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Re: optimization question: a faster way to PIXMAP?
A suggestion: don't use graphics functions. You could use
POLYFILLV (see the example code in the online help) or the
IDLanROI::ComputeMask() function (IDL 5.3) to do this without
using graphics at all (note: I have not actually timed these
alternatives, so your milage may vary).
"Dennis J. Boccippio" wrote:
> A question for the IDL gurus:
> - I have data in the form of irregular polygons, each polygon has
> an associated value (let's call it an amplitude). I want a
> composite image of the sum of all these polygons' amplitudes.
> - My current approach is to :
> (1) create a (large) WINDOW,../PIXMAP,
> (2) render each polygon using POLYFILL
> (3) TVRD() the pixmap window
> (4) add this to an accumulation array
> ... iterate (1)-(4) until all polygons have been rendered
> This works, but is painfully slow. Profiling the code shows that
> by far the most significant logjam is the TVRD() of the pixmap.
> So: does anyone know of more efficient ways to do this? Is the Z
> device an option - it seems like it can be used for internal frame
> storage, but would still have to be probed by TVRD()...?
> _/ Dennis J. Boccippio _/
> _/ http://fly.hiwaay.net/~djboccip/Dennis.html _/
Randy Frank | ASCI Visualization
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