Used in Shaman's Sanctuary.
This implementation doesn't give the same result as SACT2.dll. SACT2.dll
zigzag's the image along both axes, whereas this implementation only
does the zigzag along one axis.
This one is used quite frequently in Sengoku Rance.
The implementation here is slightly wrong, in that the anchor point for
the pixel zoom is at the lop left of the screen instead of the center.