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

This file is part of GNU Classpath.

GNU Classpath is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

GNU Classpath is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU Classpath; see the file COPYING.  If not, write to the
Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA.

As a special exception, if you link this library with other files to
produce an executable, this library does not by itself cause the
resulting executable to be covered by the GNU General Public License.
This exception does not however invalidate any other reasons why the
executable file might be covered by the GNU General Public License. */

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);
  }
}