glGetColorTableParameterSGI(3G)				      OpenGL Reference

NAME    [Toc]    [Back]

     glGetColorTableParameterfvSGI, glGetColorTableParameterivSGI - get	color
     lookup table parameters

C SPECIFICATION    [Toc]    [Back]

     void glGetColorTableParameterfvSGI( GLenum	target,
					 GLenum	pname,
					 GLfloat *params )
     void glGetColorTableParameterivSGI( GLenum	target,
					 GLenum	pname,
					 GLint *params )

PARAMETERS    [Toc]    [Back]

     target  The target	color table.  Must be GL_TEXTURE_COLOR_TABLE_SGI,
	     GL_COLOR_TABLE_SGI, GL_POST_CONVOLUTION_COLOR_TABLE_SGI,
	     GL_POST_COLOR_MATRIX_COLOR_TABLE_SGI,
	     GL_PROXY_TEXTURE_COLOR_TABLE_SGI, GL_PROXY_COLOR_TABLE_SGI,
	     GL_PROXY_POST_CONVOLUTION_COLOR_TABLE_SGI,
	     GL_PROXY_POST_COLOR_MATRIX_COLOR_TABLE_SGI.

     pname   The symbolic name of a color lookup table parameter.  Must	be one
	     of	GL_COLOR_TABLE_BIAS_SGI, GL_COLOR_TABLE_SCALE_SGI,
	     GL_COLOR_TABLE_FORMAT_SGI,	GL_COLOR_TABLE_WIDTH_SGI,
	     GL_COLOR_TABLE_RED_SIZE_SGI, GL_COLOR_TABLE_GREEN_SIZE_SGI,
	     GL_COLOR_TABLE_BLUE_SIZE_SGI, GL_COLOR_TABLE_ALPHA_SIZE_SGI,
	     GL_COLOR_TABLE_LUMINANCE_SIZE_SGI,	or
	     GL_COLOR_TABLE_INTENSITY_SIZE_SGI.

     params  A pointer to an array where the values of the parameter will be
	     stored.

DESCRIPTION    [Toc]    [Back]

     glGetColorTableParameterSGI is part of the	SGI_color_table	extension,
     which adds	several	color lookup tables to the pixel transfer path.	 It is
     also used by SGI_texture_color_table, which adds a	color table lookup to
     the texturing process.

     When pname	is set to GL_COLOR_TABLE_SCALE_SGI or GL_COLOR_TABLE_BIAS_SGI,
     glGetColorTableParameterSGI returns the color table scale or bias
     parameters	for the	table specified	by target.  For	these queries, target
     must be set to GL_TEXTURE_COLOR_TABLE_SGI,	GL_COLOR_TABLE_SGI,
     GL_POST_CONVOLUTION_COLOR_TABLE_SGI, or
     GL_POST_COLOR_MATRIX_COLOR_TABLE_SGI and _params points to	an array of
     four elements, which receive the scale or bias factors for	red, green,
     blue, and alpha, in that order.

     The scale and bias	parameters for the texture color table are set by
     glTexParameter; the scale and bias	parameters for the other tables	are
     set by glColorTableParameterSGI.




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glGetColorTableParameterSGI(3G)				      OpenGL Reference



     glGetColorTableParameterSGI can also be used to retrieve the format and
     size parameters for a color table.	For these queries, set target to
     either the	color table target or the proxy	color table target. (For
     example, set target to either GL_TEXTURE_COLOR_TABLE_SGI or
     GL_PROXY_TEXTURE_COLOR_TABLE_SGI.)	The format and size parameters are set
     by	glColorTableSGI.

     The following table lists the format and size parameters that may be
     queried.  For each	symbolic constant listed below for pname, params must
     point to an array of the given length, and	receive	the values indicated.
		    pname		  N		 Meaning

      ______________________________________________________________________
      GL_COLOR_TABLE_FORMAT_SGI		  1   Internal format (e.g. GL_RGBA)
      GL_COLOR_TABLE_WIDTH_SGI		  1   Number of	elements in table
      GL_COLOR_TABLE_RED_SIZE_SGI	  1   Size of red component, in	bits
      GL_COLOR_TABLE_GREEN_SIZE_SGI	  1   Size of green component
      GL_COLOR_TABLE_BLUE_SIZE_SGI	  1   Size of blue component
      GL_COLOR_TABLE_ALPHA_SIZE_SGI	  1   Size of alpha component
      GL_COLOR_TABLE_LUMINANCE_SIZE_SGI	  1   Size of luminance	component
      GL_COLOR_TABLE_INTENSITY_SIZE_SGI	  1   Size of intensity	component

NOTES    [Toc]    [Back]

     If	target is set to GL_TEXTURE_COLOR_TABLE_SGI and	the
     SGI_texture_color_table extension is not supported	then an
     GL_INVALID_ENUM error is generated.

     If	target is set to GL_COLOR_TABLE_SGI,
     GL_POST_CONVOLUTION_COLOR_TABLE_SGI, or
     GL_POST_COLOR_MATRIX_COLOR_TABLE_SGI and the SGI_color_table extension is
     not supported then	an GL_INVALID_ENUM error is generated.

     See glIntro for more information on using extensions.

ERRORS    [Toc]    [Back]

     GL_INVALID_ENUM is	generated if target or pname is	not an acceptable
     value.

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


MACHINE	DEPENDENCIES
     The SGI_color_table extension is not supported on RealityEngine,
     RealityEngine2, and VTX systems.

SEE ALSO    [Toc]    [Back]

     glColorTableSGI, glTexParameter, glColorTableParameterSGI.


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