[gl4java-usergroup] glReadPixels(...) not working

[<Px...@ao...>]

    I'm writing a Java application, not applet, that draws linegraphs/scatterplots, etc.  I have a swing window that has a canvas in the middle of it that displays the graph, and that canvas is a class that extends GLCanvas.
    Drawing the graph is fine---everything shows up perfectly.  My goal and problem is in saving a screenshot of the canvas.  I'm using glReadPixels but nothing's happening.  I create a pixel array: byte[] pixels = new byte[getWidth() * getHeight() * 3];  Then I call gl.glReadPixels(0,0,getWidth(), getHeight(),GL_RGB,GL_UNSIGNED_BYTE,pixels);

BUT, pixels--my array--remains unchanged.  I've tried specifying a buffer with glReadBuffer with all possible buffers but it's still not doing anything.

If a solution isn't obvious please ask me questions so I can be more specific how things are set up.  I'm pretty lost here.

btw I'm using a windows 2000 box with j2sdk1.4.0, and gl4java v. 2.8.2.0.  Any help would be greatly appreciated.

Dennis