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Re: Exceed and IDL

Mark Hadfield (m.hadfield@niwa.cri.nz) writes:

> >    (1) You are using object graphics in the window, in which
> >        case RETAIN should *always* be set to 0.
> I disagree. For object graphics draw widgets on Windows NT, I have found the
> best results (fast drawing, fast refresh when a window is re-exposed) are
> achieved with:
>     RENDERER = 0        ; "Hardware" renderer
>     RETAIN=2            ; IDL provides backing store
>     EXPOSE_EVENTS=0     ; Not necessary for widget application to redraw its
> own windows
> I imagine that other platforms have different optimum settings, but you use
> NT primarily, don't you David?

When objects first came out I noticed that my axes
labels would disappear. After about 50 frustrating hours
convincing myself that I was doing everything correctly, I
gave up and contacted RSI. I was told in no uncertain terms
that this was caused by setting the RETAIN keyword to 2
and that RETAIN should *always* be 0 in object graphics.
This made sense, because you already *have* the backing
store to repair the window: the view you want to display. 
Why carry around yet more baggage? Sure enough, it 
fixed the problem.

I was so scarred by this experience that I have just
been plodding along doing it this way from that moment
forward. Frankly, I'm shocked to hear there is another
way. :-)

With respect to rendering. I spent a pile of dough 
getting two really nice 3D graphics cards that had
OpenGL support. *Both* of those cards render slower
in hardware than they do in software, although I have
never tried setting the RENDERER keyword on the
draw widget. I just always set the Hardware Rendering
option in the Option Settings. Of course, this is
one of those situations where *nobody* in technical
support, from *either* company, wants to have anything
to do with you. It's always *their* fault.

Let's just say I *knew* I should have bought the 
Dell machine. :-(


David Fanning, Ph.D.
Fanning Software Consulting
Phone: 970-221-0438 E-Mail: davidf@dfanning.com
Coyote's Guide to IDL Programming: http://www.dfanning.com/
Toll-Free IDL Book Orders: 1-888-461-0155