source: trunk/gcc/libjava/java/awt/image/SinglePixelPackedSampleModel.java

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

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package java.awt.image;

import gnu.java.awt.BitMaskExtent;
import gnu.java.awt.Buffers;

/**
 * @author Rolf W. Rasmussen <rolfwr@ii.uib.no>
 */
public class SinglePixelPackedSampleModel extends SampleModel
{
  private int scanlineStride;
  private int[] bitMasks;
  private int[] bitOffsets;
  private int[] sampleSize;;
  
  public SinglePixelPackedSampleModel(int dataType, int w, int h,
                                      int[] bitMasks)
  {
    this(dataType, w, h, w, bitMasks);
  }

  public SinglePixelPackedSampleModel(int dataType, int w, int h,
                                      int scanlineStride, int[] bitMasks)
  {
    super(dataType, w, h, bitMasks.length);
    
    this.scanlineStride = scanlineStride;
    this.bitMasks = bitMasks;
    
    bitOffsets = new int[numBands];
    sampleSize = new int[numBands];
    
    BitMaskExtent extent = new BitMaskExtent();
    for (int b=0; b<numBands; b++)
      {
        extent.setMask(bitMasks[b]);
        sampleSize[b] = extent.bitWidth;
        bitOffsets[b] = extent.leastSignificantBit;
      }
  }

  public int getNumDataElements()
  {
    return 1;
  }

  public SampleModel createCompatibleSampleModel(int w, int h)
  {
    /* FIXME: We can avoid recalculation of bit offsets and sample
       sizes here by passing these from the current instance to a
       special private constructor. */
    return new SinglePixelPackedSampleModel(dataType, w, h, bitMasks);
  }

  public DataBuffer createDataBuffer()
  {
    // Important: use scanlineStride here, not width!
    int size = scanlineStride*height;
    return Buffers.createBuffer(getDataType(), size);
  }

  public int[] getSampleSize()
  {
    return sampleSize;
  }
  
  public int getSampleSize(int band)
  {
    return sampleSize[band];
  }

  public int getOffset(int x, int y)
  {
    return scanlineStride*y + x;
  }

  public int[] getBitOffsets()
  {
    return bitOffsets;
  }

  public int[] getBitMasks()
  {
    return bitMasks;
  }

  public int getScanlineStride()
  {
    return scanlineStride;
  }

  public SampleModel createSubsetSampleModel(int[] bands)
  {
    // FIXME: Is this the right way to interpret bands?
    
    int numBands = bands.length;
    
    int[] bitMasks = new int[numBands];

    for (int b=0; b<numBands; b++)
      bitMasks[b] = this.bitMasks[bands[b]];

    return new SinglePixelPackedSampleModel(dataType, width, height,
                                            scanlineStride, bitMasks);
  }

  public Object getDataElements(int x, int y, Object obj,
                                DataBuffer data)
  {
    int offset = scanlineStride*y + x + data.getOffset();
    
    return Buffers.getData(data, offset, obj,
                           0, // destination offset,
                           1  // length
                           );
  }

  public int[] getPixel(int x, int y, int[] iArray, DataBuffer data)
  {
    int offset = scanlineStride*y + x;
    if (iArray == null) iArray = new int[numBands];
    int samples = data.getElem(offset);

    for (int b=0; b<numBands; b++)
      iArray[b] = (samples & bitMasks[b]) >>> bitOffsets[b];
        
    return iArray;
  }

  public int[] getPixels(int x, int y, int w, int h, int[] iArray,
                         DataBuffer data)
  {
    int offset = scanlineStride*y + x;
    if (iArray == null) iArray = new int[numBands*w*h];
    int outOffset = 0;
    for (y=0; y<h; y++)
      {
        int lineOffset = offset;
        for (x=0; x<w; x++)
          {
            int samples = data.getElem(lineOffset++);
            for (int b=0; b<numBands; b++)
              iArray[outOffset++] = (samples & bitMasks[b]) >>> bitOffsets[b];
          }
        offset += scanlineStride;
      }
    return iArray;      
  }

  public int getSample(int x, int y, int b, DataBuffer data)
  {
    int offset = scanlineStride*y + x;
    int samples = data.getElem(offset);
    return (samples & bitMasks[b]) >>> bitOffsets[b];
  }

  public void setDataElements(int x, int y, Object obj, DataBuffer data)
  {
    int offset = scanlineStride*y + x + data.getOffset();
    
    int transferType = getTransferType();
    if (getTransferType() != data.getDataType())
      {
        throw new IllegalArgumentException("transfer type ("+
                                           getTransferType()+"), "+
                                           "does not match data "+
                                           "buffer type (" +
                                           data.getDataType() +
                                           ").");
      }

    try
      {
        switch (transferType)
          {
          case DataBuffer.TYPE_BYTE:
            {
              DataBufferByte out = (DataBufferByte) data;
              byte[] in = (byte[]) obj;
              out.getData()[offset] = in[0];
              return;
            }
          case DataBuffer.TYPE_USHORT:
            {
              DataBufferUShort out = (DataBufferUShort) data;
              short[] in = (short[]) obj;
              out.getData()[offset] = in[0];
              return;
            }
          case DataBuffer.TYPE_INT:
            {
              DataBufferInt out = (DataBufferInt) data;
              int[] in = (int[]) obj;
              out.getData()[offset] = in[0];
              return;
            }
            // FIXME: Fill in the other possible types.
          default:
            throw new InternalError();
          }
      }
    catch (ArrayIndexOutOfBoundsException aioobe)
      {
        String msg = "While writing data elements" +
          ", x="+x+", y="+y+
          ", width="+width+", height="+height+
          ", scanlineStride="+scanlineStride+
          ", offset="+offset+
          ", data.getSize()="+data.getSize()+
          ", data.getOffset()="+data.getOffset()+
          ": " +
          aioobe;
        throw new ArrayIndexOutOfBoundsException(msg);
      }
    }

  public void setPixel(int x, int y, int[] iArray, DataBuffer data)
  {
    int offset = scanlineStride*y + x;
    
    int samples = 0;
    for (int b=0; b<numBands; b++)
      samples |= (iArray[b] << bitOffsets[b]) & bitMasks[b];

    data.setElem(offset, samples);
  }

  public void setSample(int x, int y, int b, int s, DataBuffer data)
  {
    int offset = scanlineStride*y + x;
    int samples = data.getElem(offset);
    int bitMask = bitMasks[b];
    samples &= ~bitMask;
    samples |= (s << bitOffsets[b]) & bitMask;
    data.setElem(offset, samples);
  }
}