reactphysics3d/src/collision/narrowphase/SphereVsConvexPolyhedronAlgorithm.cpp

102 lines
5.0 KiB
C++

/********************************************************************************
* ReactPhysics3D physics library, http://www.reactphysics3d.com *
* Copyright (c) 2010-2019 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 <reactphysics3d/collision/narrowphase/SphereVsConvexPolyhedronAlgorithm.h>
#include <reactphysics3d/collision/narrowphase/GJK/GJKAlgorithm.h>
#include <reactphysics3d/collision/narrowphase/SAT/SATAlgorithm.h>
#include <reactphysics3d/collision/narrowphase/NarrowPhaseInfoBatch.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(NarrowPhaseInfoBatch& narrowPhaseInfoBatch, uint batchStartIndex, uint batchNbItems,
bool clipWithPreviousAxisIfStillColliding, MemoryAllocator& memoryAllocator) {
// First, we run the GJK algorithm
GJKAlgorithm gjkAlgorithm;
bool isCollisionFound = false;
#ifdef IS_PROFILING_ACTIVE
gjkAlgorithm.setProfiler(mProfiler);
#endif
List<GJKAlgorithm::GJKResult> gjkResults(memoryAllocator);
gjkAlgorithm.testCollision(narrowPhaseInfoBatch, batchStartIndex, batchNbItems, gjkResults);
assert(gjkResults.size() == batchNbItems);
// For each item in the batch
for (uint batchIndex = batchStartIndex; batchIndex < batchStartIndex + batchNbItems; batchIndex++) {
assert(narrowPhaseInfoBatch.collisionShapes1[batchIndex]->getType() == CollisionShapeType::CONVEX_POLYHEDRON ||
narrowPhaseInfoBatch.collisionShapes2[batchIndex]->getType() == CollisionShapeType::CONVEX_POLYHEDRON);
assert(narrowPhaseInfoBatch.collisionShapes1[batchIndex]->getType() == CollisionShapeType::SPHERE ||
narrowPhaseInfoBatch.collisionShapes2[batchIndex]->getType() == CollisionShapeType::SPHERE);
// Get the last frame collision info
LastFrameCollisionInfo* lastFrameCollisionInfo = narrowPhaseInfoBatch.lastFrameCollisionInfos[batchIndex];
lastFrameCollisionInfo->wasUsingGJK = true;
lastFrameCollisionInfo->wasUsingSAT = false;
// If we have found a contact point inside the margins (shallow penetration)
if (gjkResults[batchIndex] == GJKAlgorithm::GJKResult::COLLIDE_IN_MARGIN) {
// Return true
narrowPhaseInfoBatch.isColliding[batchIndex] = true;
isCollisionFound = true;
continue;
}
// If we have overlap even without the margins (deep penetration)
if (gjkResults[batchIndex] == GJKAlgorithm::GJKResult::INTERPENETRATE) {
// Run the SAT algorithm to find the separating axis and compute contact point
SATAlgorithm satAlgorithm(clipWithPreviousAxisIfStillColliding, memoryAllocator);
#ifdef IS_PROFILING_ACTIVE
satAlgorithm.setProfiler(mProfiler);
#endif
isCollisionFound |= satAlgorithm.testCollisionSphereVsConvexPolyhedron(narrowPhaseInfoBatch, batchIndex, 1);
lastFrameCollisionInfo->wasUsingGJK = false;
lastFrameCollisionInfo->wasUsingSAT = true;
continue;
}
}
return isCollisionFound;
}