pxlxfr(3G)pxlxfr(3G)NAMEpxlxfr - sets pixel/texel transfer modes
FORTRAN SPECIFICATION
subroutine pxlxfr(mode, index)
integer*4 mode
real index
PARAMETERS
mode expects the symbolic name of the pixel transfer parameter being
set.
value expects the value of the pixel transfer parameter being set.
DESCRIPTION
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.
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pxlxfr(3G)pxlxfr(3G)
PT_BLUE_BIAS specifies that the blue component of pixels are biased by
value.
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
convolve, pixelmap
NOTES
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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