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comparison dwt/internal/image/PngIdatChunk.d @ 34:5123b17c98ef

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Ported dwt.events.*, dwt.graphics.GC, Region, dwt.internal.image.*
author Jacob Carlborg <doob@me.com> <jacob.carlborg@gmail.com>
date Sun, 14 Sep 2008 01:45:57 +0200
parents 1a8b3cb347e0
children
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33:965ac0a77267 34:5123b17c98ef
5 * which accompanies this distribution, and is available at 5 * which accompanies this distribution, and is available at
6 * http://www.eclipse.org/legal/epl-v10.html 6 * http://www.eclipse.org/legal/epl-v10.html
7 * 7 *
8 * Contributors: 8 * Contributors:
9 * IBM Corporation - initial API and implementation 9 * IBM Corporation - initial API and implementation
10 * Port to the D programming language:
11 * Frank Benoit <benoit@tionex.de>
10 *******************************************************************************/ 12 *******************************************************************************/
11 module dwt.internal.image; 13 module dwt.internal.image.PngIdatChunk;
12 14
13 15
14 import dwt.DWT; 16 import dwt.DWT;
17 import dwt.internal.image.PngFileReadState;
18 import dwt.internal.image.PngIhdrChunk;
19 import dwt.internal.image.PngChunk;
20 import dwt.dwthelper.utils;
15 21
16 class PngIdatChunk : PngChunk { 22 class PngIdatChunk : PngChunk {
17 23
18 static final int HEADER_BYTES_LENGTH = 2; 24 static const int HEADER_BYTES_LENGTH = 2;
19 static final int ADLER_FIELD_LENGTH = 4; 25 static const int ADLER_FIELD_LENGTH = 4;
20 static final int HEADER_BYTE1_DATA_OFFSET = DATA_OFFSET + 0; 26 static const int HEADER_BYTE1_DATA_OFFSET = DATA_OFFSET + 0;
21 static final int HEADER_BYTE2_DATA_OFFSET = DATA_OFFSET + 1; 27 static const int HEADER_BYTE2_DATA_OFFSET = DATA_OFFSET + 1;
22 static final int ADLER_DATA_OFFSET = DATA_OFFSET + 2; // plus variable compressed data length 28 static const int ADLER_DATA_OFFSET = DATA_OFFSET + 2; // plus variable compressed data length
23 29
24 this(byte headerByte1, byte headerByte2, byte[] data, int adler) { 30 this(byte headerByte1, byte headerByte2, byte[] data, int adler) {
25 super(data.length + HEADER_BYTES_LENGTH + ADLER_FIELD_LENGTH); 31 super(data.length + HEADER_BYTES_LENGTH + ADLER_FIELD_LENGTH);
26 setType(TYPE_IDAT); 32 setType(TYPE_IDAT);
27 reference[HEADER_BYTE1_DATA_OFFSET] = headerByte1; 33 reference[HEADER_BYTE1_DATA_OFFSET] = headerByte1;
28 reference[HEADER_BYTE2_DATA_OFFSET] = headerByte2; 34 reference[HEADER_BYTE2_DATA_OFFSET] = headerByte2;
29 System.arraycopy(data, 0, reference, DATA_OFFSET, data.length); 35 System.arraycopy(data, 0, reference, DATA_OFFSET, data.length);
30 setInt32(ADLER_DATA_OFFSET, adler); 36 setInt32(ADLER_DATA_OFFSET, adler);
31 setCRC(computeCRC()); 37 setCRC(computeCRC());
32 } 38 }
33 39
34 this(byte[] reference) { 40 this(byte[] reference) {
35 super(reference); 41 super(reference);
36 } 42 }
37 43
38 int getChunkType() { 44 override int getChunkType() {
39 return CHUNK_IDAT; 45 return CHUNK_IDAT;
40 } 46 }
41 47
42 /** 48 /**
43 * Answer whether the chunk is a valid IDAT chunk. 49 * Answer whether the chunk is a valid IDAT chunk.
44 */ 50 */
45 void validate(PngFileReadState readState, PngIhdrChunk headerChunk) { 51 override void validate(PngFileReadState readState, PngIhdrChunk headerChunk) {
46 if (!readState.readIHDR 52 if (!readState.readIHDR
47 || (headerChunk.getMustHavePalette() && !readState.readPLTE) 53 || (headerChunk.getMustHavePalette() && !readState.readPLTE)
48 || readState.readIEND) 54 || readState.readIEND)
49 { 55 {
50 DWT.error(DWT.ERROR_INVALID_IMAGE); 56 DWT.error(DWT.ERROR_INVALID_IMAGE);
51 } else { 57 } else {
52 readState.readIDAT = true; 58 readState.readIDAT = true;
53 } 59 }
54 60
55 super.validate(readState, headerChunk); 61 super.validate(readState, headerChunk);
56 } 62 }
57 63
58 byte getDataByteAtOffset(int offset) { 64 byte getDataByteAtOffset(int offset) {
59 return reference[DATA_OFFSET + offset]; 65 return reference[DATA_OFFSET + offset];