Mercurial > projects > dwt-mac
diff dwt/internal/image/PngDecodingDataStream.d @ 34:5123b17c98ef
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 | e831403a80a9 |
children |
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--- a/dwt/internal/image/PngDecodingDataStream.d Fri Sep 12 13:53:21 2008 +0200 +++ b/dwt/internal/image/PngDecodingDataStream.d Sun Sep 14 01:45:57 2008 +0200 @@ -7,26 +7,31 @@ * * Contributors: * IBM Corporation - initial API and implementation + * Port to the D programming language: + * Frank Benoit <benoit@tionex.de> *******************************************************************************/ -module dwt.internal.image; +module dwt.internal.image.PngDecodingDataStream; -import java.io.IOException; -import java.io.InputStream; +import dwt.dwthelper.InputStream; import dwt.DWT; +import dwt.internal.image.PngLzBlockReader; public class PngDecodingDataStream : InputStream { + + alias InputStream.read read; + InputStream stream; byte currentByte; int nextBitIndex; - + PngLzBlockReader lzBlockReader; int adlerValue; - + static final int PRIME = 65521; - static final int MAX_BIT = 7; - + static final int MAX_BIT = 7; + this(InputStream stream) { super(); this.stream = stream; @@ -40,7 +45,7 @@ /** * This method should be called when the image decoder thinks * that all of the compressed image data has been read. This - * method will ensure that the next data value is an end of + * method will ensure that the next data value is an end of * block marker. If there are more blocks after this one, * the method will read them and ensure that they are empty. */ @@ -48,7 +53,7 @@ lzBlockReader.assertCompressedDataAtEnd(); } -public void close() { +public override void close() { assertImageDataAtEnd(); checkAdler(); } @@ -69,7 +74,7 @@ return (currentByte & (1 << nextBitIndex)) >> nextBitIndex++; } -byte getNextIdatByte() { +byte getNextIdatByte() { byte nextByte = cast(byte)stream.read(); nextBitIndex = MAX_BIT + 1; return nextByte; @@ -84,13 +89,13 @@ adlerValue = (high << 16) | low; } -public int read() { +public override int read() { byte nextDecodedByte = lzBlockReader.getNextByte(); updateAdler(nextDecodedByte); return nextDecodedByte & 0xFF; } -public int read(byte[] buffer, int off, int len) { +public override int read(byte[] buffer, int off, int len) { for (int i = 0; i < len; i++) { int b = read(); if (b is -1) return i; @@ -106,29 +111,30 @@ private void readCompressedDataHeader() { byte headerByte1 = getNextIdatByte(); byte headerByte2 = getNextIdatByte(); - + int number = ((headerByte1 & 0xFF) << 8) | (headerByte2 & 0xFF); if (number % 31 !is 0) error(); - + int compressionMethod = headerByte1 & 0x0F; if (compressionMethod !is 8) error(); - + int windowSizeHint = (headerByte1 & 0xF0) >> 4; if (windowSizeHint > 7) error(); int windowSize = (1 << (windowSizeHint + 8)); lzBlockReader.setWindowSize(windowSize); - + int dictionary = (headerByte2 & (1 << 5)); if (dictionary !is 0) error(); - + // int compressionLevel = (headerByte2 & 0xC0) >> 6; } void checkAdler() { - int storedAdler = ((getNextIdatByte() & 0xFF) << 24) - | ((getNextIdatByte() & 0xFF) << 16) - | ((getNextIdatByte() & 0xFF) << 8) - | (getNextIdatByte() & 0xFF); + int storedAdler = 0; + storedAdler |= ((getNextIdatByte() & 0xFF) << 24); + storedAdler |= ((getNextIdatByte() & 0xFF) << 16); + storedAdler |= ((getNextIdatByte() & 0xFF) << 8); + storedAdler |= (getNextIdatByte() & 0xFF); if (storedAdler !is adlerValue) error(); }