glGetLight(3G)		       OpenGL Reference			glGetLight(3G)



NAME
     glGetLightfv, glGetLightiv	- return light source parameter	values


C SPECIFICATION
     void glGetLightfv(	GLenum light,
			GLenum pname,
			GLfloat	*params	)
     void glGetLightiv(	GLenum light,
			GLenum pname,
			GLint *params )


PARAMETERS
     light   Specifies a light source.	The number of possible lights depends
	     on	the implementation, but	at least eight lights are supported.
	     They are identified by symbolic names of the form GL_LIGHTi where
	     0 < i < GL_MAX_LIGHTS.

     pname   Specifies a light source parameter	for light.  Accepted symbolic
	     names are GL_AMBIENT, GL_DIFFUSE, GL_SPECULAR, GL_POSITION,
	     GL_SPOT_DIRECTION,	GL_SPOT_EXPONENT, GL_SPOT_CUTOFF,
	     GL_CONSTANT_ATTENUATION, GL_LINEAR_ATTENUATION , and
	     GL_QUADRATIC_ATTENUATION.

     params  Returns the requested data.


DESCRIPTION
     glGetLight	returns	in params the value or values of a light source
     parameter.	 light names the light and is a	symbolic name of the form
     GL_LIGHTi for 0<iglGetLight(3G)		       OpenGL Reference			glGetLight(3G)



			 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.

     GL_SPECULAR	 params	returns	four integer or	floating-point values
			 representing the specular intensity of	the light
			 source.  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.

     GL_POSITION	 params	returns	four integer or	floating-point values
			 representing the position of the light	source.
			 Integer values, when requested, are computed by
			 rounding the internal floating-point values to	the
			 nearest integer value.	 The returned values are those
			 maintained in eye coordinates.	 They will not be
			 equal to the values specified using glLight, unless
			 the modelview matrix was identity at the time glLight
			 was called.

     GL_SPOT_DIRECTION	 params	returns	three integer or floating-point	values
			 representing the direction of the light source.
			 Integer values, when requested, are computed by
			 rounding the internal floating-point values to	the
			 nearest integer value.	 The returned values are those
			 maintained in eye coordinates.	 They will not be
			 equal to the values specified using glLight, unless
			 the modelview matrix was identity at the time glLight
			 was called.  Although spot direction is normalized
			 before	being used in the lighting equation, the
			 returned values are the transformed versions of the
			 specified values prior	to normalization.

     GL_SPOT_EXPONENT	 params	returns	a single integer or floating-point
			 value representing the	spot exponent of the light.
			 An integer value, when	requested, is computed by
			 rounding the internal floating-point representation
			 to the	nearest	integer.

     GL_SPOT_CUTOFF	 params	returns	a single integer or floating-point
			 value representing the	spot cutoff angle of the
			 light.	 An integer value, when	requested, is computed
			 by rounding the internal floating-point
			 representation	to the nearest integer.






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glGetLight(3G)		       OpenGL Reference			glGetLight(3G)



     GL_CONSTANT_ATTENUATION
			 params	returns	a single integer or floating-point
			 value representing the	constant (not distance
			 related) attenuation of the light.  An	integer	value,
			 when requested, is computed by	rounding the internal
			 floating-point	representation to the nearest integer.

     GL_LINEAR_ATTENUATION
			 params	returns	a single integer or floating-point
			 value representing the	linear attenuation of the
			 light.	 An integer value, when	requested, is computed
			 by rounding the internal floating-point
			 representation	to the nearest integer.

     GL_QUADRATIC_ATTENUATION
			 params	returns	a single integer or floating-point
			 value representing the	quadratic attenuation of the
			 light.	 An integer value, when	requested, is computed
			 by rounding the internal floating-point
			 representation	to the nearest integer.

NOTES
     It	is always the case that	GL_LIGHTi = GL_LIGHT0 +	i.

     If	an error is generated, no change is made to the	contents of params.

ERRORS
     GL_INVALID_ENUM is	generated if light or pname is not an accepted value.

     GL_INVALID_OPERATION is generated if glGetLight is	executed between the
     execution of glBegin and the corresponding	execution of glEnd.


SEE ALSO
     glLight




















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