Inside Macintosh: 3D Graphics Programming With QuickDraw 3D /

Chapter 4 - Geometric Objects / Geometric Objects Reference

Data Structures

Areas and Plane Equations

A two-dimensional area is defined by the TQ3Area data type.

typedef struct TQ3Area {
   TQ3Point2D                 min;
   TQ3Point2D                 max;
} TQ3Area;

Field Description

min

A two-dimensional point.

max

A two-dimensional point.

A plane equation is defined by the TQ3PlaneEquation data type.

typedef struct TQ3PlaneEquation {
   TQ3Vector3D                normal;
   float                      constant;
} TQ3PlaneEquation;

Field Description

normal

The vector that is normal (perpendicular) to the plane.

constant

The plane constant. A plane constant is the value d in the plane equation ax+by+cz+d = 0. The coefficients a, b, and c are the x, y, and z components of the normal vector.