DataBuffer.java

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

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package java.awt.image;

/** 
 * Class that manages arrays of data elements. A data buffer consists
 * of one or more banks.  A bank is a continuous region of data
 * elements.
 *
 * @author Rolf W. Rasmussen <rolfwr@ii.uib.no>
 */
public abstract class DataBuffer
{
  public static final int TYPE_BYTE      =  0;
  public static final int TYPE_USHORT    =  1;
  public static final int TYPE_SHORT     =  2;
  public static final int TYPE_INT       =  3;
  public static final int TYPE_FLOAT     =  4;
  public static final int TYPE_DOUBLE    =  5;
  public static final int TYPE_UNDEFINED = 32;
  
  /** The type of the data elements stored in the data buffer.  */
  protected int dataType;
  
  /** The number of banks in this buffer.  */
  protected int banks = 1;
  
  /** Offset into the default (0'th) bank). */
  protected int offset; // FIXME: Is offsets[0] always mirrored in offset?
  
  /** The size of the banks.  */
  protected int size;
  
  /** Offset into each bank.  */
  protected int[] offsets;
  
  protected DataBuffer(int dataType, int size)
  {
    this.dataType = dataType;
    this.size = size;
  }

  protected DataBuffer(int dataType, int size, int numBanks) {
    this(dataType, size);
    banks = numBanks;
    offsets = new int[numBanks];
  }

  protected DataBuffer(int dataType, int size, int numBanks, int offset) {
    this(dataType, size, numBanks);
    
    java.util.Arrays.fill(offsets, offset);          
    
    this.offset = offset;
  }

  protected DataBuffer(int dataType, int size, int numBanks, int[] offsets) {
    this(dataType, size);
    if (numBanks != offsets.length) 
      throw new ArrayIndexOutOfBoundsException();
    
    banks = numBanks;
    this.offsets = offsets;
    
    offset = offsets[0];
  }
  
  public static int getDataTypeSize(int dataType) {
    // Maybe this should be a lookup table instead.
    switch (dataType)
      {
      case TYPE_BYTE:
	return 8;
      case TYPE_USHORT:
      case TYPE_SHORT:
	return 16;
      case TYPE_INT:
      case TYPE_FLOAT:
	return 32;
      case TYPE_DOUBLE:
	return 64;
      default:
	throw new IllegalArgumentException();
      }
  }

  public int getDataType()
  {
    return dataType;
  }
  
  public int getSize()
  {
    return size;
  }
  
  public int getOffset()
  {
    return offset;
  }
  
  public int[] getOffsets()
  {
    if (offsets == null)
    {
      // is this necessary?
      offsets = new int[1];
      offsets[0] = offset;
    }
    return offsets;
  }

  public int getNumBanks()
  {
    return banks;
  }

  public int getElem(int i)
  {
    return getElem(0, i);
  }

  public abstract int getElem(int bank, int i);
  
  public void setElem(int i, int val)
  {
    setElem(0, i, val);
  }

  public abstract void setElem(int bank, int i, int val);
  
  public float getElemFloat(int i)
  {
    return getElem(i);
  }
    
  public float getElemFloat(int bank, int i)
  {
    return getElem(bank, i);
  }

  public void setElemFloat(int i, float val)
  {
    setElem(i, (int) val);
  }

  public void setElemFloat(int bank, int i, float val)
  {
    setElem(bank, i, (int) val);
  }

  public double getElemDouble(int i)
  {
    return getElem(i);
  }
    
  public double getElemDouble(int bank, int i)
  {
    return getElem(bank, i);
  }

  public void setElemDouble(int i, double val)
  {
    setElem(i, (int) val);
  }

  public void setElemDouble(int bank, int i, double val)
  {
    setElem(bank, i, (int) val);
  }
}