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 materi-
	       als, 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 parameters 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 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 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).

       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 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 material.  Inte-
			     ger 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 material.  Integer val-
			     ues, 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
			     lighting.)   Integer values, when requested, are computed by rounding the internal floating-point values to the near-
			     est 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

																 GLGETMATERIAL(3G)