Legacy Document

Inside Macintosh: Imaging With QuickDraw /

Chapter 2 - Basic QuickDraw / Basic QuickDraw Reference

Data Structures /

Point

You use a point, which is a data structure of type Point, to specify a location on the QuickDraw coordinate plane. For example, the window origin is specified by the point in the upper-left corner of the port rectangle of a graphics port.

TYPE VHSelect = (v,h); 
Point = 
RECORD 
   CASE Integer OF
      0: (v:\xDD\xDD Integer:    {vertical coordinate}
          h:\xDD\xDD Integer);   {horizontal coordinate}
      1: (vh:  ARRAY[VHSelect] OF Integer);
END;

Field Description

v

The vertical coordinate of the point.

h

The horizontal coordinate of the point.

vh

A variant definition in which v and h are array elements.

Note that while the vertical coordinate (v) appears first in this data structure, followed by the horizontal coordinate (h), the parameters to all QuickDraw routines expect the horizontal coordinate first and the vertical coordinate second.

QuickDraw routines for calculating and changing points are described in "Manipulating Points in Graphics Ports" beginning on page 2-47.