From 913d6e6817045e1e9b843b4a7ff7f549da4ed68e Mon Sep 17 00:00:00 2001
From: morkt <muvluv.ru@gmail.com>
Date: Sun, 31 Dec 2017 09:04:16 +0400
Subject: [PATCH] (BET): recognize non-compressed images.

---
 Legacy/System21/ImageBET.cs | 100 ++++++++++++++++++++++--------------
 1 file changed, 61 insertions(+), 39 deletions(-)

diff --git a/Legacy/System21/ImageBET.cs b/Legacy/System21/ImageBET.cs
index dae9015a..ae988f9c 100644
--- a/Legacy/System21/ImageBET.cs
+++ b/Legacy/System21/ImageBET.cs
@@ -23,6 +23,7 @@
 // IN THE SOFTWARE.
 //
 
+using System;
 using System.ComponentModel.Composition;
 using System.IO;
 using System.Windows.Media;
@@ -35,53 +36,36 @@ namespace GameRes.Formats.System21
     public class BetFormat : ImageFormat
     {
         public override string         Tag { get { return "BET"; } }
-        public override string Description { get { return "System21 compressed image format"; } }
-        public override uint     Signature { get { return 0x44445A53; } } // 'SZDD'
+        public override string Description { get { return "System21 image format"; } }
+        public override uint     Signature { get { return 0; } }
 
         public override ImageMetaData ReadMetaData (IBinaryStream file)
         {
             if (!file.Name.HasExtension (".bet"))
                 return null;
-            using (var lz = OpenLzStream (file.AsStream))
-            using (var input = new BinaryStream (lz, file.Name))
-            {
-                uint w = input.ReadUInt32();
-                uint h = input.ReadUInt32();
-                int bpp = input.ReadUInt16();
-                if ((bpp != 24 && bpp != 8) || 0 == w || w > 0x8000 || 0 == h || h > 0x8000)
-                    return null;
-                return new ImageMetaData { Width = w, Height = h, BPP = bpp };
-            }
+            uint w = file.ReadUInt32();
+            uint h = file.ReadUInt32();
+            int bpp = file.ReadUInt16();
+            if ((bpp != 24 && bpp != 8) || 0 == w || w > 0x8000 || 0 == h || h > 0x8000)
+                return null;
+            return new ImageMetaData { Width = w, Height = h, BPP = bpp };
         }
 
-        public override ImageData Read (IBinaryStream file, ImageMetaData info)
+        public override ImageData Read (IBinaryStream input, ImageMetaData info)
         {
-            using (var input = OpenLzStream (file.AsStream))
-            {
-                int stride = (int)info.Width * info.BPP / 8;
-                var pixels = new byte[stride * (int)info.Height];
-                for (int i = 0; i < 10; ++i)
-                    input.ReadByte();
-                BitmapPalette palette = null;
-                if (8 == info.BPP)
-                    palette = ReadPalette (input);
-                if (input.Read (pixels, 0, pixels.Length) != pixels.Length)
-                    throw new InvalidFormatException();
-                for (int i = 0; i < pixels.Length; ++i)
-                    pixels[i] ^= 0xFF;
-                PixelFormat format = 8 == info.BPP ? PixelFormats.Indexed8 : PixelFormats.Bgr24;
-                return ImageData.CreateFlipped (info, format, palette, pixels, stride);
-            }
-        }
-
-        Stream OpenLzStream (Stream input)
-        {
-            input.Position = 0xE;
-            var lz = new LzssStream (input, LzssMode.Decompress, true);
-            lz.Config.FrameSize = 0x1000;
-            lz.Config.FrameFill = 0x20;
-            lz.Config.FrameInitPos = 0x1000 - 0x10;
-            return lz;
+            int stride = (int)info.Width * info.BPP / 8;
+            int bitmap_length = stride * (int)info.Height;
+            var pixels = new byte[Math.Max (bitmap_length, 10)];
+            input.Read (pixels, 0, 10); // input might be non-seekable
+            BitmapPalette palette = null;
+            if (8 == info.BPP)
+                palette = ReadPalette (input.AsStream);
+            if (input.Read (pixels, 0, bitmap_length) != bitmap_length)
+                throw new InvalidFormatException();
+            for (int i = 0; i < bitmap_length; ++i)
+                pixels[i] ^= 0xFF;
+            PixelFormat format = 8 == info.BPP ? PixelFormats.Indexed8 : PixelFormats.Bgr24;
+            return ImageData.CreateFlipped (info, format, palette, pixels, stride);
         }
 
         public override void Write (Stream file, ImageData image)
@@ -89,4 +73,42 @@ namespace GameRes.Formats.System21
             throw new System.NotImplementedException ("BetFormat.Write not implemented");
         }
     }
+
+    [Export(typeof(ImageFormat))]
+    public class LzBetFormat : BetFormat
+    {
+        public override string         Tag { get { return "BET/SZDD"; } }
+        public override string Description { get { return "System21 compressed image format"; } }
+        public override uint     Signature { get { return 0x44445A53; } } // 'SZDD'
+        public override bool      CanWrite { get { return false; } }
+
+        public override ImageMetaData ReadMetaData (IBinaryStream file)
+        {
+            if (!file.Name.HasExtension (".bet"))
+                return null;
+            using (var input = OpenLzStream (file))
+                return base.ReadMetaData (input);
+        }
+
+        public override ImageData Read (IBinaryStream file, ImageMetaData info)
+        {
+            using (var input = OpenLzStream (file))
+                return base.Read (input, info);
+        }
+
+        IBinaryStream OpenLzStream (IBinaryStream input)
+        {
+            input.Position = 0xE;
+            var lz = new LzssStream (input.AsStream, LzssMode.Decompress, true);
+            lz.Config.FrameSize = 0x1000;
+            lz.Config.FrameFill = 0x20;
+            lz.Config.FrameInitPos = 0x1000 - 0x10;
+            return new BinaryStream (lz, input.Name); // XXX stream is unseekable
+        }
+
+        public override void Write (Stream file, ImageData image)
+        {
+            throw new System.NotImplementedException ("LzBetFormat.Write not implemented");
+        }
+    }
 }