Mercurial > projects > dwt-win
view dwt/internal/image/PngIdatChunk.d @ 341:f403c83322c3 default tip
fix: thx torhu
author | Frank Benoit <benoit@tionex.de> |
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date | Sun, 08 Nov 2009 20:58:32 +0100 |
parents | 36f5cb12e1a2 |
children |
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/******************************************************************************* * Copyright (c) 2000, 2006 IBM Corporation and others. * All rights reserved. This program and the accompanying materials * are made available under the terms of the Eclipse Public License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/legal/epl-v10.html * * Contributors: * IBM Corporation - initial API and implementation * Port to the D programming language: * Frank Benoit <benoit@tionex.de> *******************************************************************************/ module dwt.internal.image.PngIdatChunk; import dwt.DWT; import dwt.internal.image.PngFileReadState; import dwt.internal.image.PngIhdrChunk; import dwt.internal.image.PngChunk; import dwt.dwthelper.utils; class PngIdatChunk : PngChunk { static const int HEADER_BYTES_LENGTH = 2; static const int ADLER_FIELD_LENGTH = 4; static const int HEADER_BYTE1_DATA_OFFSET = DATA_OFFSET + 0; static const int HEADER_BYTE2_DATA_OFFSET = DATA_OFFSET + 1; static const int ADLER_DATA_OFFSET = DATA_OFFSET + 2; // plus variable compressed data length this(byte headerByte1, byte headerByte2, byte[] data, int adler) { super(data.length + HEADER_BYTES_LENGTH + ADLER_FIELD_LENGTH); setType(TYPE_IDAT); reference[HEADER_BYTE1_DATA_OFFSET] = headerByte1; reference[HEADER_BYTE2_DATA_OFFSET] = headerByte2; System.arraycopy(data, 0, reference, DATA_OFFSET, data.length); setInt32(ADLER_DATA_OFFSET, adler); setCRC(computeCRC()); } this(byte[] reference) { super(reference); } override int getChunkType() { return CHUNK_IDAT; } /** * Answer whether the chunk is a valid IDAT chunk. */ override void validate(PngFileReadState readState, PngIhdrChunk headerChunk) { if (!readState.readIHDR || (headerChunk.getMustHavePalette() && !readState.readPLTE) || readState.readIEND) { DWT.error(DWT.ERROR_INVALID_IMAGE); } else { readState.readIDAT = true; } super.validate(readState, headerChunk); } byte getDataByteAtOffset(int offset) { return reference[DATA_OFFSET + offset]; } }