/// <summary>
/// Expands compressed patch data into the given array of int values
///
/// If the value starts with bits 0: The value is zero
/// If the value starts with bits 00: The rest of the patch is zeroes
/// If the value starts with bits 000: The value is a positive integer of wordBits bits
/// If the value starts with bits 001: The value is a negative integer of wordBits bits
///
/// </summary>
/// <param name="bitPack">The bitPack to read data from</param>
/// <param name="patchSize">The number of values in the patch is patchSize * patchSize</param>
/// <param name="wordBits">The number of bits in each value</param>
/// <param name="patchData">Array to place the decoded values in</param>
public static void Decode(BitPack bitPack, int patchSize, int wordBits, int[] patchData)
{
//Logger.LogDebug($"Patch.Decode: patchSize={patchSize}, wordBits={wordBits}");
// TODO: Different for Big Endian?
int i;
int j;
for (i = 0; i < patchSize * patchSize; i++)
{
if (bitPack.GetBool() == false)
{
patchData[i] = 0;
continue;
}
if (bitPack.GetBool() == false)
{
for (j = i; j < patchSize * patchSize; j++)
{
patchData[j] = 0;
}
return;
}
bool isNegative = bitPack.GetBool();
patchData[i] = (int)bitPack.GetUInt32_Le(wordBits) * (isNegative ? -1 : 1);
}
}
public void GetUInt32_Le()
{
UInt32[] values =
{
0x00000055,
0x000000aa,
0x000055aa,
0x0000aa55,
0x0055aa55,
0x00aa55aa,
0x55aa55aa,
0xaa55aa55,
0x01234567,
0x89abcdef,
0xfedcba98,
0x76543210
};
byte[] buffer = new byte[values.Length * 4];
int destIndex = 0;
for (int i = 0; i < values.Length; i++)
{
buffer[destIndex++] = (byte)((values[i] >> 0) & 0xff);
buffer[destIndex++] = (byte)((values[i] >> 8) & 0xff);
buffer[destIndex++] = (byte)((values[i] >> 16) & 0xff);
buffer[destIndex++] = (byte)((values[i] >> 24) & 0xff);
}
BitPack bitPack = new BitPack(buffer);
for (int i = 0; i < values.Length; i++)
{
UInt32 v = bitPack.GetUInt32_Le();
Assert.AreEqual(values[i], v);
}
}
