rasterlayer.java

geotools的源码

			/* given an offset and output width we can use memoryimagesource to 
			 * do the actual drawing 
			 */
			off= (int)((starty)*dw+startx);
			/* the following works arround a bug(?) in netscape 4.05 where it
       * crashes if you try to draw part of the array in the bottom R
       * corner. Since it doesn't do this in Appletviewer or ME IE4/5 
			 * I blame netscape and work round it, the problem may be in my code
			 * or my understanding of how memoryimage source handles offsets
			 */
      if(debug)System.out.println("RaL->dw "+dw+" "+w+" "+(dw-w));
      if(debug)System.out.println("RaL->dh "+dh+" "+h+" "+(dh-h));
      int first_offset = dw*(dh-h); // the whole block at the top
      int second_offset = (dw-w)*h; // the bit down the left side
      int out_bit = w*h; // the actual image to draw
      // the sum of these three bits must be less than the total image
      if(debug)System.out.println("RaL->off "+first_offset+" "+second_offset+" "+
        out_bit+" -> "+(first_offset+second_offset+out_bit)+" "+data.length);
      if(first_offset+second_offset+out_bit>data.length){ return;} // this is bad
      /* It seems that this netscape fix breaks other vms - what do I know*/
      //if(first_offset+second_offset+out_bit==data.length){ h--;} // this is netscape

			if(debug)System.out.println("RaL->offsets "+startx+" "+(starty)+" "+off);
			if(debug)System.out.println("RaL->w/h 2"+w+" "+h);
			if(debug)System.out.println("RaL->data "+data.length+" off:"+off+" "+(w*h)+" "+(off+w*h));
			source = new MemoryImageSource(w,h,data,off,dw);
			image = obs.createImage(source);
			/* now we need to know where to draw the image, I think that this can
			 * cause a slight jump to the output raster as we're moving from a
			 * double to the nearest int pixel position but thats life!
			 */
			int origin[]=scale.toGraphics(out.x,out.y);
			int gh=scale.toGraphics(out.height);
			int gw=scale.toGraphics(out.width);
			if(debug)System.out.println("RaL->out "+out.x+" "+out.y);
			if(debug)System.out.println("RaL-> -->"+origin[0]+" "+origin[1]+" "+(origin[1]-gh));
			//	boolean fred = g.drawImage(image,origin[0],origin[1]-gh,obs);
			// we should use image.getScaledInstance here
			boolean fred = g.drawImage(image,origin[0],origin[1]-gh,
			    gw,gh,obs);
			if(debug)g.setColor(Color.yellow);
			if(debug)g.drawRect(origin[0],origin[1]-gh,gw,gh);
			if(grid){
				for(int i = origin[0];i<origin[0]+gw;i+=scale.toGraphics(cellsize)){
					g.drawLine(i,origin[1]-gh,i,origin[1]);
				}
				for(int i = origin[1];i<origin[1]+gh;i+=scale.toGraphics(cellsize)){
					g.drawLine(origin[0],i-gh,origin[0]+gw,i-gh);
				}
				int r=(int)(out.y/cellsize);
				int c=(int)(out.x/cellsize);
				int c2=scale.toGraphics(cellsize)/2;
				g.setColor(Color.black);
				for(int j = origin[1];j<origin[1]+gh;j+=scale.toGraphics(cellsize)){
					for(int i = origin[0];i<origin[0]+gw;i+=scale.toGraphics(cellsize)){
						g.drawString((""+(c++)+","+r),i,j-gh+c2);
					}
					r++;
					c=(int)(out.x/cellsize);
				}
			}
		} else{ // off screen
		}
	}

	/**
	 * @return the id of the point
	 */
	public int getID(GeoPoint p){
		return r.getCellPos(p.x,p.y);
	}
	/**
	 * @return the id of the point
	 */
	public int getID(double x, double y){
		return r.getCellPos(x,y);
	}

  /**
   * Returns all grid cell IDs indicated by rect and mode.
   *
   * @param rect the rectange that describes the region to select from
   * @param mode the mode to use when selecting gridCells
   *
   * @return an array of grid cell IDs
   *
   * @see SelectionManager
   **/
  public int[] getIDs( GeoRectangle rect, int mode ) {

    double originX = r.getOriginx();
    double originY = r.getOriginy();
    
    double cellSize = r.getCellSize();

    int minXCoord = 0;
    double minX = 0;
    int minYCoord = 0;
    double minY = 0;
    
    int xWidth = 0;
    int yWidth = 0;    

    switch ( mode ) {
    case SelectionManager.CONTAINS:

      minXCoord = (int)Math.ceil( (rect.getX() - originX) / cellSize );
      minX = r.getXCell( minXCoord );
      minYCoord = (int)Math.ceil( (rect.getY() - originY) / cellSize );
      minY = r.getYCell( minYCoord );
      
      xWidth = (int)Math.floor( (rect.getX() + rect.getWidth() - minX)
                                / cellSize );
      yWidth = (int)Math.floor( (rect.getY() + rect.getHeight() - minY)
                                / cellSize );

      break;
    case SelectionManager.CROSSES:

      minXCoord = (int)Math.floor( (rect.getX() - originX) / cellSize );
      minX = r.getXCell( minXCoord );
      minYCoord = (int)Math.floor( (rect.getY() - originY) / cellSize );
      minY = r.getYCell( minYCoord );
      
      xWidth = (int)Math.ceil( (rect.getX() + rect.getWidth() - minX)
                               / cellSize );
      yWidth = (int)Math.ceil( (rect.getY() + rect.getHeight() - minY)
                               / cellSize );

      
      break;
    default:

      throw new RuntimeException
        ( "invalid mode: expected either SelectionManager.CONTAINS or "
          + "SelectionManager.CROSSES" );

    }
    
    int[] arr = new int[ xWidth * yWidth ];
    int index = 0;

    for ( int x = 0; x < xWidth; x ++ ) {
      for ( int y = 0; y < yWidth; y ++ ) {
        arr[ index ] = r.getCellID( minXCoord + x, minYCoord + y );
        index++;
      }      
    }

    return arr;
    
  }
  
	/**
	 * @return the maximum value of the contained raster
	 */
	public double getMax(){
		return r.getMax();
	}
	/**
	 * @return the minimum value of the contained raster
	 */
	public double getMin(){
		return r.getMin();
	}
	public double getNZMin(){
		return r.getNZMin();
	}
	/**
	 * return the data associated with this layer
	 */
  public GeoData getGeoData(){
    // shoud do something in future
		return r;
  }
	/**
	 * set the data associated with this layer
	 */
  public void setGeoData(GeoData data){
		if(data instanceof Raster){
			r=(Raster)data;
		}else{
		// complain loudly
		}

  }


  public double getSparseness(){
		return r.getSparseness();
	}
	public boolean isSparse(){
		return r.isSparse();
	}
	public void changeRaster(Raster n){
		r=n;
		set=false;
		System.gc();
		notifyLayerChangedListeners(LayerChangedEvent.GEOGRAPHY);	
	}

	public void Changed(ChangedEvent e){
		set=false;
		notifyLayerChangedListeners(e.getReason());
	}

	public GeoRectangle getBoundsOf(int id){
		int row = id%r.getWidth();
		int col = id/r.getWidth();
		double x = r.getXCell(col);
		double y = r.getYCell(row);
		return new GeoRectangle(x,y,r.getCellSize(),r.getCellSize());
	}
	public GeoRectangle getBoundsOf(int id[]){
		GeoRectangle gr =  new GeoRectangle();
		for(int i=0;i<id.length;i++){
			gr.add(getBoundsOf(id[i]));
		}
		return gr;
	}

	public Image getImage(Shader shade){// returns a copy of the current screen image
	  Canvas obs = new Canvas();
		MemoryImageSource source;
		data = new int[r.getHeight()*r.getWidth()];
		int h=r.getHeight();
		int w=r.getWidth();
		int off=0;
		int pt =0;
		// set up the underlying image data
		for (int i=0;i<h;i++){
			for (int j=0; j<w;j++){
					data[pt++]=shade.getRGB(r.getCell(i,j));
			}
		}
		if(debug)System.out.println("RaL->Painted "+(pt)+" pixels");
		set=false;
		source = new MemoryImageSource(w,h,data,off,w);
		image = obs.createImage(source);
		return image;
	}


}


/*
 * $Log: RasterLayer.java,v $
 * Revision 1.7  2001/08/01 12:32:46  ianturton
 * modification submited by Michael Becke <[e-mail]> to reduce
 * memory usage.
 *
 *
 *
 */