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166 lines
4.2 KiB
C
166 lines
4.2 KiB
C
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// Copyright (C) 2002-2012 Nikolaus Gebhardt
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// This file is part of the "Irrlicht Engine".
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// For conditions of distribution and use, see copyright notice in irrlicht.h
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#pragma once
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#include "irrTypes.h"
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#include "vector3d.h"
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namespace irr
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{
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namespace core
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{
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//! 3D line between two points with intersection methods.
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template <class T>
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class line3d
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{
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public:
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//! Default constructor
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/** line from (0,0,0) to (1,1,1) */
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constexpr line3d() :
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start(0, 0, 0), end(1, 1, 1) {}
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//! Constructor with two points
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constexpr line3d(T xa, T ya, T za, T xb, T yb, T zb) :
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start(xa, ya, za), end(xb, yb, zb) {}
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//! Constructor with two points as vectors
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constexpr line3d(const vector3d<T> &start, const vector3d<T> &end) :
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start(start), end(end) {}
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// operators
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line3d<T> operator+(const vector3d<T> &point) const { return line3d<T>(start + point, end + point); }
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line3d<T> &operator+=(const vector3d<T> &point)
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{
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start += point;
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end += point;
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return *this;
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}
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line3d<T> operator-(const vector3d<T> &point) const { return line3d<T>(start - point, end - point); }
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line3d<T> &operator-=(const vector3d<T> &point)
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{
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start -= point;
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end -= point;
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return *this;
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}
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constexpr bool operator==(const line3d<T> &other) const
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{
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return (start == other.start && end == other.end) || (end == other.start && start == other.end);
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}
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constexpr bool operator!=(const line3d<T> &other) const
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{
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return !(start == other.start && end == other.end) || (end == other.start && start == other.end);
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}
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// functions
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//! Set this line to a new line going through the two points.
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void setLine(const T &xa, const T &ya, const T &za, const T &xb, const T &yb, const T &zb)
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{
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start.set(xa, ya, za);
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end.set(xb, yb, zb);
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}
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//! Set this line to a new line going through the two points.
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void setLine(const vector3d<T> &nstart, const vector3d<T> &nend)
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{
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start.set(nstart);
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end.set(nend);
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}
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//! Set this line to new line given as parameter.
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void setLine(const line3d<T> &line)
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{
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start.set(line.start);
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end.set(line.end);
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}
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//! Get length of line
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/** \return Length of line. */
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T getLength() const { return start.getDistanceFrom(end); }
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//! Get squared length of line
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/** \return Squared length of line. */
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T getLengthSQ() const { return start.getDistanceFromSQ(end); }
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//! Get middle of line
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/** \return Center of line. */
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vector3d<T> getMiddle() const
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{
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return (start + end) / (T)2;
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}
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//! Get vector of line
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/** \return vector of line. */
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vector3d<T> getVector() const
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{
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return end - start;
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}
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//! Check if the given point is between start and end of the line.
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/** Assumes that the point is already somewhere on the line.
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\param point The point to test.
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\return True if point is on the line between start and end, else false.
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*/
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bool isPointBetweenStartAndEnd(const vector3d<T> &point) const
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{
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return point.isBetweenPoints(start, end);
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}
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//! Get the closest point on this line to a point
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/** \param point The point to compare to.
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\return The nearest point which is part of the line. */
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vector3d<T> getClosestPoint(const vector3d<T> &point) const
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{
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vector3d<T> c = point - start;
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vector3d<T> v = end - start;
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T d = (T)v.getLength();
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v /= d;
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T t = v.dotProduct(c);
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if (t < (T)0.0)
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return start;
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if (t > d)
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return end;
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v *= t;
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return start + v;
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}
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//! Check if the line intersects with a sphere
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/** \param sorigin: Origin of the sphere.
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\param sradius: Radius of the sphere.
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\param outdistance: The distance to the first intersection point.
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\return True if there is an intersection.
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If there is one, the distance to the first intersection point
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is stored in outdistance. */
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bool getIntersectionWithSphere(const vector3d<T> &sorigin, T sradius, f64 &outdistance) const
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{
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const vector3d<T> q = sorigin - start;
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T c = q.getLength();
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T v = q.dotProduct(getVector().normalize());
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T d = sradius * sradius - (c * c - v * v);
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if (d < 0.0)
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return false;
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outdistance = v - core::squareroot(d);
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return true;
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}
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// member variables
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//! Start point of line
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vector3d<T> start;
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//! End point of line
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vector3d<T> end;
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};
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//! Typedef for an f32 line.
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typedef line3d<f32> line3df;
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//! Typedef for an integer line.
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typedef line3d<s32> line3di;
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} // end namespace core
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} // end namespace irr
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