GLGETMATERIAL(3G) GLGETMATERIAL(3G)
NAME
glGetMaterialfv, glGetMaterialiv - return material parameters
C SPECIFICATION
void glGetMaterialfv( GLenum face,
GLenum pname,
GLfloat *params )
void glGetMaterialiv( GLenum face,
GLenum pname,
GLint *params )
PARAMETERS
face Specifies which of the two materials is being queried. GL_FRONT or GL_BACK are accepted,
representing the front and back materials, respectively.
pname Specifies the 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
glGetMaterial returns in params the value or values of parameter pname of material face. Six parame-ters parameters
ters are defined:
GL_AMBIENT 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 nega-tive negative
tive 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 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 nega-tive negative
tive 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).
GL_SPECULAR 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 nega-tive negative
tive 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 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 nega-tive negative
tive 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 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 material. These indices are used only for
color index lighting. (All the other parameters are used only for RGBA light-ing.) lighting.)
ing.) 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 glGetMaterial is executed between the execution of glBegin and
the corresponding execution of glEnd.
SEE ALSO
glMaterial(3G)
GLGETMATERIAL(3G)
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