[Insight-developers] Filter execution dispatch based on dimension.

[Brad King]

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Hello, all:

A general problem we've been having with this toolkit is how to setup
multiple implementations of each filter, each optimized for a particular
dimension.  The attached file presents a clean solution to this problem
which has been tested on Visual C++, GCC, MIPSpro, and the Intel
compiler.  See the file for a more detailed description of the problem.

After reading the solution, you will see that we can provide several
filter dispatch classes, each defining a different combination of rules
for dimension-based filter execute calls.  Each filter will be able to
select which dispatch class to use, or define its own.

The use of these dispach classes is completely transparent to the user of
the filter, and requires little work by the implementer.  If everyone
likes this approach, I will add the dispatch classes to Insight and check
them in.

Thoughts?
-Brad

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