stensi(3G)stensi(3G)NAMEstensi - specify the number of bit planes desired to comprise the stencil
buffer
FORTRAN SPECIFICATION
subroutine stensi(planes)
integer*4 planes
PARAMETERS
planes is the number of bit planes requested to be configured as
stencil planes. Only values 0 through 8 are accepted. The
default is 0.
DESCRIPTIONstensi specifies how many bit planes are requested to be configured as
stencil planes. The constraints on planes are machine dependent. Call
getgde(GDBIST) to determine the maximum number of bit planes available
for stencil operation.
stensi takes effect only after gconfi has been called. The number of bit
planes granted for the stencil buffer may not be exactly what was
requested. Call getgco(GCSTEN) to determine how many bit planes were
configured as stencil buffer planes.
Because stencil bit planes are available only in the normal framebuffer,
stensi should be called only while draw mode is NORMAL.
SEE ALSO
drawmo, gconfi, getgco, stenci, mssize
NOTES
This routine is available only in immediate mode.
IRIS-4D B, G, GT, and GTX models, as well as the Personal Iris, Indy,
Iris Indigo Entry, and XL, do not support stensi.
XS, XS24, XZ, Elan and Extreme systems support up to 4 stencil planes,
which are borrowed from the Z buffer. The resolution of the Z buffer
decreases when using stencil planes on Elan systems.
On the IRIS-4D RealityEngine models the stencil buffer and the stencil
component in the multisample buffer are independent. When the
multisample buffer is requested in the current framebuffer configuration,
it is recommended to call stensi(0), as no stencil buffer planes are
required.
BUGS
IRIS-4D VGX machines without the optional alpha bit planes allocate
stencil bit planes from the least-significant Z buffer bit planes. Z
buffer operation compensates for this allocation automatically, so the
programmer is aware of the allocation only when the Z buffer contents are
read back using lrectr. Use getgde to determine whether your machine has
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stensi(3G)stensi(3G)
alpha bit planes.
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