git-svn-id: svn://svn.ijw.co.nz/svn/OpenRa@1061 993157c7-ee19-0410-b2c4-bb4e9862e678

2007-06-23 17:19:09 +00:00
parent 73c4ee6817
commit 1504ad3ca6
15 changed files with 64 additions and 75 deletions
--- a/OpenRa.FileFormats/Format80.cs
+++ b/OpenRa.FileFormats/Format80.cs
@@ -0,0 +1,104 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+using System.IO;
+
+namespace OpenRa.FileFormats
+{
+	public static class Format80
+	{
+		static byte ReadByte( MemoryStream input )
+		{
+			int inp = input.ReadByte();
+			if( inp == -1 )
+				throw new InvalidDataException();
+
+			return (byte)inp;
+		}
+
+		static int ReadWord( MemoryStream input )
+		{
+			int inp = ReadByte( input );
+			return inp + ( ReadByte( input ) << 8 );
+		}
+
+		static void ReplicatePrevious( byte[] dest, int destIndex, int srcIndex, int count )
+		{
+			if( srcIndex >= destIndex )
+				throw new NotImplementedException( string.Format( "srcIndex >= destIndex  {0}  {1}", srcIndex, destIndex ) );
+
+			for( int i = 0 ; i < Math.Min( count, destIndex - srcIndex ) ; i++ )
+				dest[ destIndex + i ] = dest[ srcIndex + i ];
+
+			if( srcIndex + count <= destIndex )
+				return;
+
+			for( int i = destIndex + destIndex - srcIndex ; i < destIndex + count ; i++ )
+				dest[ i ] = dest[ destIndex - 1 ];
+		}
+
+		public static int DecodeInto( MemoryStream input, byte[] dest )
+		{
+			int destIndex = 0;
+			while( true )
+			{
+				byte i = ReadByte( input );
+				if( ( i & 0x80 ) == 0 )
+				{
+					// case 2
+					byte secondByte = ReadByte( input );
+					int count = ( ( i & 0x70 ) >> 4 ) + 3;
+					int rpos = ( ( i & 0xf ) << 8 ) + secondByte;
+
+					ReplicatePrevious( dest, destIndex, destIndex - rpos, count );
+					destIndex += count;
+				}
+				else if( ( i & 0x40 ) == 0 )
+				{
+					// case 1
+					int count = i & 0x3F;
+					if( count == 0 )
+						return destIndex;
+
+					input.Read( dest, destIndex, count );
+					destIndex += count;
+				}
+				else
+				{
+					int count3 = i & 0x3F;
+					if( count3 == 0x3E )
+					{
+						// case 4
+						int count = ReadWord( input );
+						byte color = ReadByte( input );
+
+						for( int end = destIndex + count ; destIndex < end ; destIndex++ )
+							dest[ destIndex ] = color;
+					}
+					else if( count3 == 0x3F )
+					{
+						// case 5
+						int count = ReadWord( input );
+						int srcIndex = ReadWord( input );
+						if( srcIndex >= destIndex )
+							throw new NotImplementedException( string.Format( "srcIndex >= destIndex  {0}  {1}", srcIndex, destIndex ) );
+
+						for( int end = destIndex + count ; destIndex < end ; destIndex++ )
+							dest[ destIndex ] = dest[ srcIndex++ ];
+					}
+					else
+					{
+						// case 3
+						int count = count3 + 3;
+						int srcIndex = ReadWord( input );
+						if( srcIndex >= destIndex )
+							throw new NotImplementedException( string.Format( "srcIndex >= destIndex  {0}  {1}", srcIndex, destIndex ) );
+
+						for( int end = destIndex + count ; destIndex < end ; destIndex++ )
+							dest[ destIndex ] = dest[ srcIndex++ ];
+					}
+				}
+			}
+		}
+	}
+}