OffsetPtr adds the specified offset to the given pointer, ensuring that the resulting pointer is properly word-aligned.
The p parameter is the pointer that is to be offset when the routine is called; when it returns, p is the resulting pointer. The offset parameter is the number of bytes to add to the pointer’s value to obtain the new pointer.
MacApp calls OffsetPtr from a variety of methods that manipulate memory or perform low-level data access with Pascal records. You can use this routine in a similar fashion.