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<STRONG>NAME</STRONG>
<STRONG>glGetMaterialfv,</STRONG> <STRONG>glGetMaterialiv</STRONG> - return material
parameters
<STRONG>C</STRONG> <STRONG>SPECIFICATION</STRONG>
void <STRONG>glGetMaterialfv</STRONG>( GLenum <EM>face</EM>,
GLenum <EM>pname</EM>,
GLfloat *<EM>params</EM> )
void <STRONG>glGetMaterialiv</STRONG>( GLenum <EM>face</EM>,
GLenum <EM>pname</EM>,
GLint *<EM>params</EM> )
<STRONG>PARAMETERS</STRONG>
<EM>face</EM> Specifies which of the two materials is being
queried. <STRONG>GL_FRONT</STRONG> or <STRONG>GL_BACK</STRONG> are accepted,
representing the front and back materials,
respectively.
<EM>pname</EM> Specifies the material parameter to return.
<STRONG>GL_AMBIENT</STRONG>, <STRONG>GL_DIFFUSE</STRONG>, <STRONG>GL_SPECULAR</STRONG>, <STRONG>GL_EMISSION</STRONG>,
<STRONG>GL_SHININESS</STRONG>, and <STRONG>GL_COLOR_INDEXES</STRONG> are accepted.
<EM>params</EM> Returns the requested data.
<STRONG>DESCRIPTION</STRONG>
<STRONG>glGetMaterial</STRONG> returns in <EM>params</EM> the value or values of
parameter <EM>pname</EM> of material <EM>face</EM>. Six parameters are
defined:
<STRONG>GL_AMBIENT</STRONG> <EM>params</EM> 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)
<STRONG>GL_DIFFUSE</STRONG> <EM>params</EM> 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).
<STRONG>GL_SPECULAR</STRONG> <EM>params</EM> 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).
<STRONG>GL_EMISSION</STRONG> <EM>params</EM> 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).
<STRONG>GL_SHININESS</STRONG> <EM>params</EM> 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.
<STRONG>GL_COLOR_INDEXES</STRONG> <EM>params</EM> 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.
<STRONG>NOTES</STRONG>
If an error is generated, no change is made to the contents
of <EM>params</EM>.
<STRONG>ERRORS</STRONG>
<STRONG>GL_INVALID_ENUM</STRONG> is generated if <EM>face</EM> or <EM>pname</EM> is not an
accepted value.
<STRONG>GL_INVALID_OPERATION</STRONG> is generated if <STRONG>glGetMaterial</STRONG> is
executed between the execution of <STRONG>glBegin</STRONG> and the
corresponding execution of <STRONG>glEnd</STRONG>.
<STRONG>SEE</STRONG> <STRONG>ALSO</STRONG>
<STRONG>glMaterial</STRONG>
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