| /* PNGPhys.java -- |
| Copyright (C) 2006 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.javax.imageio.png; |
| |
| /** |
| * A PNG "pHYS" chunk - pixel physical dimensions |
| */ |
| public class PNGPhys extends PNGChunk |
| { |
| long x, y; |
| double ratio; |
| boolean usesRatio; |
| |
| protected PNGPhys( int type, byte[] data, int crc ) throws PNGException |
| { |
| super( type, data, crc ); |
| if( data.length < 9 ) |
| throw new PNGException("Unexpected size of pHYS chunk."); |
| x = ((data[0] & 0xFF) << 24) | ( (data[1] & 0xFF) << 16 ) | |
| ((data[2] & 0xFF) << 8) | (data[3] & 0xFF); |
| y = ((data[4] & 0xFF) << 24) | ( (data[5] & 0xFF) << 16 ) | |
| ((data[6] & 0xFF) << 8) | (data[7] & 0xFF); |
| if(data[8] == 0) |
| { |
| ratio = ((double)x)/((double)y); |
| usesRatio = true; |
| } |
| } |
| |
| public PNGPhys( double ratio ) |
| { |
| super( TYPE_PHYS ); |
| |
| this.ratio = ratio; |
| usesRatio = true; |
| |
| if( ratio < 1.0 ) |
| { |
| y = 0xFFFFFFFF; |
| x = (long)(0xFFFFFFFFL * ratio); |
| } |
| else |
| { |
| x = 0xFFFFFFFF; |
| y = (long)(0xFFFFFFFFL * ratio); |
| } |
| makeData(); |
| } |
| |
| public PNGPhys( int x, int y ) |
| { |
| super( TYPE_PHYS ); |
| usesRatio = false; |
| this.x = x; |
| this.y = y; |
| makeData(); |
| } |
| |
| private void makeData() |
| { |
| data = new byte[ 9 ]; |
| byte[] a = getInt( (int)x ); |
| byte[] b = getInt( (int)y ); |
| data[0] = a[0]; data[1] = a[1]; data[2] = a[2]; data[3] = a[3]; |
| data[4] = b[0]; data[5] = b[1]; data[6] = b[2]; data[7] = b[3]; |
| data[7] = (usesRatio) ? 0 : (byte)0xFF; |
| } |
| |
| public String toString() |
| { |
| String s = "PNG Physical pixel size chunk."; |
| if( usesRatio ) |
| return s + " Aspect ratio (x/y): " + ratio; |
| else |
| return s + " " + x + " by " + y + " pixels per meter. (x, y)."; |
| } |
| } |