private static SurfaceInfo GetSurfaceInfo(uint width, uint height, DdsImageFormat format, DdsHeader header)
{
uint rowBytes = 0;
switch (format)
{
case DdsImageFormat.Rg8SNorm:
rowBytes = (width * 16 + 7) / 8; // round up to nearest byte
break;
case DdsImageFormat.Rgba8:
rowBytes = width * (header.PixelFormat.RgbBitCount / 8);
break;
case DdsImageFormat.Rgba16Float:
rowBytes = width * 4;
break;
}
if (rowBytes > 0)
{
return(new SurfaceInfo
{
RowBytes = rowBytes,
NumRows = height,
NumBytes = rowBytes * height
});
}
uint blockSize;
switch (format)
{
case DdsImageFormat.Bc1:
blockSize = 8;
break;
case DdsImageFormat.Bc2:
case DdsImageFormat.Bc3:
blockSize = 16;
break;
default:
throw new ArgumentOutOfRangeException();
}
var numBlocksWide = width / 4;
var numBlocksHigh = height / 4;
return(new SurfaceInfo
{
RowBytes = numBlocksWide * blockSize,
NumRows = numBlocksHigh,
NumBytes = numBlocksWide * blockSize * numBlocksHigh
});
}
public static DdsFile FromStream(Stream stream)
{
using (var reader = new BinaryReader(stream, Encoding.ASCII, true))
{
var magic = reader.ReadFourCc();
if (magic != "DDS ")
{
throw new InvalidDataException();
}
var header = DdsHeader.Parse(reader);
DdsImageFormat imageFormat;
if (header.PixelFormat.Flags.HasFlag(DdsPixelFormatFlags.FourCc))
{
imageFormat = GetImageFormat(header.PixelFormat.FourCc);
}
else if (header.PixelFormat.Flags.HasFlag(DdsPixelFormatFlags.BumpDuDv))
{
imageFormat = DdsImageFormat.Rg8SNorm;
}
else if (header.PixelFormat.Flags.HasFlag(DdsPixelFormatFlags.Rgb))
{
imageFormat = DdsImageFormat.Rgba8;
}
else
{
throw new InvalidDataException();
}
var dimension = DdsTextureDimension.Texture2D;
var arraySize = 1u;
if (header.Flags.HasFlag(DdsHeaderFlags.Depth) && header.Caps2.HasFlag(DdsCaps2.Volume))
{
dimension = DdsTextureDimension.Texture3D;
}
else if (header.Caps2.HasFlag(DdsCaps2.CubeMap))
{
dimension = DdsTextureDimension.TextureCube;
if (!header.Caps2.HasFlag(DdsCaps2.AllCubeMapFaces))
{
throw new InvalidDataException();
}
arraySize = 6;
}
var isCompressed = imageFormat == DdsImageFormat.Bc1 ||
imageFormat == DdsImageFormat.Bc2 ||
imageFormat == DdsImageFormat.Bc3;
var mipMapCount = header.MipMapCount;
if (mipMapCount == 0)
{
mipMapCount = 1;
}
var mipMaps = new TextureMipMapData[mipMapCount * arraySize];
for (var arrayIndex = 0; arrayIndex < arraySize; arrayIndex++)
{
var width = header.Width;
var height = header.Height;
var depth = Math.Max(header.Depth, 1);
for (var i = 0; i < mipMapCount; i++)
{
var surfaceInfo = GetSurfaceInfo(width, height, imageFormat, header);
var numSurfaceBytes = surfaceInfo.NumBytes * depth;
var mipMapData = reader.ReadBytes((int)numSurfaceBytes);
// Set alpha bytes for 32-bit rgb images that don't include alpha data.
if (imageFormat == DdsImageFormat.Rgba8 && !header.PixelFormat.Flags.HasFlag(DdsPixelFormatFlags.AlphaPixels))
{
for (var j = 0; j < mipMapData.Length; j += 4)
{
mipMapData[j + 3] = 255;
}
}
mipMaps[(arrayIndex * mipMapCount) + i] = new TextureMipMapData(
mipMapData,
surfaceInfo.RowBytes,
surfaceInfo.NumBytes,
width,
height);
width >>= 1;
height >>= 1;
depth >>= 1;
if (isCompressed)
{
// Align width and height to multiple of 4.
width = (width + 3) / 4 * 4;
height = (height + 3) / 4 * 4;
}
else
{
width = Math.Max(width, 1);
height = Math.Max(height, 1);
}
depth = Math.Max(depth, 1);
}
}
return(new DdsFile
{
Header = header,
Dimension = dimension,
ImageFormat = imageFormat,
ArraySize = arraySize,
MipMapCount = mipMapCount,
MipMaps = mipMaps
});
}
}
public static DdsFile FromFileSystemEntry(FileSystemEntry entry)
{
using (var stream = entry.Open())
using (var reader = new BinaryReader(stream, Encoding.ASCII, true))
{
var magic = reader.ReadFourCc();
if (magic != "DDS ")
{
throw new InvalidDataException();
}
var header = DdsHeader.Parse(reader);
DdsImageFormat imageFormat;
if (header.PixelFormat.Flags.HasFlag(DdsPixelFormatFlags.FourCc))
{
imageFormat = GetImageFormat(header.PixelFormat.FourCc);
}
else if (header.PixelFormat.Flags.HasFlag(DdsPixelFormatFlags.BumpDuDv))
{
imageFormat = DdsImageFormat.Rg8SNorm;
}
else
{
throw new InvalidDataException();
}
if (header.Flags.HasFlag(DdsHeaderFlags.Depth) ||
header.Caps2.HasFlag(DdsCaps2.CubeMap) ||
header.Caps2.HasFlag(DdsCaps2.Volume))
{
throw new NotSupportedException();
}
var mipMapCount = header.MipMapCount;
if (mipMapCount == 0)
{
mipMapCount = 1;
}
var mipMaps = new DdsMipMap[mipMapCount];
var width = header.Width;
var height = header.Height;
for (var i = 0; i < mipMapCount; i++)
{
var surfaceInfo = GetSurfaceInfo(width, height, imageFormat);
var mipMapData = reader.ReadBytes((int)surfaceInfo.NumBytes);
mipMaps[i] = new DdsMipMap(mipMapData, surfaceInfo.RowBytes);
width >>= 1;
height >>= 1;
width = Math.Max(width, 1);
height = Math.Max(height, 1);
}
return(new DdsFile
{
Header = header,
ImageFormat = imageFormat,
MipMaps = mipMaps
});
}
}
