endfee(3G)endfee(3G)NAME
feedba, endfee - control feedback mode
FORTRAN 77 SPECIFICATIONPersonal Iris, Iris Entry, Indy, XL,
subroutine feedba(buffer, size)
real buffer(size)
integer*4 size
integer*4 function endfee(buffer)
real buffer(*)
Other models:
subroutine feedba(buffer, size)
integer*2 buffer(size)
integer*4 size
integer*4 function endfee(buffer)
integer*2 buffer(*)
PARAMETERS
buffer expects a buffer into which the system writes the feedback
output from the Geometry Pipeline. On the Personal Iris, Iris
Entry, Indy, XL, XS, XS24, Elan, Extreme, and VGX, the output
consists of 32-bit floating point values; on the other IRIS-4D
models, the output consists of 16-bit integer values. Be sure
you declare your buffer appropriately.
size expects the maximum number of buffer elements into which the
system will write feedback output. This must not exceed the
number of elements in buffer.
FUNCTION RETURN VALUE
The return value of endfee is the actual number of elements of buffer
that were written. The system will not write more than size elements,
even when the amount of feedback exceeds it. You should assume that
overflow has occurred whenever the return value is size.
DESCRIPTION
feedba puts the system in feedback mode. In feedback mode, the system
retains the output of the Geometry Pipeline rather than sending it to the
rendering subsystem. endfee turns off feedback mode and returns the
feedback output in buffer. This information is typically a description
of a vertex, and is machine specific. For information for interpreting
the returned buffer, see the ``Feedback'' chapter of the Graphics Library
Programming Guide.
NOTES
These routines are available only in immediate mode.
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endfee(3G)endfee(3G)
On the IRIS-4D G, GT, and GTX models the size of the buffer should never
exceed 0x10000 bytes. On the IRIS-4D VGX model the size of the buffer
should never exceed 0x80000 bytes. On the IRIS-4D RealityEngine models
the size of the buffer is limited by the amount of memory that can be
locked down by the system.
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