90 lines
2.4 KiB
Java
90 lines
2.4 KiB
Java
//******************************************************************************
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//
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// File: pHYsChunk.java
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// Package: edu.rit.image.png
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// Unit: Class edu.rit.image.png.pHYsChunk
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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.PixelUnit;
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import edu.rit.util.Packing;
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/**
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* Class pHYsChunk provides a physical pixel dimensions chunk stored in a PNG
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* file.
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*
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* @author Alan Kaminsky
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* @version 19-Jul-2013
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*/
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public class pHYsChunk
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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 pHYs chunk. This constructor is for use
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* only by object deserialization.
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*/
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public pHYsChunk()
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{
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super();
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}
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/**
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* Construct a new pHYs chunk.
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*
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* @param xPpu Pixels per unit, X axis.
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* @param yPpu Pixels per unit, Y axis.
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* @param unit Pixel units.
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*/
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public pHYsChunk
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(int xPpu,
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int yPpu,
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PixelUnit unit)
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{
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super (0x70485973, getData (xPpu, yPpu, unit));
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}
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private static byte[] getData
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(int xPpu,
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int yPpu,
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PixelUnit unit)
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{
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byte[] data = new byte [9];
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if (unit == PixelUnit.NONE)
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{
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Packing.unpackIntBigEndian (xPpu, data, 0);
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Packing.unpackIntBigEndian (yPpu, data, 4);
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data[8] = (byte) 0;
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}
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else
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{
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Packing.unpackIntBigEndian (unit.toPpm (xPpu), data, 0);
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Packing.unpackIntBigEndian (unit.toPpm (yPpu), data, 4);
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data[8] = (byte) 1;
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}
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return data;
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}
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}
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