glgetconvolutionparameter(3g) [osx man page]

GLGETCONVOLUTIONPARAMETER(3G)											     GLGETCONVOLUTIONPARAMETER(3G)

NAME

       glGetConvolutionParameterfv, glGetConvolutionParameteriv - get convolution parameters

C SPECIFICATION

       void glGetConvolutionParameterfv( GLenum target,
					 GLenum pname,
					 GLfloat *params )
       void glGetConvolutionParameteriv( GLenum target,
					 GLenum pname,
					 GLint *params )

PARAMETERS

       target  The filter whose parameters are to be retrieved.  Must be one of GL_CONVOLUTION_1D, GL_CONVOLUTION_2D, or GL_SEPARABLE_2D.

       pname   The    parameter    to	 be    retrieved.     Must    be    one    of	GL_CONVOLUTION_BORDER_MODE,   GL_CONVOLUTION_BORDER_COLOR,
	       GL_CONVOLUTION_FILTER_SCALE,  GL_CONVOLUTION_FILTER_BIAS,   GL_CONVOLUTION_FORMAT,   GL_CONVOLUTION_WIDTH,   GL_CONVOLUTION_HEIGHT,
	       GL_MAX_CONVOLUTION_WIDTH, or GL_MAX_CONVOLUTION_HEIGHT.

       params  Pointer to storage for the parameters to be retrieved.

DESCRIPTION

       glGetConvolutionParameter retrieves convolution parameters.  target determines which convolution filter is queried.  pname determines which
       parameter is returned:

       GL_CONVOLUTION_BORDER_MODE
	      The convolution border mode.  See glConvolutionParameter for a list of border modes.

       GL_CONVOLUTION_BORDER_COLOR
	      The current convolution border color.  params must be a pointer to an array of four elements, which will	receive  the  red,  green,
	      blue, and alpha border colors.

       GL_CONVOLUTION_FILTER_SCALE
	      The  current  filter scale factors.  params must be a pointer to an array of four elements, which will receive the red, green, blue,
	      and alpha filter scale factors in that order.

       GL_CONVOLUTION_FILTER_BIAS
	      The current filter bias factors.	params must be a pointer to an array of four elements, which will receive the  red,  green,  blue,
	      and alpha filter bias terms in that order.

       GL_CONVOLUTION_FORMAT
	      The current internal .  See glConvolutionFilter1D, glConvolutionFilter2D, and glSeparableFilter2D for lists of allowable formats.

       GL_CONVOLUTION_WIDTH
	      The current filter image width.

       GL_CONVOLUTION_HEIGHT
	      The current filter image height.

       GL_MAX_CONVOLUTION_WIDTH
	      The maximum acceptable filter image width.

       GL_MAX_CONVOLUTION_HEIGHT
	      The maximum acceptable filter image height.

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 target is GL_CONVOLUTION_1D and pname is GL_CONVOLUTION_HEIGHT or GL_MAX_CONVOLUTION_HEIGHT.

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

SEE ALSO

       glGetConvolutionFilter, glGetSeparableFilter2D, glConvolutionParameter

														     GLGETCONVOLUTIONPARAMETER(3G)

GLCONVOLUTIONPARAMETER(3G)												GLCONVOLUTIONPARAMETER(3G)

NAME

       glConvolutionParameterf, glConvolutionParameteri, glConvolutionParameterfv, glConvolutionParameteriv - set convolution parameters

C SPECIFICATION

       void glConvolutionParameterf( GLenum target,
				     GLenum pname,
				     GLfloat params )
       void glConvolutionParameteri( GLenum target,
				     GLenum pname,
				     GLint params )

PARAMETERS

       target  The target for the convolution parameter.  Must be one of GL_CONVOLUTION_1D, GL_CONVOLUTION_2D, or GL_SEPARABLE_2D.

       pname   The parameter to be set.  Must be GL_CONVOLUTION_BORDER_MODE.

       params  The parameter value.  Must be one of GL_REDUCE, GL_CONSTANT_BORDER, GL_REPLICATE_BORDER.

C SPECIFICATION

       void glConvolutionParameterfv( GLenum target,
				      GLenum pname,
				      const GLfloat *params )
       void glConvolutionParameteriv( GLenum target,
				      GLenum pname,
				      const GLint *params )

PARAMETERS

       target The target for the convolution parameter.  Must be one of GL_CONVOLUTION_1D, GL_CONVOLUTION_2D, or GL_SEPARABLE_2D.

       pname  The  parameter  to  be set.  Must be one of GL_CONVOLUTION_BORDER_MODE, GL_CONVOLUTION_BORDER_COLOR, GL_CONVOLUTION_FILTER_SCALE, or
	      GL_CONVOLUTION_FILTER_BIAS.

       params The  parameter  value.   If  pname  is  GL_CONVOLUTION_BORDER_MODE,  params  must  be  one  of  GL_REDUCE,  GL_CONSTANT_BORDER,	or
	      GL_REPLICATE_BORDER.   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), or biasing (when pname is GL_CONVOLUTION_FILTER_BIAS) a convolution filter ker-
	      nel or setting the constant border color (when pname is GL_CONVOLUTION_BORDER_COLOR.

DESCRIPTION

       glConvolutionParameter sets the value of a convolution parameter.

       target selects the convolution filter to be affected: GL_CONVOLUTION_1D, GL_CONVOLUTION_2D, or GL_SEPARABLE_2D for the 1D, 2D, or separable
       2D filter, respectively.

       pname selects the parameter to be changed.  GL_CONVOLUTION_FILTER_SCALE and GL_CONVOLUTION_FILTER_BIAS affect the definition of the  convo-
       lution  filter kernel; see glConvolutionFilter1D, glConvolutionFilter2D, and glSeparableFilter2D for details.  In these cases, params is an
       array of four values to be applied to red, green, blue, and alpha values, respectively. The initial value  for  GL_CONVOLUTION_FILTER_SCALE
       is (1, 1, 1, 1), and the initial value for GL_CONVOLUTION_FILTER_BIAS is (0, 0, 0, 0).

       A pname value of GL_CONVOLUTION_BORDER_MODE controls the convolution border mode. The accepted modes are:

       GL_REDUCE
	      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 coordi-
	      nates of the image resulting from convolution are zero through Ws-Wf in width and zero through Hs-Hf in height.

       GL_CONSTANT_BORDER
	      The image resulting from convolution is the same size as the source image, and processed as if the source image were  surrounded	by
	      pixels with their color specified by the GL_CONVOLUTION_BORDER_COLOR.

       GL_REPLICATE_BORDER
	      The  image resulting from convolution is the same size as the source image, and processed as if the outermost pixel on the border of
	      the source image were replicated.

NOTES

       glConvolutionParameter is present only if GL_ARB_imaging is returned when glGetString is called with an argument of GL_EXTENSIONS.

       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 GL_REDUCE border mode is
       in effect, 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	and  params  is  not  one  of  GL_REDUCE,  GL_CONSTANT_BORDER,	or
       GL_REPLICATE_BORDER.

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

ASSOCIATED GETS

       glGetConvolutionParameter

SEE ALSO

       glConvolutionFilter1D(3G), glConvolutionFilter2D(3G), glSeparableFilter2D(3G), glGetConvolutionParameter(3G)

															GLCONVOLUTIONPARAMETER(3G)