Read() public method

public Read ( BinaryReader reader ) : void
reader System.IO.BinaryReader
return void
Ejemplo n.º 1
0
        public void Load(Stream input)
        {
            BinaryReader reader = new BinaryReader(input);
            //
            // Read the DDS tag. If it's not right, then bail..
            //
            uint signature = reader.ReadUInt32();

            if (signature != HeaderValues.DdsSignature)
            {
                throw new FormatException("File does not appear to be a DDS image");
            }

            header = new DdsHeader();
            //
            // Read everything in.. for now assume it worked like a charm..
            //
            header.Read(reader);

            if ((header.PixelFormat.Flags & (int)PixelFormatFlags.FourCC) != 0)
            {
                SquishFlags squishFlags;

                switch (header.PixelFormat.FourCC)
                {
                case FourCCFormat.Dxt1: {
                    squishFlags = SquishFlags.Dxt1;

                    break;
                }

                case FourCCFormat.Dxt3: {
                    squishFlags = SquishFlags.Dxt3;

                    break;
                }

                case FourCCFormat.Dxt5: {
                    squishFlags = SquishFlags.Dxt5;

                    break;
                }

                default: {
                    throw new FormatException("File is not a supported DDS format");
                }
                }
                //
                // Compute size of compressed block area
                //
                int blockCount = (Width + 3) / 4 * ((Height + 3) / 4);
                int blockSize  = (squishFlags & SquishFlags.Dxt1) != 0 ? 8 : 16;
                //
                // Allocate room for compressed blocks, and read data into it.
                //
                byte[] compressedBlocks = new byte[blockCount * blockSize];

                input.Read(compressedBlocks, 0, compressedBlocks.GetLength(0));
                //
                // Now decompress..
                //
                largestMipMap = DdsSquish.DecompressImage(Width, Height, compressedBlocks, squishFlags, null);
            }
            else
            {
                //
                // We can only deal with the non-DXT formats we know about..  this is a bit of a mess..
                // Sorry..
                //
                FileFormat fileFormat = FileFormat.Unknown;

                if ((header.PixelFormat.Flags == (int)PixelFormatFlags.RGBA) && (header.PixelFormat.RgbBitCount == 32) &&
                    (header.PixelFormat.RBitMask == 0x00ff0000) && (header.PixelFormat.GBitMask == 0x0000ff00) &&
                    (header.PixelFormat.BBitMask == 0x000000ff) && (header.PixelFormat.ABitMask == 0xff000000))
                {
                    fileFormat = FileFormat.A8R8G8B8;
                }
                else if ((header.PixelFormat.Flags == (int)PixelFormatFlags.RGB) && (header.PixelFormat.RgbBitCount == 32) &&
                         (header.PixelFormat.RBitMask == 0x00ff0000) && (header.PixelFormat.GBitMask == 0x0000ff00) &&
                         (header.PixelFormat.BBitMask == 0x000000ff) && (header.PixelFormat.ABitMask == 0x00000000))
                {
                    fileFormat = FileFormat.X8R8G8B8;
                }
                else if ((header.PixelFormat.Flags == (int)PixelFormatFlags.RGBA) && (header.PixelFormat.RgbBitCount == 32) &&
                         (header.PixelFormat.RBitMask == 0x000000ff) && (header.PixelFormat.GBitMask == 0x0000ff00) &&
                         (header.PixelFormat.BBitMask == 0x00ff0000) && (header.PixelFormat.ABitMask == 0xff000000))
                {
                    fileFormat = FileFormat.A8B8G8R8;
                }
                else if ((header.PixelFormat.Flags == (int)PixelFormatFlags.RGB) && (header.PixelFormat.RgbBitCount == 32) &&
                         (header.PixelFormat.RBitMask == 0x000000ff) && (header.PixelFormat.GBitMask == 0x0000ff00) &&
                         (header.PixelFormat.BBitMask == 0x00ff0000) && (header.PixelFormat.ABitMask == 0x00000000))
                {
                    fileFormat = FileFormat.X8B8G8R8;
                }
                else if ((header.PixelFormat.Flags == (int)PixelFormatFlags.RGBA) && (header.PixelFormat.RgbBitCount == 16) &&
                         (header.PixelFormat.RBitMask == 0x00007c00) && (header.PixelFormat.GBitMask == 0x000003e0) &&
                         (header.PixelFormat.BBitMask == 0x0000001f) && (header.PixelFormat.ABitMask == 0x00008000))
                {
                    fileFormat = FileFormat.A1R5G5B5;
                }
                else if ((header.PixelFormat.Flags == (int)PixelFormatFlags.RGBA) && (header.PixelFormat.RgbBitCount == 16) &&
                         (header.PixelFormat.RBitMask == 0x00000f00) && (header.PixelFormat.GBitMask == 0x000000f0) &&
                         (header.PixelFormat.BBitMask == 0x0000000f) && (header.PixelFormat.ABitMask == 0x0000f000))
                {
                    fileFormat = FileFormat.A4R4G4B4;
                }
                else if ((header.PixelFormat.Flags == (int)PixelFormatFlags.RGB) && (header.PixelFormat.RgbBitCount == 24) &&
                         (header.PixelFormat.RBitMask == 0x00ff0000) && (header.PixelFormat.GBitMask == 0x0000ff00) &&
                         (header.PixelFormat.BBitMask == 0x000000ff) && (header.PixelFormat.ABitMask == 0x00000000))
                {
                    fileFormat = FileFormat.R8G8B8;
                }
                else if ((header.PixelFormat.Flags == (int)PixelFormatFlags.RGB) && (header.PixelFormat.RgbBitCount == 16) &&
                         (header.PixelFormat.RBitMask == 0x0000f800) && (header.PixelFormat.GBitMask == 0x000007e0) &&
                         (header.PixelFormat.BBitMask == 0x0000001f) && (header.PixelFormat.ABitMask == 0x00000000))
                {
                    fileFormat = FileFormat.R5G6B5;
                }
                else if ((header.PixelFormat.Flags == (int)PixelFormatFlags.Gray) && (header.PixelFormat.RgbBitCount == 8) &&
                         (header.PixelFormat.RBitMask == 0x000000ff) && (header.PixelFormat.GBitMask == 0x00000000) &&
                         (header.PixelFormat.BBitMask == 0x00000000) && (header.PixelFormat.ABitMask == 0x00000000))
                {
                    fileFormat = FileFormat.G8;
                }
                //
                // If fileFormat is still invalid, then it's an unsupported format.
                //
                if (fileFormat == FileFormat.Unknown)
                {
                    throw new FormatException("File is not a supported DDS format");
                }
                //
                // Size of a source pixel, in bytes
                //
                int srcPixelSize = ((int)header.PixelFormat.RgbBitCount / 8);
                //
                // We need the pitch for a row, so we can allocate enough memory for the load.
                //
                int rowPitch;

                if ((header.HeaderFlags & (int)HeaderFlags.Pitch) != 0)
                {
                    //
                    // Pitch specified.. so we can use directly
                    //
                    rowPitch = (int)header.PitchOrLinearSize;
                }
                else if ((header.HeaderFlags & (int)HeaderFlags.LinearSize) != 0)
                {
                    //
                    // Linear size specified.. compute row pitch. Of course, this should never happen
                    // as linear size is *supposed* to be for compressed textures. But Microsoft don't
                    // always play by the rules when it comes to DDS output.
                    //
                    rowPitch = (int)header.PitchOrLinearSize / (int)header.Height;
                }
                else
                {
                    //
                    // Another case of Microsoft not obeying their standard is the 'Convert to..' shell extension
                    // that ships in the DirectX SDK. Seems to always leave flags empty..so no indication of pitch
                    // or linear size. And - to cap it all off - they leave pitchOrLinearSize as *zero*. Zero??? If
                    // we get this bizarre set of inputs, we just go 'screw it' and compute row pitch ourselves.
                    //
                    rowPitch = (int)header.Width * srcPixelSize;
                }
                //
                // Ok.. now, we need to allocate room for the bytes to read in from.. it's rowPitch bytes * height
                //
                byte[] readPixelData = new byte[rowPitch * header.Height];

                input.Read(readPixelData, 0, readPixelData.GetLength(0));
                //
                // We now need space for the real pixel data.. that's width * height * 4..
                //
                largestMipMap = new byte[header.Width * header.Height * 4];
                //
                // And now we have the arduous task of filling that up with stuff..
                //
                for (int destY = 0; destY < (int)header.Height; destY++)
                {
                    for (int destX = 0; destX < (int)header.Width; destX++)
                    {
                        //
                        // Compute source pixel offset
                        //
                        int srcPixelOffset = destY * rowPitch + destX * srcPixelSize;
                        //
                        // Read our pixel
                        //
                        uint pixelColour = 0;
                        uint pixelRed    = 0;
                        uint pixelGreen  = 0;
                        uint pixelBlue   = 0;
                        uint pixelAlpha  = 0;
                        //
                        // Build our pixel colour as a DWORD
                        //
                        for (int loop = 0; loop < srcPixelSize; loop++)
                        {
                            pixelColour |= (uint)(readPixelData[srcPixelOffset + loop] << (8 * loop));
                        }

                        switch (fileFormat)
                        {
                        case FileFormat.A8R8G8B8: {
                            pixelAlpha = (pixelColour >> 24) & 0xff;
                            pixelRed   = (pixelColour >> 16) & 0xff;
                            pixelGreen = (pixelColour >> 8) & 0xff;
                            pixelBlue  = (pixelColour >> 0) & 0xff;

                            break;
                        }

                        case FileFormat.X8R8G8B8: {
                            pixelAlpha = 0xff;

                            pixelRed   = (pixelColour >> 16) & 0xff;
                            pixelGreen = (pixelColour >> 8) & 0xff;
                            pixelBlue  = (pixelColour >> 0) & 0xff;

                            break;
                        }

                        case FileFormat.A8B8G8R8: {
                            pixelAlpha = (pixelColour >> 24) & 0xff;
                            pixelRed   = (pixelColour >> 0) & 0xff;
                            pixelGreen = (pixelColour >> 8) & 0xff;
                            pixelBlue  = (pixelColour >> 16) & 0xff;

                            break;
                        }

                        case FileFormat.X8B8G8R8: {
                            pixelAlpha = 0xff;

                            pixelRed   = (pixelColour >> 0) & 0xff;
                            pixelGreen = (pixelColour >> 8) & 0xff;
                            pixelBlue  = (pixelColour >> 16) & 0xff;

                            break;
                        }

                        case FileFormat.A1R5G5B5: {
                            pixelAlpha = (pixelColour >> 15) & 0xff;
                            pixelRed   = (pixelColour >> 10) & 0x1f;
                            pixelGreen = (pixelColour >> 5) & 0x1f;
                            pixelBlue  = (pixelColour >> 0) & 0x1f;

                            pixelRed   = (pixelRed << 3) | (pixelRed >> 2);
                            pixelGreen = (pixelGreen << 3) | (pixelGreen >> 2);
                            pixelBlue  = (pixelBlue << 3) | (pixelBlue >> 2);

                            break;
                        }

                        case FileFormat.A4R4G4B4: {
                            pixelAlpha = (pixelColour >> 12) & 0xff;
                            pixelRed   = (pixelColour >> 8) & 0x0f;
                            pixelGreen = (pixelColour >> 4) & 0x0f;
                            pixelBlue  = (pixelColour >> 0) & 0x0f;

                            pixelAlpha = (pixelAlpha << 4) | (pixelAlpha >> 0);
                            pixelRed   = (pixelRed << 4) | (pixelRed >> 0);
                            pixelGreen = (pixelGreen << 4) | (pixelGreen >> 0);
                            pixelBlue  = (pixelBlue << 4) | (pixelBlue >> 0);

                            break;
                        }

                        case FileFormat.R8G8B8: {
                            pixelAlpha = 0xff;

                            pixelRed   = (pixelColour >> 16) & 0xff;
                            pixelGreen = (pixelColour >> 8) & 0xff;
                            pixelBlue  = (pixelColour >> 0) & 0xff;

                            break;
                        }

                        case FileFormat.R5G6B5: {
                            pixelAlpha = 0xff;

                            pixelRed   = (pixelColour >> 11) & 0x1f;
                            pixelGreen = (pixelColour >> 5) & 0x3f;
                            pixelBlue  = (pixelColour >> 0) & 0x1f;

                            pixelRed   = (pixelRed << 3) | (pixelRed >> 2);
                            pixelGreen = (pixelGreen << 2) | (pixelGreen >> 4);
                            pixelBlue  = (pixelBlue << 3) | (pixelBlue >> 2);

                            break;
                        }

                        case FileFormat.G8: {
                            pixelAlpha = 0xff;

                            pixelRed = pixelGreen = pixelBlue = pixelColour & 0xff;

                            break;
                        }
                        }
                        //
                        // Write the colours away..
                        //
                        int destPixelOffset = destY * (int)header.Width * 4 + destX * 4;

                        largestMipMap[destPixelOffset + 0] = (byte)pixelRed;
                        largestMipMap[destPixelOffset + 1] = (byte)pixelGreen;
                        largestMipMap[destPixelOffset + 2] = (byte)pixelBlue;
                        largestMipMap[destPixelOffset + 3] = (byte)pixelAlpha;
                    }
                }
            }

            MipMaps = new List <DdsMipMap> {
                new DdsMipMap(Width, Height, largestMipMap)
            };
        }
Ejemplo n.º 2
0
    public void Load(Stream input) {
      BinaryReader reader = new BinaryReader(input);
      //
      // Read the DDS tag. If it's not right, then bail..
      //
      uint signature = reader.ReadUInt32();

      if (signature != HeaderValues.DdsSignature) throw new FormatException("File does not appear to be a DDS image");

      header = new DdsHeader();
      //
      // Read everything in.. for now assume it worked like a charm..
      //
      header.Read(reader);

      if ((header.PixelFormat.Flags & (int)PixelFormatFlags.FourCC) != 0) {
        SquishFlags squishFlags;

        switch(header.PixelFormat.FourCC) {
          case FourCCFormat.Dxt1: {
            squishFlags = SquishFlags.Dxt1;

            break;
          }
          case FourCCFormat.Dxt3: {
            squishFlags = SquishFlags.Dxt3;

            break;
          }

          case FourCCFormat.Dxt5: {
            squishFlags = SquishFlags.Dxt5;

            break;
          }
          default: {
            throw new FormatException("File is not a supported DDS format");
          }
        }
        //
        // Compute size of compressed block area
        //
        int blockCount = (Width + 3) / 4 * ((Height + 3) / 4);
        int blockSize  = (squishFlags & SquishFlags.Dxt1) != 0 ? 8 : 16;
        //
        // Allocate room for compressed blocks, and read data into it.
        //
        byte[] compressedBlocks = new byte[blockCount * blockSize];

        input.Read(compressedBlocks, 0, compressedBlocks.GetLength(0));
        //
        // Now decompress..
        //
        largestMipMap = DdsSquish.DecompressImage(Width, Height, compressedBlocks, squishFlags, null);
      }
      else {
        //
        // We can only deal with the non-DXT formats we know about..  this is a bit of a mess..
        // Sorry..
        //
        FileFormat fileFormat = FileFormat.Unknown;

        if ((header.PixelFormat.Flags == (int)PixelFormatFlags.RGBA) && (header.PixelFormat.RgbBitCount == 32) &&
            (header.PixelFormat.RBitMask == 0x00ff0000) && (header.PixelFormat.GBitMask == 0x0000ff00) &&
            (header.PixelFormat.BBitMask == 0x000000ff) && (header.PixelFormat.ABitMask == 0xff000000)) fileFormat = FileFormat.A8R8G8B8;
        else if ((header.PixelFormat.Flags == (int)PixelFormatFlags.RGB) && (header.PixelFormat.RgbBitCount == 32) &&
                 (header.PixelFormat.RBitMask == 0x00ff0000) && (header.PixelFormat.GBitMask == 0x0000ff00) &&
                 (header.PixelFormat.BBitMask == 0x000000ff) && (header.PixelFormat.ABitMask == 0x00000000)) fileFormat = FileFormat.X8R8G8B8;
        else if ((header.PixelFormat.Flags == (int)PixelFormatFlags.RGBA) && (header.PixelFormat.RgbBitCount == 32) &&
                 (header.PixelFormat.RBitMask == 0x000000ff) && (header.PixelFormat.GBitMask == 0x0000ff00) &&
                 (header.PixelFormat.BBitMask == 0x00ff0000) && (header.PixelFormat.ABitMask == 0xff000000)) fileFormat = FileFormat.A8B8G8R8;
        else if ((header.PixelFormat.Flags == (int)PixelFormatFlags.RGB) && (header.PixelFormat.RgbBitCount == 32) &&
                 (header.PixelFormat.RBitMask == 0x000000ff) && (header.PixelFormat.GBitMask == 0x0000ff00) &&
                 (header.PixelFormat.BBitMask == 0x00ff0000) && (header.PixelFormat.ABitMask == 0x00000000)) fileFormat = FileFormat.X8B8G8R8;
        else if ((header.PixelFormat.Flags == (int)PixelFormatFlags.RGBA) && (header.PixelFormat.RgbBitCount == 16) &&
                 (header.PixelFormat.RBitMask == 0x00007c00) && (header.PixelFormat.GBitMask == 0x000003e0) &&
                 (header.PixelFormat.BBitMask == 0x0000001f) && (header.PixelFormat.ABitMask == 0x00008000)) fileFormat = FileFormat.A1R5G5B5;
        else if ((header.PixelFormat.Flags == (int)PixelFormatFlags.RGBA) && (header.PixelFormat.RgbBitCount == 16) &&
                 (header.PixelFormat.RBitMask == 0x00000f00) && (header.PixelFormat.GBitMask == 0x000000f0) &&
                 (header.PixelFormat.BBitMask == 0x0000000f) && (header.PixelFormat.ABitMask == 0x0000f000)) fileFormat = FileFormat.A4R4G4B4;
        else if ((header.PixelFormat.Flags == (int)PixelFormatFlags.RGB) && (header.PixelFormat.RgbBitCount == 24) &&
                 (header.PixelFormat.RBitMask == 0x00ff0000) && (header.PixelFormat.GBitMask == 0x0000ff00) &&
                 (header.PixelFormat.BBitMask == 0x000000ff) && (header.PixelFormat.ABitMask == 0x00000000)) fileFormat = FileFormat.R8G8B8;
        else if ((header.PixelFormat.Flags == (int)PixelFormatFlags.RGB) && (header.PixelFormat.RgbBitCount == 16) &&
                 (header.PixelFormat.RBitMask == 0x0000f800) && (header.PixelFormat.GBitMask == 0x000007e0) &&
                 (header.PixelFormat.BBitMask == 0x0000001f) && (header.PixelFormat.ABitMask == 0x00000000)) fileFormat = FileFormat.R5G6B5;
        else if ((header.PixelFormat.Flags == (int)PixelFormatFlags.Gray) && (header.PixelFormat.RgbBitCount == 8) &&
                 (header.PixelFormat.RBitMask == 0x000000ff) && (header.PixelFormat.GBitMask == 0x00000000) &&
                 (header.PixelFormat.BBitMask == 0x00000000) && (header.PixelFormat.ABitMask == 0x00000000)) fileFormat = FileFormat.G8;
        //
        // If fileFormat is still invalid, then it's an unsupported format.
        //
        if (fileFormat == FileFormat.Unknown) throw new FormatException("File is not a supported DDS format");
        //
        // Size of a source pixel, in bytes
        //
        int srcPixelSize = ((int)header.PixelFormat.RgbBitCount / 8);
        //
        // We need the pitch for a row, so we can allocate enough memory for the load.
        //
        int rowPitch;

        if ((header.HeaderFlags & (int)HeaderFlags.Pitch) != 0) {
          //
          // Pitch specified.. so we can use directly
          //
          rowPitch = (int)header.PitchOrLinearSize;
        }
        else if ((header.HeaderFlags & (int)HeaderFlags.LinearSize) != 0) {
          //
          // Linear size specified.. compute row pitch. Of course, this should never happen
          // as linear size is *supposed* to be for compressed textures. But Microsoft don't
          // always play by the rules when it comes to DDS output.
          //
          rowPitch = (int)header.PitchOrLinearSize / (int)header.Height;
        }
        else {
          //
          // Another case of Microsoft not obeying their standard is the 'Convert to..' shell extension
          // that ships in the DirectX SDK. Seems to always leave flags empty..so no indication of pitch
          // or linear size. And - to cap it all off - they leave pitchOrLinearSize as *zero*. Zero??? If
          // we get this bizarre set of inputs, we just go 'screw it' and compute row pitch ourselves.
          //
          rowPitch = (int)header.Width * srcPixelSize;
        }
        //
        // Ok.. now, we need to allocate room for the bytes to read in from.. it's rowPitch bytes * height
        //
        byte[] readPixelData = new byte[rowPitch * header.Height];

        input.Read(readPixelData, 0, readPixelData.GetLength(0));
        //
        // We now need space for the real pixel data.. that's width * height * 4..
        //
        largestMipMap = new byte[header.Width * header.Height * 4];
        //
        // And now we have the arduous task of filling that up with stuff..
        //
        for(int destY = 0; destY < (int)header.Height; destY++) {
          for(int destX = 0; destX < (int)header.Width; destX++) {
            //
            // Compute source pixel offset
            //
            int srcPixelOffset = destY * rowPitch + destX * srcPixelSize;
            //
            // Read our pixel
            //
            uint pixelColour = 0;
            uint pixelRed    = 0;
            uint pixelGreen  = 0;
            uint pixelBlue   = 0;
            uint pixelAlpha  = 0;
            //
            // Build our pixel colour as a DWORD
            //
            for(int loop = 0; loop < srcPixelSize; loop++) pixelColour |= (uint)(readPixelData[srcPixelOffset + loop] << (8 * loop));

            switch(fileFormat) {
              case FileFormat.A8R8G8B8: {
                pixelAlpha = (pixelColour >> 24) & 0xff;
                pixelRed   = (pixelColour >> 16) & 0xff;
                pixelGreen = (pixelColour >> 8)  & 0xff;
                pixelBlue  = (pixelColour >> 0)  & 0xff;

                break;
              }
              case FileFormat.X8R8G8B8: {
                pixelAlpha = 0xff;

                pixelRed   = (pixelColour >> 16) & 0xff;
                pixelGreen = (pixelColour >> 8)  & 0xff;
                pixelBlue  = (pixelColour >> 0)  & 0xff;

                break;
              }
              case FileFormat.A8B8G8R8: {
                pixelAlpha = (pixelColour >> 24) & 0xff;
                pixelRed   = (pixelColour >> 0)  & 0xff;
                pixelGreen = (pixelColour >> 8)  & 0xff;
                pixelBlue  = (pixelColour >> 16) & 0xff;

                break;
              }
              case FileFormat.X8B8G8R8: {
                pixelAlpha = 0xff;

                pixelRed   = (pixelColour >> 0)  & 0xff;
                pixelGreen = (pixelColour >> 8)  & 0xff;
                pixelBlue  = (pixelColour >> 16) & 0xff;

                break;
              }
              case FileFormat.A1R5G5B5: {
                pixelAlpha = (pixelColour >> 15) & 0xff;
                pixelRed   = (pixelColour >> 10) & 0x1f;
                pixelGreen = (pixelColour >> 5)  & 0x1f;
                pixelBlue  = (pixelColour >> 0)  & 0x1f;

                pixelRed   = (pixelRed   << 3) | (pixelRed   >> 2);
                pixelGreen = (pixelGreen << 3) | (pixelGreen >> 2);
                pixelBlue  = (pixelBlue  << 3) | (pixelBlue  >> 2);

                break;
              }
              case FileFormat.A4R4G4B4: {
                pixelAlpha = (pixelColour >> 12) & 0xff;
                pixelRed   = (pixelColour >> 8)  & 0x0f;
                pixelGreen = (pixelColour >> 4)  & 0x0f;
                pixelBlue  = (pixelColour >> 0)  & 0x0f;

                pixelAlpha = (pixelAlpha << 4) | (pixelAlpha >> 0);
                pixelRed   = (pixelRed   << 4) | (pixelRed   >> 0);
                pixelGreen = (pixelGreen << 4) | (pixelGreen >> 0);
                pixelBlue  = (pixelBlue  << 4) | (pixelBlue  >> 0);

                break;
              }
              case FileFormat.R8G8B8: {
                pixelAlpha = 0xff;

                pixelRed   = (pixelColour >> 16) & 0xff;
                pixelGreen = (pixelColour >> 8)  & 0xff;
                pixelBlue  = (pixelColour >> 0)  & 0xff;

                break;
              }
              case FileFormat.R5G6B5: {
                pixelAlpha = 0xff;

                pixelRed   = (pixelColour >> 11) & 0x1f;
                pixelGreen = (pixelColour >> 5)  & 0x3f;
                pixelBlue  = (pixelColour >> 0)  & 0x1f;

                pixelRed   = (pixelRed   << 3) | (pixelRed   >> 2);
                pixelGreen = (pixelGreen << 2) | (pixelGreen >> 4);
                pixelBlue  = (pixelBlue  << 3) | (pixelBlue  >> 2);

                break;
              }
              case FileFormat.G8: {
                pixelAlpha = 0xff;

                pixelRed = pixelGreen = pixelBlue = pixelColour & 0xff;

                break;
              }
            }
            //
            // Write the colours away..
            //
            int destPixelOffset = destY * (int)header.Width * 4 + destX * 4;

            largestMipMap[destPixelOffset + 0] = (byte)pixelRed;
            largestMipMap[destPixelOffset + 1] = (byte)pixelGreen;
            largestMipMap[destPixelOffset + 2] = (byte)pixelBlue;
            largestMipMap[destPixelOffset + 3] = (byte)pixelAlpha;
          }
        }
      }

      MipMaps = new List<DdsMipMap> { new DdsMipMap(Width, Height, largestMipMap) };
    }