RE: [OpenMap Users] RE: [OpenMap UserMapbean performance on Linux/Xwindows (revisited)

From: Rob Ratcliff <>
Date: Thu, 4 Aug 2005 09:11:09 -0500

Oh, I thought this was a remote X server situation...sorry about that.

In that case, a few things to try are:

1.) set pmoffscreen=true

2.) Use com.bbn.openmap.layer.policy.BufferedImageRenderPolicy
for your layers that do lots of line drawings such as VPF layers
and don't change for given projection. (You may have already done
something similar to this with your BufferedLayer.)

3.) Reduce the number of repaints per second. One way is to put the
repaint of the layers in a timer thread and only paint when there
is dirty areas of the screen and no more than say 4 times per second.

4.) Specify the dirty region rectangle in your calls to repaint. This can
have a huge impact, especially for cases where only a small part of the
overall map is changing, if you're willing to track the dirty regions.

Also, since you're using Java 5, it might be interesting to
try out some of the new OpenGL-based Java2D rendering that it supports.

To track down the exact layer that is the biggest performance hog,
I've found it useful to turn on one layer at a time while monitoring the
CPU usage.

Finally, if you happen to be drawing a lot of
multiline segments make sure you use use
Graphics.drawPolyline() rather than multiple
calls to Graphics().drawLine()

Let us know what you find out!



> I had already read 2D graphic white paper and experimented with the various
> environment variables and property settings.
> Here's the vital of the application and environment.
> OS: Redhat Enterprise 3
> Metcity X server (I believe)
> Java 5.0 update 4 (Java 1.5.0_04)
> The application runs on a local X server.

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Received on Thu Aug 04 2005 - 10:14:55 EDT

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