I've been reading the StreamingRenderer trying to understand how the layer's drawing process works.
When the StreamingRenderer draws the layer[1] it uses the
Graphics2D.drawImage method. Wouldn't be better to use the
Graphics2D.drawRenderedImage to apply the transformation (and get better
performance?).
Who is the developer of StreamingRenderer?
[1]
-- start code StreamingRenderer code (line 1585)
// graphics.setTransform( new AffineTransform() );
for (int t = 0; t < n_lfts; t++) {
if (fts_array[t].myImage != null) // this is the case for the
// first one (ie.
// fts_array[t].graphics ==
// graphics)
{
graphics.drawImage(fts_array[t].myImage, 0, 0, null);
fts_array[t].myImage.flush();
fts_array[t].graphics.dispose();
}
}
-- end code
On mar, 2007-12-11 at 13:50 -0800, Jody Garnett wrote:
> Okay; so JPanel does double buffering by default (so your paint method
> is being passed a Graphics object that is backed onto a BuferedImage -
> check it out in a debugger). Needless to say this is not what you want
> for performance...
>
> Have a read of this:
> - http://www.exampledepot.com/egs/java.awt.image/VolImage.html
>
> Now there is a good chance I am leading you down the garden path here;
> performance tuning is a difficult balance. Please try rendering to a
> VolatileImage and let it me know if it works in your situation. I know
> it does wonders for doing the usual range of JAI activities; but
> resampling down onto disk may stretch the limits.
>
> The source code for JAI is online; you may want to look exactly at what
> DisplayJAI is doing.
> Cheers,
> Jody
> > I append the full source code[1] but the painting part is:
> >
> > private class PanelMap extends JPanel {
> >
> > @Override
> > public void paint(Graphics g) {
> > try {
> > Graphics2D g2d = (Graphics2D) g;
> > Rectangle rectangle = new Rectangle(getSize());
> >
> > //System.out.println("Map size (px): "+ rectangle.height
> > + "x" + rectangle.width);
> >
> > renderer.paint(g2d, rectangle,
> > mapContext.getLayerBounds());
> > } catch (IOException ex) {
> >
> > Logger.getLogger(PanelGeoMap.class.getName()).log(Level.SEVERE,
> > null, ex);
> > }
> > }
> > }
> >
> > I override the JPanel's paint method. PanelMap is inside a JScrollPane
> > and the renderer, in theory, only have to draw the visible viewport.
> >
>
--
Diego Fdez. Durán <[EMAIL PROTECTED]> | http://www.goedi.net
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