public void Read(UnityBinaryReader r)
{
var size = r.ReadLEUInt32();
if (size != 124)
{
throw new FileFormatException($"Invalid DDS file header size: {size}.");
}
dwFlags = (DDSFlags)r.ReadLEUInt32();
if (!Utils.ContainsBitFlags((int)dwFlags, (int)DDSFlags.Height, (int)DDSFlags.Width))
{
throw new FileFormatException($"Invalid DDS file flags: {dwFlags}.");
}
dwHeight = r.ReadLEUInt32();
dwWidth = r.ReadLEUInt32();
dwPitchOrLinearSize = r.ReadLEUInt32();
dwDepth = r.ReadLEUInt32();
dwMipMapCount = r.ReadLEUInt32();
dwReserved1 = new uint[11];
for (var i = 0; i < 11; i++)
{
dwReserved1[i] = r.ReadLEUInt32();
}
ddspf = new DDSPixelFormat(r);
dwCaps = (DDSCaps)r.ReadLEUInt32();
if (!Utils.ContainsBitFlags((int)dwCaps, (int)DDSCaps.Texture))
{
throw new FileFormatException($"Invalid DDS file caps: {dwCaps}.");
}
dwCaps2 = (DDSCaps2)r.ReadLEUInt32();
dwCaps3 = r.ReadLEUInt32();
dwCaps4 = r.ReadLEUInt32();
dwReserved2 = r.ReadLEUInt32();
}
static byte[] DecodeDXT5ToARGB(byte[] compressedData, uint width, uint height, DDSPixelFormat pixelFormat, uint mipmapCount)
{
return(DecodeDXTToARGB(5, compressedData, width, height, pixelFormat, mipmapCount));
}
/// <summary>
/// Decodes DXT data to ARGB.
/// </summary>
static byte[] DecodeDXTToARGB(int DXTVersion, byte[] compressedData, uint width, uint height, DDSPixelFormat pixelFormat, uint mipmapCount)
{
var alphaFlag = Utils.ContainsBitFlags((int)pixelFormat.dwFlags, (int)DDSPixelFormats.AlphaPixels);
var containsAlpha = alphaFlag || (pixelFormat.dwRGBBitCount == 32 && pixelFormat.dwABitMask != 0);
using (var r = new UnityBinaryReader(new MemoryStream(compressedData)))
{
var argb = new byte[TextureUtils.CalculateMipMappedTextureDataSize((int)width, (int)height, 4)];
var mipMapWidth = (int)width;
var mipMapHeight = (int)height;
var baseARGBIndex = 0;
for (var mipMapIndex = 0; mipMapIndex < mipmapCount; mipMapIndex++)
{
for (var rowIndex = 0; rowIndex < mipMapHeight; rowIndex += 4)
{
for (var columnIndex = 0; columnIndex < mipMapWidth; columnIndex += 4)
{
Color32[] colors = null;
switch (DXTVersion) // Doing a switch instead of using a delegate for speed.
{
case 1: colors = DecodeDXT1TexelBlock(r, containsAlpha); break;
case 3: colors = DecodeDXT3TexelBlock(r); break;
case 5: colors = DecodeDXT5TexelBlock(r); break;
default: throw new NotImplementedException($"Tried decoding a DDS file using an unsupported DXT format: DXT {DXTVersion}");
}
CopyDecodedTexelBlock(colors, argb, baseARGBIndex, rowIndex, columnIndex, mipMapWidth, mipMapHeight);
}
}
baseARGBIndex += mipMapWidth * mipMapHeight * 4;
mipMapWidth /= 2;
mipMapHeight /= 2;
}
return(argb);
}
}
