gcc/libjava/classpath/java/awt/image/Raster.java

/* Copyright (C) 2000, 2002, 2003, 2006,  Free Software Foundation

This file is part of GNU Classpath.

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package java.awt.image;

import java.awt.Point;
import java.awt.Rectangle;

/**
 * A rectangular collection of pixels composed from a {@link DataBuffer} which
 * stores the pixel values, and a {@link SampleModel} which is used to retrieve
 * the pixel values.
 * 
 * @author Rolf W. Rasmussen (rolfwr@ii.uib.no)
 */
public class Raster
{
  /** The sample model used to access the pixel values. */
  protected SampleModel sampleModel;
  
  /** The data buffer used to store the pixel values. */
  protected DataBuffer dataBuffer;
  
  /** The x-coordinate of the top left corner of the raster. */
  protected int minX;
  
  /** The y-coordinate of the top left corner of the raster. */
  protected int minY;
  
  /** The width of the raster. */
  protected int width;
  
  /** The height of the raster. */
  protected int height;
  
  protected int sampleModelTranslateX;
  
  protected int sampleModelTranslateY;
  
  /** The number of bands. */
  protected int numBands;
  
  protected int numDataElements;
  
  /** The raster's parent. */
  protected Raster parent;
  
  /**
   * Creates a new raster.
   * 
   * @param sampleModel  the sample model.
   * @param origin  the origin.
   */
  protected Raster(SampleModel sampleModel, Point origin)
  {
    this(sampleModel, sampleModel.createDataBuffer(), origin);
  }
  
  /**
   * Creates a new raster.
   * 
   * @param sampleModel  the sample model.
   * @param dataBuffer  the data buffer.
   * @param origin  the origin.
   */
  protected Raster(SampleModel sampleModel, DataBuffer dataBuffer,
                   Point origin)
  {
    this(sampleModel, dataBuffer, new Rectangle(origin.x, origin.y,
         sampleModel.getWidth(), sampleModel.getHeight()), origin, null);
  }

  /**
   * Creates a new raster.
   * 
   * @param sampleModel  the sample model.
   * @param dataBuffer  the data buffer.
   * @param aRegion  the raster's bounds.
   * @param sampleModelTranslate  the translation (<code>null</code> permitted).
   * @param parent  the raster's parent.
   */
  protected Raster(SampleModel sampleModel, DataBuffer dataBuffer,
      Rectangle aRegion, Point sampleModelTranslate, Raster parent)
  {
    this.sampleModel = sampleModel;
    this.dataBuffer = dataBuffer;
    this.minX = aRegion.x;
    this.minY = aRegion.y;
    this.width = aRegion.width;
    this.height = aRegion.height;
    
    // If sampleModelTranslate is null, use (0,0).  Methods such as
    // Raster.createRaster are specified to allow for a null argument.
    if (sampleModelTranslate != null)
    {
      this.sampleModelTranslateX = sampleModelTranslate.x;
      this.sampleModelTranslateY = sampleModelTranslate.y;
    }

    this.numBands = sampleModel.getNumBands();
    this.numDataElements = sampleModel.getNumDataElements();
    this.parent = parent;
  }
    
  /**
   * Creates an interleaved raster using the specified data type.
   * 
   * @param dataType  the data type.
   * @param w  the width.
   * @param h  the height.
   * @param bands  the number of bands.
   * @param location
   * 
   * @return The new raster.
   */
  public static WritableRaster createInterleavedRaster(int dataType,
      int w, int h, int bands, Point location)
  {
    int[] bandOffsets = new int[bands];
    // TODO: Maybe not generate this every time.
    for (int b = 0; b < bands; b++) 
      bandOffsets[b] = b;
    
    int scanlineStride = bands * w;
    return createInterleavedRaster(dataType, w, h, scanlineStride, bands,
                                   bandOffsets, location);
  }

  /**
   * Creates an interleaved raster.
   * 
   * @param dataType  the data type.
   * @param w  the width.
   * @param h  the height.
   * @param scanlineStride  the number of data elements from a sample on one 
   *     row to the corresponding sample on the next row.
   * @param pixelStride  the number of elements from a sample in one pixel to
   *     the corresponding sample in the next pixel.
   * @param bandOffsets  the band offsets.
   * @param location
   * 
   * @return The new raster.
   */
  public static WritableRaster createInterleavedRaster(int dataType, 
      int w, int h, int scanlineStride, int pixelStride, int[] bandOffsets,
      Point location)
  {
    SampleModel sm = new ComponentSampleModel(dataType, w, h, pixelStride,
        scanlineStride, bandOffsets);
    return createWritableRaster(sm, location);
  }

  /**
   * Creates a new banded raster.
   * 
   * @param dataType  the data type.
   * @param w  the width.
   * @param h  the height.
   * @param bands  the number of bands.
   * @param location  
   * 
   * @return The new raster.
   */
  public static WritableRaster createBandedRaster(int dataType, int w, int h, 
      int bands, Point location)
  {
    SampleModel sm = new BandedSampleModel(dataType, w, h, bands);
    return createWritableRaster(sm, location);
  }

  /**
   * Creates a new banded raster.
   * 
   * @param dataType  the data type.
   * @param w  the width.
   * @param h  the height.
   * @param scanlineStride  the number of data elements from a sample on one 
   *     row to the corresponding sample on the next row.
   * @param bankIndices  the index for each bank.
   * @param bandOffsets  the offset for each band.
   * @param location
   * 
   * @return The new raster.
   */
  public static WritableRaster createBandedRaster(int dataType, int w, int h,
      int scanlineStride, int[] bankIndices, int[] bandOffsets, Point location)
  {
    SampleModel sm = new BandedSampleModel(dataType, w, h, scanlineStride,
                                           bankIndices, bandOffsets);
    return createWritableRaster(sm, location);
  }
  
  /**
   * Creates a new packed raster.
   * 
   * @param dataType  the data type.
   * @param w  the width.
   * @param h  the height.
   * @param bandMasks  the bit mask for each band.
   * @param location 
   * 
   * @return The new raster.
   */
  public static WritableRaster createPackedRaster(int dataType, int w, int h,
      int[] bandMasks, Point location)
  {
    SampleModel sm = new SinglePixelPackedSampleModel(dataType, w, h,
                                                     bandMasks);
    return createWritableRaster(sm, location);
  }

  /**
   * Creates a new raster.
   * 
   * @param dataType  the data type.
   * @param w  the width.
   * @param h  the height.
   * @param bands  the number of bands.
   * @param bitsPerBand  the number of bits per band.
   * @param location
   * 
   * @return The new raster.
   */
  public static WritableRaster createPackedRaster(int dataType,
      int w, int h, int bands, int bitsPerBand, Point location)
  {
    if (bands <= 0 || (bands * bitsPerBand > getTypeBits(dataType)))
      throw new IllegalArgumentException();

    SampleModel sm;

    if (bands == 1)
      sm = new MultiPixelPackedSampleModel(dataType, w, h, bitsPerBand);
    else
      {
        int[] bandMasks = new int[bands];
        int mask = 0x1;
        for (int bits = bitsPerBand; --bits != 0;)
          mask = (mask << 1) | 0x1;
        for (int i = 0; i < bands; i++)
          {
            bandMasks[i] = mask;
            mask <<= bitsPerBand;
          }
          
        sm = new SinglePixelPackedSampleModel(dataType, w, h, bandMasks);
      }
    return createWritableRaster(sm, location);
  }

  /**
   * Creates a new interleaved raster.
   * 
   * @param dataBuffer  the data buffer.
   * @param w  the width.
   * @param h  the height.
   * @param scanlineStride  the number of data elements from a sample on one 
   *     row to the corresponding sample on the next row.
   * @param pixelStride  the number of elements from a sample in one pixel to
   *     the corresponding sample in the next pixel.
   * @param bandOffsets  the offset for each band.
   * @param location
   * 
   * @return The new raster.
   */
  public static WritableRaster createInterleavedRaster(DataBuffer dataBuffer, 
      int w, int h, int scanlineStride, int pixelStride, int[] bandOffsets, 
      Point location)
  {
    SampleModel sm = new ComponentSampleModel(dataBuffer.getDataType(),
        w, h, pixelStride, scanlineStride, bandOffsets);
    return createWritableRaster(sm, dataBuffer, location);
  }

  /**
   * Creates a new banded raster.
   * 
   * @param dataBuffer  the data buffer.
   * @param w  the width.
   * @param h  the height.
   * @param scanlineStride  the number of data elements from a sample on one 
   *     row to the corresponding sample on the next row.
   * @param bankIndices  the index for each bank.
   * @param bandOffsets  the band offsets.
   * @param location
   * 
   * @return The new raster.
   */
  public static WritableRaster createBandedRaster(DataBuffer dataBuffer,
      int w, int h, int scanlineStride, int[] bankIndices, int[] bandOffsets,
      Point location)
  {
    SampleModel sm = new BandedSampleModel(dataBuffer.getDataType(),
        w, h, scanlineStride, bankIndices, bandOffsets);
    return createWritableRaster(sm, dataBuffer, location);
  }
  
  /**
   * Creates a new packed raster.
   * 
   * @param dataBuffer  the data buffer.
   * @param w  the width.
   * @param h  the height.
   * @param scanlineStride  the number of data elements from a sample on one 
   *     row to the corresponding sample on the next row.
   * @param bandMasks  the bit mask for each band.
   * @param location
   * 
   * @return The new raster.
   */
  public static WritableRaster createPackedRaster(DataBuffer dataBuffer,
      int w, int h, int scanlineStride, int[] bandMasks, Point location)
 {
    SampleModel sm = new SinglePixelPackedSampleModel(dataBuffer.getDataType(),
        w, h, scanlineStride, bandMasks);
    return createWritableRaster(sm, dataBuffer, location);
  }
  
  /**
   * Creates a new packed raster.
   * 
   * @param dataBuffer  the data buffer.
   * @param w  the width.
   * @param h  the height.
   * @param bitsPerPixel  the number of bits per pixel.
   * @param location
   * 
   * @return The new raster.
   */
  public static WritableRaster createPackedRaster(DataBuffer dataBuffer,
      int w, int h, int bitsPerPixel, Point location)
  {
    SampleModel sm = new MultiPixelPackedSampleModel(dataBuffer.getDataType(),
        w, h, bitsPerPixel);
    return createWritableRaster(sm, dataBuffer, location);
  }
    
  /**
   * Creates a new raster.
   * 
   * @param sm  the sample model.
   * @param db  the data buffer.
   * @param location
   * 
   * @return The new raster.
   */
  public static Raster createRaster(SampleModel sm, DataBuffer db,
                                    Point location)
  {
    return new Raster(sm, db, location);
  }

  /**
   * Creates a new writable raster.
   * 
   * @param sm  the sample model.
   * @param location
   * 
   * @return The new writable raster.
   */
  public static WritableRaster createWritableRaster(SampleModel sm,
                                                    Point location)
  {
    return new WritableRaster(sm, location);
  }

  /**
   * Creates a new writable raster.
   * 
   * @param sm  the sample model.
   * @param db  the data buffer.
   * @param location 
   * 
   * @return The new writable raster.
   */
  public static WritableRaster createWritableRaster(SampleModel sm,
      DataBuffer db, Point location)
  {
    return new WritableRaster(sm, db, location);
  }

  /**
   * Returns the raster's parent.
   * 
   * @return The raster's parent.
   */
  public Raster getParent()
  {
    return parent;
  }

  /**
   * Returns the x-translation.
   * 
   * @return The x-translation.
   */
  public final int getSampleModelTranslateX()
  {
    return sampleModelTranslateX;
  }

  /**
   * Returns the y-translation.
   * 
   * @return The y-translation.
   */
  public final int getSampleModelTranslateY()
  {
    return sampleModelTranslateY;
  }

  /**
   * Creates a new writable raster that is compatible with this raster.
   * 
   * @return A new writable raster.
   */
  public WritableRaster createCompatibleWritableRaster()
  {
    return new WritableRaster(getSampleModel(), new Point(minX, minY));
  }

  /**
   * Creates a new writable raster that is compatible with this raster.
   * 
   * @param w  the width.
   * @param h  the height.
   * 
   * @return A new writable raster.
   */
  public WritableRaster createCompatibleWritableRaster(int w, int h)
  {
    return createCompatibleWritableRaster(minX, minY, w, h);
  }

  /**
   * Creates a new writable raster that is compatible with this raster, with
   * the specified bounds.
   * 
   * @param rect  the raster bounds.
   * 
   * @return A new writable raster.
   */
  public WritableRaster createCompatibleWritableRaster(Rectangle rect)
  {
    return createCompatibleWritableRaster(rect.x, rect.y,
                                          rect.width, rect.height);
  }

  /**
   * Creates a new writable raster that is compatible with this raster, with
   * the specified bounds.
   * 
   * @param x  the x-coordinate of the top-left corner of the raster.
   * @param y  the y-coordinate of the top-left corner of the raster.
   * @param w  the raster width.
   * @param h  the raster height.
   * 
   * @return A new writable raster.
   */
  public WritableRaster createCompatibleWritableRaster(int x, int y,
                                                       int w, int h)
  {
    SampleModel sm = getSampleModel().createCompatibleSampleModel(w, h);
    return new WritableRaster(sm, sm.createDataBuffer(), new Point(x, y));
  }

  public Raster createTranslatedChild(int childMinX, int childMinY) {
    int tcx = sampleModelTranslateX - minX + childMinX;
    int tcy = sampleModelTranslateY - minY + childMinY;
    
    return new Raster(sampleModel, dataBuffer,
                      new Rectangle(childMinX, childMinY, width, height),
                      new Point(tcx, tcy), this);
  }

  public Raster createChild(int parentX, int parentY, int width,
                            int height, int childMinX, int childMinY,
                            int[] bandList)
  {
    if (parentX < minX || parentX + width > minX + this.width
        || parentY < minY || parentY + height > minY + this.height)
      throw new RasterFormatException("Child raster extends beyond parent");
    
    SampleModel sm = (bandList == null) ?
      sampleModel :
      sampleModel.createSubsetSampleModel(bandList);

    /*
        data origin
       /
      +-------------------------
      |\. __ parent trans
      | \`.  
      |  \ `.    parent origin
      |   \  `. /
      |   /\   +-------- - -
      |trans\ /<\-- deltaTrans
      |child +-+-\---- - - 
      |     /|`|  \__ parent [x, y]
      |child | |`. \
      |origin| :  `.\
      |      |    / `\
      |      :   /    +
      | child [x, y] 

      parent_xy - parent_trans = child_xy - child_trans

      child_trans = parent_trans + child_xy - parent_xy
    */

    return new Raster(sm, dataBuffer,
        new Rectangle(childMinX, childMinY, width, height),
        new Point(sampleModelTranslateX + childMinX - parentX,
                  sampleModelTranslateY + childMinY - parentY),
        this);
  }

  /**
   * Returns a new rectangle containing the bounds of this raster.
   * 
   * @return A new rectangle containing the bounds of this raster.
   */
  public Rectangle getBounds()
  {
    return new Rectangle(minX, minY, width, height);
  }

  /**
   * Returns the x-coordinate of the top left corner of the raster.
   * 
   * @return The x-coordinate of the top left corner of the raster.
   */
  public final int getMinX()
  {
    return minX;
  }

  /**
   * Returns the t-coordinate of the top left corner of the raster.
   * 
   * @return The t-coordinate of the top left corner of the raster.
   */
  public final int getMinY()
  {
    return minY;
  }

  /**
   * Returns the width of the raster.
   * 
   * @return The width of the raster.
   */
  public final int getWidth()
  {
    return width;
  }

  /**
   * Returns the height of the raster.
   * 
   * @return The height of the raster.
   */
  public final int getHeight()
  {
    return height;
  }

  /**
   * Returns the number of bands for this raster.
   * 
   * @return The number of bands.
   */
  public final int getNumBands()
  {
    return numBands;
  }
    
  public final int getNumDataElements()
  {
    return numDataElements;
  }
  
  /**
   * Returns the transfer type for the raster (this is determined by the 
   * raster's sample model).
   * 
   * @return The transfer type.
   */
  public final int getTransferType()
  {
    return sampleModel.getTransferType();
  }

  /**
   * Returns the data buffer that stores the pixel data for this raster.
   * 
   * @return The data buffer.
   */
  public DataBuffer getDataBuffer()
  {
    return dataBuffer;
  }

  /**
   * Returns the sample model that accesses the data buffer (to extract pixel
   * data) for this raster.
   * 
   * @return The sample model.
   */
  public SampleModel getSampleModel()
  {
    return sampleModel;
  }

  public Object getDataElements(int x, int y, Object outData)
  {
    return sampleModel.getDataElements(x - sampleModelTranslateX,
        y - sampleModelTranslateY, outData, dataBuffer);
  }

  public Object getDataElements(int x, int y, int w, int h, Object outData)
  {
    return sampleModel.getDataElements(x - sampleModelTranslateX,
        y - sampleModelTranslateY, w, h, outData, dataBuffer);
  }

  /**
   * Returns an array containing the samples for the pixel at (x, y) in the
   * raster.  If <code>iArray</code> is not <code>null</code>, it will be 
   * populated with the sample values and returned as the result of
   * this function (this avoids allocating a new array instance).
   * 
   * @param x  the x-coordinate of the pixel.
   * @param y  the y-coordinate of the pixel.
   * @param iArray  an array to populate with the sample values and return as 
   *     the result (if <code>null</code>, a new array will be allocated).
   * 
   * @return The pixel sample values.
   */
  public int[] getPixel(int x, int y, int[] iArray)
  {
    return sampleModel.getPixel(x - sampleModelTranslateX,
        y - sampleModelTranslateY, iArray, dataBuffer);
  }

  /**
   * Returns an array containing the samples for the pixel at (x, y) in the
   * raster.  If <code>fArray</code> is not <code>null</code>, it will be 
   * populated with the sample values and returned as the result of
   * this function (this avoids allocating a new array instance).
   * 
   * @param x  the x-coordinate of the pixel.
   * @param y  the y-coordinate of the pixel.
   * @param fArray  an array to populate with the sample values and return as 
   *     the result (if <code>null</code>, a new array will be allocated).
   * 
   * @return The pixel sample values.
   */
  public float[] getPixel(int x, int y, float[] fArray)
  {
    return sampleModel.getPixel(x - sampleModelTranslateX,
        y - sampleModelTranslateY, fArray, dataBuffer);
  }

  /**
   * Returns an array containing the samples for the pixel at (x, y) in the
   * raster.  If <code>dArray</code> is not <code>null</code>, it will be 
   * populated with the sample values and returned as the result of
   * this function (this avoids allocating a new array instance).
   * 
   * @param x  the x-coordinate of the pixel.
   * @param y  the y-coordinate of the pixel.
   * @param dArray  an array to populate with the sample values and return as 
   *     the result (if <code>null</code>, a new array will be allocated).
   * 
   * @return The pixel sample values.
   */
  public double[] getPixel(int x, int y, double[] dArray)
  {
    return sampleModel.getPixel(x - sampleModelTranslateX,
        y - sampleModelTranslateY, dArray, dataBuffer);
  }

  /**
   * Returns an array containing the samples for the pixels in the region 
   * specified by (x, y, w, h) in the raster.  The array is ordered by pixels 
   * (that is, all the samples for the first pixel are grouped together, 
   * followed by all the samples for the second pixel, and so on).  
   * If <code>iArray</code> is not <code>null</code>, it will be populated 
   * with the sample values and returned as the result of this function (this 
   * avoids allocating a new array instance).
   * 
   * @param x  the x-coordinate of the top-left pixel.
   * @param y  the y-coordinate of the top-left pixel.
   * @param w  the width of the region of pixels.
   * @param h  the height of the region of pixels.
   * @param iArray  an array to populate with the sample values and return as 
   *     the result (if <code>null</code>, a new array will be allocated).
   * 
   * @return The pixel sample values.
   */
  public int[] getPixels(int x, int y, int w, int h, int[] iArray)
  {
    return sampleModel.getPixels(x - sampleModelTranslateX,
        y - sampleModelTranslateY, w, h, iArray, dataBuffer);
  }

  /**
   * Returns an array containing the samples for the pixels in the region 
   * specified by (x, y, w, h) in the raster.  The array is ordered by pixels 
   * (that is, all the samples for the first pixel are grouped together, 
   * followed by all the samples for the second pixel, and so on).  
   * If <code>fArray</code> is not <code>null</code>, it will be populated 
   * with the sample values and returned as the result of this function (this 
   * avoids allocating a new array instance).
   * 
   * @param x  the x-coordinate of the top-left pixel.
   * @param y  the y-coordinate of the top-left pixel.
   * @param w  the width of the region of pixels.
   * @param h  the height of the region of pixels.
   * @param fArray  an array to populate with the sample values and return as 
   *     the result (if <code>null</code>, a new array will be allocated).
   * 
   * @return The pixel sample values.
   */
  public float[] getPixels(int x, int y, int w, int h, float[] fArray)
  {
    return sampleModel.getPixels(x - sampleModelTranslateX,
        y - sampleModelTranslateY, w, h, fArray, dataBuffer);
  }

  /**
   * Returns an array containing the samples for the pixels in the region 
   * specified by (x, y, w, h) in the raster.  The array is ordered by pixels 
   * (that is, all the samples for the first pixel are grouped together, 
   * followed by all the samples for the second pixel, and so on).  
   * If <code>dArray</code> is not <code>null</code>, it will be populated 
   * with the sample values and returned as the result of this function (this 
   * avoids allocating a new array instance).
   * 
   * @param x  the x-coordinate of the top-left pixel.
   * @param y  the y-coordinate of the top-left pixel.
   * @param w  the width of the region of pixels.
   * @param h  the height of the region of pixels.
   * @param dArray  an array to populate with the sample values and return as 
   *     the result (if <code>null</code>, a new array will be allocated).
   * 
   * @return The pixel sample values.
   */
  public double[] getPixels(int x, int y, int w, int h, double[] dArray)
  {
    return sampleModel.getPixels(x - sampleModelTranslateX,
        y - sampleModelTranslateY, w, h, dArray, dataBuffer);
  }

  /**
   * Returns the sample value for the pixel at (x, y) in the raster.
   * 
   * @param x  the x-coordinate of the pixel.
   * @param y  the y-coordinate of the pixel.
   * @param b  the band (in the range <code>0</code> to 
   *     <code>getNumBands() - 1</code>).
   * 
   * @return The sample value.
   */
  public int getSample(int x, int y, int b)
  {
    return sampleModel.getSample(x - sampleModelTranslateX,
        y - sampleModelTranslateY, b, dataBuffer);
  }

  /**
   * Returns the sample value for the pixel at (x, y) in the raster.
   * 
   * @param x  the x-coordinate of the pixel.
   * @param y  the y-coordinate of the pixel.
   * @param b  the band (in the range <code>0</code> to 
   *     <code>getNumBands() - 1</code>).
   * 
   * @return The sample value.
   * 
   * @see #getSample(int, int, int)
   */
  public float getSampleFloat(int x, int y, int b)
  {
    return sampleModel.getSampleFloat(x - sampleModelTranslateX,
        y - sampleModelTranslateY, b, dataBuffer);
  }

  /**
   * Returns the sample value for the pixel at (x, y) in the raster.
   * 
   * @param x  the x-coordinate of the pixel.
   * @param y  the y-coordinate of the pixel.
   * @param b  the band (in the range <code>0</code> to 
   *     <code>getNumBands() - 1</code>).
   * 
   * @return The sample value.
   * 
   * @see #getSample(int, int, int)
   */
  public double getSampleDouble(int x, int y, int b)
  {
    return sampleModel.getSampleDouble(x - sampleModelTranslateX,
        y - sampleModelTranslateY, b, dataBuffer);
  }

  /**
   * Returns an array containing the samples from one band for the pixels in 
   * the region specified by (x, y, w, h) in the raster.  If 
   * <code>iArray</code> is not <code>null</code>, it will be 
   * populated with the sample values and returned as the result of this 
   * function (this avoids allocating a new array instance).
   * 
   * @param x  the x-coordinate of the top-left pixel.
   * @param y  the y-coordinate of the top-left pixel.
   * @param w  the width of the region of pixels.
   * @param h  the height of the region of pixels.
   * @param b  the band (in the range <code>0</code> to 
   *     </code>getNumBands() - 1</code>).
   * @param iArray  an array to populate with the sample values and return as 
   *     the result (if <code>null</code>, a new array will be allocated).
   * 
   * @return The sample values.
   */
  public int[] getSamples(int x, int y, int w, int h, int b,
                          int[] iArray)
  {
    return sampleModel.getSamples(x - sampleModelTranslateX,
        y - sampleModelTranslateY, w, h, b, iArray, dataBuffer);
  }

  /**
   * Returns an array containing the samples from one band for the pixels in 
   * the region specified by (x, y, w, h) in the raster.  If 
   * <code>fArray</code> is not <code>null</code>, it will be 
   * populated with the sample values and returned as the result of this 
   * function (this avoids allocating a new array instance).
   *
   * @param x  the x-coordinate of the top-left pixel.
   * @param y  the y-coordinate of the top-left pixel.
   * @param w  the width of the region of pixels.
   * @param h  the height of the region of pixels.
   * @param b  the band (in the range <code>0</code> to 
   *     </code>getNumBands() - 1</code>).
   * @param fArray  an array to populate with the sample values and return as 
   *     the result (if <code>null</code>, a new array will be allocated).
   * 
   * @return The sample values.
   */  
  public float[] getSamples(int x, int y, int w, int h, int b, float[] fArray)
  {
    return sampleModel.getSamples(x - sampleModelTranslateX,
        y - sampleModelTranslateY, w, h, b, fArray, dataBuffer);
  }

  /**
   * Returns an array containing the samples from one band for the pixels in 
   * the region specified by (x, y, w, h) in the raster.  If 
   * <code>dArray</code> is not <code>null</code>, it will be 
   * populated with the sample values and returned as the result of this 
   * function (this avoids allocating a new array instance).
   * 
   * @param x  the x-coordinate of the top-left pixel.
   * @param y  the y-coordinate of the top-left pixel.
   * @param w  the width of the region of pixels.
   * @param h  the height of the region of pixels.
   * @param b  the band (in the range <code>0</code> to 
   *     </code>getNumBands() - 1</code>).
   * @param dArray  an array to populate with the sample values and return as 
   *     the result (if <code>null</code>, a new array will be allocated).
   * 
   * @return The sample values.
   */
  public double[] getSamples(int x, int y, int w, int h, int b, 
                             double[] dArray)
  {
    return sampleModel.getSamples(x - sampleModelTranslateX,
        y - sampleModelTranslateY, w, h, b, dArray, dataBuffer);
  }
  
  /**
   * Create a String representing the state of this Raster.
   * 
   * @return A String representing the stat of this Raster.
   */
  public String toString()
  {
    StringBuffer result = new StringBuffer();
    
    result.append(getClass().getName());
    result.append("[(");
    result.append(minX).append(",").append(minY).append("), ");
    result.append(width).append(" x ").append(height).append(",");
    result.append(sampleModel).append(",");
    result.append(dataBuffer);
    result.append("]");
    
    return result.toString();
  }

  /**
   * Returns the number of bits used to represent the specified data type.  
   * Valid types are:
   * <ul>
   *   <li>{@link DataBuffer#TYPE_BYTE};</li>
   *   <li>{@link DataBuffer#TYPE_USHORT};</li>
   *   <li>{@link DataBuffer#TYPE_SHORT};</li>
   *   <li>{@link DataBuffer#TYPE_INT};</li>
   *   <li>{@link DataBuffer#TYPE_FLOAT};</li>
   *   <li>{@link DataBuffer#TYPE_DOUBLE};</li>
   * </ul>
   * This method returns 0 for invalid data types.
   * 
   * @param dataType  the data type.
   * 
   * @return The number of bits used to represent the specified data type.
   */
  private static int getTypeBits(int dataType)
  {
    switch (dataType)
      {
      case DataBuffer.TYPE_BYTE:
        return 8;
      case DataBuffer.TYPE_USHORT:
      case DataBuffer.TYPE_SHORT:
        return 16;
      case DataBuffer.TYPE_INT:
      case DataBuffer.TYPE_FLOAT:
        return 32;
      case DataBuffer.TYPE_DOUBLE:
        return 64;
      default:
        return 0;
      }
  }
}