(DDS): DXT5 compression.

ArcFormats/ArcFormats.csproj

@@ -99,6 +99,7 @@
     <Compile Include="Cadath\ImageCGF.cs" />
     <Compile Include="Crowd\ImageCRZ.cs" />
     <Compile Include="Cyberworks\ArcApp.cs" />
+    <Compile Include="DirectDraw\DxtDecoder.cs" />
     <Compile Include="ExHibit\ArcGRP.cs" />
     <Compile Include="Foster\ArcC24.cs" />
     <Compile Include="Foster\ArcFA2.cs" />

ArcFormats/DirectDraw/DxtDecoder.cs

@@ -0,0 +1,150 @@
+//! \file       DxtDecoder.cs
+//! \date       Fri Apr 14 07:34:50 2017
+//! \brief      DXT decompressor.
+//
+// Copyright (C) 2016 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
+// deal in the Software without restriction, including without limitation the
+// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+// sell copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+// IN THE SOFTWARE.
+//
+
+using GameRes.Utility;
+
+namespace GameRes.Formats.DirectDraw
+{
+    public class DxtDecoder
+    {
+        byte[]      m_input;
+        byte[]      m_output;
+        int         m_width;
+        int         m_height;
+        int         m_output_stride;
+
+        public DxtDecoder (byte[] input, ImageMetaData info)
+        {
+            m_input = input;
+            m_width = (int)info.Width;
+            m_output_stride = m_width * 4;
+            m_height = (int)info.Height;
+            m_output = new byte[m_output_stride*m_height];
+        }
+
+        public byte[] UnpackDXT5 ()
+        {
+            int src = 0;
+            for (int y = 0; y < m_height; y += 4)
+            for (int x = 0; x < m_width; x += 4)
+            {
+                DecompressDXT5Block (m_input, src, y, x);
+                src += 16;
+            }
+            return m_output;
+        }
+
+        byte[] m_dxt5_alpha = new byte[16];
+
+        void DecompressDXT5Block (byte[] input, int src, int block_y, int block_x)
+        {
+            byte alpha0 = input[src];
+            byte alpha1 = input[src+1];
+
+            DecompressDXT5Alpha (input, src+2, m_dxt5_alpha);
+
+            ushort color0 = LittleEndian.ToUInt16 (input, src+8);
+            ushort color1 = LittleEndian.ToUInt16 (input, src+10);
+
+            int t = (color0 >> 11) * 255 + 16;
+            byte r0 = (byte)((t / 32 + t) / 32);
+            t = ((color0 & 0x07E0) >> 5) * 255 + 32;
+            byte g0 = (byte)((t / 64 + t) / 64);
+            t = (color0 & 0x001F) * 255 + 16;
+            byte b0 = (byte)((t / 32 + t) / 32);
+
+            t = (color1 >> 11) * 255 + 16;
+            byte r1 = (byte)((t / 32 + t) / 32);
+            t = ((color1 & 0x07E0) >> 5) * 255 + 32;
+            byte g1 = (byte)((t / 64 + t) / 64);
+            t = (color1 & 0x001F) * 255 + 16;
+            byte b1 = (byte)((t / 32 + t) / 32);
+
+            uint code = LittleEndian.ToUInt32 (input, src+12);
+
+            for (int y = 0; y < 4 && (block_y + y) < m_height; ++y)
+            for (int x = 0; x < 4 && (block_x + x) < m_width; ++x)
+            {
+                int alpha_code = m_dxt5_alpha[4 * y + x];
+                byte alpha;
+                if (0 == alpha_code)
+                    alpha = alpha0;
+                else if (1 == alpha_code)
+                    alpha = alpha1;
+                else if (alpha0 > alpha1)
+                    alpha = (byte)(((8 - alpha_code) * alpha0 + (alpha_code - 1) * alpha1) / 7);
+                else if (6 == alpha_code)
+                    alpha = 0;
+                else if (7 == alpha_code)
+                    alpha = 0xFF;
+                else
+                    alpha = (byte)(((6 - alpha_code) * alpha0 + (alpha_code - 1) * alpha1) / 5);
+
+                int dst = m_output_stride * (block_y + y) + (block_x + x) * 4;
+                switch (code & 3)
+                {
+                case 0:
+                    PutPixel (dst, r0, g0, b0, alpha);
+                    break;
+                case 1:
+                    PutPixel (dst, r1, g1, b1, alpha);
+                    break;
+                case 2:
+                    PutPixel (dst, (byte)((2 * r0 + r1) / 3), (byte)((2 * g0 + g1) / 3), (byte)((2 * b0 + b1) / 3), alpha);
+                    break;
+                case 3:
+                    PutPixel (dst, (byte)((r0 + 2 * r1) / 3), (byte)((g0 + 2 * g1) / 3), (byte)((b0 + 2 * b1) / 3), alpha);
+                    break;
+                }
+                code >>= 2;
+            }
+        }
+
+        static void DecompressDXT5Alpha (byte[] input, int src, byte[] output)
+        {
+            int dst = 0;
+            for (int j = 0; j < 2; ++j)
+            {
+                int block = input[src++];
+                block |= input[src++] << 8;
+                block |= input[src++] << 16;
+
+                for (int i = 0; i < 8; ++i)
+                {
+                    output[dst++] = (byte)(block & 7);
+                    block >>= 3;
+                }
+            }
+        }
+
+        void PutPixel (int dst, byte r, byte g, byte b, byte a)
+        {
+            m_output[dst]   = b;
+            m_output[dst+1] = g;
+            m_output[dst+2] = r;
+            m_output[dst+3] = a;
+        }
+    }
+}

ArcFormats/DirectDraw/ImageDDS.cs

@@ -30,7 +30,7 @@ using System.Text;
 using System.Windows.Media;
 using GameRes.Utility;
 
-namespace GameRes.Formats.Microsoft
+namespace GameRes.Formats.DirectDraw
 {
     internal class DdsMetaData : ImageMetaData
     {
@@ -91,17 +91,29 @@ namespace GameRes.Formats.Microsoft
             var meta = (DdsMetaData)info;
             if (meta.PixelFlags.HasFlag (DdsPF.Yuv | DdsPF.Luminance))
                 throw new NotSupportedException ("Not supported DDS texture color format");
-            if (!string.IsNullOrEmpty (meta.FourCC))
+            byte[] pixels;
-                throw new NotImplementedException ("Compressed DDS textures not implemented");
-            if (meta.PixelFlags.HasFlag (DdsPF.Rgb)
-                && (0 == meta.RBitMask || 0 == meta.GBitMask || 0 == meta.BBitMask))
-                throw new InvalidFormatException();
-            var pixels = ReadPixelData (stream.AsStream, meta);
             PixelFormat format;
-            if (meta.PixelFlags.HasFlag (DdsPF.AlphaPixels) && meta.ABitMask != 0)
+            if (string.IsNullOrEmpty (meta.FourCC))
+            {
+                if (meta.PixelFlags.HasFlag (DdsPF.Rgb)
+                    && (0 == meta.RBitMask || 0 == meta.GBitMask || 0 == meta.BBitMask))
+                    throw new InvalidFormatException();
+                pixels = ReadPixelData (stream.AsStream, meta);
+                if (meta.PixelFlags.HasFlag (DdsPF.AlphaPixels) && meta.ABitMask != 0)
+                    format = PixelFormats.Bgra32;
+                else
+                    format = PixelFormats.Bgr32;
+            }
+            else if ("DXT5" == meta.FourCC)
+            {
+                stream.Position = meta.DataOffset;
+                var input = stream.ReadBytes ((int)meta.Width * (int)meta.Height);
+                var dxt = new DxtDecoder (input, meta);
+                pixels = dxt.UnpackDXT5();
                 format = PixelFormats.Bgra32;
+            }
             else
-                format = PixelFormats.Bgr32;
+                throw new NotImplementedException ("Compressed DDS textures not implemented");
             return ImageData.Create (info, format, null, pixels);
         }