Expose events [message #17085] |
Tue, 14 September 1999 00:00 |
philaldis
Messages: 32 Registered: March 1999
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I've been having some trouble with expose events. I'm writing this
object/direct graphics window which automatically protects its colours
when the computer is running in 8 bit mode. So rather than having to
redraw the objects each time I get an expose event, I thought it would
be better to employ a pixmap. So I draw into the pixmap and then copy
to the screen,. Everytime a refresh is required I Device, COPY to teh
window form the pixmap. However for some reason as soon as the program
finishes, i.e. after it finishes the first initial drawing, the window
wipes itself blank for no reason. Then the further device, copies
whenever there are expose events don't do anything. I have played
around and it seems that when expose events are on (and so retain is =
0) the device copy is a very dubious beast.
Also, I find that if someone resizes a window, the I get about 15 secs
of non-stop resize events which is stupid. Does anyone know why there
are so many?
I'd appreciate any suggestions, as I'd prefer not to have to end up
just redrawing evrything every time.
I'm using windows NT and IDL 5.1
Cheers,
Phil
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