forked from aya/aya
135 lines
2.7 KiB
C++
135 lines
2.7 KiB
C++
/**
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@file Plane.cpp
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@maintainer Morgan McGuire, http://graphics.cs.williams.edu
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@created 2003-02-06
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@edited 2006-01-29
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*/
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#include "platform.hpp"
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#include "Plane.hpp"
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#include "stringutils.hpp"
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namespace G3D
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{
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Plane::Plane(Vector4 point0, Vector4 point1, Vector4 point2)
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{
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debugAssertM(point0.w != 0 || point1.w != 0 || point2.w != 0, "At least one point must be finite.");
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// Rotate the points around so that the finite points come first.
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while ((point0.w == 0) && ((point1.w == 0) || (point2.w != 0)))
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{
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Vector4 temp = point0;
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point0 = point1;
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point1 = point2;
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point2 = temp;
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}
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Vector3 dir1;
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Vector3 dir2;
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if (point1.w == 0)
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{
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// 1 finite, 2 infinite points; the plane must contain
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// the direction of the two direcitons
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dir1 = point1.xyz();
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dir2 = point2.xyz();
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}
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else if (point2.w != 0)
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{
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// 3 finite points, the plane must contain the directions
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// betwseen the points.
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dir1 = point1.xyz() - point0.xyz();
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dir2 = point2.xyz() - point0.xyz();
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}
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else
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{
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// 2 finite, 1 infinite point; the plane must contain
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// the direction between the first two points and the
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// direction of the third point.
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dir1 = point1.xyz() - point0.xyz();
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dir2 = point2.xyz();
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}
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_normal = dir1.cross(dir2).direction();
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_distance = _normal.dot(point0.xyz());
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}
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Plane::Plane(const Vector3& point0, const Vector3& point1, const Vector3& point2)
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{
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_normal = (point1 - point0).cross(point2 - point0).direction();
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_distance = _normal.dot(point0);
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}
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Plane::Plane(const Vector3& __normal, const Vector3& point)
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{
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_normal = __normal.direction();
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_distance = _normal.dot(point);
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}
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Plane Plane::fromEquation(float a, float b, float c, float d)
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{
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Vector3 n(a, b, c);
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float magnitude = n.magnitude();
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d /= magnitude;
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n /= magnitude;
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return Plane(n, -d);
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}
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void Plane::flip()
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{
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_normal = -_normal;
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_distance = -_distance;
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}
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void Plane::getEquation(Vector3& n, float& d) const
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{
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double _d;
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getEquation(n, _d);
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d = (float)_d;
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}
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void Plane::getEquation(Vector3& n, double& d) const
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{
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n = _normal;
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d = -_distance;
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}
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void Plane::getEquation(float& a, float& b, float& c, float& d) const
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{
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double _a, _b, _c, _d;
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getEquation(_a, _b, _c, _d);
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a = (float)_a;
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b = (float)_b;
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c = (float)_c;
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d = (float)_d;
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}
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void Plane::getEquation(double& a, double& b, double& c, double& d) const
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{
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a = _normal.x;
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b = _normal.y;
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c = _normal.z;
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d = -_distance;
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}
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std::string Plane::toString() const
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{
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return format("Plane(%g, %g, %g, %g)", _normal.x, _normal.y, _normal.z, _distance);
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}
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} // namespace G3D
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