From 0f7fb19f88f2628ca4ed030975101de4b13420c2 Mon Sep 17 00:00:00 2001
From: morkt <muvluv.ru@gmail.com>
Date: Thu, 23 Nov 2017 18:24:21 +0400
Subject: [PATCH] (GRD): use common LzssStream class for decompression.

---
 ArcFormats/Silky/ImageGRD.cs | 136 ++++-------------------------------
 1 file changed, 14 insertions(+), 122 deletions(-)

diff --git a/ArcFormats/Silky/ImageGRD.cs b/ArcFormats/Silky/ImageGRD.cs
index a902cd2c..bc2251c2 100644
--- a/ArcFormats/Silky/ImageGRD.cs
+++ b/ArcFormats/Silky/ImageGRD.cs
@@ -2,7 +2,7 @@
 //! \date       Sun Apr 12 21:05:44 2015
 //! \brief      Silky's GRD image format.
 //
-// Copyright (C) 2015 by morkt
+// Copyright (C) 2015-2017 by morkt
 //
 // Permission is hereby granted, free of charge, to any person obtaining a copy
 // of this software and associated documentation files (the "Software"), to
@@ -24,27 +24,17 @@
 //
 
 using System;
-using System.Collections.Generic;
 using System.ComponentModel.Composition;
 using System.IO;
-using System.Text;
-using System.Windows;
-using System.Windows.Media;
-using System.Windows.Media.Imaging;
-using GameRes.Utility;
+using GameRes.Compression;
 
 namespace GameRes.Formats.Silky
 {
-    internal class GrdMetaData : ImageMetaData
-    {
-        public int DataSize;
-    }
-
     [Export(typeof(ImageFormat))]
     public class GrdFormat : ImageFormat
     {
         public override string         Tag { get { return "GRD"; } }
-        public override string Description { get { return "Silky's RGB image format"; } }
+        public override string Description { get { return "Silky's compressed bitmap format"; } }
         public override uint     Signature { get { return 0x5f504d43u; } } // 'CMP_'
 
         public override void Write (Stream file, ImageData image)
@@ -54,120 +44,22 @@ namespace GameRes.Formats.Silky
 
         public override ImageMetaData ReadMetaData (IBinaryStream stream)
         {
-            stream.Seek (4, SeekOrigin.Current);
-            int data_size = stream.ReadInt32();
-            stream.Seek (4, SeekOrigin.Current);
-            using (var reader = new Reader (stream.AsStream, 0x22)) // BMP header
-            {
-                reader.Unpack();
-                var bmp = reader.Data;
-                if (bmp[0] != 'B' || bmp[1] != 'M')
-                    return null;
-                int width = LittleEndian.ToInt32 (bmp, 0x12);
-                int height = LittleEndian.ToInt32 (bmp, 0x16);
-                int bpp = LittleEndian.ToInt16 (bmp, 0x1c);
-                return new GrdMetaData
-                {
-                    Width = (uint)width,
-                    Height = (uint)height,
-                    BPP = bpp,
-                    DataSize = data_size,
-                };
-            }
+            using (var bmp = DecompressStream (stream))
+                return Bmp.ReadMetaData (bmp);
         }
 
         public override ImageData Read (IBinaryStream stream, ImageMetaData info)
         {
-            var meta = (GrdMetaData)info;
+            using (var bmp = DecompressStream (stream))
+                return Bmp.Read (bmp, info);
+        }
+
+        internal IBinaryStream DecompressStream (IBinaryStream stream)
+        {
             stream.Position = 12;
-            using (var reader = new Reader (stream.AsStream, meta.DataSize))
-            {
-                reader.Unpack();
-                byte[] pixels = reader.Data;
-                using (var bmp = new MemoryStream (reader.Data))
-                {
-                    var decoder = new BmpBitmapDecoder (bmp,
-                        BitmapCreateOptions.None, BitmapCacheOption.OnLoad);
-                    BitmapSource frame = decoder.Frames[0];
-                    frame.Freeze();
-                    return new ImageData (frame, info);
-                }
-            }
+            var input = new LzssStream (stream.AsStream, LzssMode.Decompress, true);
+            input.Config.FrameFill = 0x20;
+            return new BinaryStream (input, stream.Name);
         }
     }
-
-    // custom LZSS reader
-    //
-    internal class Reader : IDisposable
-    {
-        Stream          m_input;
-        byte[]          m_output;
-
-        public byte[] Data { get { return m_output; } }
-
-        public Reader (Stream file, int dst_size)
-        {
-            m_input = file;
-            m_output = new byte[dst_size];
-        }
-
-        public void Unpack ()
-        {
-            var frame = new byte[0x1000];
-            int frame_pos = 0xfee;
-            for (int i = 0; i < frame_pos; ++i)
-                frame[i] = 32;
-            int ctl = 0;
-            int dst = 0;
-            while (dst < m_output.Length)
-            {
-                ctl >>= 1;
-                if (0 == (ctl & 0x100))
-                {
-                    int b = m_input.ReadByte();
-                    if (-1 == b)
-                        break;
-                    ctl = b | 0xff00;
-                }
-                if (0 != (ctl & 1))
-                {
-                    int b = m_input.ReadByte();
-                    if (-1 == b)
-                        break;
-                    m_output[dst++] = (byte)b;
-                    frame[frame_pos++] = (byte)b;
-                    frame_pos &= 0xfff;
-                }
-                else
-                {
-                    int lo = m_input.ReadByte();
-                    if (-1 == lo)
-                        break;
-                    int hi = m_input.ReadByte();
-                    if (-1 == hi)
-                        break;
-                    int offset = (hi & 0xF0) << 4 | lo;
-                    int count = (hi & 0xF) + 3;
-                    for (int i = 0; i < count && dst < m_output.Length; ++i)
-                    {
-                        byte b = frame[(offset + i) & 0xfff];
-                        m_output[dst++] = b;
-                        frame[frame_pos++] = b;
-                        frame_pos &= 0xfff;
-                    }
-                }
-            }
-        }
-
-        #region IDisposable Members
-        public void Dispose ()
-        {
-            if (null != m_input)
-            {
-                m_input = null;
-            }
-            GC.SuppressFinalize (this);
-        }
-        #endregion
-    }
 }