public static HeaderStruct FromBytes(byte[] bytearray)
{
HeaderStruct obj = new HeaderStruct();
int len = Marshal.SizeOf(obj);
IntPtr i = Marshal.AllocHGlobal(len);
Marshal.Copy(bytearray, 0, i, len);
obj = (HeaderStruct)Marshal.PtrToStructure(i, obj.GetType());
Marshal.FreeHGlobal(i);
return(obj);
}
public HeaderStruct ReadHeader(BitArray pixelData, out int pixelPtr)
{
var dataPtr = 0;
int pixelDataPtr = NextWritableBitHeader(-1);
BitArray data = new BitArray(HeaderStruct.BitSize);
while (dataPtr < data.Length)
{
data[dataPtr++] = pixelData[pixelDataPtr];
pixelDataPtr = NextWritableBitHeader(pixelDataPtr);
}
// finish off this pixel, then go to next pixel
pixelPtr = (pixelDataPtr / 32) + 1 + 1;
var bytes = new byte[HeaderStruct.BitSize / 8];
data.CopyTo(bytes, 0);
return(HeaderStruct.FromBytes(bytes));
}
// Use this to ensure we only write to a rectangle within the image
public bool IsWritablePixel(HeaderStruct header, int pixelPtr, int width, int height)
{
var x = pixelPtr % width;
var y = pixelPtr / width;
int minX = header.MinX;
int maxX = header.MaxX;
int minY = header.MinY;
int maxY = header.MaxY;
if (minX == maxX && minY == maxY)
{
return(true); // if not set, dont constrain at all
}
bool xInRange = (minX <= x) && (x <= maxX);
bool yInRange = (minY <= y) && (y <= maxY);
return(xInRange && yInRange);
}
public BitArray WriteHeader(BitArray pixelData, HeaderStruct header, out int pixelPtr)
{
var bytes = header.ToBytes();
BitArray headerBits = new BitArray(bytes);
var dataPtr = 0;
int pixelDataPtr = NextWritableBitHeader(-1);
while (dataPtr < headerBits.Length)
{
pixelData[pixelDataPtr] = headerBits[dataPtr++];
pixelDataPtr = NextWritableBitHeader(pixelDataPtr);
}
// finish off this pixel, then go to next pixel
pixelPtr = (pixelDataPtr / 32) + 1 + 1;
//Dump(pixelData, "Wrote header");
return(pixelData);
}
