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			609 lines
		
	
	
		
			23 KiB
		
	
	
	
		
			Java
		
	
	
	
			
		
		
	
	
			609 lines
		
	
	
		
			23 KiB
		
	
	
	
		
			Java
		
	
	
	
| /* AffineTransformOp.java --  This class performs affine
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|    transformation between two images or rasters in 2 dimensions.
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|    Copyright (C) 2004, 2006 Free Software Foundation
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| 
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| This file is part of GNU Classpath.
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| 
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| GNU Classpath is free software; you can redistribute it and/or modify
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| it under the terms of the GNU General Public License as published by
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| the Free Software Foundation; either version 2, or (at your option)
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| any later version.
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| 
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| GNU Classpath is distributed in the hope that it will be useful, but
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| WITHOUT ANY WARRANTY; without even the implied warranty of
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| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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| General Public License for more details.
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| 
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| You should have received a copy of the GNU General Public License
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| along with GNU Classpath; see the file COPYING.  If not, write to the
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| Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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| 02110-1301 USA.
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| 
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| Linking this library statically or dynamically with other modules is
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| making a combined work based on this library.  Thus, the terms and
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| conditions of the GNU General Public License cover the whole
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| combination.
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| 
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| As a special exception, the copyright holders of this library give you
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| permission to link this library with independent modules to produce an
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| executable, regardless of the license terms of these independent
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| modules, and to copy and distribute the resulting executable under
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| terms of your choice, provided that you also meet, for each linked
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| independent module, the terms and conditions of the license of that
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| module.  An independent module is a module which is not derived from
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| or based on this library.  If you modify this library, you may extend
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| this exception to your version of the library, but you are not
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| obligated to do so.  If you do not wish to do so, delete this
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| exception statement from your version. */
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| 
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| package java.awt.image;
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| 
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| import java.awt.Graphics2D;
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| import java.awt.Point;
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| import java.awt.Rectangle;
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| import java.awt.RenderingHints;
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| import java.awt.geom.AffineTransform;
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| import java.awt.geom.NoninvertibleTransformException;
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| import java.awt.geom.Point2D;
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| import java.awt.geom.Rectangle2D;
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| import java.util.Arrays;
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| 
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| /**
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|  * AffineTransformOp performs matrix-based transformations (translations,
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|  * scales, flips, rotations, and shears).
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|  *
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|  * If interpolation is required, nearest neighbour, bilinear, and bicubic
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|  * methods are available.
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|  *
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|  * @author Olga Rodimina (rodimina@redhat.com)
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|  * @author Francis Kung (fkung@redhat.com)
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|  */
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| public class AffineTransformOp implements BufferedImageOp, RasterOp
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| {
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|     public static final int TYPE_NEAREST_NEIGHBOR = 1;
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| 
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|     public static final int TYPE_BILINEAR = 2;
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| 
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|     /**
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|      * @since 1.5.0
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|      */
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|     public static final int TYPE_BICUBIC = 3;
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| 
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|     private AffineTransform transform;
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|     private RenderingHints hints;
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| 
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|     /**
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|      * Construct AffineTransformOp with the given xform and interpolationType.
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|      * Interpolation type can be TYPE_BILINEAR, TYPE_BICUBIC or
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|      * TYPE_NEAREST_NEIGHBOR.
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|      *
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|      * @param xform AffineTransform that will applied to the source image
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|      * @param interpolationType type of interpolation used
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|      * @throws ImagingOpException if the transform matrix is noninvertible
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|      */
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|     public AffineTransformOp (AffineTransform xform, int interpolationType)
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|     {
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|       this.transform = xform;
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|       if (xform.getDeterminant() == 0)
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|         throw new ImagingOpException(null);
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| 
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|       switch (interpolationType)
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|       {
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|       case TYPE_BILINEAR:
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|         hints = new RenderingHints (RenderingHints.KEY_INTERPOLATION,
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|                                     RenderingHints.VALUE_INTERPOLATION_BILINEAR);
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|         break;
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|       case TYPE_BICUBIC:
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|         hints = new RenderingHints (RenderingHints.KEY_INTERPOLATION,
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|                                     RenderingHints.VALUE_INTERPOLATION_BICUBIC);
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|         break;
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|       default:
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|         hints = new RenderingHints (RenderingHints.KEY_INTERPOLATION,
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|                                     RenderingHints.VALUE_INTERPOLATION_NEAREST_NEIGHBOR);
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|       }
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|     }
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| 
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|     /**
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|      * Construct AffineTransformOp with the given xform and rendering hints.
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|      *
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|      * @param xform AffineTransform that will applied to the source image
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|      * @param hints rendering hints that will be used during transformation
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|      * @throws ImagingOpException if the transform matrix is noninvertible
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|      */
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|     public AffineTransformOp (AffineTransform xform, RenderingHints hints)
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|     {
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|       this.transform = xform;
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|       this.hints = hints;
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|       if (xform.getDeterminant() == 0)
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|         throw new ImagingOpException(null);
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|     }
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| 
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|     /**
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|      * Creates a new BufferedImage with the size equal to that of the
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|      * transformed image and the correct number of bands. The newly created
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|      * image is created with the specified ColorModel.
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|      * If a ColorModel is not specified, an appropriate ColorModel is used.
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|      *
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|      * @param src the source image.
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|      * @param destCM color model for the destination image (can be null).
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|      * @return a new compatible destination image.
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|      */
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|     public BufferedImage createCompatibleDestImage (BufferedImage src,
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|                                                     ColorModel destCM)
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|     {
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|       if (destCM != null)
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|         return new BufferedImage(destCM,
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|                                  createCompatibleDestRaster(src.getRaster()),
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|                                  src.isAlphaPremultiplied(), null);
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| 
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|       // This behaviour was determined by Mauve testcases, and is compatible
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|       // with the reference implementation
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|       if (src.getType() == BufferedImage.TYPE_INT_ARGB_PRE
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|           || src.getType() == BufferedImage.TYPE_4BYTE_ABGR
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|           || src.getType() == BufferedImage.TYPE_4BYTE_ABGR_PRE)
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|         return new BufferedImage(src.getWidth(), src.getHeight(), src.getType());
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| 
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|       else
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|         return new BufferedImage(src.getWidth(), src.getHeight(),
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|                                  BufferedImage.TYPE_INT_ARGB);
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|     }
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| 
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|     /**
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|      * Creates a new WritableRaster with the size equal to the transformed
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|      * source raster and correct number of bands .
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|      *
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|      * @param src the source raster.
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|      * @throws RasterFormatException if resulting width or height of raster is 0.
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|      * @return a new compatible raster.
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|      */
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|     public WritableRaster createCompatibleDestRaster (Raster src)
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|     {
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|       Rectangle2D rect = getBounds2D(src);
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| 
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|       if (rect.getWidth() == 0 || rect.getHeight() == 0)
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|         throw new RasterFormatException("width or height is 0");
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| 
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|       return src.createCompatibleWritableRaster((int) rect.getWidth(),
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|                                                 (int) rect.getHeight());
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|     }
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| 
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|     /**
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|      * Transforms source image using transform specified at the constructor.
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|      * The resulting transformed image is stored in the destination image if one
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|      * is provided; otherwise a new BufferedImage is created and returned.
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|      *
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|      * @param src source image
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|      * @param dst destination image
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|      * @throws IllegalArgumentException if the source and destination image are
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|      *          the same
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|      * @return transformed source image.
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|      */
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|     public final BufferedImage filter (BufferedImage src, BufferedImage dst)
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|     {
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|       if (dst == src)
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|         throw new IllegalArgumentException("src image cannot be the same as "
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|                                          + "the dst image");
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| 
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|       // If the destination image is null, then use a compatible BufferedImage
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|       if (dst == null)
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|         dst = createCompatibleDestImage(src, null);
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| 
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|       Graphics2D gr = dst.createGraphics();
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|       gr.setRenderingHints(hints);
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|       gr.drawImage(src, transform, null);
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|       return dst;
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|     }
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| 
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|     /**
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|      * Transforms source raster using transform specified at the constructor.
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|      * The resulting raster is stored in the destination raster if it is not
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|      * null, otherwise a new raster is created and returned.
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|      *
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|      * @param src source raster
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|      * @param dst destination raster
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|      * @throws IllegalArgumentException if the source and destination are not
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|      *          compatible
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|      * @return transformed raster.
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|      */
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|     public final WritableRaster filter(Raster src, WritableRaster dst)
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|     {
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|       // Initial checks
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|       if (dst == src)
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|         throw new IllegalArgumentException("src image cannot be the same as"
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|                                            + " the dst image");
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| 
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|       if (dst == null)
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|         dst = createCompatibleDestRaster(src);
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| 
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|       if (src.getNumBands() != dst.getNumBands())
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|         throw new IllegalArgumentException("src and dst must have same number"
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|                                            + " of bands");
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| 
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|       // Optimization for rasters that can be represented in the RGB colormodel:
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|       // wrap the rasters in images, and let Cairo do the transformation
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|       if (ColorModel.getRGBdefault().isCompatibleSampleModel(src.getSampleModel())
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|           && ColorModel.getRGBdefault().isCompatibleSampleModel(dst.getSampleModel()))
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|         {
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|           WritableRaster src2 = Raster.createWritableRaster(src.getSampleModel(),
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|                                                             src.getDataBuffer(),
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|                                                             new Point(src.getMinX(),
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|                                                                       src.getMinY()));
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|           BufferedImage iSrc = new BufferedImage(ColorModel.getRGBdefault(),
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|                                                  src2, false, null);
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|           BufferedImage iDst = new BufferedImage(ColorModel.getRGBdefault(), dst,
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|                                                  false, null);
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| 
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|           return filter(iSrc, iDst).getRaster();
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|         }
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| 
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|       // Otherwise, we need to do the transformation in java code...
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|       // Create arrays to hold all the points
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|       double[] dstPts = new double[dst.getHeight() * dst.getWidth() * 2];
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|       double[] srcPts = new double[dst.getHeight() * dst.getWidth() * 2];
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| 
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|       // Populate array with all points in the *destination* raster
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|       int i = 0;
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|       for (int x = 0; x < dst.getWidth(); x++)
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|         {
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|           for (int y = 0; y < dst.getHeight(); y++)
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|             {
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|               dstPts[i++] = x;
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|               dstPts[i++] = y;
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|             }
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|         }
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|       Rectangle srcbounds = src.getBounds();
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| 
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|       // Use an inverse transform to map each point in the destination to
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|       // a point in the source.  Note that, while all points in the destination
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|       // matrix are integers, this is not necessarily true for points in the
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|       // source (hence why interpolation is required)
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|       try
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|         {
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|           AffineTransform inverseTx = transform.createInverse();
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|           inverseTx.transform(dstPts, 0, srcPts, 0, dstPts.length / 2);
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|         }
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|       catch (NoninvertibleTransformException e)
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|         {
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|           // Shouldn't happen since the constructor traps this
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|           throw new ImagingOpException(e.getMessage());
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|         }
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| 
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|       // Different interpolation methods...
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|       if (hints.containsValue(RenderingHints.VALUE_INTERPOLATION_NEAREST_NEIGHBOR))
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|         filterNearest(src, dst, dstPts, srcPts);
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| 
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|       else if (hints.containsValue(RenderingHints.VALUE_INTERPOLATION_BILINEAR))
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|         filterBilinear(src, dst, dstPts, srcPts);
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| 
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|       else          // bicubic
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|         filterBicubic(src, dst, dstPts, srcPts);
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| 
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|       return dst;
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|     }
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| 
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|     /**
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|      * Transforms source image using transform specified at the constructor and
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|      * returns bounds of the transformed image.
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|      *
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|      * @param src image to be transformed
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|      * @return bounds of the transformed image.
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|      */
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|     public final Rectangle2D getBounds2D (BufferedImage src)
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|     {
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|       return getBounds2D (src.getRaster());
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|     }
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| 
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|     /**
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|      * Returns bounds of the transformed raster.
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|      *
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|      * @param src raster to be transformed
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|      * @return bounds of the transformed raster.
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|      */
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|     public final Rectangle2D getBounds2D (Raster src)
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|     {
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|       return transform.createTransformedShape(src.getBounds()).getBounds2D();
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|     }
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| 
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|     /**
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|      * Returns interpolation type used during transformations.
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|      *
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|      * @return interpolation type
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|      */
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|     public final int getInterpolationType ()
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|     {
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|       if (hints.containsValue(RenderingHints.VALUE_INTERPOLATION_BILINEAR))
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|         return TYPE_BILINEAR;
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| 
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|       else if (hints.containsValue(RenderingHints.VALUE_INTERPOLATION_BICUBIC))
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|         return TYPE_BICUBIC;
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| 
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|       else
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|         return TYPE_NEAREST_NEIGHBOR;
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|     }
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| 
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|     /**
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|      * Returns location of the transformed source point. The resulting point
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|      * is stored in the dstPt if one is specified.
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|      *
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|      * @param srcPt point to be transformed
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|      * @param dstPt destination point
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|      * @return the location of the transformed source point.
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|      */
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|     public final Point2D getPoint2D (Point2D srcPt, Point2D dstPt)
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|     {
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|       return transform.transform (srcPt, dstPt);
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|     }
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| 
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|     /**
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|      * Returns rendering hints that are used during transformation.
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|      *
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|      * @return the rendering hints used in this Op.
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|      */
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|     public final RenderingHints getRenderingHints ()
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|     {
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|       return hints;
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|     }
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| 
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|     /**
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|      * Returns transform used in transformation between source and destination
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|      * image.
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|      *
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|      * @return the transform used in this Op.
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|      */
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|     public final AffineTransform getTransform ()
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|     {
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|       return transform;
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|     }
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| 
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|     /**
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|      * Perform nearest-neighbour filtering
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|      *
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|      * @param src the source raster
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|      * @param dst the destination raster
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|      * @param dpts array of points on the destination raster
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|      * @param pts array of corresponding points on the source raster
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|      */
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|     private void filterNearest(Raster src, WritableRaster dst, double[] dpts,
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|                                double[] pts)
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|     {
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|       Rectangle srcbounds = src.getBounds();
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| 
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|       // For all points on the destination raster, copy the value from the
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|       // corrosponding (rounded) source point
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|       for (int i = 0; i < dpts.length; i += 2)
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|         {
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|           int srcX = (int) Math.round(pts[i]) + src.getMinX();
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|           int srcY = (int) Math.round(pts[i + 1]) + src.getMinY();
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| 
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|           if (srcbounds.contains(srcX, srcY))
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|             dst.setDataElements((int) dpts[i] + dst.getMinX(),
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|                                 (int) dpts[i + 1] + dst.getMinY(),
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|                                 src.getDataElements(srcX, srcY, null));
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|         }
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|     }
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| 
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|     /**
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|      * Perform bilinear filtering
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|      *
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|      * @param src the source raster
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|      * @param dst the destination raster
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|      * @param dpts array of points on the destination raster
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|      * @param pts array of corresponding points on the source raster
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|      */
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|     private void filterBilinear(Raster src, WritableRaster dst, double[] dpts,
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|                               double[] pts)
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|     {
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|       Rectangle srcbounds = src.getBounds();
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| 
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|       Object xyarr = null;
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|       Object xp1arr = null;
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|       Object yp1arr = null;
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|       Object xyp1arr = null;
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| 
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|       double xy;
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|       double xp1;
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|       double yp1;
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|       double xyp1;
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| 
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|       double[] result = new double[src.getNumBands()];
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| 
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|       // For all points in the destination raster, use bilinear interpolation
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|       // to find the value from the corrosponding source points
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|       for (int i = 0; i < dpts.length; i += 2)
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|         {
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|           int srcX = (int) Math.round(pts[i]) + src.getMinX();
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|           int srcY = (int) Math.round(pts[i + 1]) + src.getMinY();
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| 
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|           if (srcbounds.contains(srcX, srcY))
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|             {
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|               // Corner case at the bottom or right edge; use nearest neighbour
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|               if (pts[i] >= src.getWidth() - 1
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|                   || pts[i + 1] >= src.getHeight() - 1)
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|                 dst.setDataElements((int) dpts[i] + dst.getMinX(),
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|                                     (int) dpts[i + 1] + dst.getMinY(),
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|                                     src.getDataElements(srcX, srcY, null));
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| 
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|               // Standard case, apply the bilinear formula
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|               else
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|                 {
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|                   int x = (int) Math.floor(pts[i] + src.getMinX());
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|                   int y = (int) Math.floor(pts[i + 1] + src.getMinY());
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|                   double xdiff = pts[i] + src.getMinX() - x;
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|                   double ydiff = pts[i + 1] + src.getMinY() - y;
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| 
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|                   // Get surrounding pixels used in interpolation... optimized
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|                   // to use the smallest datatype possible.
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|                   if (src.getTransferType() == DataBuffer.TYPE_DOUBLE
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|                       || src.getTransferType() == DataBuffer.TYPE_FLOAT)
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|                     {
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|                       xyarr = src.getPixel(x, y, (double[])xyarr);
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|                       xp1arr  = src.getPixel(x+1, y, (double[])xp1arr);
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|                       yp1arr = src.getPixel(x, y+1, (double[])yp1arr);
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|                       xyp1arr = src.getPixel(x+1, y+1, (double[])xyp1arr);
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|                     }
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|                   else
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|                     {
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|                       xyarr = src.getPixel(x, y, (int[])xyarr);
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|                       xp1arr  = src.getPixel(x+1, y, (int[])xp1arr);
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|                       yp1arr = src.getPixel(x, y+1, (int[])yp1arr);
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|                       xyp1arr = src.getPixel(x+1, y+1, (int[])xyp1arr);
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|                     }
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|                   // using
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|                   // array[] pixels = src.getPixels(x, y, 2, 2, pixels);
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|                   // instead of doing four individual src.getPixel() calls
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|                   // should be faster, but benchmarking shows that it's not...
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| 
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|                   // Run interpolation for each band
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|                   for (int j = 0; j < src.getNumBands(); j++)
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|                     {
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|                       // Pull individual sample values out of array
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|                       if (src.getTransferType() == DataBuffer.TYPE_DOUBLE
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|                           || src.getTransferType() == DataBuffer.TYPE_FLOAT)
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|                         {
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|                           xy = ((double[])xyarr)[j];
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|                           xp1  = ((double[])xp1arr)[j];
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|                           yp1 = ((double[])yp1arr)[j];
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|                           xyp1 = ((double[])xyp1arr)[j];
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|                         }
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|                       else
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|                         {
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|                           xy = ((int[])xyarr)[j];
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|                           xp1  = ((int[])xp1arr)[j];
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|                           yp1 = ((int[])yp1arr)[j];
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|                           xyp1 = ((int[])xyp1arr)[j];
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|                         }
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| 
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|                       // If all four samples are identical, there's no need to
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|                       // calculate anything
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|                       if (xy == xp1 && xy == yp1 && xy == xyp1)
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|                         result[j] = xy;
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| 
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|                       // Run bilinear interpolation formula
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|                       else
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|                         result[j] = (xy * (1-xdiff) + xp1 * xdiff)
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|                                       * (1-ydiff)
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|                                     + (yp1 * (1-xdiff) + xyp1 * xdiff)
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|                                       * ydiff;
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|                     }
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| 
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|                   dst.setPixel((int)dpts[i] + dst.getMinX(),
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|                                (int)dpts[i+1] + dst.getMinY(),
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|                                result);
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|                 }
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|             }
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|         }
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|     }
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| 
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|     /**
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|      * Perform bicubic filtering
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|      * based on http://local.wasp.uwa.edu.au/~pbourke/colour/bicubic/
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|      *
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|      * @param src the source raster
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|      * @param dst the destination raster
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|      * @param dpts array of points on the destination raster
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|      * @param pts array of corresponding points on the source raster
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|      */
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|     private void filterBicubic(Raster src, WritableRaster dst, double[] dpts,
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|                                double[] pts)
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|     {
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|       Rectangle srcbounds = src.getBounds();
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|       double[] result = new double[src.getNumBands()];
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|       Object pixels = null;
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| 
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|       // For all points on the destination raster, perform bicubic interpolation
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|       // from corrosponding source points
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|       for (int i = 0; i < dpts.length; i += 2)
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|         {
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|           if (srcbounds.contains((int) Math.round(pts[i]) + src.getMinX(),
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|                                  (int) Math.round(pts[i + 1]) + src.getMinY()))
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|             {
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|               int x = (int) Math.floor(pts[i] + src.getMinX());
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|               int y = (int) Math.floor(pts[i + 1] + src.getMinY());
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|               double dx = pts[i] + src.getMinX() - x;
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|               double dy = pts[i + 1] + src.getMinY() - y;
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|               Arrays.fill(result, 0);
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| 
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|               for (int m = - 1; m < 3; m++)
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|                 for (int n = - 1; n < 3; n++)
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|                   {
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|                     // R(x) = ( P(x+2)^3 - 4 P(x+1)^3 + 6 P(x)^3 - 4 P(x-1)^3 ) / 6
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|                     double r1 = 0;
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|                     double r2 = 0;
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| 
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|                     // Calculate R(m - dx)
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|                     double rx = m - dx + 2;
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|                     r1 += rx * rx * rx;
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| 
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|                     rx = m - dx + 1;
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|                     if (rx > 0)
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|                       r1 -= 4 * rx * rx * rx;
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| 
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|                     rx = m - dx;
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|                     if (rx > 0)
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|                       r1 += 6 * rx * rx * rx;
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| 
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|                     rx = m - dx - 1;
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|                     if (rx > 0)
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|                       r1 -= 4 * rx * rx * rx;
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| 
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|                     r1 /= 6;
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| 
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|                     // Calculate R(dy - n);
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|                     rx = dy - n + 2;
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|                     if (rx > 0)
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|                       r2 += rx * rx * rx;
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| 
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|                     rx = dy - n + 1;
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|                     if (rx > 0)
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|                       r2 -= 4 * rx * rx * rx;
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| 
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|                     rx = dy - n;
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|                     if (rx > 0)
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|                       r2 += 6 * rx * rx * rx;
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| 
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|                     rx = dy - n - 1;
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|                     if (rx > 0)
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|                       r2 -= 4 * rx * rx * rx;
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| 
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|                     r2 /= 6;
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| 
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|                     // Calculate F(i+m, j+n) R(m - dx) R(dy - n)
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|                     // Check corner cases
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|                     int srcX = x + m;
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|                     if (srcX >= src.getMinX() + src.getWidth())
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|                       srcX = src.getMinX() + src.getWidth() - 1;
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|                     else if (srcX < src.getMinX())
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|                       srcX = src.getMinX();
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| 
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|                     int srcY = y + n;
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|                     if (srcY >= src.getMinY() + src.getHeight())
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|                       srcY = src.getMinY() + src.getHeight() - 1;
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|                     else if (srcY < src.getMinY())
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|                       srcY = src.getMinY();
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| 
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|                     // Calculate once for each band, using the smallest
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|                     // datatype possible
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|                     if (src.getTransferType() == DataBuffer.TYPE_DOUBLE
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|                         || src.getTransferType() == DataBuffer.TYPE_FLOAT)
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|                       {
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|                         pixels = src.getPixel(srcX, srcY, (double[])pixels);
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|                         for (int j = 0; j < result.length; j++)
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|                           result[j] += ((double[])pixels)[j] * r1 * r2;
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|                       }
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|                     else
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|                       {
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|                         pixels = src.getPixel(srcX, srcY, (int[])pixels);
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|                         for (int j = 0; j < result.length; j++)
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|                           result[j] += ((int[])pixels)[j] * r1 * r2;
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|                       }
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|                   }
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| 
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|               // Put it all together
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|               dst.setPixel((int)dpts[i] + dst.getMinX(),
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|                            (int)dpts[i+1] + dst.getMinY(),
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|                            result);
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|             }
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|         }
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|     }
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| }
 |