reactphysics3d/src/collision/narrowphase/SphereVsConvexPolyhedronAlgorithm.cpp

73 lines
3.9 KiB
C++

/********************************************************************************
* ReactPhysics3D physics library, http://www.reactphysics3d.com *
* Copyright (c) 2010-2016 Daniel Chappuis *
*********************************************************************************
* *
* This software is provided 'as-is', without any express or implied warranty. *
* In no event will the authors be held liable for any damages arising from the *
* use of this software. *
* *
* Permission is granted to anyone to use this software for any purpose, *
* including commercial applications, and to alter it and redistribute it *
* freely, subject to the following restrictions: *
* *
* 1. The origin of this software must not be misrepresented; you must not claim *
* that you wrote the original software. If you use this software in a *
* product, an acknowledgment in the product documentation would be *
* appreciated but is not required. *
* *
* 2. Altered source versions must be plainly marked as such, and must not be *
* misrepresented as being the original software. *
* *
* 3. This notice may not be removed or altered from any source distribution. *
* *
********************************************************************************/
// Libraries
#include "SphereVsConvexPolyhedronAlgorithm.h"
#include "GJK/GJKAlgorithm.h"
#include "SAT/SATAlgorithm.h"
// We want to use the ReactPhysics3D namespace
using namespace reactphysics3d;
// Compute the narrow-phase collision detection between a sphere and a convex polyhedron
// This technique is based on the "Robust Contact Creation for Physics Simulations" presentation
// by Dirk Gregorius.
bool SphereVsConvexPolyhedronAlgorithm::testCollision(NarrowPhaseInfo* narrowPhaseInfo, bool reportContacts) {
assert(narrowPhaseInfo->collisionShape1->getType() == CollisionShapeType::CONVEX_POLYHEDRON ||
narrowPhaseInfo->collisionShape2->getType() == CollisionShapeType::CONVEX_POLYHEDRON);
assert(narrowPhaseInfo->collisionShape1->getType() == CollisionShapeType::SPHERE ||
narrowPhaseInfo->collisionShape2->getType() == CollisionShapeType::SPHERE);
// First, we run the GJK algorithm
GJKAlgorithm gjkAlgorithm;
GJKAlgorithm::GJKResult result = gjkAlgorithm.testCollision(narrowPhaseInfo, reportContacts);
narrowPhaseInfo->overlappingPair->getLastFrameCollisionInfo().wasUsingGJK = true;
narrowPhaseInfo->overlappingPair->getLastFrameCollisionInfo().wasUsingSAT = false;
// If we have found a contact point inside the margins (shallow penetration)
if (result == GJKAlgorithm::GJKResult::COLLIDE_IN_MARGIN) {
// Return true
return true;
}
// If we have overlap even without the margins (deep penetration)
if (result == GJKAlgorithm::GJKResult::INTERPENETRATE) {
// Run the SAT algorithm to find the separating axis and compute contact point
SATAlgorithm satAlgorithm;
bool isColliding = satAlgorithm.testCollisionSphereVsConvexPolyhedron(narrowPhaseInfo, reportContacts);
narrowPhaseInfo->overlappingPair->getLastFrameCollisionInfo().wasUsingGJK = false;
narrowPhaseInfo->overlappingPair->getLastFrameCollisionInfo().wasUsingSAT = true;
return isColliding;
}
return false;
}