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glGetMaterial(3G)
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glGetMaterial, glGetMaterialfv, glGetMaterialiv - return
material parameters
void glGetMaterialfv(
GLenum face,
GLenum pname,
GLfloat *params ); void glGetMaterialiv(
GLenum face,
GLenum pname,
GLint *params );
Specifies which of the two materials is being queried.
GL_FRONT or GL_BACK are accepted, representing the front
and back materials, respectively. Specifies the material
parameter to return. GL_AMBIENT, GL_DIFFUSE, GL_SPECULAR,
GL_EMISSION, GL_SHININESS, and GL_COLOR_INDEXES are
accepted. Returns the requested data.
glGetMaterial() returns in params the value or values of
parameter pname of material face. Six parameters are
defined: 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) 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 floatingpoint
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). 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 floatingpoint
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). params returns four integer or floatingpoint
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).
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. 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 lighting.) Integer
values, when requested, are computed by rounding the
internal floating-point values to the nearest integer values.
If an error is generated, no change is made to the contents
of params.
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().
glMaterial(3)
glGetMaterial(3G)
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