OnPaint vs. using a cached background image

[PJ6]

I thought this was going to be a no-brainer. Instead of constantly
re-rending with OnPaint, my plotter was going to render its entire image
once to a bitmap OnResize as a way of caching its display. Only...
displaying a cahced bitmap performs *signifigantly* worse than using
OnPaint, especially when I'm zoomed in and scrolling around, and the bitmap
is quite large. I was *not* expecting that.

I know there has to be a right way of doing this. Is there anything I can do
to squeeze greater performance out of picture rendering?

Man I hope I get an answer to this one. This will be the fourth question
I've asked here that nobody has answered :(

Paul

[Peter Proost]

Hi PJ6

if you don't get an answer here maybe you could post to:
microsoft.public.dotnet.framework.drawing
which is the ng for drawing in .net
And maybe if you post some code for this question that some people here can
help you.

Greetz Peter

--
Programming today is a race between software engineers striving to build
bigger and better idiot-proof programs, and the Universe trying to produce
bigger and better idiots. So far, the Universe is winning. (Rich Cook)

"PJ6" <no****@nowhere.net> schreef in bericht
news:eM**************@TK2MSFTNGP03.phx.gbl...

I thought this was going to be a no-brainer. Instead of constantly
re-rending with OnPaint, my plotter was going to render its entire image
once to a bitmap OnResize as a way of caching its display. Only...
displaying a cahced bitmap performs *signifigantly* worse than using
OnPaint, especially when I'm zoomed in and scrolling around, and the bitmap is quite large. I was *not* expecting that.

I know there has to be a right way of doing this. Is there anything I can do to squeeze greater performance out of picture rendering?

Man I hope I get an answer to this one. This will be the fourth question
I've asked here that nobody has answered :(

Paul