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Re: [udig-devel] double buffering
Right, there are some timing associated with refreshing the screen. They are set for content that takes a fair while to draw (so it is kinder to watch a large shapefile, or slow database "draw" onto the screen as it happens).

Not sure what you would like to do? This is one of the more sensible uses for a "layer group" I have heard of ...
-- 
Jody Garnett

On Wednesday, 17 April 2013 at 4:36 PM, Juho Kokkonen wrote:

Hi Jody

Lets say that i have two different layers. First is one geotiff file for big scale like an europe map
and second is geotiff file on some area (like an scandinavia) smaller scale.

i'll set zorder 0 on europe and zorder 1 on scandinavian.

Now i'll see both of them on screen but when zoom executes it first render a europe because it is lighter and faster to draw and
then it will render scandinavian map.

So users see europe and after 1 second scandinavian map, so it's kind a flicker.

Is there any listener or something like that where i can check that all layers has been done and then show image on screen?

- Juho


----- Original Message -----
From: "Jody Garnett" <jody.garnett@xxxxxxxxx>
To: "User-friendly Desktop Internet GIS" <udig-devel@xxxxxxxxxxxxxxxxxxxxx>
Sent: Wednesday, April 17, 2013 12:47:10 AM
Subject: Re: [udig-devel] double buffering

For raster layers:
- We use the JAI tool chain to render into an AWT BufferedImage (one buffer).
- And then transfer those bytes over to an SWT Image (second buffer).
- And then finally draw the SWT images into a buffer for the layer.

And from there normal "composition" of the layers into a single image takes place:
- The buffer from each layer is drawn onto an SWT image
- Any outstanding drawing commands (such as visual feedback from the tools) is drawn
- Any thing on the glass layer is drawn

The resulting image is the "buffer" we use to draw the control when asked by SWT.


--
Jody Garnett



On Wednesday, 17 April 2013 at 6:29 AM, Juho Kokkonen wrote:


Hi

I read that udig supports double buffering during render raster layers. I use mapviewer and i'll set SWT.double_buffered flag at constructor. But how i can use multi layer renderer on rendering my raster layers?

- Juho
_______________________________________________
User-friendly Desktop Internet GIS (uDig)


_______________________________________________
User-friendly Desktop Internet GIS (uDig)
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User-friendly Desktop Internet GIS (uDig)

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