private static Dictionary <string, MetadataValue> ParseMetadata(byte[] inputArray, bool shouldSwapEndianness)
{
Dictionary <string, MetadataValue> returnDictionary = new Dictionary <string, MetadataValue>();
int position = 0;
while (position < inputArray.Length)
{
uint combinedKeyAndValueSizeInBytes = shouldSwapEndianness ? KtxBitFiddling.SwapEndian(BitConverter.ToUInt32(inputArray, position)) : BitConverter.ToUInt32(inputArray, position);
// Pair must be larger than 0 bytes
if (combinedKeyAndValueSizeInBytes == 0)
{
throw new InvalidOperationException("Metadata: combinedKeyAndValueSize cannot be 0!");
}
position += Common.sizeOfUint;
// Error out in case size is larger than bytes left
if (combinedKeyAndValueSizeInBytes + 4 > (uint)inputArray.Length)
{
throw new InvalidOperationException("Metadata: combinedKeyAndValueSize cannot be larger than whole metadata!");
}
// Find NUL since key should always have it
int indexOfFirstNul = Array.IndexOf(inputArray, Common.nulByte, position);
if (indexOfFirstNul < 0)
{
throw new InvalidOperationException("Metadata: No Nul found when looking for key");
}
int keyLength = indexOfFirstNul - position;
if (keyLength > combinedKeyAndValueSizeInBytes)
{
throw new InvalidOperationException("Metadata: Key length is longer than combinedKeyAndValueSizeInBytes!");
}
string key = System.Text.Encoding.UTF8.GetString(bytes: inputArray, index: position, count: keyLength);
position += (keyLength + 1 /* Because we have to skip nul byte*/);
int valueLength = (int)combinedKeyAndValueSizeInBytes - keyLength;
byte[] bytesOfValue = new byte[valueLength];
Buffer.BlockCopy(src: inputArray, srcOffset: position, dst: bytesOfValue, dstOffset: 0, count: valueLength);
returnDictionary[key] = new MetadataValue(bytesOfValue);
position += valueLength;
// Skip value paddings if there are any
while (position % 4 != 0)
{
position++;
}
}
return(returnDictionary);
}
public static (bool isValid, string possibleError) ValidateTextureData(MemoryStream memoryStream, KtxHeader header, uint expectedTextureDataSize)
{
// Use the memory stream in a binary reader.
try
{
using (BinaryReader reader = new BinaryReader(memoryStream, Encoding.UTF8, leaveOpen: true))
{
// Specs say that if value of certain things is zero (0) then it should be used as one (1)
uint mipmapLevels = (header.numberOfMipmapLevels == 0) ? 1 : header.numberOfMipmapLevels;
uint numberOfArrayElements = (header.numberOfArrayElements == 0) ? 1 : header.numberOfArrayElements;
uint pixelDepth = (header.pixelDepth == 0) ? 1 : header.pixelDepth;
uint pixelHeight = (header.pixelHeight == 0) ? 1 : header.pixelHeight;
uint totalLengthOfTextureDataSection = 0;
// Check if length reads should be endian swapped
bool shouldSwapEndianness = (header.endiannessValue != Common.expectedEndianValue);
// Check each mipmap level separately
for (uint u = 0; u < mipmapLevels; u++)
{
uint imageSize = shouldSwapEndianness ? KtxBitFiddling.SwapEndian(reader.ReadUInt32()) : reader.ReadUInt32();
totalLengthOfTextureDataSection += (imageSize + (uint)Common.sizeOfUint);
if (imageSize > expectedTextureDataSize || totalLengthOfTextureDataSection > expectedTextureDataSize)
{
return(isValid : false, "Texture data: More data than expected!");
}
// TODO: More checks!
// Read but do not use data for anything
reader.ReadBytes((int)imageSize);
// Skip possible padding bytes
while (imageSize % 4 != 0)
{
imageSize++;
// Read but ignore values
reader.ReadByte();
}
}
}
}
catch (Exception e)
{
return(isValid : false, e.ToString());
}
return(isValid : true, possibleError : "");
}
private static (bool isValid, string possibleError) ValidateMetadata(BinaryReader reader, uint bytesOfKeyValueData, bool shouldSwapEndianness)
{
uint currentPosition = 0;
while (currentPosition < bytesOfKeyValueData)
{
uint combinedKeyAndValueSize = shouldSwapEndianness ? KtxBitFiddling.SwapEndian(reader.ReadUInt32()) : reader.ReadUInt32();
currentPosition += (uint)Common.sizeOfUint;
if ((currentPosition + combinedKeyAndValueSize) > bytesOfKeyValueData)
{
return(isValid : false, possibleError : "Metadata: combinedKeyAndValueSize would go beyond Metadata array!");
}
// There should be at least NUL
byte[] keyAndValueAsBytes = reader.ReadBytes((int)combinedKeyAndValueSize);
if (!keyAndValueAsBytes.Contains(Common.nulByte))
{
return(isValid : false, possibleError : "Metadata: KeyValue pair does not contain NUL byte!");
}
// Check if key is valid UTF-8 byte combination
try
{
UTF8Encoding utf8ThrowException = new UTF8Encoding(false, true);
string notUsed = utf8ThrowException.GetString(keyAndValueAsBytes, 0, keyAndValueAsBytes.Length);
}
catch (Exception e)
{
return(isValid : false, possibleError : $"Byte array to UTF-8 failed: {e}!");
}
currentPosition += combinedKeyAndValueSize;
// Skip value paddings if there are any
while (currentPosition % 4 != 0)
{
currentPosition++;
reader.ReadByte();
}
}
return(isValid : true, possibleError : "");
}
private static (bool isValid, string possibleError) ValidateMetadata(BinaryReader reader, uint bytesOfKeyValueData, bool shouldSwapEndianness)
{
uint currentPosition = 0;
while (currentPosition < bytesOfKeyValueData)
{
uint combinedKeyAndValueSize = shouldSwapEndianness ? KtxBitFiddling.SwapEndian(reader.ReadUInt32()) : reader.ReadUInt32();
currentPosition += (uint)Common.sizeOfUint;
if ((currentPosition + combinedKeyAndValueSize) > bytesOfKeyValueData)
{
return(isValid : false, possibleError : "Metadata: combinedKeyAndValueSize would go beyond Metadata array!");
}
// There should be at least NUL
byte[] keyAndValueAsBytes = reader.ReadBytes((int)combinedKeyAndValueSize);
if (!keyAndValueAsBytes.Contains(Common.nulByte))
{
return(isValid : false, possibleError : "Metadata: KeyValue pair does not contain NUL byte!");
}
// TODO: Check if key is valid UTF-8 byte combination
currentPosition += combinedKeyAndValueSize;
// Skip value paddings if there are any
while (currentPosition % 4 != 0)
{
currentPosition++;
reader.ReadByte();
}
}
return(isValid : true, possibleError : "");
}
/// <summary>
/// Constructor for texture data
/// </summary>
/// <param name="header">Header</param>
/// <param name="stream">Stream for reading</param>
public KtxTextureData(KtxHeader header, Stream stream)
{
//this.totalTextureDataLength = (uint)stream.Length;
// Try to figure out texture type basic
bool containsMipmaps = header.numberOfMipmapLevels > 1;
if (header.numberOfArrayElements == 0 || header.numberOfArrayElements == 1)
{
// Is NOT texture array
if (header.numberOfFaces == 0 || header.numberOfFaces == 1)
{
// Is NOT cube texture
if (header.pixelDepth == 0 || header.pixelDepth == 1)
{
// Is not 3D texture
if (header.pixelHeight == 0 || header.pixelHeight == 1)
{
// 1D texture
this.textureType = containsMipmaps ? TextureTypeBasic.Basic1DWithMipmaps : TextureTypeBasic.Basic1DNoMipmaps;
}
else
{
// 2D texture
this.textureType = containsMipmaps ? TextureTypeBasic.Basic2DWithMipmaps : TextureTypeBasic.Basic2DNoMipmaps;
}
}
else
{
// Is 3D texture
this.textureType = containsMipmaps ? TextureTypeBasic.Basic3DWithMipmaps : TextureTypeBasic.Basic3DNoMipmaps;
}
}
else
{
// Is cube texture
}
}
else
{
// Is Texture array
}
uint mipmapLevels = header.numberOfMipmapLevels;
if (mipmapLevels == 0)
{
mipmapLevels = 1;
}
// Since we know how many mipmap levels there are, allocate the capacity
this.textureDataOfMipmapLevel = new List <byte[]>((int)mipmapLevels);
// Check if length reads should be endian swapped
bool shouldSwapEndianness = (header.endiannessValue != Common.expectedEndianValue);
using (BinaryReader reader = new BinaryReader(stream, Encoding.UTF8, leaveOpen: true))
{
for (int i = 0; i < mipmapLevels; i++)
{
uint amountOfDataInThisMipmapLevel = shouldSwapEndianness ? KtxBitFiddling.SwapEndian(reader.ReadUInt32()) : reader.ReadUInt32();
this.textureDataOfMipmapLevel.Add(reader.ReadBytes((int)amountOfDataInThisMipmapLevel));
// Skip possible padding bytes
while (amountOfDataInThisMipmapLevel % 4 != 0)
{
amountOfDataInThisMipmapLevel++;
// Read but ignore values
reader.ReadByte();
}
}
}
}
private static void WriteUintAsBigEndian(BinaryWriter writer, uint value)
{
writer.Write(KtxBitFiddling.SwapEndian(value));
}
/// <summary>
/// KtxHeader constructor
/// </summary>
/// <param name="stream">Stream for reading</param>
public KtxHeader(Stream stream)
{
// Skip first 12 bytes since they only contain identifier
stream.Seek(12, SeekOrigin.Begin);
// Read endianness as bytes
byte[] endiannessBytes = new byte[4];
int bytesRead = stream.Read(buffer: endiannessBytes, offset: 0, count: endiannessBytes.Length);
if (bytesRead != 4)
{
throw new InvalidOperationException("Cannot read enough bytes from stream!");
}
if (!Common.littleEndianAsBytes.SequenceEqual(endiannessBytes) && !Common.bigEndianAsBytes.SequenceEqual(endiannessBytes))
{
throw new InvalidOperationException("Endianness info in header is not valid!");
}
this.isInputLittleEndian = Common.littleEndianAsBytes.SequenceEqual(endiannessBytes);
// Turn endianness as bytes to uint
this.endiannessValue = BitConverter.ToUInt32(endiannessBytes, 0);
// See if following uint reads need endian swap
bool shouldSwapEndianness = (this.endiannessValue != Common.expectedEndianValue);
// Use the stream in a binary reader.
using (BinaryReader reader = new BinaryReader(stream, Encoding.UTF8, leaveOpen: true))
{
// Swap endianness for every KTX variable if needed
this.glTypeAsUint = shouldSwapEndianness ? KtxBitFiddling.SwapEndian(reader.ReadUInt32()) : reader.ReadUInt32();
if (GlDataType.IsDefined(typeof(GlDataType), this.glTypeAsUint))
{
this.glDataType = (GlDataType)this.glTypeAsUint;
}
else
{
this.glDataType = GlDataType.NotKnown;
}
this.glTypeSizeAsUint = shouldSwapEndianness ? KtxBitFiddling.SwapEndian(reader.ReadUInt32()) : reader.ReadUInt32();
this.glFormatAsUint = shouldSwapEndianness ? KtxBitFiddling.SwapEndian(reader.ReadUInt32()) : reader.ReadUInt32();
if (GlPixelFormat.IsDefined(typeof(GlPixelFormat), this.glFormatAsUint))
{
this.glFormat = (GlPixelFormat)this.glFormatAsUint;
}
else
{
this.glFormat = GlPixelFormat.NotKnown;
}
this.glInternalFormatAsUint = shouldSwapEndianness ? KtxBitFiddling.SwapEndian(reader.ReadUInt32()) : reader.ReadUInt32();
if (GlInternalFormat.IsDefined(typeof(GlInternalFormat), this.glInternalFormatAsUint))
{
this.glInternalFormat = (GlInternalFormat)this.glInternalFormatAsUint;
}
else
{
this.glInternalFormat = GlInternalFormat.NotKnown;
}
this.glBaseInternalFormatAsUint = shouldSwapEndianness ? KtxBitFiddling.SwapEndian(reader.ReadUInt32()) : reader.ReadUInt32();
if (GlPixelFormat.IsDefined(typeof(GlPixelFormat), this.glBaseInternalFormatAsUint))
{
this.glPixelFormat = (GlPixelFormat)this.glBaseInternalFormatAsUint;
}
else
{
this.glPixelFormat = GlPixelFormat.NotKnown;
}
this.pixelWidth = shouldSwapEndianness ? KtxBitFiddling.SwapEndian(reader.ReadUInt32()) : reader.ReadUInt32();
this.pixelHeight = shouldSwapEndianness ? KtxBitFiddling.SwapEndian(reader.ReadUInt32()) : reader.ReadUInt32();
this.pixelDepth = shouldSwapEndianness ? KtxBitFiddling.SwapEndian(reader.ReadUInt32()) : reader.ReadUInt32();
this.numberOfArrayElements = shouldSwapEndianness ? KtxBitFiddling.SwapEndian(reader.ReadUInt32()) : reader.ReadUInt32();
this.numberOfFaces = shouldSwapEndianness ? KtxBitFiddling.SwapEndian(reader.ReadUInt32()) : reader.ReadUInt32();
this.numberOfMipmapLevels = shouldSwapEndianness ? KtxBitFiddling.SwapEndian(reader.ReadUInt32()) : reader.ReadUInt32();
this.bytesOfKeyValueData = shouldSwapEndianness ? KtxBitFiddling.SwapEndian(reader.ReadUInt32()) : reader.ReadUInt32();
// Check that bytesOfKeyValueData is mod 4
if (this.bytesOfKeyValueData % 4 != 0)
{
throw new InvalidOperationException(ErrorGen.Modulo4Error(nameof(this.bytesOfKeyValueData), this.bytesOfKeyValueData));
}
this.metadataDictionary = ParseMetadata(reader.ReadBytes((int)this.bytesOfKeyValueData), shouldSwapEndianness);
}
}
public static (bool isValid, string possibleError) ValidateHeaderData(MemoryStream memoryStream)
{
// Use the memory stream in a binary reader.
try
{
using (BinaryReader reader = new BinaryReader(memoryStream, Encoding.UTF8, leaveOpen: true))
{
// Start validating header
byte[] tempIdentifier = reader.ReadBytes(Common.onlyValidIdentifier.Length);
if (!Common.onlyValidIdentifier.SequenceEqual(tempIdentifier))
{
return(isValid : false, possibleError : "Identifier does not match requirements!");
}
uint tempEndian = reader.ReadUInt32();
if (Common.expectedEndianValue != tempEndian && Common.otherValidEndianValue != tempEndian)
{
return(isValid : false, possibleError : "Endianness does not match requirements!");
}
bool shouldSwapEndianness = (tempEndian != Common.expectedEndianValue);
uint glTypeTemp = shouldSwapEndianness ? KtxBitFiddling.SwapEndian(reader.ReadUInt32()) : reader.ReadUInt32();
// TODO: uint glType to enum
// If glType is 0 it should mean that this is compressed texture
bool assumeCompressedTexture = (glTypeTemp == 0);
uint glTypeSizeTemp = shouldSwapEndianness ? KtxBitFiddling.SwapEndian(reader.ReadUInt32()) : reader.ReadUInt32();
if (assumeCompressedTexture && glTypeSizeTemp != 1)
{
return(isValid : false, possibleError : "glTypeSize should be 1 for compressed textures!");
}
uint glFormatTemp = shouldSwapEndianness ? KtxBitFiddling.SwapEndian(reader.ReadUInt32()) : reader.ReadUInt32();
if (assumeCompressedTexture && glFormatTemp != 0)
{
return(isValid : false, possibleError : "glFormat should be 0 for compressed textures!");
}
uint glInternalFormatTemp = shouldSwapEndianness ? KtxBitFiddling.SwapEndian(reader.ReadUInt32()) : reader.ReadUInt32();
uint glBaseInternalFormatTemp = shouldSwapEndianness ? KtxBitFiddling.SwapEndian(reader.ReadUInt32()) : reader.ReadUInt32();
uint pixelWidthTemp = shouldSwapEndianness ? KtxBitFiddling.SwapEndian(reader.ReadUInt32()) : reader.ReadUInt32();
uint pixelHeightTemp = shouldSwapEndianness ? KtxBitFiddling.SwapEndian(reader.ReadUInt32()) : reader.ReadUInt32();
uint pixelDepthTemp = shouldSwapEndianness ? KtxBitFiddling.SwapEndian(reader.ReadUInt32()) : reader.ReadUInt32();
uint numberOfArrayElementsTemp = shouldSwapEndianness ? KtxBitFiddling.SwapEndian(reader.ReadUInt32()) : reader.ReadUInt32();
uint numberOfFacesTemp = shouldSwapEndianness ? KtxBitFiddling.SwapEndian(reader.ReadUInt32()) : reader.ReadUInt32();
uint numberOfMipmapLevelsTemp = shouldSwapEndianness ? KtxBitFiddling.SwapEndian(reader.ReadUInt32()) : reader.ReadUInt32();
uint sizeOfKeyValueDataTemp = shouldSwapEndianness ? KtxBitFiddling.SwapEndian(reader.ReadUInt32()) : reader.ReadUInt32();
if (sizeOfKeyValueDataTemp % 4 != 0)
{
return(isValid : false, possibleError : ErrorGen.Modulo4Error(nameof(sizeOfKeyValueDataTemp), sizeOfKeyValueDataTemp));
}
// Validate metadata
(bool validMedata, string possibleMetadataError) = ValidateMetadata(reader, sizeOfKeyValueDataTemp, shouldSwapEndianness);
if (!validMedata)
{
return(isValid : false, possibleError : possibleMetadataError);
}
}
}
catch (Exception e)
{
return(isValid : false, e.ToString());
}
return(isValid : true, possibleError : "");
}
