[Insight-developers] Progress behaviour

[Lorensen, William E (Research)]

Folks,
We are assessing the state of progress reporting in the system. For the most
part, the ProgressReporter and ProgressAccumulator work great.

The ProgressReporter requires a guess for the number of pixels to be
visitied.

The trouble appears in filters that are iterative. These filters seldom know
how many iterations will be performed. Sometimes we can make a guess based
upon worse cases or averages.

Two results are possible when the guess is wrong. If we guess too many
iterations, the progress may jump from a low number to 1 at the end of the
filter. If we guess too few, the progress can exceed one. The later is not
acceptable. We can fix this by clamping or wrapping.

What do people prefer:

1) Jumping: progress increments, jumps to end
2) Wrapping: progress increments, if it reaches 1, drops back.

Bill