiv( GLenum face,
GLenum pname,
GLint *params )
PARAMETERS
face Specifies which of the two materials is being queried.
GLFRONT or GLBACK are accepted, representing the front and
back materials, respectively.
pname Specifies the material parameter to return. GLAMBIENT,
GLDIFUSE, GLSPECULAR, GLEMISION, GLSHININES, and
GLCOLORINDEXES are accepted.
params Returns the requested data.
DESCRIPTION
glGetaterial returns in params the value or values of parameter pname
of material face. Six parameters are defined:
GLAMBIENT params returns four integer or floating-point
values representing the ambient reflectance of
the 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)
GLDIFUSE params returns four integer or floating-point
values representing the diffuse reflectance of
the 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).
GLSPECULAR params returns four integer or floating-point
values representing the specular reflectance of
the 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).
GLEMISION params returns four integer or floating-point
values representing the emitted light intensity
of the 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).
GLSHININES params returns one integer or floating-point
value representing the specular exponent of the
material. Integer values, when requested, are
computed by rounding the internal floating-point
value to the nearest integer value. The initial
value is 0.
GLCOLORINDEXES params returns three integer or floating-point
values representing the ambient, diffuse, and
specular indices of the material. These indices
are used only for color index lighting. (All the
other parameters are used only for RGBA light-
ing.) Integer values, when requested, are com-
puted 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.
ERORS
GLINVALIDENUM is generated if face or pname is not an accepted value.
GLINVALIDOPERATION is generated if glGetaterial is executed between
the execution of glBegin and the corresponding execution of glEnd.
SEE ALSO
glaterial
GLGETMATERIAL(3G)
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