tesseract_compound_collision_algorithm.cpp

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/*
Bullet Continuous Collision Detection and Physics Library
Copyright (c) 2003-2006 Erwin Coumans  http://continuousphysics.com/Bullet/
 
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.
 
*/
 
#include <tesseract_common/macros.h>
TESSERACT_COMMON_IGNORE_WARNINGS_PUSH
#include <BulletCollision/CollisionDispatch/btCollisionObject.h>
#include <BulletCollision/CollisionShapes/btCompoundShape.h>
#include <BulletCollision/CollisionShapes/btCollisionShape.h>
#include <BulletCollision/BroadphaseCollision/btDbvt.h>
#include <LinearMath/btIDebugDraw.h>
#include <LinearMath/btAabbUtil2.h>
#include <BulletCollision/CollisionDispatch/btManifoldResult.h>
#include <BulletCollision/CollisionDispatch/btCollisionObjectWrapper.h>
TESSERACT_COMMON_IGNORE_WARNINGS_POP
 
#include <tesseract_collision/bullet/tesseract_compound_collision_algorithm.h>
#include <tesseract_collision/core/types.h>
 
// LCOV_EXCL_START
// See tesseract issue: https://github.com/tesseract-robotics/tesseract/issues/934
TESSERACT_COMMON_IGNORE_WARNINGS_PUSH
namespace tesseract_collision::tesseract_collision_bullet
{
TesseractCompoundCollisionAlgorithm::TesseractCompoundCollisionAlgorithm(const btCollisionAlgorithmConstructionInfo& ci,
                                                                         const btCollisionObjectWrapper* body0Wrap,
                                                                         const btCollisionObjectWrapper* body1Wrap,
                                                                         bool isSwapped)
  : btActivatingCollisionAlgorithm(ci, body0Wrap, body1Wrap), m_isSwapped(isSwapped), m_sharedManifold(ci.m_manifold)
{
  const btCollisionObjectWrapper* colObjWrap = m_isSwapped ? body1Wrap : body0Wrap;
  btAssert(colObjWrap->getCollisionShape()->isCompound());
 
  const auto* compoundShape = static_cast<const btCompoundShape*>(colObjWrap->getCollisionShape());
  m_compoundShapeRevision = compoundShape->getUpdateRevision();
 
  preallocateChildAlgorithms(body0Wrap, body1Wrap);
}
 
void TesseractCompoundCollisionAlgorithm::preallocateChildAlgorithms(const btCollisionObjectWrapper* body0Wrap,
                                                                     const btCollisionObjectWrapper* body1Wrap)
{
  const btCollisionObjectWrapper* colObjWrap = m_isSwapped ? body1Wrap : body0Wrap;
  const btCollisionObjectWrapper* otherObjWrap = m_isSwapped ? body0Wrap : body1Wrap;
  btAssert(colObjWrap->getCollisionShape()->isCompound());
 
  const auto* compoundShape = static_cast<const btCompoundShape*>(colObjWrap->getCollisionShape());
 
  int numChildren = compoundShape->getNumChildShapes();
 
  m_childCollisionAlgorithms.resize(numChildren);
  for (int i = 0; i < numChildren; i++)
  {
    if (compoundShape->getDynamicAabbTree() != nullptr)
    {
      m_childCollisionAlgorithms[i] = nullptr;
    }
    else
    {
      const btCollisionShape* childShape = compoundShape->getChildShape(i);
 
      btCollisionObjectWrapper childWrap(colObjWrap,
                                         childShape,
                                         colObjWrap->getCollisionObject(),
                                         colObjWrap->getWorldTransform(),
                                         -1,
                                         i);  // wrong child trans, but unused (hopefully)
      m_childCollisionAlgorithms[i] =
          m_dispatcher->findAlgorithm(&childWrap, otherObjWrap, m_sharedManifold, BT_CONTACT_POINT_ALGORITHMS);
 
      btAlignedObjectArray<btCollisionAlgorithm*> m_childCollisionAlgorithmsContact;
      btAlignedObjectArray<btCollisionAlgorithm*> m_childCollisionAlgorithmsClosestPoints;
    }
  }
}
 
void TesseractCompoundCollisionAlgorithm::removeChildAlgorithms()
{
  int numChildren = m_childCollisionAlgorithms.size();
  for (int i = 0; i < numChildren; i++)
  {
    if (m_childCollisionAlgorithms[i] != nullptr)
    {
      m_childCollisionAlgorithms[i]->~btCollisionAlgorithm();
      m_dispatcher->freeCollisionAlgorithm(m_childCollisionAlgorithms[i]);
    }
  }
}
 
TesseractCompoundCollisionAlgorithm::~TesseractCompoundCollisionAlgorithm() { removeChildAlgorithms(); }
 
struct TesseractCompoundLeafCallback : btDbvt::ICollide
{
public:
  const btCollisionObjectWrapper* m_compoundColObjWrap;
  const btCollisionObjectWrapper* m_otherObjWrap;
  btDispatcher* m_dispatcher;
  const btDispatcherInfo& m_dispatchInfo;  // NOLINT
  btManifoldResult* m_resultOut;
  btCollisionAlgorithm** m_childCollisionAlgorithms;
  btPersistentManifold* m_sharedManifold;
  ContactTestData* m_contact_test_data;
 
  TesseractCompoundLeafCallback(const btCollisionObjectWrapper* compoundObjWrap,
                                const btCollisionObjectWrapper* otherObjWrap,
                                btDispatcher* dispatcher,
                                const btDispatcherInfo& dispatchInfo,
                                btManifoldResult* resultOut,
                                btCollisionAlgorithm** childCollisionAlgorithms,
                                btPersistentManifold* sharedManifold)
    : m_compoundColObjWrap(compoundObjWrap)
    , m_otherObjWrap(otherObjWrap)
    , m_dispatcher(dispatcher)
    , m_dispatchInfo(dispatchInfo)
    , m_resultOut(resultOut)
    , m_childCollisionAlgorithms(childCollisionAlgorithms)
    , m_sharedManifold(sharedManifold)
    , m_contact_test_data(static_cast<ContactTestData*>(compoundObjWrap->m_collisionObject->getUserPointer()))
  {
  }
 
  void ProcessChildShape(const btCollisionShape* childShape, int index)
  {
    btAssert(index >= 0);
    const auto* compoundShape = static_cast<const btCompoundShape*>(m_compoundColObjWrap->getCollisionShape());
    btAssert(index < compoundShape->getNumChildShapes());
 
    if (m_contact_test_data->done)
      return;
 
    // backup
    btTransform orgTrans = m_compoundColObjWrap->getWorldTransform();
 
    const btTransform& childTrans = compoundShape->getChildTransform(index);
    btTransform newChildWorldTrans = orgTrans * childTrans;
 
    // perform an AABB check first
    btVector3 aabbMin0, aabbMax0;
    childShape->getAabb(newChildWorldTrans, aabbMin0, aabbMax0);
 
    btVector3 extendAabb(m_resultOut->m_closestPointDistanceThreshold,
                         m_resultOut->m_closestPointDistanceThreshold,
                         m_resultOut->m_closestPointDistanceThreshold);
    aabbMin0 -= extendAabb;
    aabbMax0 += extendAabb;
 
    btVector3 aabbMin1, aabbMax1;
    m_otherObjWrap->getCollisionShape()->getAabb(m_otherObjWrap->getWorldTransform(), aabbMin1, aabbMax1);
 
    if (TestAabbAgainstAabb2(aabbMin0, aabbMax0, aabbMin1, aabbMax1))
    {
#if BT_BULLET_VERSION >= 300
      btTransform preTransform = childTrans;
      if (this->m_compoundColObjWrap->m_preTransform != nullptr)
      {
        preTransform = preTransform * (*(this->m_compoundColObjWrap->m_preTransform));
      }
      btCollisionObjectWrapper compoundWrap(this->m_compoundColObjWrap,
                                            childShape,
                                            m_compoundColObjWrap->getCollisionObject(),
                                            newChildWorldTrans,
                                            preTransform,
                                            -1,
                                            index);
#else
      btCollisionObjectWrapper compoundWrap(this->m_compoundColObjWrap,
                                            childShape,
                                            m_compoundColObjWrap->getCollisionObject(),
                                            newChildWorldTrans,
                                            -1,
                                            index);
#endif
 
      btCollisionAlgorithm* algo = nullptr;
      bool allocatedAlgorithm = false;
 
      if (m_resultOut->m_closestPointDistanceThreshold > 0)
      {
        algo = m_dispatcher->findAlgorithm(&compoundWrap, m_otherObjWrap, nullptr, BT_CLOSEST_POINT_ALGORITHMS);
        allocatedAlgorithm = true;
      }
      else
      {
        // the contactpoint is still projected back using the original inverted worldtrans
        if (m_childCollisionAlgorithms[index] == nullptr)
        {
          m_childCollisionAlgorithms[index] =
              m_dispatcher->findAlgorithm(&compoundWrap, m_otherObjWrap, m_sharedManifold, BT_CONTACT_POINT_ALGORITHMS);
        }
        algo = m_childCollisionAlgorithms[index];
      }
 
      const btCollisionObjectWrapper* tmpWrap = nullptr;
 
      if (m_resultOut->getBody0Internal() == m_compoundColObjWrap->getCollisionObject())
      {
        tmpWrap = m_resultOut->getBody0Wrap();
        m_resultOut->setBody0Wrap(&compoundWrap);
        m_resultOut->setShapeIdentifiersA(-1, index);
      }
      else
      {
        tmpWrap = m_resultOut->getBody1Wrap();
        m_resultOut->setBody1Wrap(&compoundWrap);
        m_resultOut->setShapeIdentifiersB(-1, index);
      }
 
      algo->processCollision(&compoundWrap, m_otherObjWrap, m_dispatchInfo, m_resultOut);
 
#if 0  // NOLINT
                        if (m_dispatchInfo.m_debugDraw && (m_dispatchInfo.m_debugDraw->getDebugMode() & btIDebugDraw::DBG_DrawAabb))
                        {
                                btVector3 worldAabbMin,worldAabbMax;
                                m_dispatchInfo.m_debugDraw->drawAabb(aabbMin0,aabbMax0,btVector3(1,1,1));
                                m_dispatchInfo.m_debugDraw->drawAabb(aabbMin1,aabbMax1,btVector3(1,1,1));
                        }
#endif
 
      if (m_resultOut->getBody0Internal() == m_compoundColObjWrap->getCollisionObject())
      {
        m_resultOut->setBody0Wrap(tmpWrap);
      }
      else
      {
        m_resultOut->setBody1Wrap(tmpWrap);
      }
      if (allocatedAlgorithm)
      {
        algo->~btCollisionAlgorithm();
        m_dispatcher->freeCollisionAlgorithm(algo);
      }
    }
  }
  void Process(const btDbvtNode* leaf)  // NOLINT
  {
    int index = leaf->dataAsInt;
 
    const auto* compoundShape = static_cast<const btCompoundShape*>(m_compoundColObjWrap->getCollisionShape());
    const btCollisionShape* childShape = compoundShape->getChildShape(index);
 
#if 0  // NOLINT
                if (m_dispatchInfo.m_debugDraw && (m_dispatchInfo.m_debugDraw->getDebugMode() & btIDebugDraw::DBG_DrawAabb))
                {
                        btVector3 worldAabbMin,worldAabbMax;
                        btTransform     orgTrans = m_compoundColObjWrap->getWorldTransform();
                        btTransformAabb(leaf->volume.Mins(),leaf->volume.Maxs(),0.,orgTrans,worldAabbMin,worldAabbMax);
                        m_dispatchInfo.m_debugDraw->drawAabb(worldAabbMin,worldAabbMax,btVector3(1,0,0));
                }
#endif
 
    ProcessChildShape(childShape, index);
  }
};
 
void TesseractCompoundCollisionAlgorithm::processCollision(const btCollisionObjectWrapper* body0Wrap,
                                                           const btCollisionObjectWrapper* body1Wrap,
                                                           const btDispatcherInfo& dispatchInfo,
                                                           btManifoldResult* resultOut)
{
  const btCollisionObjectWrapper* colObjWrap = m_isSwapped ? body1Wrap : body0Wrap;
  const btCollisionObjectWrapper* otherObjWrap = m_isSwapped ? body0Wrap : body1Wrap;
 
  btAssert(colObjWrap->getCollisionShape()->isCompound());
  const auto* compoundShape = static_cast<const btCompoundShape*>(colObjWrap->getCollisionShape());
 
  if (compoundShape->getUpdateRevision() != m_compoundShapeRevision)
  {
    removeChildAlgorithms();
 
    preallocateChildAlgorithms(body0Wrap, body1Wrap);
    m_compoundShapeRevision = compoundShape->getUpdateRevision();
  }
 
  if (m_childCollisionAlgorithms.size() == 0)
    return;
 
  const btDbvt* tree = compoundShape->getDynamicAabbTree();
  // use a dynamic aabb tree to cull potential child-overlaps
  TesseractCompoundLeafCallback callback(colObjWrap,
                                         otherObjWrap,
                                         m_dispatcher,
                                         dispatchInfo,
                                         resultOut,
                                         &m_childCollisionAlgorithms[0],
                                         m_sharedManifold);
 
  {
    manifoldArray.resize(0);
    for (int i = 0; i < m_childCollisionAlgorithms.size(); i++)
    {
      if (m_childCollisionAlgorithms[i] != nullptr)
      {
        // See tesseract issue: https://github.com/tesseract-robotics/tesseract/issues/934
        m_childCollisionAlgorithms[i]->getAllContactManifolds(manifoldArray);
        for (int m = 0; m < manifoldArray.size(); m++)
        {
          if (manifoldArray[m]->getNumContacts() != 0)
          {
            resultOut->setPersistentManifold(manifoldArray[m]);
            resultOut->refreshContactPoints();
            resultOut->setPersistentManifold(nullptr);  //??necessary?
          }
        }
        manifoldArray.resize(0);
      }
    }
  }
 
  if (tree != nullptr)
  {
    btVector3 localAabbMin, localAabbMax;
    btTransform otherInCompoundSpace;
    otherInCompoundSpace = colObjWrap->getWorldTransform().inverse() * otherObjWrap->getWorldTransform();
    otherObjWrap->getCollisionShape()->getAabb(otherInCompoundSpace, localAabbMin, localAabbMax);
    btVector3 extraExtends(resultOut->m_closestPointDistanceThreshold,
                           resultOut->m_closestPointDistanceThreshold,
                           resultOut->m_closestPointDistanceThreshold);
    localAabbMin -= extraExtends;
    localAabbMax += extraExtends;
 
    const ATTRIBUTE_ALIGNED16(btDbvtVolume) bounds = btDbvtVolume::FromMM(localAabbMin, localAabbMax);
    // process all children, that overlap with  the given AABB bounds
    tree->collideTVNoStackAlloc(tree->m_root, bounds, stack2, callback);
  }
  else
  {
    // iterate over all children, perform an AABB check inside ProcessChildShape
    int numChildren = m_childCollisionAlgorithms.size();
    for (int i = 0; i < numChildren; i++)
    {
      callback.ProcessChildShape(compoundShape->getChildShape(i), i);
    }
  }
 
  {
    // iterate over all children, perform an AABB check inside ProcessChildShape
    int numChildren = m_childCollisionAlgorithms.size();
    manifoldArray.resize(0);
    const btCollisionShape* childShape = nullptr;
    btTransform orgTrans;
 
    btTransform newChildWorldTrans;
    btVector3 aabbMin0, aabbMax0, aabbMin1, aabbMax1;
 
    for (int i = 0; i < numChildren; i++)
    {
      if (m_childCollisionAlgorithms[i] != nullptr)
      {
        childShape = compoundShape->getChildShape(i);
        // if not longer overlapping, remove the algorithm
        orgTrans = colObjWrap->getWorldTransform();
 
        const btTransform& childTrans = compoundShape->getChildTransform(i);
        newChildWorldTrans = orgTrans * childTrans;
 
        // perform an AABB check first
        childShape->getAabb(newChildWorldTrans, aabbMin0, aabbMax0);
        otherObjWrap->getCollisionShape()->getAabb(otherObjWrap->getWorldTransform(), aabbMin1, aabbMax1);
 
        if (!TestAabbAgainstAabb2(aabbMin0, aabbMax0, aabbMin1, aabbMax1))
        {
          m_childCollisionAlgorithms[i]->~btCollisionAlgorithm();
          m_dispatcher->freeCollisionAlgorithm(m_childCollisionAlgorithms[i]);
          m_childCollisionAlgorithms[i] = nullptr;
        }
      }
    }
  }
}
 
btScalar TesseractCompoundCollisionAlgorithm::calculateTimeOfImpact(btCollisionObject* body0,
                                                                    btCollisionObject* body1,
                                                                    const btDispatcherInfo& dispatchInfo,
                                                                    btManifoldResult* resultOut)
{
  btAssert(0);
  // needs to be fixed, using btCollisionObjectWrapper and NOT modifying internal data structures
  btCollisionObject* colObj = m_isSwapped ? body1 : body0;
  btCollisionObject* otherObj = m_isSwapped ? body0 : body1;
 
  btAssert(colObj->getCollisionShape()->isCompound());
 
  auto* compoundShape = static_cast<btCompoundShape*>(colObj->getCollisionShape());
 
  // We will use the OptimizedBVH, AABB tree to cull potential child-overlaps
  // If both proxies are Compound, we will deal with that directly, by performing sequential/parallel tree traversals
  // given Proxy0 and Proxy1, if both have a tree, Tree0 and Tree1, this means:
  // determine overlapping nodes of Proxy1 using Proxy0 AABB against Tree1
  // then use each overlapping node AABB against Tree0
  // and vise versa.
 
  auto hitFraction = btScalar(1.);
 
  int numChildren = m_childCollisionAlgorithms.size();
  btTransform orgTrans;
  for (int i = 0; i < numChildren; i++)
  {
    // btCollisionShape* childShape = compoundShape->getChildShape(i);
 
    // backup
    orgTrans = colObj->getWorldTransform();
 
    const btTransform& childTrans = compoundShape->getChildTransform(i);
    // btTransform      newChildWorldTrans = orgTrans*childTrans ;
    colObj->setWorldTransform(orgTrans * childTrans);
 
    // btCollisionShape* tmpShape = colObj->getCollisionShape();
    // colObj->internalSetTemporaryCollisionShape( childShape );
    btScalar frac = m_childCollisionAlgorithms[i]->calculateTimeOfImpact(colObj, otherObj, dispatchInfo, resultOut);
    hitFraction = std::min(frac, hitFraction);
 
    // revert back
    // colObj->internalSetTemporaryCollisionShape( tmpShape);
    colObj->setWorldTransform(orgTrans);
  }
  return hitFraction;
}
}  // namespace tesseract_collision::tesseract_collision_bullet
TESSERACT_COMMON_IGNORE_WARNINGS_POP
// LCOV_EXCL_STOP