pBitmap (PBYTE) - input
Pointer to the pel data of the bit map. This data is stored in the order that the coordinates appear on a display screen, that is, the pel in the lower-left corner is the first in the bit map. Pels are scanned to the right, and upward, from that position. The bits of the first pel are stored beginning with the most significant bits of the first byte. The data for pels in each scan line is packed together tightly. However, all scan lines are padded at the end so that each one begins on a ULONG boundary. That is, three bytes of pel data will hold one 24-bit pel, three 8-bit pels, six 4-bit pels, or twenty-four 1-bit pels. If those three bytes are the only pel data for that scan line, one more byte of 0s would be required to pad the line to a ULONG boundary.