DragonFly On-Line Manual Pages

vpGetTimer(3)         DragonFly Library Functions Manual         vpGetTimer(3)

NAME
       vpGetTimer, vpClearTimer - interval timer facility

SYNOPSIS
       #include <volpack.h>

       vpResult
       vpGetTimer(vpc, option, iptr)
           vpContext *vpc;
           int option;
           int *iptr;;

       vpResult
       vpClearTimer(vpc, option)
           vpContext *vpc;
           int option;

ARGUMENTS
       vpc    VolPack context from vpCreateContext.

       option Constant that specifies a particular timer.

       iptr   Location for storing the timer value.

DESCRIPTION
       These functions are used for measuring the performance of the VolPack
       library.  To use them, the library must be compiled with a special
       flag: either -DHAVE_LORES_TIMER (for machine that support the
       gettimeofday C library call) or -DHAVE_HIRES_TIMER (for SGI machines
       that support high-resolution memory-mapped I/O timers; on a Challenge
       or ONYX, the -DHAVE_64BIT_TIMER must also be specified).  If one of
       these flags is specified at compile time then VolPack maintains a table
       recording the accumulated time spent in various operations.  Note that
       some of the operations can only be timed with a high-resolution timer;
       time values will not be recorded and will appear to be zero if a low
       resolution timer is specified at compile time.

       vpGetTimer retrieves the accumulated time for a particular operation.
       The option argument specifies which operation:

       VPTIMER_SHADE
              Time the routine that computes the contents of the shading
              lookup table.

       VPTIMER_RENDER
              Time the routine that renders a volume (includes
              VPTIMER_CLSFY_OCTREE, VPTIMER_COMPOSITE, VPTIMER_DEPTHCUE, and
              VPTIMER_WARP).

       VPTIMER_COMPOSITE
              Time the routine that computes the intermediate image from the
              volume (includes VPTIMER_CLEAR, VPTIMER_TRAVERSE_OCTREE,
              VPTIMER_ERT, VPTIMER_TRAVERSE_RUNS, and VPTIMER_PROCESS_VOXELS).

       VPTIMER_DEPTHCUE
              Time the routine that performs the depth cueing fixup on the
              intermediate image.

       VPTIMER_WARP
              Time the routine that warps the intermediate image into the
              final image.

       VPTIMER_TRAVERSE_RUNS
              Time the portion of the compositing routine devoted to
              traversing the volume data structures.

       VPTIMER_PROCESS_VOXELS
              Time the portion of the compositing routine devoted to
              compositing voxels into the intermediate image.

       VPTIMER_ERT
              Time the early-ray termination checks during compositing.

       VPTIMER_CLSFY_OCTREE
              Time the octree classification stage.

       VPTIMER_TRAVERSE_OCTREE
              Time the portion of the compositing routine devoted to
              traversing the octree.

       VPTIMER_CLEAR
              Time the routine that clears the intermediate image at the
              beginning of compositing.

       The routine stores the accumulated time since the last call to
       vpClearTimer (or since the beginning of the program) in the location
       specified by iptr.  The units of the value are microseconds.

       vpClearTimer sets the specified timer value back to zero.

ERRORS
       The normal return value is VP_OK.  The following error return value is
       possible:

       VPERROR_BAD_OPTION
              The option argument is invalid.

SEE ALSO
       VolPack(3), vpCreateContext(3)

VolPack                                                          vpGetTimer(3)