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// Geometric Tools, LLC
// Copyright (c) 1998-2014
// Distributed under the Boost Software License, Version 1.0.
// http://www.boost.org/LICENSE_1_0.txt
// http://www.geometrictools.com/License/Boost/LICENSE_1_0.txt
//
// File Version: 5.2.0 (2010/06/21)
#ifndef RTSPHERETRIANGLE_H
#define RTSPHERETRIANGLE_H
#include "Wm5Vector3.h"
using namespace Wm5;
// Compute the first time of contact and the corresponding first point of
// contact for a moving sphere and a moving triangle.
struct SphereStruct
{
Vector3f C;
float R;
float RSqr;
// Call this after R is modified.
inline void ComputeDerived ()
{
RSqr = R*R;
}
};
struct TriangleStruct
{
Vector3f P[3]; // vertex positions
Vector3f E[3]; // edge directions (unit length)
float H[3]; // edge half-lengths
Vector3f M[3]; // midpoints of edges
Vector3f N; // triangle normal
Vector3f EN[3]; // edge normals (unit length, outer pointing)
// Call this after any of P0, P1, or P2 have been modified.
inline void ComputeDerived ()
{
E[0] = P[1] - P[0];
E[1] = P[2] - P[1];
E[2] = P[0] - P[2];
H[0] = 0.5f*E[0].Normalize();
H[1] = 0.5f*E[1].Normalize();
H[2] = 0.5f*E[2].Normalize();
M[0] = P[0] + H[0]*E[0];
M[1] = P[1] + H[1]*E[1];
M[2] = P[2] + H[2]*E[2];
N = E[0].UnitCross(E[1]);
EN[0] = E[0].Cross(N);
EN[1] = E[1].Cross(N);
EN[2] = E[2].Cross(N);
}
};
enum ContactType
{
SEPARATED,
CONTACT,
OVERLAPPING
};
// The time interval of the query is [0,tMax]. On return,
// type = SEPARATED: No intersection during the time interval, so
// contactTime and contactPoint are invalid.
// type = CONTACT: A single time and point of contact during the
// time interval, so contactTime and contactPoint are valid.
// type = OVERLAPPING: The sphere and triangle overlap at time zero. The
// set of intersection has infinitely many points. The contactTime
// stores zero. The contactPoint stores the triangle point that is
// closest to the sphere center.
ContactType Collide (const SphereStruct& sph, const Vector3f& sphVelocity,
const TriangleStruct& tri, const Vector3f& triVelocity, float tMax,
float& contactTime, Vector3f& contactPoint);
#endif
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