Plane.cpp

/* ------------------------------------------------------

   Plane - Std3D

--------------------------------------------------------*/


#include "Plane.h"
#include <stdio.h>


Plane::Plane()
: normal()
, d(0.f)
{}


Plane::Plane(const Vec3 &v1, const Vec3 &v2, const Vec3 &v3)
{
   set3Points(v1, v2, v3);
}


void Plane::set3Points(const Vec3 &v1, const Vec3 &v2, const Vec3 &v3)
{
   normal = Vec3::cross((v2 - v1), (v3 - v1));
   normal.normalize();
   d = -Vec3::dot(normal, v1);
}

void Plane::setNormalAndPoint(const Vec3 &normal, const Vec3 &point)
{
   this->normal = normal;
   this->normal.normalize();
   d = -Vec3::dot(normal, point);
}

void Plane::setCoefficients(float a, float b, float c, float d)
{
   // set the normal vector
   normal.set(a, b, c);
   //compute the lenght of the vector
   float l = normal.length();
   // normalize the vector
   normal.set(a/l, b/l, c/l);
   // and divide d by th length as well
   this->d = d/l;
}


float Plane::distance(const Vec3 &p) const
{
   return (d + Vec3::dot(normal, p));
}

void Plane::print()
{
   printf("Plane(");
   normal.print();
   printf("# %f)", d);
}