Java DataBufferByte.getOffset方法代码示例

import java.awt.image.DataBufferByte; //导入方法依赖的package包/类
/**
 * Constructs a BytePackedRaster with the given SampleModel,
 * DataBuffer, and parent.  DataBuffer must be a DataBufferByte and
 * SampleModel must be of type MultiPixelPackedSampleModel.
 * When translated into the base Raster's
 * coordinate system, aRegion must be contained by the base Raster.
 * Origin is the coordinate in the new Raster's coordinate system of
 * the origin of the base Raster.  (The base Raster is the Raster's
 * ancestor which has no parent.)
 *
 * 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 DataBufferShort that contains the image data.
 * @param aRegion         The Rectangle that specifies the image area.
 * @param origin          The Point that specifies the origin.
 * @param parent          The parent (if any) of this raster.
 *
 * @exception RasterFormatException if the parameters do not conform
 * to requirements of this Raster type.
 */
public BytePackedRaster(SampleModel sampleModel,
                        DataBuffer dataBuffer,
                        Rectangle aRegion,
                        Point origin,
                        BytePackedRaster parent){
    super(sampleModel,dataBuffer,aRegion,origin, parent);
    this.maxX = minX + width;
    this.maxY = minY + height;

    if (!(dataBuffer instanceof DataBufferByte)) {
       throw new RasterFormatException("BytePackedRasters must have" +
            "byte DataBuffers");
    }
    DataBufferByte dbb = (DataBufferByte)dataBuffer;
    this.data = stealData(dbb, 0);
    if (dbb.getNumBanks() != 1) {
        throw new
            RasterFormatException("DataBuffer for BytePackedRasters"+
                                  " must only have 1 bank.");
    }
    int dbOffset = dbb.getOffset();

    if (sampleModel instanceof MultiPixelPackedSampleModel) {
        MultiPixelPackedSampleModel mppsm =
            (MultiPixelPackedSampleModel)sampleModel;
        this.type = IntegerComponentRaster.TYPE_BYTE_BINARY_SAMPLES;
        pixelBitStride = mppsm.getPixelBitStride();
        if (pixelBitStride != 1 &&
            pixelBitStride != 2 &&
            pixelBitStride != 4) {
            throw new RasterFormatException
              ("BytePackedRasters must have a bit depth of 1, 2, or 4");
        }
        scanlineStride = mppsm.getScanlineStride();
        dataBitOffset = mppsm.getDataBitOffset() + dbOffset*8;
        int xOffset = aRegion.x - origin.x;
        int yOffset = aRegion.y - origin.y;
        dataBitOffset += xOffset*pixelBitStride + yOffset*scanlineStride*8;
        bitMask = (1 << pixelBitStride) -1;
        shiftOffset = 8 - pixelBitStride;
    } else {
        throw new RasterFormatException("BytePackedRasters must have"+
            "MultiPixelPackedSampleModel");
    }
    verify(false);
}
 

import java.awt.image.DataBufferByte; //导入方法依赖的package包/类
/**
 * Constructs a BytePackedRaster with the given SampleModel,
 * DataBuffer, and parent.  DataBuffer must be a DataBufferByte and
 * SampleModel must be of type MultiPixelPackedSampleModel.
 * When translated into the base Raster's
 * coordinate system, aRegion must be contained by the base Raster.
 * Origin is the coordinate in the new Raster's coordinate system of
 * the origin of the base Raster.  (The base Raster is the Raster's
 * ancestor which has no parent.)
 *
 * 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 DataBufferByte that contains the image data.
 * @param aRegion         The Rectangle that specifies the image area.
 * @param origin          The Point that specifies the origin.
 * @param parent          The parent (if any) of this raster.
 *
 * @exception RasterFormatException if the parameters do not conform
 * to requirements of this Raster type.
 */
public BytePackedRaster(SampleModel sampleModel,
                        DataBufferByte dataBuffer,
                        Rectangle aRegion,
                        Point origin,
                        BytePackedRaster parent)
{
    super(sampleModel,dataBuffer,aRegion,origin, parent);
    this.maxX = minX + width;
    this.maxY = minY + height;

    this.data = stealData(dataBuffer, 0);
    if (dataBuffer.getNumBanks() != 1) {
        throw new
            RasterFormatException("DataBuffer for BytePackedRasters"+
                                  " must only have 1 bank.");
    }
    int dbOffset = dataBuffer.getOffset();

    if (sampleModel instanceof MultiPixelPackedSampleModel) {
        MultiPixelPackedSampleModel mppsm =
            (MultiPixelPackedSampleModel)sampleModel;
        this.type = IntegerComponentRaster.TYPE_BYTE_BINARY_SAMPLES;
        pixelBitStride = mppsm.getPixelBitStride();
        if (pixelBitStride != 1 &&
            pixelBitStride != 2 &&
            pixelBitStride != 4) {
            throw new RasterFormatException
              ("BytePackedRasters must have a bit depth of 1, 2, or 4");
        }
        scanlineStride = mppsm.getScanlineStride();
        dataBitOffset = mppsm.getDataBitOffset() + dbOffset*8;
        int xOffset = aRegion.x - origin.x;
        int yOffset = aRegion.y - origin.y;
        dataBitOffset += xOffset*pixelBitStride + yOffset*scanlineStride*8;
        bitMask = (1 << pixelBitStride) -1;
        shiftOffset = 8 - pixelBitStride;
    } else {
        throw new RasterFormatException("BytePackedRasters must have"+
            "MultiPixelPackedSampleModel");
    }
    verify(false);
}