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GLCOPYCONVOLUTIONFIL(3G)		  OpenGL Manual 		 GLCOPYCONVOLUTIONFIL(3G)

NAME
       glCopyConvolutionFilter1D - copy pixels into a one-dimensional convolution filter

C SPECIFICATION
       void glCopyConvolutionFilter1D(GLenum target, GLenum internalformat, GLint x, GLint y,
				      GLsizei width);

PARAMETERS
       target
	   Must be GL_CONVOLUTION_1D.

       internalformat
	   The internal format of the convolution filter kernel. The allowable values are
	   GL_ALPHA, GL_ALPHA4, GL_ALPHA8, GL_ALPHA12, GL_ALPHA16, GL_LUMINANCE, GL_LUMINANCE4,
	   GL_LUMINANCE8, GL_LUMINANCE12, GL_LUMINANCE16, GL_LUMINANCE_ALPHA,
	   GL_LUMINANCE4_ALPHA4, GL_LUMINANCE6_ALPHA2, GL_LUMINANCE8_ALPHA8,
	   GL_LUMINANCE12_ALPHA4, GL_LUMINANCE12_ALPHA12, GL_LUMINANCE16_ALPHA16, GL_INTENSITY,
	   GL_INTENSITY4, GL_INTENSITY8, GL_INTENSITY12, GL_INTENSITY16, GL_R3_G3_B2, GL_RGB,
	   GL_RGB4, GL_RGB5, GL_RGB8, GL_RGB10, GL_RGB12, GL_RGB16, GL_RGBA, GL_RGBA2, GL_RGBA4,
	   GL_RGB5_A1, GL_RGBA8, GL_RGB10_A2, GL_RGBA12, or GL_RGBA16.

       x, y
	   The window space coordinates of the lower-left coordinate of the pixel array to copy.

       width
	   The width of the pixel array to copy.

DESCRIPTION
       glCopyConvolutionFilter1D defines a one-dimensional convolution filter kernel with pixels
       from the current GL_READ_BUFFER (rather than from main memory, as is the case for
       glConvolutionFilter1D()).

       The screen-aligned pixel rectangle with lower-left corner at (x,\ y), width width and
       height 1 is used to define the convolution filter. If any pixels within this region are
       outside the window that is associated with the GL context, the values obtained for those
       pixels are undefined.

       The pixels in the rectangle are processed exactly as if glReadPixels() had been called
       with format set to RGBA, but the process stops just before final conversion. The R, G, B,
       and A components of each pixel are next scaled by the four 1D GL_CONVOLUTION_FILTER_SCALE
       parameters and biased by the four 1D GL_CONVOLUTION_FILTER_BIAS parameters. (The scale and
       bias parameters are set by glConvolutionParameter() using the GL_CONVOLUTION_1D target and
       the names GL_CONVOLUTION_FILTER_SCALE and GL_CONVOLUTION_FILTER_BIAS. The parameters
       themselves are vectors of four values that are applied to red, green, blue, and alpha, in
       that order.) The R, G, B, and A values are not clamped to [0,1] at any time during this
       process.

       Each pixel is then converted to the internal format specified by internalformat. This
       conversion simply maps the component values of the pixel (R, G, B, and A) to the values
       included in the internal format (red, green, blue, alpha, luminance, and intensity). The
       mapping is as follows:

       +---------------------------------+-----------------------------+-------------------------------+------------------------------+-------------------------------+-----------------------------------+-----------------------------------+
       |				 |			       |			       |			      | 			      | 				  |				      |
       |			Internal |			   Red |			 Green |			 Blue | 			Alpha | 			Luminance |			    Intensity |
       |Format				 |			       |			       |			      | 			      | 				  |				      |
       |				 |			       |			       |			      | 			      | 				  |				      |
       +---------------------------------+-----------------------------+-------------------------------+------------------------------+-------------------------------+-----------------------------------+-----------------------------------+
       |GL_ALPHA			 |			       |			       |			      | 	      A 	      | 				  |				      |
       +---------------------------------+-----------------------------+-------------------------------+------------------------------+-------------------------------+-----------------------------------+-----------------------------------+
       |GL_LUMINANCE			 |			       |			       |			      | 			      | 		R		  |				      |
       +---------------------------------+-----------------------------+-------------------------------+------------------------------+-------------------------------+-----------------------------------+-----------------------------------+
       |GL_LUMINANCE_ALPHA		 |			       |			       |			      | 	      A 	      | 		R		  |				      |
       +---------------------------------+-----------------------------+-------------------------------+------------------------------+-------------------------------+-----------------------------------+-----------------------------------+
       |GL_INTENSITY			 |			       |			       |			      | 			      | 				  |		    R		      |
       +---------------------------------+-----------------------------+-------------------------------+------------------------------+-------------------------------+-----------------------------------+-----------------------------------+
       |GL_RGB				 |		R	       |	       G	       |	      B 	      | 			      | 				  |				      |
       +---------------------------------+-----------------------------+-------------------------------+------------------------------+-------------------------------+-----------------------------------+-----------------------------------+
       |GL_RGBA 			 |		R	       |	       G	       |	      B 	      | 	      A 	      | 				  |				      |
       +---------------------------------+-----------------------------+-------------------------------+------------------------------+-------------------------------+-----------------------------------+-----------------------------------+

       The red, green, blue, alpha, luminance, and/or intensity components of the resulting
       pixels are stored in floating-point rather than integer format.

       Pixel ordering is such that lower x screen coordinates correspond to lower i filter image
       coordinates.

       Note that after a convolution is performed, the resulting color components are also scaled
       by their corresponding GL_POST_CONVOLUTION_c_SCALE parameters and biased by their
       corresponding GL_POST_CONVOLUTION_c_BIAS parameters (where c takes on the values RED,
       GREEN, BLUE, and ALPHA). These parameters are set by glPixelTransfer().

NOTES
       glCopyConvolutionFilter1D is present only if ARB_imaging is returned when glGetString() is
       called with an argument of GL_EXTENSIONS.

ERRORS
       GL_INVALID_ENUM is generated if target is not GL_CONVOLUTION_1D.

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

       GL_INVALID_VALUE is generated if width is less than zero or greater than the maximum
       supported value. This value may be queried with glGetConvolutionParameter() using target
       GL_CONVOLUTION_1D and name GL_MAX_CONVOLUTION_WIDTH.

       GL_INVALID_OPERATION is generated if glCopyConvolutionFilter1D is executed between the
       execution of glBegin() and the corresponding execution of glEnd().

ASSOCIATED GETS
       glGetConvolutionParameter(), glGetConvolutionFilter()

SEE ALSO
       glConvolutionFilter1D(), glConvolutionParameter(), glPixelTransfer()

COPYRIGHT
       Copyright (C) 1991-2006 Silicon Graphics, Inc. This document is licensed under the SGI
       Free Software B License. For details, see http://oss.sgi.com/projects/FreeB/.

AUTHORS
       opengl.org

opengl.org				    06/10/2014			 GLCOPYCONVOLUTIONFIL(3G)
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