Optimisation

[Roger H. <rog...@mi...>]

Here is a stand alone optimisation which is part of the larger group
of optimisations which I have submitted for approval. This one stands
on its own merit and I would like permission to incorporate it into the
official cvs source. It has been incorporated into the issued version
of Microspot Interiors so it does not seem to cause any problems.

The changes are totally within E3View.c

In the current cvs source, TQ3ViewData has a field viewState which
is used to switch into the appropriate piece of code whenever an
object is submitted, including objects within groups in retained mode.
.My version adds a pair of pointers to functions, one for immediate
mode and one for retained mode. Whenever viewState gets changed
then so do the two function pointers.

e3view_submit_object disappears entirely and E3View_SubmitRetained
and E3View_SubmitImmediate become simply calls to the appropriate
function pointer. All the tests at the bottom of E3View_SubmitRetained
are rolled into the routines which get vectored to. There are two for
each value of viewState, including the 'Error' and 'BadMode' cases.

As the routines know exactly what mode they are in they are quite 
simple,
though they still have to check for nil pointers etc.

The benefits are faster execution, a simpler stack crawl when you are
debugging. The only slight downside is that e3view_submit_begin is
a little bit bigger and that there is no central submit routine where 
code
could be placed. Anything truly common could be put into both the
immediate and retained mode submit routines, though I think that the
code is now stable enough that this would be unlikely.

Can I go ahead with this?

Roger Holmes.