libjava/java/awt/image/BandCombineOp.java

   1 /* Copyright (C) 2004  Free Software Foundation
   2
   3 This file is part of GNU Classpath.
   4
   5 GNU Classpath is free software; you can redistribute it and/or modify
   6 it under the terms of the GNU General Public License as published by
   7 the Free Software Foundation; either version 2, or (at your option)
   8 any later version.
   9
  10 GNU Classpath is distributed in the hope that it will be useful, but
  11 WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13 General Public License for more details.
  14
  15 You should have received a copy of the GNU General Public License
  16 along with GNU Classpath; see the file COPYING.  If not, write to the
  17 Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18 02111-1307 USA.
  19
  20 Linking this library statically or dynamically with other modules is
  21 making a combined work based on this library.  Thus, the terms and
  22 conditions of the GNU General Public License cover the whole
  23 combination.
  24
  25 As a special exception, the copyright holders of this library give you
  26 permission to link this library with independent modules to produce an
  27 executable, regardless of the license terms of these independent
  28 modules, and to copy and distribute the resulting executable under
  29 terms of your choice, provided that you also meet, for each linked
  30 independent module, the terms and conditions of the license of that
  31 module.  An independent module is a module which is not derived from
  32 or based on this library.  If you modify this library, you may extend
  33 this exception to your version of the library, but you are not
  34 obligated to do so.  If you do not wish to do so, delete this
  35 exception statement from your version. */
  36
  37 package java.awt.image;
  38
  39 import java.awt.Point;
  40 import java.awt.RenderingHints;
  41 import java.awt.geom.Point2D;
  42 import java.awt.geom.Rectangle2D;
  43
  44 /**
  45  * Filter Raster pixels by applying a matrix.
  46  *
  47  * BandCombineOp applies a matrix to each pixel to produce new pixel values.
  48  * The width of the matrix must be the same or one more than the number of
  49  * bands in the source Raster.  If one more, the pixels in the source are
  50  * assumed to contain an implicit 1.0 at the end.
  51  *
  52  * The rows of the matrix are multiplied by the pixel to produce the values
  53  * for the destination.  Therefore the destination Raster must contain the
  54  * same number of bands as the number of rows in the filter matrix.
  55  *
  56  * @author Jerry Quinn (jlquinn@optonline.net)
  57  */
  58 public class BandCombineOp implements RasterOp
  59 {
  60   private RenderingHints hints;
  61   private float[][] matrix;
  62
  63   /**
  64    * Construct a BandCombineOp.
  65    *
  66    * @param matrix The matrix to filter pixels with.
  67    * @param hints Rendering hints to apply.  Ignored.
  68    */
  69   public BandCombineOp(float[][] matrix, RenderingHints hints)
  70   {
  71     this.matrix = matrix;
  72     this.hints = hints;
  73   }
  74
  75   /**
  76    * Filter Raster pixels through a matrix.
  77    *
  78    * Applies the Op matrix to source pixes to produce dest pixels.  Each row
  79    * of the matrix is multiplied by the src pixel components to produce the
  80    * dest pixel.  If matrix is one more than the number of bands in the src,
  81    * the last element is implicitly multiplied by 1, i.e. added to the sum
  82    * for that dest component.
  83    *
  84    * If dest is null, a suitable Raster is created.  This implementation uses
  85    * createCompatibleDestRaster.
  86    *
  87    * @param src The source Raster.
  88    * @param dest  The destination Raster, or null.
  89    * @returns The destination Raster or an allocated Raster.
  90    * @see java.awt.image.RasterOp#filter(java.awt.image.Raster,
  91    *java.awt.image.WritableRaster)
  92    */
  93   public WritableRaster filter(Raster src, WritableRaster dest) {
  94     if (dest == null)
  95       dest = createCompatibleDestRaster(src);
  96
  97     // Filter the pixels
  98     float[] spix = new float[matrix[0].length];
  99     float[] dpix = new float[matrix.length];
 100     for (int y = src.getMinY(); y < src.getHeight() + src.getMinY(); y++)
 101       for (int x = src.getMinX(); x < src.getWidth() + src.getMinX(); x++)
 102       {
 103         // In case matrix rows have implicit translation
 104         spix[spix.length - 1] = 1.0f;
 105         src.getPixel(x, y, spix);
 106         for (int i = 0; i < matrix.length; i++)
 107         {
 108           dpix[i] = 0;
 109           for (int j = 0; j < matrix[0].length; j++)
 110             dpix[i] += spix[j] * matrix[i][j];
 111         }
 112         dest.setPixel(x, y, dpix);
 113       }
 114
 115     return dest;
 116   }
 117
 118   /* (non-Javadoc)
 119    * @see java.awt.image.RasterOp#getBounds2D(java.awt.image.Raster)
 120    */
 121   public Rectangle2D getBounds2D(Raster src)
 122   {
 123     return src.getBounds();
 124   }
 125
 126   /**
 127    * Creates a new WritableRaster that can be used as the destination for this
 128    * Op.  This implementation creates a Banded Raster with data type FLOAT.
 129    * @see
 130    *java.awt.image.RasterOp#createCompatibleDestRaster(java.awt.image.Raster)
 131    */
 132   public WritableRaster createCompatibleDestRaster(Raster src)
 133   {
 134     return Raster.createBandedRaster(DataBuffer.TYPE_FLOAT, src.getWidth(),
 135         src.getHeight(), matrix.length,
 136         new Point(src.getMinX(), src.getMinY()));
 137   }
 138
 139   /** Return corresponding destination point for source point.
 140    *
 141    * LookupOp will return the value of src unchanged.
 142    * @param src The source point.
 143    * @param dst The destination point.
 144    * @see java.awt.image.RasterOp#getPoint2D(java.awt.geom.Point2D,
 145    *java.awt.geom.Point2D)
 146    */
 147   public Point2D getPoint2D(Point2D src, Point2D dst)
 148   {
 149     if (dst == null) return (Point2D)src.clone();
 150     dst.setLocation(src);
 151     return dst;
 152   }
 153
 154   /* (non-Javadoc)
 155    * @see java.awt.image.RasterOp#getRenderingHints()
 156    */
 157   public RenderingHints getRenderingHints()
 158   {
 159     return hints;
 160   }
 161
 162   /** Return the matrix for this Op. */
 163   public float[][] getMatrix()
 164   {
 165     return matrix;
 166   }
 167
 168 }