source: trunk/gui/vizservers/nanovis/Plane.cpp @ 226

/*
 * ----------------------------------------------------------------------
 * Plane.cpp: plane class
 *
 * ======================================================================
 *  AUTHOR:  Wei Qiao <qiaow@purdue.edu>
 *           Purdue Rendering and Perceptualization Lab (PURPL)
 *
 *  Copyright (c) 2004-2006  Purdue Research Foundation
 *
 *  See the file "license.terms" for information on usage and
 *  redistribution of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 * ======================================================================
 */
#include <assert.h>
#include "Plane.h"

Plane::Plane(){}

Plane::Plane(float _a, float _b, float _c, float _d) {
    this->a = _a;
    this->b = _b;
    this->c = _c;
    this->d = _d;

    assert(a != 0 || b != 0 || c != 0);
}

Plane::Plane(float coeffs[4]) {
    a = coeffs[0];
    b = coeffs[1];
    c = coeffs[2];
    d = coeffs[3];

    assert(a != 0 || b != 0 || c != 0);
}

void Plane::get_normal(Vector3 &normal){
    normal.x = a;
    normal.y = b;
    normal.z = c;
}

void Plane::get_point(Vector3 &point){
    if(a != 0){ 
                point.x = -d/a;
                point.y = 0;
                point.z = 0;
    } 
        else if(b != 0){
                point.y = -d/b;
                point.x = 0;
                point.z = 0;
    } 
        else if(c != 0){
                point.z = -d /c;
                point.y = 0;
                point.x = 0;
    } 
        else{
                assert(false);
    }
}

Vector4 Plane::get_coeffs(){
    Vector4 ret(a, b, c, d);
        return ret;
}

void Plane::set_coeffs(float _a, float _b, float _c, float _d){
    a = _a;
    b = _b;
    c = _c;
    d = _d;
}

void Plane::transform(Mat4x4 mat) {
    Vector4 coeffs(a, b, c, d);
        Mat4x4 inv = mat.inverse();
        Vector4 new_coeffs = inv.multiply_row_vector(coeffs);

    a = new_coeffs.x;
    b = new_coeffs.y;
    c = new_coeffs.z;
    d = new_coeffs.w;
}

void Plane::transform(float *m){
        Mat4x4 mat(m);
        transform(mat);
}

bool Plane::retains(Vector3 point){
    return (a * point.x + b * point.y + c * point.z + d >= 0);
}