/// <summary>
/// Loads a KTX file from a stream.
/// </summary>
public static KtxFile Load(Stream s)
{
using (BinaryReader br = new BinaryReader(s, UTF8, true))
{
KtxHeader header = br.ReadStruct <KtxHeader>();
if (header.NumberOfArrayElements > 0)
{
throw new NotSupportedException("KTX files with arrays are not supported.");
}
KtxFile ktx = new KtxFile(header);
int keyValuePairBytesRead = 0;
while (keyValuePairBytesRead < header.BytesOfKeyValueData)
{
KtxKeyValuePair kvp = KtxKeyValuePair.ReadKeyValuePair(br, out int read);
keyValuePairBytesRead += read;
ktx.KeyValuePairs.Add(kvp);
}
uint numberOfFaces = Math.Max(1, header.NumberOfFaces);
ktx.MipMaps.Capacity = (int)header.NumberOfMipmapLevels;
for (uint mipLevel = 0; mipLevel < header.NumberOfMipmapLevels; mipLevel++)
{
uint imageSize = br.ReadUInt32();
uint mipWidth = header.PixelWidth / (uint)(Math.Pow(2, mipLevel));
uint mipHeight = header.PixelHeight / (uint)(Math.Pow(2, mipLevel));
ktx.MipMaps.Add(new KtxMipmap(imageSize, mipWidth, mipHeight, numberOfFaces));
bool cubemap = header.NumberOfFaces > 1 && header.NumberOfArrayElements == 0;
for (uint face = 0; face < numberOfFaces; face++)
{
byte[] faceData = br.ReadBytes((int)imageSize);
ktx.MipMaps[(int)mipLevel].Faces[(int)face] = new KtxMipFace(faceData, mipWidth, mipHeight);
if (cubemap)
{
uint cubePadding = 0u;
cubePadding = 3 - ((imageSize + 3) % 4);
br.SkipPadding(cubePadding);
}
}
uint mipPaddingBytes = 3 - ((imageSize + 3) % 4);
br.SkipPadding(mipPaddingBytes);
}
return(ktx);
}
}
public static KtxHeader InitializeCompressed(int width, int height, GlInternalFormat internalFormat, GLFormat baseInternalFormat)
{
KtxHeader header = new KtxHeader();
Span <byte> id = stackalloc byte[] { 0xAB, 0x4B, 0x54, 0x58, 0x20, 0x31, 0x31, 0xBB, 0x0D, 0x0A, 0x1A, 0x0A };
for (int i = 0; i < id.Length; i++)
{
header.Identifier[i] = id[i];
}
header.Endianness = 0x04030201;
header.PixelWidth = (uint)width;
header.PixelHeight = (uint)height;
header.GlType = 0;
header.GlTypeSize = 1;
header.GlFormat = 0;
header.GlInternalFormat = internalFormat;
header.GlBaseInternalFormat = baseInternalFormat;
return(header);
}
public KtxFile(KtxHeader header)
{
Header = header;
}