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// 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
{
//! 3D line between two points with intersection methods.
template <class T>
class line3d
{
public:
//! Default constructor
/** line from (0,0,0) to (1,1,1) */
line3d() : start(0,0,0), end(1,1,1) {}
//! Constructor with two points
line3d(T xa, T ya, T za, T xb, T yb, T zb) : start(xa, ya, za), end(xb, yb, zb) {}
//! Constructor with two points as vectors
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
//! Set this line to a new line going through the two points.
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);}
//! Set this line to a new line going through the two points.
void setLine(const vector3d<T>& nstart, const vector3d<T>& nend)
{start.set(nstart); end.set(nend);}
//! Set this line to new line given as parameter.
void setLine(const line3d<T>& line)
{start.set(line.start); end.set(line.end);}
//! Get length of line
/** \return Length of line. */
T getLength() const { return start.getDistanceFrom(end); }
//! Get squared length of line
/** \return Squared length of line. */
T getLengthSQ() const { return start.getDistanceFromSQ(end); }
//! Get middle of line
/** \return Center of line. */
vector3d<T> getMiddle() const
{
return (start + end)/(T)2;
}
//! Get vector of line
/** \return vector of line. */
vector3d<T> getVector() const
{
return end - start;
}
//! Check if the given point is between start and end of the line.
/** Assumes that the point is already somewhere on the line.
\param point The point to test.
\return True if point is on the line between start and end, else false.
*/
bool isPointBetweenStartAndEnd(const vector3d<T>& point) const
{
return point.isBetweenPoints(start, end);
}
//! Get the closest point on this line to a point
/** \param point The point to compare to.
\return The nearest point which is part of the line. */
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;
}
//! Check if the line intersects with a shpere
/** \param sorigin: Origin of the shpere.
\param sradius: Radius of the sphere.
\param outdistance: The distance to the first intersection point.
\return True if there is an intersection.
If there is one, the distance to the first intersection point
is stored in outdistance. */
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
//! Start point of line
vector3d<T> start;
//! End point of line
vector3d<T> end;
};
//! Typedef for an f32 line.
typedef line3d<f32> line3df;
//! Typedef for an integer line.
typedef line3d<s32> line3di;
} // end namespace core
} // end namespace irr
#endif
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