pixeltransfer(3G)					     pixeltransfer(3G)

NAME    [Toc]    [Back]

     pixeltransfer -  sets pixel/texel transfer	modes

C SPECIFICATION    [Toc]    [Back]

     void pixeltransfer(int mode, float	value)

PARAMETERS    [Toc]    [Back]

     mode   expects the	symbolic name of the pixel transfer parameter being
	    set.

     value  expects the	value of the pixel transfer parameter being set.

DESCRIPTION    [Toc]    [Back]

     RealityEngine supports a sequence of of floating point image processing
     operations.  The operations are performed in the following	order: integer
     to	floating point conversion, scale, bias,	convolution, floating point to
     integer conversion, and finally lookup table mapping.

     The pixels	are converted from integers in the range specified by
     pixmode(PM_INPUT_TYPE), to	the floating point range [0.,1.] if the	input
     type was unsigned or (-1.,1] if the input type was	signed.	The pixels are
     multiplied	by a color scale and then a color bias is added.  The scale
     and bias values are specified using the pixeltransfer() function. The
     resulting pixels are convolved, if	convolution has	been enabled by	the
     convolve()	function.  The resulting pixels	are converted back to integers
     where the range [0.0,1.0] maps to [0,4095]	if pixeltransfer(PT_MAP_COLOR)
     is	disabled or [0,lookup_table_size), if table lookup mapping is enabled.
     The result	is written to the framebuffer.

     The operation of lrectwrite, rectcopy, lrectread, subtexload and
     fbsubtexload can be altered with the pixel	transfer command. The
     following modes are recognized

     PT_RED_SCALE specifies that the red, or luminance component of pixels and
     all texel components are scaled by	value.

     PT_RED_BIAS specifies that	the red, or luminance component	of pixels and
     all texel components are biased by	value.

     PT_GREEN_SCALE specifies that the green component of pixels are scaled by
     value.

     PT_GREEN_BIAS specifies that the green component of pixels	are biased by
     value.

     PT_BLUE_SCALE specifies that the blue component of	pixels are scaled by
     value.

     PT_BLUE_BIAS specifies that the blue component of pixels are biased by
     value.





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pixeltransfer(3G)					     pixeltransfer(3G)



     PT_ALPHA_SCALE specifies that the alpha component of pixels are scaled by
     value.

     PT_ALPHA_BIAS specifies that the alpha component of pixels	are biased by
     value.

     PT_MAP_COLOR enables or disables the LUTS (LookUp Tables) defined by
     pixelmap.	The values allowed are PT_MAP_ENABLE, PT_MAP_DISABLE, and
     PT_MAP_CLAMP which	may be logically ored with PT_MAP_ENABLE to force
     clamping of values. The need to clamp may slow the	LUT operation.
     PT_MAP_COLOR has no effect	on lrectread.

SEE ALSO    [Toc]    [Back]

     convolve, pixelmap

NOTES    [Toc]    [Back]

     pixeltransfer only	works on RealityEngine systems running 5.0.1 or
     greater.  It requires that	the pixelzoom factors are both 1.0.


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