93 lines
2.7 KiB
Java
93 lines
2.7 KiB
Java
//******************************************************************************
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//
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// File: PLTEChunk.java
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// Package: edu.rit.image.png
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// Unit: Class edu.rit.image.png.PLTEChunk
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//
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// This Java source file is copyright (C) 2013 by Alan Kaminsky. All rights
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// reserved. For further information, contact the author, Alan Kaminsky, at
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// ark@cs.rit.edu.
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//
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// This Java source file is part of the Parallel Java 2 Library ("PJ2"). PJ2 is
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// free software; you can redistribute it and/or modify it under the terms of
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// the GNU General Public License as published by the Free Software Foundation;
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// either version 3 of the License, or (at your option) any later version.
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//
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// PJ2 is distributed in the hope that it will be useful, but WITHOUT ANY
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// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
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// A PARTICULAR PURPOSE. See the GNU General Public License for more details.
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//
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// A copy of the GNU General Public License is provided in the file gpl.txt. You
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// may also obtain a copy of the GNU General Public License on the World Wide
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// Web at http://www.gnu.org/licenses/gpl.html.
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//
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//******************************************************************************
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package edu.rit.image.png;
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import edu.rit.image.Color;
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import edu.rit.util.AList;
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/**
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* Class PLTEChunk provides a palette chunk stored in a PNG file.
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*
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* @author Alan Kaminsky
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* @version 26-Jun-2013
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*/
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public class PLTEChunk
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extends Chunk
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{
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// Exported constructors.
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/**
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* Construct a new uninitialized PLTE chunk. This constructor is for use
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* only by object deserialization.
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*/
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public PLTEChunk()
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{
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super();
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}
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/**
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* Construct a new PLTE chunk. The palette is an {@linkplain
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* edu.rit.util.AList Alist} of {@linkplain edu.rit.image.Color Color}s; it
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* must contain at least 1 and at most 256 elements.
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*
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* @param palette Palette.
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*
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* @exception NullPointerException
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* (unchecked exception) Thrown if <TT>palette</TT> is null.
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* @exception IllegalArgumentException
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* (unchecked exception) Thrown if the number of elements in
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* <TT>palette</TT> is illegal.
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*/
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public PLTEChunk
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(AList<Color> palette)
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{
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super (0x504c5445, getData (palette));
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}
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private static byte[] getData
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(AList<Color> palette)
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{
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if (palette == null)
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throw new NullPointerException
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("PLTEChunk(): palette is null");
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int n = palette.size();
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if (1 > n || n > 256)
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throw new IllegalArgumentException (String.format
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("PLTEChunk(): palette size = %d illegal", n));
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byte[] data = new byte [3*n];
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for (int i = 0; i < n; ++ i)
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{
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Color color = palette.get (i);
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data[3*i ] = (byte) color.red();
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data[3*i+1] = (byte) color.green();
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data[3*i+2] = (byte) color.blue();
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}
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return data;
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}
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}
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