line3d.h

// Copyright (C) 2002-2012 Nikolaus Gebhardt
// This file is part of the "Irrlicht Engine".
// For conditions of distribution and use, see copyright notice in irrlicht.h
 
#ifndef __IRR_LINE_3D_H_INCLUDED__
#define __IRR_LINE_3D_H_INCLUDED__
 
#include "irrTypes.h"
#include "vector3d.h"
 
namespace irr
{
namespace core
{

template <class T>
class line3d
{
    public:


        line3d() : start(0,0,0), end(1,1,1) {}
        line3d(T xa, T ya, T za, T xb, T yb, T zb) : start(xa, ya, za), end(xb, yb, zb) {}
        line3d(const vector3d<T>& start, const vector3d<T>& end) : start(start), end(end) {}
 
        // operators
 
        line3d<T> operator+(const vector3d<T>& point) const { return line3d<T>(start + point, end + point); }
        line3d<T>& operator+=(const vector3d<T>& point) { start += point; end += point; return *this; }
 
        line3d<T> operator-(const vector3d<T>& point) const { return line3d<T>(start - point, end - point); }
        line3d<T>& operator-=(const vector3d<T>& point) { start -= point; end -= point; return *this; }
 
        bool operator==(const line3d<T>& other) const
        { return (start==other.start && end==other.end) || (end==other.start && start==other.end);}
        bool operator!=(const line3d<T>& other) const
        { return !(start==other.start && end==other.end) || (end==other.start && start==other.end);}
 
        // functions
        void setLine(const T& xa, const T& ya, const T& za, const T& xb, const T& yb, const T& zb)
        {start.set(xa, ya, za); end.set(xb, yb, zb);}

        void setLine(const vector3d<T>& nstart, const vector3d<T>& nend)
        {start.set(nstart); end.set(nend);}

        void setLine(const line3d<T>& line)
        {start.set(line.start); end.set(line.end);}


        T getLength() const { return start.getDistanceFrom(end); }


        T getLengthSQ() const { return start.getDistanceFromSQ(end); }


        vector3d<T> getMiddle() const
        {
            return (start + end)/(T)2;
        }


        vector3d<T> getVector() const
        {
            return end - start;
        }


        bool isPointBetweenStartAndEnd(const vector3d<T>& point) const
        {
            return point.isBetweenPoints(start, end);
        }


        vector3d<T> getClosestPoint(const vector3d<T>& point) const
        {
            vector3d<T> c = point - start;
            vector3d<T> v = end - start;
            T d = (T)v.getLength();
            v /= d;
            T t = v.dotProduct(c);
 
            if (t < (T)0.0)
                return start;
            if (t > d)
                return end;
 
            v *= t;
            return start + v;
        }


        bool getIntersectionWithSphere(vector3d<T> sorigin, T sradius, f64& outdistance) const
        {
            const vector3d<T> q = sorigin - start;
            T c = q.getLength();
            T v = q.dotProduct(getVector().normalize());
            T d = sradius * sradius - (c*c - v*v);
 
            if (d < 0.0)
                return false;
 
            outdistance = v - core::squareroot ( d );
            return true;
        }
 
        // member variables

        vector3d<T> start;
        vector3d<T> end;
};

    typedef line3d<f32> line3df;
    typedef line3d<s32> line3di;
 
} // end namespace core
} // end namespace irr
 
#endif