81 lines
2.4 KiB
C#
81 lines
2.4 KiB
C#
//
|
|
// LZPL2CompressionModule.cs - provides a CompressionModule for handling LZPL2 compression
|
|
//
|
|
// Author:
|
|
// Michael Becker <alcexhim@gmail.com>
|
|
//
|
|
// Copyright (c) 2020 Mike Becker's Software
|
|
//
|
|
// This program is free software: you can redistribute it and/or modify
|
|
// it under the terms of the GNU General Public License as published by
|
|
// the Free Software Foundation, either version 3 of the License, or
|
|
// (at your option) any later version.
|
|
//
|
|
// This program is distributed in the hope that it will be useful,
|
|
// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
// GNU General Public License for more details.
|
|
//
|
|
// You should have received a copy of the GNU General Public License
|
|
// along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
namespace UniversalEditor.Compression.LZPL2
|
|
{
|
|
/// <summary>
|
|
/// Provides a <see cref="CompressionModule" /> for handling LZPL2 compression.
|
|
/// </summary>
|
|
public class LZPL2CompressionModule
|
|
{
|
|
private int mvarBufferSize = 4096;
|
|
public int BufferSize { get { return mvarBufferSize; } set { mvarBufferSize = value; } }
|
|
|
|
private static LZPL2CompressionModule mvarDefaultModule = new LZPL2CompressionModule();
|
|
public static LZPL2CompressionModule DefaultModule { get { return mvarDefaultModule; } }
|
|
|
|
public byte[] Decompress(byte[] data, uint decompressedSize)
|
|
{
|
|
byte[] buffer = new byte[mvarBufferSize];
|
|
byte mask = 0, flags = 0, x = 0, y = 0, b = 0;
|
|
|
|
uint srcpos = 0, dstpos = 0;
|
|
|
|
byte[] decompressedData = new byte[decompressedSize];
|
|
while ((srcpos < data.Length) && (dstpos < decompressedData.Length))
|
|
{
|
|
if (mask == 0)
|
|
{
|
|
flags = data[srcpos++];
|
|
if (srcpos >= data.Length) break;
|
|
mask = 1;
|
|
}
|
|
|
|
if ((flags & mask) != 0)
|
|
{
|
|
// Raw byte
|
|
buffer[dstpos % mvarBufferSize] = data[srcpos];
|
|
decompressedData[dstpos++] = data[srcpos++];
|
|
}
|
|
else
|
|
{
|
|
// Pointer: 0xAB 0xCD (CAB=pointer, D=length)
|
|
x = data[srcpos++];
|
|
y = data[srcpos++];
|
|
|
|
int off = (((y & 0xf0) << 4) | x) + 18;
|
|
int len = (y & 0x0f) + 3;
|
|
|
|
while ((len-- > 0) && (dstpos < decompressedData.Length))
|
|
{
|
|
b = buffer[off++ % mvarBufferSize];
|
|
buffer[dstpos % mvarBufferSize] = b;
|
|
decompressedData[dstpos++] = b;
|
|
}
|
|
}
|
|
mask <<= 1;
|
|
}
|
|
return decompressedData;
|
|
}
|
|
|
|
}
|
|
}
|