glConvolutionParameterEXT(3G)  OpenGL Reference	 glConvolutionParameterEXT(3G)



NAME
     glConvolutionParameterfEXT, glConvolutionParameteriEXT,
     glConvolutionParameterfvEXT, glConvolutionParameterivEXT -	set
     convolution parameters


C SPECIFICATION
     void glConvolutionParameterfEXT( GLenum target,
				      GLenum pname,
				      GLfloat params )
     void glConvolutionParameteriEXT( GLenum target,
				      GLenum pname,
				      GLint params )

PARAMETERS
     target  The target	for the	convolution parameter.	Must be	one of
	     GL_CONVOLUTION_1D_EXT, GL_CONVOLUTION_2D_EXT, or
	     GL_SEPARABLE_2D_EXT.

     pname   The parameter to be set.  Must be GL_CONVOLUTION_BORDER_MODE_EXT.

     params  The parameter value.  Must	be GL_REDUCE_EXT.



C SPECIFICATION
     void glConvolutionParameterfvEXT( GLenum target,
				       GLenum pname,
				       const GLfloat *params )
     void glConvolutionParameterivEXT( GLenum target,
				       GLenum pname,
				       const GLint *params )

PARAMETERS
     target
	  The target for the convolution parameter.  Must be one of
	  GL_CONVOLUTION_1D_EXT, GL_CONVOLUTION_2D_EXT,	or
	  GL_SEPARABLE_2D_EXT.

     pname
	  The parameter	to be set.  Must be one	of
	  GL_CONVOLUTION_BORDER_MODE_EXT, GL_CONVOLUTION_FILTER_SCALE_EXT, or
	  GL_CONVOLUTION_FILTER_BIAS_EXT.

     params
	  The parameter	value.	Must be	GL_REDUCE_EXT if pname is
	  GL_CONVOLUTION_BORDER_MODE_EXT.  Otherwise, must be a	vector of four
	  values (for red, green, blue,	and alpha, respectively) to be used
	  for scaling (when pname is GL_CONVOLUTION_FILTER_SCALE_EXT) or for
	  biasing (when	pname is GL_CONVOLUTION_FILTER_BIAS_EXT) a convolution
	  filter kernel.




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glConvolutionParameterEXT(3G)  OpenGL Reference	 glConvolutionParameterEXT(3G)



DESCRIPTION
     glConvolutionParameterEXT sets the	value of a convolution parameter.

     target selects the	convolution filter to be affected:
     GL_CONVOLUTION_1D_EXT, GL_CONVOLUTION_2D_EXT, or GL_SEPARABLE_2D_EXT for
     the 1D, 2D, or separable 2D filter, respectively.

     pname selects the parameter to be changed.
     GL_CONVOLUTION_FILTER_SCALE_EXT and GL_CONVOLUTION_FILTER_BIAS_EXT	affect
     the definition of the convolution filter kernel; see
     glConvolutionFilter1DEXT, glConvolutionFilter2DEXT, and
     glSeparableFilter2DEXT for	details.  In these cases, params is an array
     of	four values to be applied to red, green, blue, and alpha values
     respectively.

     A pname value of GL_CONVOLUTION_BORDER_MODE_EXT controls the convolution
     border mode.  Currently the only acceptable parameter value is
     GL_REDUCE_EXT.  When this mode is in effect, the image resulting from
     convolution is smaller than the source image.  If the filter width	is Wf
     and height	is Hf, and the source image width is Ws	and height is Hs, then
     the convolved image width will be Ws-Wf+1 and height will be Hs-Hf+1.
     (If this reduction	would generate an image	with zero or negative width
     and/or height, the	output is simply null, with no error generated.)  The
     coordinates of the	image resulting	from convolution are zero through Ws-
     Wf	in width and zero through Hs-Hf	in height.

NOTES
     In	cases where errors can result from the specification of	invalid	image
     dimensions, it is the dimensions after convolution	that are tested, not
     the dimensions of the source image.  For example, glTexImage1D requires
     power-of-two image	size.  When REDUCE_EXT border mode is in effect
     (currently	this is	always true), the source image must be larger than the
     final power-of-two	size by	one less than the size of the 1D filter
     kernel.

ERRORS
     GL_INVALID_ENUM is	generated if target is not one of the allowable
     values.

     GL_INVALID_ENUM is	generated if pname is not one of the allowable values.

     GL_INVALID_ENUM is	generated if pname is GL_CONVOLUTION_BORDER_MODE_EXT
     and params	is not GL_REDUCE_EXT.

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

ASSOCIATED GETS
     glGetConvolutionParameterEXT





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glConvolutionParameterEXT(3G)  OpenGL Reference	 glConvolutionParameterEXT(3G)



SEE ALSO
     glConvolutionFilter1DEXT, glConvolutionFilter2DEXT,
     glSeparableFilter2DEXT, glGetConvolutionParameterEXT.




















































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