Adjusted terminology, added some documentation.

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Max G 2019-02-27 00:32:16 -06:00 committed by GitHub
parent f80d6942cc
commit e49222cf00
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@ -10,38 +10,43 @@ namespace RobloxFiles.BinaryFormat
public BinaryRobloxReader(Stream stream) : base(stream) { }
private byte[] lastStringBuffer = new byte[0] { };
public T[] ReadInterlaced<T>(int count, Func<byte[], int, T> decode) where T : struct
// Reads 'count * sizeof(T)' interleaved bytes and converts them
// into an array of T[count] where each value in the array has
// been transformed by the provided 'transform' function.
public T[] ReadInterleaved<T>(int count, Func<byte[], int, T> transform) where T : struct
{
int bytesPerBlock = Marshal.SizeOf<T>();
byte[] interlaced = ReadBytes(count * bytesPerBlock);
int bufferSize = Marshal.SizeOf<T>();
byte[] interleaved = ReadBytes(count * bufferSize);
T[] values = new T[count];
for (int i = 0; i < count; i++)
{
long block = 0;
long buffer = 0;
for (int pack = 0; pack < bytesPerBlock; pack++)
for (int column = 0; column < bufferSize; column++)
{
long bits = interlaced[(pack * count) + i];
int shift = (bytesPerBlock - pack - 1) * 8;
block |= (bits << shift);
long block = interleaved[(column * count) + i];
int shift = (bufferSize - column - 1) * 8;
buffer |= (block << shift);
}
byte[] buffer = BitConverter.GetBytes(block);
values[i] = decode(buffer, 0);
byte[] sequence = BitConverter.GetBytes(buffer);
values[i] = transform(sequence, 0);
}
return values;
}
private int ReadInterlacedInt(byte[] buffer, int startIndex)
// Transforms an int from an interleaved buffer.
private int TransformInt(byte[] buffer, int startIndex)
{
int value = BitConverter.ToInt32(buffer, startIndex);
return (value >> 1) ^ (-(value & 1));
}
private float ReadInterlacedFloat(byte[] buffer, int startIndex)
// Transforms a float from an interleaved buffer.
private float TransformFloat(byte[] buffer, int startIndex)
{
uint u = BitConverter.ToUInt32(buffer, startIndex);
uint i = (u >> 1) | (u << 31);
@ -50,16 +55,19 @@ namespace RobloxFiles.BinaryFormat
return BitConverter.ToSingle(b, 0);
}
// Reads an interleaved buffer of integers.
public int[] ReadInts(int count)
{
return ReadInterlaced(count, ReadInterlacedInt);
return ReadInterleaved(count, TransformInt);
}
// Reads an interleaved buffer of floats.
public float[] ReadFloats(int count)
{
return ReadInterlaced(count, ReadInterlacedFloat);
return ReadInterleaved(count, TransformFloat);
}
// Reads and accumulates an interleaved buffer of integers.
public int[] ReadInstanceIds(int count)
{
int[] values = ReadInts(count);