double point_vs_plane ( SS_XYZ *p, SS_COEF *coef )

SS_XYZ  *p;       // address of a 3D point

SS_COEF *coef;    // address of plane structure

Synopsis

#include "silver.h"

The point_vs_plane function compares point p with the plane specified by coef .

Parameters

p is the address of a 3D point. coef is the address of an SS_COEF struct which holds the representation of the plane equation.

Return Value

point_vs_plane returns a value such that:

1. The absolute value of the value returned by point_vs_plane is the distance of p from the plane if coef is normalized.

2. A negative value indicates that the point lies on the negative side of the plane.

3. If the distance of p from the plane is less than epsilon (the system equality threshold), then 0.0 is returned