writableraster.java

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/*
 * @(#)WritableRaster.java	1.46 03/01/23
 *
 * Copyright 2003 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

/* ****************************************************************
 ******************************************************************
 ******************************************************************
 *** COPYRIGHT (c) Eastman Kodak Company, 1997
 *** As  an unpublished  work pursuant to Title 17 of the United
 *** States Code.  All rights reserved.
 ******************************************************************
 ******************************************************************
 ******************************************************************/

package java.awt.image;
import java.awt.Rectangle;
import java.awt.Point;

/**
 * This class extends Raster to provide pixel writing capabilities.
 * Refer to the class comment for Raster for descriptions of how
 * a Raster stores pixels.
 *
 * <p> The constructors of this class are protected.  To instantiate
 * a WritableRaster, use one of the createWritableRaster factory methods
 * in the Raster class.
 */
public class WritableRaster extends Raster {

    /**
     *  Constructs a WritableRaster with the given SampleModel.  The
     *  WritableRaster's upper left corner is origin and it is the
     *  same size as the  SampleModel.  A DataBuffer large enough to
     *  describe the WritableRaster is automatically created.
     *  @param sampleModel     The SampleModel that specifies the layout.
     *  @param origin          The Point that specifies the origin.
     *  @throws RasterFormatException if computing either
     *          <code>origin.x + sampleModel.getWidth()</code> or
     *          <code>origin.y + sampleModel.getHeight()</code> results
     *          in integer overflow
     */
    protected WritableRaster(SampleModel sampleModel,
                             Point origin) {
        this(sampleModel,
             sampleModel.createDataBuffer(),
             new Rectangle(origin.x,
                           origin.y,
                           sampleModel.getWidth(),
                           sampleModel.getHeight()),
             origin,
             null);
    }

    /**
     *  Constructs a WritableRaster with the given SampleModel and DataBuffer.
     *  The WritableRaster's upper left corner is origin and it is the same
     *  size as the SampleModel.  The DataBuffer is not initialized and must
     *  be compatible with SampleModel.
     *  @param sampleModel     The SampleModel that specifies the layout.
     *  @param dataBuffer      The DataBuffer that contains the image data.
     *  @param origin          The Point that specifies the origin.
     *  @throws RasterFormatException if computing either
     *          <code>origin.x + sampleModel.getWidth()</code> or
     *          <code>origin.y + sampleModel.getHeight()</code> results
     *          in integer overflow
     */
    protected WritableRaster(SampleModel sampleModel,
                             DataBuffer dataBuffer,
                             Point origin) {
        this(sampleModel,
             dataBuffer,
             new Rectangle(origin.x,
                           origin.y,
                           sampleModel.getWidth(),
                           sampleModel.getHeight()),
             origin,
             null);
    }

    /**
     * Constructs a WritableRaster with the given SampleModel, DataBuffer,
     * and parent.  aRegion specifies the bounding rectangle of the new
     * Raster.  When translated into the base Raster's coordinate
     * system, aRegion must be contained by the base Raster.
     * (The base Raster is the Raster's ancestor which has no parent.)
     * sampleModelTranslate specifies the sampleModelTranslateX and
     * sampleModelTranslateY values of the new Raster.
     *
     * Note that this constructor should generally be called by other
     * constructors or create methods, it should not be used directly.
     * @param sampleModel     The SampleModel that specifies the layout.
     * @param dataBuffer      The DataBuffer that contains the image data.
     * @param aRegion         The Rectangle that specifies the image area.     
     * @param sampleModelTranslate  The Point that specifies the translation
     *                        from SampleModel to Raster coordinates.
     * @param parent          The parent (if any) of this raster.
     * @throws RasterFormatException if <code>aRegion</code> has width
     *         or height less than or equal to zero, or computing either
     *         <code>aRegion.x + aRegion.width</code> or
     *         <code>aRegion.y + aRegion.height</code> results in integer
     *         overflow
     */
    protected WritableRaster(SampleModel sampleModel,
                             DataBuffer dataBuffer,
                             Rectangle aRegion,
                             Point sampleModelTranslate,
                             WritableRaster parent){
        super(sampleModel,dataBuffer,aRegion,sampleModelTranslate,parent);
    }

    /** Returns the parent WritableRaster (if any) of this WritableRaster,
     *  or else null.
     *  @return the parent of this <code>WritableRaster</code>, or 
     *          <code>null</code>.
     */
    public WritableRaster getWritableParent() {
        return (WritableRaster)parent;
    }

    /**
     * Create a WritableRaster with the same size, SampleModel and DataBuffer
     * as this one, but with a different location.  The new WritableRaster
     * will possess a reference to the current WritableRaster, accessible
     * through its getParent() and getWritableParent() methods.
     *
     * @param childMinX X coord of the upper left corner of the new Raster.
     * @param childMinY Y coord of the upper left corner of the new Raster.
     * @return a <code>WritableRaster</code> the same as this one except
     *         for the specified location.
     * @throws RasterFormatException if  computing either
     *         <code>childMinX + this.getWidth()</code> or
     *         <code>childMinY + this.getHeight()</code> results in integer
     *         overflow
     */
    public WritableRaster createWritableTranslatedChild(int childMinX,
                                                        int childMinY) {
        return createWritableChild(minX,minY,width,height,
                                   childMinX,childMinY,null);
    }

    /**
     * Returns a new WritableRaster which shares all or part of this
     * WritableRaster's DataBuffer.  The new WritableRaster will
     * possess a reference to the current WritableRaster, accessible
     * through its getParent() and getWritableParent() methods.
     *
     * <p> The parentX, parentY, width and height parameters form a
     * Rectangle in this WritableRaster's coordinate space, indicating
     * the area of pixels to be shared.  An error will be thrown if
     * this Rectangle is not contained with the bounds of the current
     * WritableRaster.
     *
     * <p> The new WritableRaster may additionally be translated to a
     * different coordinate system for the plane than that used by the current
     * WritableRaster.  The childMinX and childMinY parameters give
     * the new (x, y) coordinate of the upper-left pixel of the
     * returned WritableRaster; the coordinate (childMinX, childMinY)
     * in the new WritableRaster will map to the same pixel as the
     * coordinate (parentX, parentY) in the current WritableRaster.
     *
     * <p> The new WritableRaster may be defined to contain only a
     * subset of the bands of the current WritableRaster, possibly
     * reordered, by means of the bandList parameter.  If bandList is
     * null, it is taken to include all of the bands of the current
     * WritableRaster in their current order.
     *
     * <p> To create a new WritableRaster that contains a subregion of
     * the current WritableRaster, but shares its coordinate system
     * and bands, this method should be called with childMinX equal to
     * parentX, childMinY equal to parentY, and bandList equal to
     * null.
     *
     * @param parentX    X coordinate of the upper left corner in this
     *                   WritableRaster's coordinates.
     * @param parentY    Y coordinate of the upper left corner in this
     *                   WritableRaster's coordinates.
     * @param w          Width of the region starting at (parentX, parentY).
     * @param h          Height of the region starting at (parentX, parentY).
     * @param childMinX  X coordinate of the upper left corner of
     *                   the returned WritableRaster.
     * @param childMinY  Y coordinate of the upper left corner of
     *                   the returned WritableRaster.
     * @param bandList   Array of band indices, or null to use all bands.
     * @return a <code>WritableRaster</code> sharing all or part of the
     *         <code>DataBuffer</code> of this <code>WritableRaster</code>.
     * @exception RasterFormatException if the subregion is outside of the
     *                               raster bounds.
     * @throws RasterFormatException if <code>w</code> or
     *         <code>h</code>
     *         is less than or equal to zero, or computing any of
     *         <code>parentX + w</code>, <code>parentY + h</code>,
     *         <code>childMinX + w</code>, or
     *         <code>childMinY + h</code> results in integer
     *         overflow
     */
    public WritableRaster createWritableChild(int parentX, int parentY,
                                              int w, int h,
                                              int childMinX, int childMinY,
                                              int bandList[]) {
        if (parentX < this.minX) {
            throw new RasterFormatException("parentX lies outside raster");
        }
        if (parentY < this.minY) {
            throw new RasterFormatException("parentY lies outside raster");
        }
        if ((parentX+w < parentX) || (parentX+w > this.width + this.minX)) {
            throw new RasterFormatException("(parentX + width) is outside raster");
        }
        if ((parentY+h < parentY) || (parentY+h > this.height + this.minY)) {
            throw new RasterFormatException("(parentY + height) is outside raster");
        }

        SampleModel sm;
        // Note: the SampleModel for the child Raster should have the same
        // width and height as that for the parent, since it represents
        // the physical layout of the pixel data.  The child Raster's width
        // and height represent a "virtual" view of the pixel data, so
        // they may be different than those of the SampleModel.
        if (bandList != null) {
            sm = sampleModel.createSubsetSampleModel(bandList);
        }
        else {
            sm = sampleModel;
        }

        int deltaX = childMinX - parentX;
        int deltaY = childMinY - parentY;

        return new WritableRaster(sm,
                                  dataBuffer,
                                  new Rectangle(childMinX,childMinY,
                                                w, h),
                                  new Point(sampleModelTranslateX+deltaX,
                                            sampleModelTranslateY+deltaY),
                                  this);
    }

    /**
     * Sets the data for a single pixel from a