AddPt
AddPt Add coordinates of two points
#include <Quickdraw.h> Quickdraw
void AddPt(srcPt, destPt );
Point srcPt ; first coordinate pair
Point *destPt ; second coordinate pair; receives sum
AddPt adds the coordinates of two Points, storing the result into the second.
srcPt is a 4-byte Point structure. Its low word is the horizontal
coordinate and its high word is the vertical coordinate.
destPt is the address of a 4-byte Point structure. Upon return, it will
contain the sums (srcPt.h+destPt.h) and (srcPt.v+destPt.v).
Returns: none

Notes: AddPt is functionally equivalent to:
destPt.h += srcPt.h;
destPt.v += srcPt.v;
Use SubPt or DeltaPoint to calculate the difference between two Points.