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131 lines
No EOL
4.6 KiB
C#
131 lines
No EOL
4.6 KiB
C#
#region License Information (GPL v3)
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/*
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ShareX - A program that allows you to take screenshots and share any file type
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Copyright (C) 2008-2014 ShareX Developers
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This program is free software; you can redistribute it and/or
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modify it under the terms of the GNU General Public License
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as published by the Free Software Foundation; either version 2
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of the License, or (at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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Optionally you can also view the license at <http://www.gnu.org/licenses/>.
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*/
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#endregion License Information (GPL v3)
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using System;
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using System.Drawing;
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using System.IO;
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namespace HelpersLib
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{
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public class GifCreator : IDisposable
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{
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private byte[] graphicControlExtensionBlock, loopBlock;
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private MemoryStream gifStream;
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private BinaryWriter binaryWriter;
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private int frameNum;
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public GifCreator(int delay, int repeat = 0)
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{
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byte[] signature = new byte[] { (byte)'G', (byte)'I', (byte)'F', (byte)'8', (byte)'9', (byte)'a' };
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graphicControlExtensionBlock = CreateGraphicControlExtensionBlock(delay);
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loopBlock = CreateLoopBlock(repeat);
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gifStream = new MemoryStream();
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binaryWriter = new BinaryWriter(gifStream);
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binaryWriter.Write(signature);
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}
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public void AddFrame(Image img, GIFQuality quality = GIFQuality.Default)
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{
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GifClass gif = new GifClass();
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gif.LoadGifPicture(img, quality);
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if (frameNum == 0)
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{
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binaryWriter.Write(gif.m_ScreenDescriptor.ToArray());
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}
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binaryWriter.Write(graphicControlExtensionBlock);
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binaryWriter.Write(gif.m_ImageDescriptor.ToArray());
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binaryWriter.Write(gif.m_ColorTable.ToArray());
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binaryWriter.Write(gif.m_ImageData.ToArray());
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frameNum++;
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}
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public void AddFrame(string path, GIFQuality quality = GIFQuality.Default)
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{
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using (Image img = ImageHelpers.LoadImage(path))
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{
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AddFrame(img, quality);
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}
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}
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public void Finish()
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{
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binaryWriter.Write(CreateLoopBlock());
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binaryWriter.Write(0x3B); // Image terminator
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}
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public void Save(string filePath)
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{
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gifStream.WriteToFile(filePath);
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}
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private byte[] CreateGraphicControlExtensionBlock(int delay)
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{
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byte[] buffer = new byte[8];
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buffer[0] = 0x21; // Extension introducer
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buffer[1] = 0xF9; // Graphic control extension
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buffer[2] = 0x04; // Size of block
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buffer[3] = 0x09; // Flags: reserved, disposal method, user input, transparent color
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buffer[4] = (byte)(delay / 10 % 0x100); // Delay time low byte
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buffer[5] = (byte)(delay / 10 / 0x100); // Delay time high byte
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buffer[6] = 0xFF; // Transparent color index
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buffer[7] = 0x00; // Block terminator
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return buffer;
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}
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private byte[] CreateLoopBlock(int repeat = 0)
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{
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byte[] buffer = new byte[19];
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buffer[0] = 0x21; // Extension introducer
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buffer[1] = 0xFF; // Application extension
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buffer[2] = 0x0B; // Size of block
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buffer[3] = (byte)'N';
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buffer[4] = (byte)'E';
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buffer[5] = (byte)'T';
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buffer[6] = (byte)'S';
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buffer[7] = (byte)'C';
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buffer[8] = (byte)'A';
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buffer[9] = (byte)'P';
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buffer[10] = (byte)'E';
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buffer[11] = (byte)'2';
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buffer[12] = (byte)'.';
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buffer[13] = (byte)'0';
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buffer[14] = 0x03; // Size of block
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buffer[15] = 0x01; // Loop indicator
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buffer[16] = (byte)(repeat % 0x100); // Number of repetitions
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buffer[17] = (byte)(repeat / 0x100); // 0 for endless loop
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buffer[18] = 0x00; // Block terminator
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return buffer;
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}
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public void Dispose()
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{
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if (gifStream != null) gifStream.Dispose();
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if (binaryWriter != null) binaryWriter.Close();
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}
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}
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} |