lRGBra(3G)lRGBra(3G)NAMElRGBra - sets the range of RGB colors used for depth-cueing
FORTRAN 77 SPECIFICATION
subroutine lRGBra(rmin, gmin, bmin, rmax, gmax, bmax, znear, zfar)
integer*2 rmin, gmin, bmin, rmax, gmax, bmax
integer*4 znear, zfar
PARAMETERS
rmin expects the minimum value to be stored in the red bitplanes.
gmin expects the minimum value to be stored in the green bitplanes.
bmin expects the minimum value to be stored in the blue bitplanes.
rmax expects the maximum value to be stored in the red bitplanes.
gmax expects the maximum value to be stored in the green bitplanes.
bmax expects the maximum value to be stored in the blue bitplanes.
znear expects the nearer screen z, to which the maximum colors are
mapped.
zfar expects the farther screen z, to which the minimum colors are
mapped.
DESCRIPTIONlRGBra sets the range of RGB colors used for depth-cueing in RGB mode.
The screen z range [znear, zfar] is mapped linearly into the RGB color
range [ (rmax,gmax,bmax), (rmin,gmin,bmin) ]. Screen z values nearer
than znear are mapped to (rmax,gmax,bmax); screen z values farther than
zfar are mapped to (rmin,gmin,bmin).
The valid range for znear and zfar depends on the state of the GLCZRA
compatibility mode (see glcomp). If it is 0, the valid range depends on
the graphics hardware. When multisample is enabled, and multisample
buffers exist in the current framebuffer configuration in the current
drawmode, the minimum is the value returned by getgco(GCMZMI) and the
maximum is the value returned by getgco(GCMZMA). Otherwise, the minimum
is the value returned by getgco(GCZMIN) and the maximum is the value
returned by getgco(GCZMAX). If the state of the GLCZRA compatibility
mode is 1, the minimum is $0 and the maximum is $7FFFFF. Znear and zfar
should be chosen to be consistent with the near and far parameters passed
to lsetde. If near < far, then znear should be less than zfar. If
near > far, then znear should be greater than zfar. In either case, the
range [near, far] should bound the range [znear, zfar].
SEE ALSO
depthc, getgde, glcomp, lsetde
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lRGBra(3G)lRGBra(3G)NOTE
When using this routine, you should always explicitly set the GLCZRA mode
of glcomp because its default is different on different models.
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