DeltaPoint
Point bPt ; any other point, same coordinate system returns hiword = vertical distance; low=horiz
DeltaPoint returns the distance between two points, returned as a 32-bit value with the high-order word being the vertical distance and the low-order
word being the horizontal distance.
aPt and . . .
bPt are any two points, expressed in the same coordinate system.
Returns: a 32-bit long integer; it identifies the distance between aPt and bPt. The high word is the vertical offset and the low word is the
horizontal offset. Negative values indicate that bPt is above and to
the left of aPt ; positive values indicate below and to the right.
Notes: This performs the same function as SubPt, except the difference is given as the returned value instead of stored into a variable.