////  Plane.cpp//  libraries/shared/src/////  Created by Brad Hefta-Gaub on 04/11/13.//  Copyright 2013 High Fidelity, Inc.////  Originally from lighthouse3d. Modified to utilize glm::vec3 and clean up to our coding standards//  Simple plane class.////  Distributed under the Apache License, Version 2.0.//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html// #include "Plane.h" #include <stdio.h>#include <QtCore/QDebug> #include "SharedLogging.h"  void Plane::set3Points(const glm::vec3 &v1, const glm::vec3 &v2, const glm::vec3 &v3) {    glm::vec3 linev1v2, linev1v3;     linev1v2 = v2 - v1;    linev1v3 = v3 - v1;     // this will be perpendicular to both lines    _normal = glm::cross(linev1v2,linev1v3);    _normal = glm::normalize(_normal);     // this is a point on the plane    _point = v2;     // the D coefficient from the form Ax+By+Cz=D    _dCoefficient = -(glm::dot(_normal,_point));} void Plane::setNormalAndPoint(const glm::vec3 &normal, const glm::vec3 &point) {    _point = point;    _normal = normal;    glm::normalize(_normal);     // the D coefficient from the form Ax+By+Cz=D    _dCoefficient = -(glm::dot(_normal,_point));} void Plane::setCoefficients(float a, float b, float c, float d) {    // set the normal vector    _normal = glm::vec3(a,b,c);     //compute the lenght of the vector    float l = glm::length(_normal);     // normalize the vector    _normal = glm::vec3(a/l,b/l,c/l);     // and divide d by th length as well    _dCoefficient = d/l;} float Plane::distance(const glm::vec3 &point) const {    return (_dCoefficient + glm::dot(_normal,point));} void Plane::print() const {    qCDebug(shared, "Plane - point (x=%f y=%f z=%f) normal (x=%f y=%f z=%f) d=%f",            (double)_point.x, (double)_point.y, (double)_point.z,            (double)_normal.x, (double)_normal.y, (double)_normal.z, (double)_dCoefficient);}