mirror of git://gcc.gnu.org/git/gcc.git
				
				
				
			
		
			
				
	
	
		
			226 lines
		
	
	
		
			7.3 KiB
		
	
	
	
		
			Java
		
	
	
	
			
		
		
	
	
			226 lines
		
	
	
		
			7.3 KiB
		
	
	
	
		
			Java
		
	
	
	
| /* Buffers.java --
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|    Copyright (C) 2000, 2002, 2004  Free Software Foundation
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| 
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| This file is part of GNU Classpath.
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| 
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| GNU Classpath is free software; you can redistribute it and/or modify
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| it under the terms of the GNU General Public License as published by
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| the Free Software Foundation; either version 2, or (at your option)
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| any later version.
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| 
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| GNU Classpath is distributed in the hope that it will be useful, but
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| WITHOUT ANY WARRANTY; without even the implied warranty of
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| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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| General Public License for more details.
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| 
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| You should have received a copy of the GNU General Public License
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| along with GNU Classpath; see the file COPYING.  If not, write to the
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| Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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| 02110-1301 USA.
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| 
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| Linking this library statically or dynamically with other modules is
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| making a combined work based on this library.  Thus, the terms and
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| conditions of the GNU General Public License cover the whole
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| combination.
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| 
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| As a special exception, the copyright holders of this library give you
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| permission to link this library with independent modules to produce an
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| executable, regardless of the license terms of these independent
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| modules, and to copy and distribute the resulting executable under
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| terms of your choice, provided that you also meet, for each linked
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| independent module, the terms and conditions of the license of that
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| module.  An independent module is a module which is not derived from
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| or based on this library.  If you modify this library, you may extend
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| this exception to your version of the library, but you are not
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| obligated to do so.  If you do not wish to do so, delete this
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| exception statement from your version. */
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| 
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| 
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| package gnu.java.awt;
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| 
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| import java.awt.image.DataBuffer;
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| import java.awt.image.DataBufferByte;
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| import java.awt.image.DataBufferDouble;
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| import java.awt.image.DataBufferFloat;
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| import java.awt.image.DataBufferInt;
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| import java.awt.image.DataBufferShort;
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| import java.awt.image.DataBufferUShort;
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| 
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| /**
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|  * Utility class for creating and accessing data buffers of arbitrary
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|  * data types.
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|  */
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| public final class Buffers
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| {
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|   /**
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|    * Create a data buffer of a particular type.
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|    *
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|    * @param dataType the desired data type of the buffer.
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|    * @param data an array containing data, or null
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|    * @param size the size of the data buffer bank
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|    */
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|   public static DataBuffer createBuffer(int dataType, Object data,
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|                                         int size)
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|   {
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|     if (data == null) return createBuffer(dataType, size, 1);
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| 
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|     return createBufferFromData(dataType, data, size);
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|   }
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| 
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| 
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|   /**
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|    * Create a data buffer of a particular type.
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|    *
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|    * @param dataType the desired data type of the buffer.
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|    * @param size the size of the data buffer bank
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|    */
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|   public static DataBuffer createBuffer(int dataType, int size) {
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|     return createBuffer(dataType, size, 1);
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|   }
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| 
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|   /**
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|    * Create a data buffer of a particular type.
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|    *
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|    * @param dataType the desired data type of the buffer.
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|    * @param size the size of the data buffer bank
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|    * @param numBanks the number of banks the buffer should have
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|    */
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|   public static DataBuffer createBuffer(int dataType, int size, int numBanks)
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|   {
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|     switch (dataType)
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|       {
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|       case DataBuffer.TYPE_BYTE:
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|         return new DataBufferByte(size, numBanks);
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|       case DataBuffer.TYPE_SHORT:
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|         return new DataBufferShort(size, numBanks);
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|       case DataBuffer.TYPE_USHORT:
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|         return new DataBufferUShort(size, numBanks);
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|       case DataBuffer.TYPE_INT:
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|         return new DataBufferInt(size, numBanks);
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|       case DataBuffer.TYPE_FLOAT:
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|         return new DataBufferFloat(size, numBanks);
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|       case DataBuffer.TYPE_DOUBLE:
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|         return new DataBufferDouble(size, numBanks);
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|       default:
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|         throw new UnsupportedOperationException();
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|       }
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|   }
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| 
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|   /**
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|    * Create a data buffer of a particular type.
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|    *
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|    * @param dataType the desired data type of the buffer
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|    * @param data an array containing the data
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|    * @param size the size of the data buffer bank
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|    */
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|   public static DataBuffer createBufferFromData(int dataType, Object data,
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|                                                 int size)
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|   {
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|     switch (dataType)
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|       {
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|       case DataBuffer.TYPE_BYTE:
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|         return new DataBufferByte((byte[]) data, size);
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|       case DataBuffer.TYPE_SHORT:
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|         return new DataBufferShort((short[]) data, size);
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|       case DataBuffer.TYPE_USHORT:
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|         return new DataBufferUShort((short[]) data, size);
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|       case DataBuffer.TYPE_INT:
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|         return new DataBufferInt((int[]) data, size);
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|       case DataBuffer.TYPE_FLOAT:
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|         return new DataBufferFloat((float[]) data, size);
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|       case DataBuffer.TYPE_DOUBLE:
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|         return new DataBufferDouble((double[]) data, size);
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|       default:
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|         throw new UnsupportedOperationException();
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|       }
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|   }
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| 
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|   /**
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|    * Return the data array of a data buffer, regardless of the data
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|    * type.
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|    *
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|    * @return an array of primitive values. The actual array type
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|    * depends on the data type of the buffer.
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|    */
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|   public static Object getData(DataBuffer buffer)
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|   {
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|     return getData(buffer, 0, null, 0, buffer.getSize());
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|   }
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| 
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| 
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|   /**
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|    * Copy data from array contained in data buffer, much like
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|    * System.arraycopy. Create a suitable destination array if the
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|    * given destination array is null.
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|    */
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|   public static Object getData(DataBuffer src, int srcOffset,
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|                                Object dest,  int dstOffset,
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|                                int length)
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|   {
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|     Object from;
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|     switch(src.getDataType())
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|       {
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|       case DataBuffer.TYPE_BYTE:
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|         if (dest == null) dest = new byte[length+dstOffset];
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|         for(int i = 0; i < length; i++)
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|           ((byte[])dest)[i + dstOffset] = (byte)src.getElem(i + srcOffset);
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|         break;
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| 
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|       case DataBuffer.TYPE_DOUBLE:
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|         if (dest == null) dest = new double[length+dstOffset];
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|         for(int i = 0; i < length; i++)
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|           ((double[])dest)[i + dstOffset] = src.getElemDouble(i + srcOffset);
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|         break;
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| 
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|       case DataBuffer.TYPE_FLOAT:
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|         if (dest == null) dest = new float[length+dstOffset];
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|         for(int i = 0; i < length; i++)
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|           ((float[])dest)[i + dstOffset] = src.getElemFloat(i + srcOffset);
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|         break;
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| 
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|       case DataBuffer.TYPE_INT:
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|         if (dest == null) dest = new int[length+dstOffset];
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|         for(int i = 0; i < length; i++)
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|           ((int[])dest)[i + dstOffset] = src.getElem(i + srcOffset);
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|         break;
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| 
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|       case DataBuffer.TYPE_SHORT:
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|       case DataBuffer.TYPE_USHORT:
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|         if (dest == null) dest = new short[length+dstOffset];
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|         for(int i = 0; i < length; i++)
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|           ((short[])dest)[i + dstOffset] = (short)src.getElem(i + srcOffset);
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|         break;
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| 
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|       case DataBuffer.TYPE_UNDEFINED:
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|         throw new ClassCastException("Unknown data buffer type");
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|       }
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|     return dest;
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|   }
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| 
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|   /**
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|    * @param bits the width of a data element measured in bits
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|    *
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|    * @return the smallest data type that can store data elements of
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|    * the given number of bits, without any truncation.
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|    */
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|   public static int smallestAppropriateTransferType(int bits)
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|   {
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|     if (bits <= 8)
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|       {
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|         return DataBuffer.TYPE_BYTE;
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|       }
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|     else if (bits <= 16)
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|       {
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|         return DataBuffer.TYPE_USHORT;
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|       }
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|     else if (bits <= 32)
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|       {
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|         return DataBuffer.TYPE_INT;
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|       }
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|     else
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|       {
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|         return DataBuffer.TYPE_UNDEFINED;
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|       }
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|   }
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| }
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