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Diffstat (limited to 'gcc-4.4.3/libjava/classpath/gnu/javax/imageio/png/PNGHeader.java')
| -rw-r--r-- | gcc-4.4.3/libjava/classpath/gnu/javax/imageio/png/PNGHeader.java | 257 |
1 files changed, 257 insertions, 0 deletions
diff --git a/gcc-4.4.3/libjava/classpath/gnu/javax/imageio/png/PNGHeader.java b/gcc-4.4.3/libjava/classpath/gnu/javax/imageio/png/PNGHeader.java new file mode 100644 index 000000000..c9ef2dc37 --- /dev/null +++ b/gcc-4.4.3/libjava/classpath/gnu/javax/imageio/png/PNGHeader.java @@ -0,0 +1,257 @@ +/* PNGHeader.java -- PNG Header + 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 Header chunk. + */ +public class PNGHeader extends PNGChunk +{ + private int width, height, depth; + private int colorType, compression, filter, interlace; + + /** + * The valid interlace types. + */ + public static final int INTERLACE_NONE = 0; + public static final int INTERLACE_ADAM7 = 1; + + /** + * The valid color types. + */ + public static final int GRAYSCALE = 0; + public static final int RGB = 2; + public static final int INDEXED = 3; + public static final int GRAYSCALE_WITH_ALPHA = 4; + public static final int RGB_WITH_ALPHA = 6; + + /** + * Parses a PNG Header chunk. + */ + protected PNGHeader( int type, byte[] data, int crc ) throws PNGException + { + super( type, data, crc ); + if( data.length < 13 ) + throw new PNGException("Unexpectedly short header chunk. (" + data.length + + " bytes)"); + + width = ((data[0] & 0xFF) << 24) | ( (data[1] & 0xFF) << 16 ) | + ((data[2] & 0xFF) << 8) | (data[3] & 0xFF); + height = ((data[4] & 0xFF) << 24) | ( (data[5] & 0xFF) << 16 ) | + ((data[6] & 0xFF) << 8) | (data[7] & 0xFF); + depth = (data[8] & 0xFF); + colorType = (data[9] & 0xFF); + compression = (data[10] & 0xFF); + filter = (data[11] & 0xFF); + interlace = (data[12] & 0xFF); + } + + /** + * Create a PNG header chunk. + * Warning: This trusts that the parameters are valid. + */ + public PNGHeader(int width, int height, int depth, + int colorType, boolean interlace) + { + super( TYPE_HEADER ); + data = new byte[ 13 ]; + + this.width = width; + this.height = height; + this.depth = depth; + compression = filter = 0; + this.colorType = colorType; + this.interlace = interlace ? 1 : 0; + + // Build the data chunk. + byte[] a = getInt( width ); + byte[] b = getInt( height ); + 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[8] = (byte)depth; + data[9] = (byte)colorType; + data[10] = (byte)compression; + data[11] = (byte)filter; + data[12] = (byte)this.interlace; + } + + /** + * Validates the header fields + */ + public boolean isValidChunk() + { + if( !super.isValidChunk() ) + return false; + + // width and height must be nonzero + if( width == 0 || height == 0 ) + return false; + // colorType can be 0,2,3,4,6 + if( (colorType & 0xFFFFFFF8) != 0 || colorType == 5 || colorType == 1) + return false; + // Possible valid depths are 1,2,4,8,16 + if( !((depth == 1) || (depth == 2) || (depth == 4) || + (depth == 8) || (depth == 16)) ) + return false; + if( colorType == INDEXED && depth == 16 ) + return false; + if( ( colorType == RGB || colorType == GRAYSCALE_WITH_ALPHA || + colorType == RGB_WITH_ALPHA ) && + depth < 8 ) + return false; + // Only compression and filter methods zero are defined + if( compression != 0 || filter != 0 ) + return false; + // Interlace methods, 0 and 1 are valid values. + if( (interlace & 0xFFFFFFFE) != 0 ) + return false; + + return true; + } + + /** + * Returns <code>true</code> if this PNG is indexed-color + */ + public boolean isIndexed() + { + return (colorType == INDEXED); + } + + /** + * Returns <code>true</code> if this PNG is grayscale + */ + public boolean isGrayscale() + { + return ((colorType == GRAYSCALE) || (colorType == GRAYSCALE_WITH_ALPHA)); + } + + /** + * Returns the color type of the image. + */ + public int getColorType() + { + return colorType; + } + + /** + * Returns whether the image is interlaced or not. + */ + public boolean isInterlaced() + { + return (interlace != 0); + } + + /** + * Returns the number of bytes per pixel. + */ + public int bytesPerPixel() + { + switch( colorType ) + { + case GRAYSCALE_WITH_ALPHA: + return ((depth * 2) >> 3); + case RGB: + return ((depth * 3) >> 3); + case RGB_WITH_ALPHA: + return ((depth * 4) >> 3); + + default: + case GRAYSCALE: + case INDEXED: + int i = (depth >> 3); + if( i > 0 ) return i; + return 1; // if bytes per pixel < 1, return 1 anyway. + } + } + + /** + * Returns the stride of one scanline, in bytes. + */ + public int getScanlineStride() + { + long nBits = 0; // bits per scanline - scanlines are on byte offsets. + switch( colorType ) + { + case GRAYSCALE: + nBits = width * depth; + break; + case RGB: + nBits = width * depth * 3; + break; + case INDEXED: + nBits = depth * width; + break; + case GRAYSCALE_WITH_ALPHA: + nBits = depth * width * 2; + break; + case RGB_WITH_ALPHA: + nBits = depth * width * 4; + break; + } + // Round up number of bits to the nearest byte + if( (nBits & 0x07) != 0 ) + nBits += (8 - (nBits & 0x07)); + + return (int)(nBits >> 3); // return # of bytes. + } + + public int getWidth() + { + return width; + } + + public int getHeight() + { + return height; + } + + public int getDepth() + { + return depth; + } + + /** + * Debugging string. + */ + public String toString() + { + return "Header Chunk. Image width:"+width+" height:"+height+ + " depth:"+depth+" color type:"+colorType+" compression type:"+ + compression+" filter type:"+ filter+" interlace:"+interlace; + } +} |