Hi Thomas,
You could get this effect by creating an OMGraphicHandlerLayer, then
adding your OMScalingRaster to it. You can get access to the
OMGraphicList by calling getList(), making sure it's not null, and
then adding a removing OMGraphics to it at will.
Scaling an image down should be pretty fast, 2 seconds seems long,
but that depends on the source image size, too. Might be worth doing
a test case and seeing what the performance gain is.
- Don
On Jun 16, 2006, at 1:52 AM, Thomas Schar wrote:
> Not sure if this can be done a different way, but I'm including
> source for a very trivial layer that really just supports
> programmatic addition/deletion of simple bitmaps to a layer. (Very
> similar to the com.bbn.openmap.plugin.CSVTiledImagePlugin except
> that you can add files in dynamically).
>
> CVSTiledImagePlugin would have been fine for my requirements,
> except I couldn't dynamically add images, and was restricted to
> using files to load images. Perhaps, a refactor of
> CSVTiledImagePlugin would be better?
> Perhaps something like, "GenericImagePlugin" and subclass
> "CVSTiledImagePlugin"? (Where GenericImagePlugin allows
> programmatic dynamic addition/deletion of images to the layer and
> CSVTiledImagePlugin simply uses a constructor file property based
> initialisation?)
>
> If it's worth doing, reply to this and I'll submit a proper patch.
> Moreover, I'm looking into the OMScalingRaster to see if a pre-
> generated mip mapped approach would be faster for 2d blits. (ie.
> for example, in our instance, the 64MB OMScalingRaster takes a good
> 2 seconds to render when zoomed out. I'm guessing this is due to
> having to blit the entire thing down to a small area. A pre-
> generated mipmap would reduce the data size to a small single digit
> percentage of the entire bitmap). If it speeds things up, I'll
> submit a patch for this too.
>
> Apologies if this is in the wrong area.
>
> Cheers
> Tom.
>
> /**
> * This class is a very naive implementation of a bitmap rendering
> layer. It simply invokes
> * the generate methods of the OMScalingRaster instances contained.
> The OMScalingRaster instances
> * do not (seem) to do any smarts with mip mapping, or hierarchical
> tiled rendering.
> * _at_author txs
> */
> public class BitmapLayer extends OMGraphicHandlerLayer {
> ArrayList<OMScalingRaster> m_aryImgs=new
> ArrayList<OMScalingRaster>();
> /**
> * This adds an image to the layer and returns a handle to the
> image raster
> * _at_throws IOException
> */
> public OMScalingRaster addImage(String strFilePath, LatLonPoint
> latlonTopLeft, LatLonPoint latlonBotRight)throws IOException{
> File fileImg=new java.io.File(strFilePath);
> FileInputStream fisImg=new FileInputStream(fileImg);
> FileCacheImageInputStream fciis = new
> FileCacheImageInputStream(fisImg, null);
> BufferedImage bufImg = ImageIO.read(fciis);
> OMScalingRaster rasterImg=new OMScalingRaster
> (latlonTopLeft.getLatitude(), latlonTopLeft.getLongitude(),
> latlonBotRight.getLatitude(), latlonBotRight.getLongitude
> (), bufImg);
> m_aryImgs.add(rasterImg);
> return(rasterImg);
> }
>
> /**
> * Removes the specified OMScalingRaster image from the layer if
> it has been added
> * _at_param rasterImg
> */
> public void removeImage(OMScalingRaster rasterImg){
> m_aryImgs.remove(rasterImg);
> }
> /* (non-Javadoc)
> * _at_see com.bbn.openmap.layer.OMGraphicHandlerLayer#prepare()
> */
> public synchronized OMGraphicList prepare(){
> OMGraphicList list=super.prepare();
> Projection proj=getProjection();
> // iterate through the entire array
> if(list==null)
> list=new OMGraphicList();
> for(int iImg=0; iImg<m_aryImgs.size(); ++iImg){
> OMScalingRaster rasterImg=m_aryImgs.get(iImg);
> if(rasterImg.isOnMap(proj)){
> rasterImg.generate(proj);
> list.add(rasterImg);
> }
> }
> return(list);
> }
> }
>
> --
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Received on Fri Jun 16 2006 - 15:58:50 EDT