DDSMapResponse.java

/* (c) 2014 Open Source Geospatial Foundation - all rights reserved
 * (c) 2001 - 2013 OpenPlans
 * This code is licensed under the GPL 2.0 license, available at the root
 * application directory.
 */
package org.geoserver.wms.worldwind;

import gov.nasa.worldwind.formats.dds.DDSConverter;
import gov.nasa.worldwind.util.Logging;

import java.awt.image.BufferedImage;
import java.awt.image.ColorModel;
import java.awt.image.RenderedImage;
import java.awt.image.WritableRaster;
import java.io.IOException;
import java.io.OutputStream;
import java.nio.ByteBuffer;
import java.util.Collections;
import java.util.Hashtable;
import java.util.Set;

import org.geoserver.platform.ServiceException;
import org.geoserver.wms.MapProducerCapabilities;
import org.geoserver.wms.WMS;
import org.geoserver.wms.WMSMapContent;
import org.geoserver.wms.map.RenderedImageMapResponse;

public class DDSMapResponse extends RenderedImageMapResponse {

	/** the only MIME type this map producer supports */
	static final String MIME_TYPE = "image/dds";

	/**
	 * convenient singleton Set to expose the output format this producer
	 * supports
	 */
	private static final Set SUPPORTED_FORMATS = Collections
			.singleton(MIME_TYPE);
	
	public DDSMapResponse(WMS wms) {
		super(MIME_TYPE, wms);		
	}

	public void formatImageOutputStream(RenderedImage img, OutputStream os, 
	        WMSMapContent mapContent)
			throws ServiceException, IOException {	
			BufferedImage bimg = convertRenderedImage(img);
			ByteBuffer bb = DDSConverter.convertToDxt3(bimg);
			saveBuffer(bb,os);
	}
	
	public static boolean saveBuffer(ByteBuffer buffer, OutputStream os) throws IOException
    {
        if (buffer == null)
        {
            String message = "nullValue.BufferNull";
            Logging.logger().severe(message);
            throw new IllegalArgumentException(message);
        }

        if (os == null)
        {
            String message = "nullValue.FileIsNull";
            Logging.logger().severe(message);
            throw new IllegalArgumentException(message);
        }        
      
        int numBytesRead = 0;
        //WWIO.saveBuffer(buffer, new File("C:\\testdds\\image.dds"));
        os.write(buffer.array());
        return true;        
    }
	
	/**
	 * Covert RenderedImage to BufferedImage
	 * with correct colour model
	 * (lifted from http://www.jguru.com/faq/view.jsp?EID=114602)
	 * @param img
	 *
	 */
	protected BufferedImage convertRenderedImage(RenderedImage img) {
		if (img instanceof BufferedImage) {
			return (BufferedImage)img;	
		}	
		ColorModel cm = img.getColorModel();
		int width = img.getWidth();
		int height = img.getHeight();
		WritableRaster raster = cm.createCompatibleWritableRaster(width, height);
		boolean isAlphaPremultiplied = cm.isAlphaPremultiplied();
		Hashtable properties = new Hashtable();
		String[] keys = img.getPropertyNames();
		if (keys!=null) {
			for (int i = 0; i < keys.length; i++) {
				properties.put(keys[i], img.getProperty(keys[i]));
			}
		}
		BufferedImage bimg = new BufferedImage(cm, raster, isAlphaPremultiplied, properties);
		img.copyData(raster);
		return bimg;
	}

	/**
	 * DXT3 does support transparency, unless alpha is pre-multiplied
	 */
	@Override
	public MapProducerCapabilities getCapabilities(String outputFormat) {
		// FIXME Become more capable
		return new MapProducerCapabilities(false, false, false, true, null);
	}

}