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