first commit
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864
LibreHardwareMonitor-0.9.4/Aga.Controls/GifDecoder.cs
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864
LibreHardwareMonitor-0.9.4/Aga.Controls/GifDecoder.cs
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#pragma warning disable 675 // Bitwise-or operator used on a sign-extended operand
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#region Java Info
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/**
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* Class GifDecoder - Decodes a GIF file into one or more frames.
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* <br><pre>
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* Example:
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* GifDecoder d = new GifDecoder();
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* d.read("sample.gif");
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* int n = d.getFrameCount();
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* for (int i = 0; i < n; i++) {
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* BufferedImage frame = d.getFrame(i); // frame i
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* int t = d.getDelay(i); // display duration of frame in milliseconds
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* // do something with frame
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* }
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* </pre>
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* No copyright asserted on the source code of this class. May be used for
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* any purpose, however, refer to the Unisys LZW patent for any additional
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* restrictions. Please forward any corrections to kweiner@fmsware.com.
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*
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* @author Kevin Weiner, FM Software; LZW decoder adapted from John Cristy's ImageMagick.
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* @version 1.03 November 2003
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*
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*/
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#endregion
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using System;
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using System.Collections;
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using System.Drawing;
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using System.Drawing.Imaging;
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using System.IO;
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namespace Aga.Controls
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{
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public class GifFrame
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{
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private Image _image;
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public Image Image
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{
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get { return _image; }
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}
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private int _delay;
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public int Delay
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{
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get { return _delay; }
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}
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public GifFrame(Image im, int del)
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{
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_image = im;
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_delay = del;
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}
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}
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public class GifDecoder
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{
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public const int StatusOK = 0;//File read status: No errors.
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public const int StatusFormatError = 1; //File read status: Error decoding file (may be partially decoded)
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public const int StatusOpenError = 2; //Unable to open source.
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private Stream inStream;
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private int status;
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private int width; // full image width
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private int height; // full image height
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private bool gctFlag; // global color table used
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private int gctSize; // size of global color table
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private int loopCount = 1; // iterations; 0 = repeat forever
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private int[] gct; // global color table
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private int[] lct; // local color table
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private int[] act; // active color table
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private int bgIndex; // background color index
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private int bgColor; // background color
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private int lastBgColor; // previous bg color
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private int pixelAspect; // pixel aspect ratio
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private bool lctFlag; // local color table flag
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private bool interlace; // interlace flag
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private int lctSize; // local color table size
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private int ix, iy, iw, ih; // current image rectangle
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private Rectangle lastRect; // last image rect
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private Image image; // current frame
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private Bitmap bitmap;
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private Image lastImage; // previous frame
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private byte[] block = new byte[256]; // current data block
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private int blockSize = 0; // block size
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// last graphic control extension info
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private int dispose = 0;
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// 0=no action; 1=leave in place; 2=restore to bg; 3=restore to prev
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private int lastDispose = 0;
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private bool transparency = false; // use transparent color
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private int delay = 0; // delay in milliseconds
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private int transIndex; // transparent color index
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private const int MaxStackSize = 4096;
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// max decoder pixel stack size
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// LZW decoder working arrays
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private short[] prefix;
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private byte[] suffix;
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private byte[] pixelStack;
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private byte[] pixels;
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private ArrayList frames; // frames read from current file
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private int frameCount;
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private bool _makeTransparent;
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/**
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* Gets the number of frames read from file.
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* @return frame count
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*/
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public int FrameCount
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{
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get
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{
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return frameCount;
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}
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}
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/**
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* Gets the first (or only) image read.
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*
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* @return BufferedImage containing first frame, or null if none.
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*/
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public Image Image
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{
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get
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{
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return GetFrame(0).Image;
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}
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}
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/**
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* Gets the "Netscape" iteration count, if any.
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* A count of 0 means repeat indefinitiely.
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*
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* @return iteration count if one was specified, else 1.
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*/
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public int LoopCount
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{
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get
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{
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return loopCount;
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}
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}
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public GifDecoder(Stream stream, bool makeTransparent)
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{
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_makeTransparent = makeTransparent;
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if (Read(stream) != 0)
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throw new InvalidOperationException();
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}
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/**
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* Creates new frame image from current data (and previous
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* frames as specified by their disposition codes).
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*/
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private int[] GetPixels(Bitmap bitmap)
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{
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int [] pixels = new int [ 3 * image.Width * image.Height ];
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int count = 0;
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for (int th = 0; th < image.Height; th++)
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{
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for (int tw = 0; tw < image.Width; tw++)
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{
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Color color = bitmap.GetPixel(tw, th);
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pixels[count] = color.R;
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count++;
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pixels[count] = color.G;
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count++;
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pixels[count] = color.B;
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count++;
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}
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}
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return pixels;
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}
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private void SetPixels(int[] pixels)
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{
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int count = 0;
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for (int th = 0; th < image.Height; th++)
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{
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for (int tw = 0; tw < image.Width; tw++)
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{
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Color color = Color.FromArgb( pixels[count++] );
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bitmap.SetPixel( tw, th, color );
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}
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}
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if (_makeTransparent)
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bitmap.MakeTransparent(bitmap.GetPixel(0, 0));
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}
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private void SetPixels()
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{
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// expose destination image's pixels as int array
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// int[] dest =
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// (( int ) image.getRaster().getDataBuffer()).getData();
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int[] dest = GetPixels( bitmap );
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// fill in starting image contents based on last image's dispose code
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if (lastDispose > 0)
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{
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if (lastDispose == 3)
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{
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// use image before last
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int n = frameCount - 2;
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if (n > 0)
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{
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lastImage = GetFrame(n - 1).Image;
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}
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else
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{
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lastImage = null;
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}
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}
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if (lastImage != null)
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{
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// int[] prev =
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// ((DataBufferInt) lastImage.getRaster().getDataBuffer()).getData();
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int[] prev = GetPixels( new Bitmap( lastImage ) );
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Array.Copy(prev, 0, dest, 0, width * height);
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// copy pixels
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if (lastDispose == 2)
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{
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// fill last image rect area with background color
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Graphics g = Graphics.FromImage( image );
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Color c = Color.Empty;
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if (transparency)
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{
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c = Color.FromArgb( 0, 0, 0, 0 ); // assume background is transparent
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}
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else
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{
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c = Color.FromArgb( lastBgColor ) ;
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// c = new Color(lastBgColor); // use given background color
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}
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Brush brush = new SolidBrush( c );
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g.FillRectangle( brush, lastRect );
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brush.Dispose();
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g.Dispose();
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}
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}
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}
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// copy each source line to the appropriate place in the destination
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int pass = 1;
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int inc = 8;
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int iline = 0;
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for (int i = 0; i < ih; i++)
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{
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int line = i;
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if (interlace)
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{
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if (iline >= ih)
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{
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pass++;
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switch (pass)
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{
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case 2 :
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iline = 4;
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break;
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case 3 :
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iline = 2;
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inc = 4;
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break;
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case 4 :
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iline = 1;
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inc = 2;
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break;
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}
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}
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line = iline;
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iline += inc;
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}
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line += iy;
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if (line < height)
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{
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int k = line * width;
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int dx = k + ix; // start of line in dest
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int dlim = dx + iw; // end of dest line
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if ((k + width) < dlim)
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{
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dlim = k + width; // past dest edge
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}
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int sx = i * iw; // start of line in source
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while (dx < dlim)
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{
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// map color and insert in destination
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int index = ((int) pixels[sx++]) & 0xff;
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int c = act[index];
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if (c != 0)
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{
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dest[dx] = c;
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}
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dx++;
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}
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}
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}
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SetPixels( dest );
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}
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/**
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* Gets the image contents of frame n.
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*
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* @return BufferedImage representation of frame.
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*/
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public GifFrame GetFrame(int n)
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{
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if ((n >= 0) && (n < frameCount))
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return (GifFrame)frames[n];
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else
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throw new ArgumentOutOfRangeException();
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}
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/**
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* Gets image size.
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*
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* @return GIF image dimensions
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*/
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public Size FrameSize
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{
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get
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{
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return new Size(width, height);
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}
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}
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/**
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* Reads GIF image from stream
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*
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* @param BufferedInputStream containing GIF file.
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* @return read status code (0 = no errors)
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*/
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private int Read( Stream inStream )
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{
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Init();
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if ( inStream != null)
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{
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this.inStream = inStream;
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ReadHeader();
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if (!Error())
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{
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ReadContents();
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if (frameCount < 0)
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{
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status = StatusFormatError;
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}
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}
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inStream.Close();
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}
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else
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{
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status = StatusOpenError;
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}
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return status;
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}
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/**
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* Decodes LZW image data into pixel array.
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* Adapted from John Cristy's ImageMagick.
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*/
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private void DecodeImageData()
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{
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int NullCode = -1;
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int npix = iw * ih;
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int available,
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clear,
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code_mask,
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code_size,
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end_of_information,
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in_code,
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old_code,
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bits,
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code,
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count,
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i,
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datum,
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data_size,
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first,
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top,
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bi,
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pi;
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if ((pixels == null) || (pixels.Length < npix))
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{
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pixels = new byte[npix]; // allocate new pixel array
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}
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if (prefix == null) prefix = new short[MaxStackSize];
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if (suffix == null) suffix = new byte[MaxStackSize];
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if (pixelStack == null) pixelStack = new byte[MaxStackSize + 1];
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// Initialize GIF data stream decoder.
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data_size = Read();
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clear = 1 << data_size;
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end_of_information = clear + 1;
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available = clear + 2;
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old_code = NullCode;
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code_size = data_size + 1;
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code_mask = (1 << code_size) - 1;
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for (code = 0; code < clear; code++)
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{
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prefix[code] = 0;
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suffix[code] = (byte) code;
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}
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// Decode GIF pixel stream.
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datum = bits = count = first = top = pi = bi = 0;
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for (i = 0; i < npix;)
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{
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if (top == 0)
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{
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if (bits < code_size)
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{
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// Load bytes until there are enough bits for a code.
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if (count == 0)
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{
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// Read a new data block.
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count = ReadBlock();
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if (count <= 0)
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break;
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bi = 0;
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}
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datum += (((int) block[bi]) & 0xff) << bits;
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bits += 8;
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bi++;
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count--;
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continue;
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}
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// Get the next code.
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code = datum & code_mask;
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datum >>= code_size;
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bits -= code_size;
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// Interpret the code
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if ((code > available) || (code == end_of_information))
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break;
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if (code == clear)
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{
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// Reset decoder.
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code_size = data_size + 1;
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code_mask = (1 << code_size) - 1;
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available = clear + 2;
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old_code = NullCode;
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continue;
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}
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if (old_code == NullCode)
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{
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pixelStack[top++] = suffix[code];
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old_code = code;
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first = code;
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continue;
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}
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in_code = code;
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if (code == available)
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{
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pixelStack[top++] = (byte) first;
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code = old_code;
|
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}
|
||||
while (code > clear)
|
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{
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pixelStack[top++] = suffix[code];
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code = prefix[code];
|
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}
|
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first = ((int) suffix[code]) & 0xff;
|
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|
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// Add a new string to the string table,
|
||||
|
||||
if (available >= MaxStackSize)
|
||||
break;
|
||||
pixelStack[top++] = (byte) first;
|
||||
prefix[available] = (short) old_code;
|
||||
suffix[available] = (byte) first;
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available++;
|
||||
if (((available & code_mask) == 0)
|
||||
&& (available < MaxStackSize))
|
||||
{
|
||||
code_size++;
|
||||
code_mask += available;
|
||||
}
|
||||
old_code = in_code;
|
||||
}
|
||||
|
||||
// Pop a pixel off the pixel stack.
|
||||
|
||||
top--;
|
||||
pixels[pi++] = pixelStack[top];
|
||||
i++;
|
||||
}
|
||||
|
||||
for (i = pi; i < npix; i++)
|
||||
{
|
||||
pixels[i] = 0; // clear missing pixels
|
||||
}
|
||||
|
||||
}
|
||||
|
||||
/**
|
||||
* Returns true if an error was encountered during reading/decoding
|
||||
*/
|
||||
private bool Error()
|
||||
{
|
||||
return status != StatusOK;
|
||||
}
|
||||
|
||||
/**
|
||||
* Initializes or re-initializes reader
|
||||
*/
|
||||
private void Init()
|
||||
{
|
||||
status = StatusOK;
|
||||
frameCount = 0;
|
||||
frames = new ArrayList();
|
||||
gct = null;
|
||||
lct = null;
|
||||
}
|
||||
|
||||
/**
|
||||
* Reads a single byte from the input stream.
|
||||
*/
|
||||
private int Read()
|
||||
{
|
||||
int curByte = 0;
|
||||
try
|
||||
{
|
||||
curByte = inStream.ReadByte();
|
||||
}
|
||||
catch (IOException)
|
||||
{
|
||||
status = StatusFormatError;
|
||||
}
|
||||
return curByte;
|
||||
}
|
||||
|
||||
/**
|
||||
* Reads next variable length block from input.
|
||||
*
|
||||
* @return number of bytes stored in "buffer"
|
||||
*/
|
||||
private int ReadBlock()
|
||||
{
|
||||
blockSize = Read();
|
||||
int n = 0;
|
||||
if (blockSize > 0)
|
||||
{
|
||||
try
|
||||
{
|
||||
int count = 0;
|
||||
while (n < blockSize)
|
||||
{
|
||||
count = inStream.Read(block, n, blockSize - n);
|
||||
if (count == -1)
|
||||
break;
|
||||
n += count;
|
||||
}
|
||||
}
|
||||
catch (IOException)
|
||||
{
|
||||
}
|
||||
|
||||
if (n < blockSize)
|
||||
{
|
||||
status = StatusFormatError;
|
||||
}
|
||||
}
|
||||
return n;
|
||||
}
|
||||
|
||||
/**
|
||||
* Reads color table as 256 RGB integer values
|
||||
*
|
||||
* @param ncolors int number of colors to read
|
||||
* @return int array containing 256 colors (packed ARGB with full alpha)
|
||||
*/
|
||||
private int[] ReadColorTable(int ncolors)
|
||||
{
|
||||
int nbytes = 3 * ncolors;
|
||||
int[] tab = null;
|
||||
byte[] c = new byte[nbytes];
|
||||
int n = 0;
|
||||
try
|
||||
{
|
||||
n = inStream.Read(c, 0, c.Length );
|
||||
}
|
||||
catch (IOException)
|
||||
{
|
||||
}
|
||||
if (n < nbytes)
|
||||
{
|
||||
status = StatusFormatError;
|
||||
}
|
||||
else
|
||||
{
|
||||
tab = new int[256]; // max size to avoid bounds checks
|
||||
int i = 0;
|
||||
int j = 0;
|
||||
while (i < ncolors)
|
||||
{
|
||||
int r = ((int) c[j++]) & 0xff;
|
||||
int g = ((int) c[j++]) & 0xff;
|
||||
int b = ((int) c[j++]) & 0xff;
|
||||
tab[i++] = ( int ) ( 0xff000000 | (r << 16) | (g << 8) | b );
|
||||
}
|
||||
}
|
||||
return tab;
|
||||
}
|
||||
|
||||
/**
|
||||
* Main file parser. Reads GIF content blocks.
|
||||
*/
|
||||
private void ReadContents()
|
||||
{
|
||||
// read GIF file content blocks
|
||||
bool done = false;
|
||||
while (!(done || Error()))
|
||||
{
|
||||
int code = Read();
|
||||
switch (code)
|
||||
{
|
||||
|
||||
case 0x2C : // image separator
|
||||
ReadImage();
|
||||
break;
|
||||
|
||||
case 0x21 : // extension
|
||||
code = Read();
|
||||
switch (code)
|
||||
{
|
||||
case 0xf9 : // graphics control extension
|
||||
ReadGraphicControlExt();
|
||||
break;
|
||||
|
||||
case 0xff : // application extension
|
||||
ReadBlock();
|
||||
String app = "";
|
||||
for (int i = 0; i < 11; i++)
|
||||
{
|
||||
app += (char) block[i];
|
||||
}
|
||||
if (app.Equals("NETSCAPE2.0"))
|
||||
{
|
||||
ReadNetscapeExt();
|
||||
}
|
||||
else
|
||||
Skip(); // don't care
|
||||
break;
|
||||
|
||||
default : // uninteresting extension
|
||||
Skip();
|
||||
break;
|
||||
}
|
||||
break;
|
||||
|
||||
case 0x3b : // terminator
|
||||
done = true;
|
||||
break;
|
||||
|
||||
case 0x00 : // bad byte, but keep going and see what happens
|
||||
break;
|
||||
|
||||
default :
|
||||
status = StatusFormatError;
|
||||
break;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Reads Graphics Control Extension values
|
||||
*/
|
||||
private void ReadGraphicControlExt()
|
||||
{
|
||||
Read(); // block size
|
||||
int packed = Read(); // packed fields
|
||||
dispose = (packed & 0x1c) >> 2; // disposal method
|
||||
if (dispose == 0)
|
||||
{
|
||||
dispose = 1; // elect to keep old image if discretionary
|
||||
}
|
||||
transparency = (packed & 1) != 0;
|
||||
delay = ReadShort() * 10; // delay in milliseconds
|
||||
transIndex = Read(); // transparent color index
|
||||
Read(); // block terminator
|
||||
}
|
||||
|
||||
/**
|
||||
* Reads GIF file header information.
|
||||
*/
|
||||
private void ReadHeader()
|
||||
{
|
||||
String id = "";
|
||||
for (int i = 0; i < 6; i++)
|
||||
{
|
||||
id += (char) Read();
|
||||
}
|
||||
if (!id.StartsWith("GIF"))
|
||||
{
|
||||
status = StatusFormatError;
|
||||
return;
|
||||
}
|
||||
|
||||
ReadLSD();
|
||||
if (gctFlag && !Error())
|
||||
{
|
||||
gct = ReadColorTable(gctSize);
|
||||
bgColor = gct[bgIndex];
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Reads next frame image
|
||||
*/
|
||||
private void ReadImage()
|
||||
{
|
||||
ix = ReadShort(); // (sub)image position & size
|
||||
iy = ReadShort();
|
||||
iw = ReadShort();
|
||||
ih = ReadShort();
|
||||
|
||||
int packed = Read();
|
||||
lctFlag = (packed & 0x80) != 0; // 1 - local color table flag
|
||||
interlace = (packed & 0x40) != 0; // 2 - interlace flag
|
||||
// 3 - sort flag
|
||||
// 4-5 - reserved
|
||||
lctSize = 2 << (packed & 7); // 6-8 - local color table size
|
||||
|
||||
if (lctFlag)
|
||||
{
|
||||
lct = ReadColorTable(lctSize); // read table
|
||||
act = lct; // make local table active
|
||||
}
|
||||
else
|
||||
{
|
||||
act = gct; // make global table active
|
||||
if (bgIndex == transIndex)
|
||||
bgColor = 0;
|
||||
}
|
||||
int save = 0;
|
||||
if (transparency)
|
||||
{
|
||||
save = act[transIndex];
|
||||
act[transIndex] = 0; // set transparent color if specified
|
||||
}
|
||||
|
||||
if (act == null)
|
||||
{
|
||||
status = StatusFormatError; // no color table defined
|
||||
}
|
||||
|
||||
if (Error()) return;
|
||||
|
||||
DecodeImageData(); // decode pixel data
|
||||
Skip();
|
||||
|
||||
if (Error()) return;
|
||||
|
||||
frameCount++;
|
||||
|
||||
// create new image to receive frame data
|
||||
// image =
|
||||
// new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB_PRE);
|
||||
|
||||
bitmap = new Bitmap( width, height );
|
||||
image = bitmap;
|
||||
SetPixels(); // transfer pixel data to image
|
||||
|
||||
frames.Add(new GifFrame(bitmap, delay)); // add image to frame list
|
||||
|
||||
if (transparency)
|
||||
{
|
||||
act[transIndex] = save;
|
||||
}
|
||||
ResetFrame();
|
||||
|
||||
}
|
||||
|
||||
/**
|
||||
* Reads Logical Screen Descriptor
|
||||
*/
|
||||
private void ReadLSD()
|
||||
{
|
||||
|
||||
// logical screen size
|
||||
width = ReadShort();
|
||||
height = ReadShort();
|
||||
|
||||
// packed fields
|
||||
int packed = Read();
|
||||
gctFlag = (packed & 0x80) != 0; // 1 : global color table flag
|
||||
// 2-4 : color resolution
|
||||
// 5 : gct sort flag
|
||||
gctSize = 2 << (packed & 7); // 6-8 : gct size
|
||||
|
||||
bgIndex = Read(); // background color index
|
||||
pixelAspect = Read(); // pixel aspect ratio
|
||||
}
|
||||
|
||||
/**
|
||||
* Reads Netscape extenstion to obtain iteration count
|
||||
*/
|
||||
private void ReadNetscapeExt()
|
||||
{
|
||||
do
|
||||
{
|
||||
ReadBlock();
|
||||
if (block[0] == 1)
|
||||
{
|
||||
// loop count sub-block
|
||||
int b1 = ((int) block[1]) & 0xff;
|
||||
int b2 = ((int) block[2]) & 0xff;
|
||||
loopCount = (b2 << 8) | b1;
|
||||
}
|
||||
} while ((blockSize > 0) && !Error());
|
||||
}
|
||||
|
||||
/**
|
||||
* Reads next 16-bit value, LSB first
|
||||
*/
|
||||
private int ReadShort()
|
||||
{
|
||||
// read 16-bit value, LSB first
|
||||
return Read() | (Read() << 8);
|
||||
}
|
||||
|
||||
/**
|
||||
* Resets frame state for reading next image.
|
||||
*/
|
||||
private void ResetFrame()
|
||||
{
|
||||
lastDispose = dispose;
|
||||
lastRect = new Rectangle(ix, iy, iw, ih);
|
||||
lastImage = image;
|
||||
lastBgColor = bgColor;
|
||||
// int dispose = 0;
|
||||
lct = null;
|
||||
}
|
||||
|
||||
/**
|
||||
* Skips variable length blocks up to and including
|
||||
* next zero length block.
|
||||
*/
|
||||
private void Skip()
|
||||
{
|
||||
do
|
||||
{
|
||||
ReadBlock();
|
||||
} while ((blockSize > 0) && !Error());
|
||||
}
|
||||
}
|
||||
}
|
||||
Reference in New Issue
Block a user