raster.java

JAVA基本类源代码,大家可以学习学习!

                case DataBuffer.TYPE_USHORT:
                    return new ShortInterleavedRaster(sm, db, location);
            }
        } else if (sm instanceof SinglePixelPackedSampleModel) {
            switch(dataType) {
                case DataBuffer.TYPE_BYTE:
                    return new ByteInterleavedRaster(sm, db, location);

                case DataBuffer.TYPE_USHORT:
                    return new ShortInterleavedRaster(sm, db, location);

                case DataBuffer.TYPE_INT:
                    return new IntegerInterleavedRaster(sm, db, location);
            }
        } else if (sm instanceof MultiPixelPackedSampleModel &&
                   dataType == DataBuffer.TYPE_BYTE &&
                   sm.getSampleSize(0) < 8) {
            return new BytePackedRaster(sm, db, location);
        }

        // we couldn't do anything special - do the generic thing

        return new Raster(sm,db,location);
    }

    /**
     *  Creates a WritableRaster with the specified SampleModel.
     *  The upper left corner of the Raster is given by the location argument.
     *  If location is null, (0, 0) will be used.
     *  @param sm the specified <code>SampleModel</code>
     *  @param location the upper-left corner of the 
     *         <code>WritableRaster</code>
     *  @return a <code>WritableRaster</code> with the specified 
     *          <code>SampleModel</code> and location.
     *  @throws RasterFormatException if computing either
     *          <code>location.x + sm.getWidth()</code> or
     *          <code>location.y + sm.getHeight()</code> results in integer
     *          overflow
     */
    public static WritableRaster createWritableRaster(SampleModel sm,
                                                      Point location) {
        if (location == null) {
           location = new Point(0,0);
        }

        return createWritableRaster(sm,
                                    sm.createDataBuffer(),
                                    location);
    }

    /**
     *  Creates a WritableRaster with the specified SampleModel and DataBuffer.
     *  The upper left corner of the Raster is given by the location argument.
     *  If location is null, (0, 0) will be used.
     *  @param sm the specified <code>SampleModel</code>
     *  @param db the specified <code>DataBuffer</code>
     *  @param location the upper-left corner of the 
     *         <code>WritableRaster</code>
     *  @return a <code>WritableRaster</code> with the specified 
     *          <code>SampleModel</code>, <code>DataBuffer</code>, and
     *          location.
     * @throws RasterFormatException if computing either
     *         <code>location.x + sm.getWidth()</code> or
     *         <code>location.y + sm.getHeight()</code> results in integer
     *         overflow
     * @throws RasterFormatException if <code>dataBuffer</code> has more
     *         than one bank and the <code>sampleModel</code> is
     *         PixelInterleavedSampleModel, SinglePixelPackedSampleModel,
     *         or MultiPixelPackedSampleModel.
     * @throws NullPointerException if either SampleModel or DataBuffer is null
     */
    public static WritableRaster createWritableRaster(SampleModel sm,
                                                      DataBuffer db,
                                                      Point location) {
        if ((sm == null) || (db == null)) {
            throw new NullPointerException("SampleModel and DataBuffer cannot be null");
        }
        if (location == null) {
           location = new Point(0,0);
        }

        int dataType = sm.getDataType();

        if (sm instanceof PixelInterleavedSampleModel) {
            switch(dataType) {
                case DataBuffer.TYPE_BYTE:
                    return new ByteInterleavedRaster(sm, db, location);

                case DataBuffer.TYPE_USHORT:
                    return new ShortInterleavedRaster(sm, db, location);
            }
        } else if (sm instanceof SinglePixelPackedSampleModel) {
            switch(dataType) {
                case DataBuffer.TYPE_BYTE:
                    return new ByteInterleavedRaster(sm, db, location);

                case DataBuffer.TYPE_USHORT:
                    return new ShortInterleavedRaster(sm, db, location);

                case DataBuffer.TYPE_INT:
                    return new IntegerInterleavedRaster(sm, db, location);
            }
        } else if (sm instanceof MultiPixelPackedSampleModel &&
                   dataType == DataBuffer.TYPE_BYTE &&
                   sm.getSampleSize(0) < 8) {
            return new BytePackedRaster(sm, db, location);
        }

        // we couldn't do anything special - do the generic thing

        return new SunWritableRaster(sm,db,location);
    }

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

    /**
     *  Constructs a Raster with the given SampleModel and DataBuffer.
     *  The Raster'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
     *  @throws NullPointerException either <code>sampleModel</code> or
     *          <code>origin</code> is null
     */
    protected Raster(SampleModel sampleModel,
                     DataBuffer dataBuffer,
                     Point origin) {
	this(sampleModel,
             dataBuffer,
             new Rectangle(origin.x,
                           origin.y,
                           sampleModel.getWidth(),
                           sampleModel.getHeight()),
             origin,
             null);
    }

    /**
     * Constructs a Raster 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 NullPointerException if any of <code>sampleModel</code>, 
     *         <code>dataBuffer</code>, <code>aRegion</code> or 
     *         <code>sampleModelTranslate</code> is null
     * @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 Raster(SampleModel sampleModel,
                     DataBuffer dataBuffer,
                     Rectangle aRegion,
                     Point sampleModelTranslate,
	             Raster parent) {
        
        if ((sampleModel == null) || (dataBuffer == null) || 
            (aRegion == null) || (sampleModelTranslate == null)) {
            throw new NullPointerException("SampleModel, dataBuffer, aRegion and " +
                                           "sampleModelTranslate cannot be null");
        }
       this.sampleModel = sampleModel;
       this.dataBuffer = dataBuffer;
       minX = aRegion.x;
       minY = aRegion.y;
       width = aRegion.width;
       height = aRegion.height;
       if (width <= 0 || height <= 0) {
           throw new RasterFormatException("negative or zero " +
               ((width <= 0) ? "width" : "height"));
       }
       if ((minX + width) < minX) {
           throw new RasterFormatException(
               "overflow condition for X coordinates of Raster");
       }
       if ((minY + height) < minY) {
           throw new RasterFormatException(
               "overflow condition for Y coordinates of Raster");
       }
 
       sampleModelTranslateX = sampleModelTranslate.x;
       sampleModelTranslateY = sampleModelTranslate.y;

       numBands = sampleModel.getNumBands();
       numDataElements = sampleModel.getNumDataElements();
       this.parent = parent;
    }


    /** 
     * Returns the parent Raster (if any) of this Raster or null. 
     * @return the parent Raster or <code>null</code>.
     */
    public Raster getParent() {
        return parent;
    }

    /**
     * Returns the X translation from the coordinate system of the
     * SampleModel to that of the Raster.  To convert a pixel's X
     * coordinate from the Raster coordinate system to the SampleModel
     * coordinate system, this value must be subtracted.
     * @return the X translation from the coordinate space of the
     *         Raster's SampleModel to that of the Raster.
     */
    final public int getSampleModelTranslateX() {
	return sampleModelTranslateX;
    }

    /**
     * Returns the Y translation from the coordinate system of the
     * SampleModel to that of the Raster.  To convert a pixel's Y
     * coordinate from the Raster coordinate system to the SampleModel
     * coordinate system, this value must be subtracted.
     * @return the Y translation from the coordinate space of the
     *         Raster's SampleModel to that of the Raster.
     */
    final public int getSampleModelTranslateY() {
	return sampleModelTranslateY;
    }

    /**
     * Create a compatible WritableRaster the same size as this Raster with
     * the same SampleModel and a new initialized DataBuffer.
     * @return a compatible <code>WritableRaster</code> with the same sample
     *         model and a new data buffer.
     */
    public WritableRaster createCompatibleWritableRaster() {
        return new SunWritableRaster(sampleModel, new Point(0,0));
    }

    /**
     * Create a compatible WritableRaster with the specified size, a new
     * SampleModel, and a new initialized DataBuffer.
     * @param w the specified width of the new <code>WritableRaster</code>
     * @param h the specified height of the new <code>WritableRaster</code>
     * @return a compatible <code>WritableRaster</code> with the specified 
     *         size and a new sample model and data buffer.
     * @exception RasterFormatException if the width or height is less than
     *                               or equal to zero.
     */
    public WritableRaster createCompatibleWritableRaster(int w, int h) {
        if (w <= 0 || h <=0) {
            throw new RasterFormatException("negative " +
                                          ((w <= 0) ? "width" : "height"));
        }

        SampleModel sm = sampleModel.createCompatibleSampleModel(w,h);

        return new SunWritableRaster(sm, new Point(0,0));