btSoftRigidDynamicsWorld.cpp

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/*
Bullet Continuous Collision Detection and Physics Library
Copyright (c) 2003-2006 Erwin Coumans  https://bulletphysics.org
 
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 "btSoftRigidDynamicsWorld.h"
#include "LinearMath/btQuickprof.h"
 
//softbody & helpers
#include "btSoftBody.h"
#include "btSoftBodyHelpers.h"
#include "btSoftBodySolvers.h"
#include "btDefaultSoftBodySolver.h"
#include "LinearMath/btSerializer.h"
 
btSoftRigidDynamicsWorld::btSoftRigidDynamicsWorld(
        btDispatcher* dispatcher,
        btBroadphaseInterface* pairCache,
        btConstraintSolver* constraintSolver,
        btCollisionConfiguration* collisionConfiguration,
        btSoftBodySolver* softBodySolver) : btDiscreteDynamicsWorld(dispatcher, pairCache, constraintSolver, collisionConfiguration),
                                                                                m_softBodySolver(softBodySolver),
                                                                                m_ownsSolver(false)
{
        if (!m_softBodySolver)
        {
                void* ptr = btAlignedAlloc(sizeof(btDefaultSoftBodySolver), 16);
                m_softBodySolver = new (ptr) btDefaultSoftBodySolver();
                m_ownsSolver = true;
        }
 
        m_drawFlags = fDrawFlags::Std;
        m_drawNodeTree = true;
        m_drawFaceTree = false;
        m_drawClusterTree = false;
        m_sbi.m_broadphase = pairCache;
        m_sbi.m_dispatcher = dispatcher;
        m_sbi.m_sparsesdf.Initialize();
        m_sbi.m_sparsesdf.Reset();
 
        m_sbi.air_density = (btScalar)1.2;
        m_sbi.water_density = 0;
        m_sbi.water_offset = 0;
        m_sbi.water_normal = btVector3(0, 0, 0);
        m_sbi.m_gravity.setValue(0, -10, 0);
 
        m_sbi.m_sparsesdf.Initialize();
}
 
btSoftRigidDynamicsWorld::~btSoftRigidDynamicsWorld()
{
        if (m_ownsSolver)
        {
                m_softBodySolver->~btSoftBodySolver();
                btAlignedFree(m_softBodySolver);
        }
}
 
void btSoftRigidDynamicsWorld::predictUnconstraintMotion(btScalar timeStep)
{
        btDiscreteDynamicsWorld::predictUnconstraintMotion(timeStep);
        {
                BT_PROFILE("predictUnconstraintMotionSoftBody");
                m_softBodySolver->predictMotion(float(timeStep));
        }
}
 
void btSoftRigidDynamicsWorld::internalSingleStepSimulation(btScalar timeStep)
{
        // Let the solver grab the soft bodies and if necessary optimize for it
        m_softBodySolver->optimize(getSoftBodyArray());
 
        if (!m_softBodySolver->checkInitialized())
        {
                btAssert("Solver initialization failed\n");
        }
 
        btDiscreteDynamicsWorld::internalSingleStepSimulation(timeStep);
 
        solveSoftBodiesConstraints(timeStep);
 
        //self collisions
        for (int i = 0; i < m_softBodies.size(); i++)
        {
                btSoftBody* psb = (btSoftBody*)m_softBodies[i];
                psb->defaultCollisionHandler(psb);
        }
 
        m_softBodySolver->updateSoftBodies();
 
        // End solver-wise simulation step
        // ///////////////////////////////
}
 
void btSoftRigidDynamicsWorld::solveSoftBodiesConstraints(btScalar timeStep)
{
        BT_PROFILE("solveSoftConstraints");
 
        if (m_softBodies.size())
        {
                btSoftBody::solveClusters(m_softBodies);
        }
 
        // Solve constraints solver-wise
        m_softBodySolver->solveConstraints(timeStep * m_softBodySolver->getTimeScale());
}
 
void btSoftRigidDynamicsWorld::addSoftBody(btSoftBody* body, int collisionFilterGroup, int collisionFilterMask)
{
        m_softBodies.push_back(body);
 
        // Set the soft body solver that will deal with this body
        // to be the world's solver
        body->setSoftBodySolver(m_softBodySolver);
 
        btCollisionWorld::addCollisionObject(body,
                                                                                 collisionFilterGroup,
                                                                                 collisionFilterMask);
}
 
void btSoftRigidDynamicsWorld::removeSoftBody(btSoftBody* body)
{
        m_softBodies.remove(body);
 
        btCollisionWorld::removeCollisionObject(body);
}
 
void btSoftRigidDynamicsWorld::removeCollisionObject(btCollisionObject* collisionObject)
{
        btSoftBody* body = btSoftBody::upcast(collisionObject);
        if (body)
                removeSoftBody(body);
        else
                btDiscreteDynamicsWorld::removeCollisionObject(collisionObject);
}
 
void btSoftRigidDynamicsWorld::debugDrawWorld()
{
        btDiscreteDynamicsWorld::debugDrawWorld();
 
        if (getDebugDrawer())
        {
                int i;
                for (i = 0; i < this->m_softBodies.size(); i++)
                {
                        btSoftBody* psb = (btSoftBody*)this->m_softBodies[i];
                        if (getDebugDrawer() && (getDebugDrawer()->getDebugMode() & (btIDebugDraw::DBG_DrawWireframe)))
                        {
                                btSoftBodyHelpers::DrawFrame(psb, m_debugDrawer);
                                btSoftBodyHelpers::Draw(psb, m_debugDrawer, m_drawFlags);
                        }
 
                        if (m_debugDrawer && (m_debugDrawer->getDebugMode() & btIDebugDraw::DBG_DrawAabb))
                        {
                                if (m_drawNodeTree) btSoftBodyHelpers::DrawNodeTree(psb, m_debugDrawer);
                                if (m_drawFaceTree) btSoftBodyHelpers::DrawFaceTree(psb, m_debugDrawer);
                                if (m_drawClusterTree) btSoftBodyHelpers::DrawClusterTree(psb, m_debugDrawer);
                        }
                }
        }
}
 
struct btSoftSingleRayCallback : public btBroadphaseRayCallback
{
        btVector3 m_rayFromWorld;
        btVector3 m_rayToWorld;
        btTransform m_rayFromTrans;
        btTransform m_rayToTrans;
        btVector3 m_hitNormal;
 
        const btSoftRigidDynamicsWorld* m_world;
        btCollisionWorld::RayResultCallback& m_resultCallback;
 
        btSoftSingleRayCallback(const btVector3& rayFromWorld, const btVector3& rayToWorld, const btSoftRigidDynamicsWorld* world, btCollisionWorld::RayResultCallback& resultCallback)
                : m_rayFromWorld(rayFromWorld),
                  m_rayToWorld(rayToWorld),
                  m_world(world),
                  m_resultCallback(resultCallback)
        {
                m_rayFromTrans.setIdentity();
                m_rayFromTrans.setOrigin(m_rayFromWorld);
                m_rayToTrans.setIdentity();
                m_rayToTrans.setOrigin(m_rayToWorld);
 
                btVector3 rayDir = (rayToWorld - rayFromWorld);
 
                rayDir.normalize();
                m_rayDirectionInverse[0] = rayDir[0] == btScalar(0.0) ? btScalar(1e30) : btScalar(1.0) / rayDir[0];
                m_rayDirectionInverse[1] = rayDir[1] == btScalar(0.0) ? btScalar(1e30) : btScalar(1.0) / rayDir[1];
                m_rayDirectionInverse[2] = rayDir[2] == btScalar(0.0) ? btScalar(1e30) : btScalar(1.0) / rayDir[2];
                m_signs[0] = m_rayDirectionInverse[0] < 0.0;
                m_signs[1] = m_rayDirectionInverse[1] < 0.0;
                m_signs[2] = m_rayDirectionInverse[2] < 0.0;
 
                m_lambda_max = rayDir.dot(m_rayToWorld - m_rayFromWorld);
        }
 
        virtual bool process(const btBroadphaseProxy* proxy)
        {
                if (m_resultCallback.m_closestHitFraction == btScalar(0.f))
                        return false;
 
                btCollisionObject* collisionObject = (btCollisionObject*)proxy->m_clientObject;
 
                //only perform raycast if filterMask matches
                if (m_resultCallback.needsCollision(collisionObject->getBroadphaseHandle()))
                {
                        //RigidcollisionObject* collisionObject = ctrl->GetRigidcollisionObject();
                        //btVector3 collisionObjectAabbMin,collisionObjectAabbMax;
#if 0
#ifdef RECALCULATE_AABB
                        btVector3 collisionObjectAabbMin,collisionObjectAabbMax;
                        collisionObject->getCollisionShape()->getAabb(collisionObject->getWorldTransform(),collisionObjectAabbMin,collisionObjectAabbMax);
#else
                        //getBroadphase()->getAabb(collisionObject->getBroadphaseHandle(),collisionObjectAabbMin,collisionObjectAabbMax);
                        const btVector3& collisionObjectAabbMin = collisionObject->getBroadphaseHandle()->m_aabbMin;
                        const btVector3& collisionObjectAabbMax = collisionObject->getBroadphaseHandle()->m_aabbMax;
#endif
#endif
                        //btScalar hitLambda = m_resultCallback.m_closestHitFraction;
                        //culling already done by broadphase
                        //if (btRayAabb(m_rayFromWorld,m_rayToWorld,collisionObjectAabbMin,collisionObjectAabbMax,hitLambda,m_hitNormal))
                        {
                                m_world->rayTestSingle(m_rayFromTrans, m_rayToTrans,
                                                                           collisionObject,
                                                                           collisionObject->getCollisionShape(),
                                                                           collisionObject->getWorldTransform(),
                                                                           m_resultCallback);
                        }
                }
                return true;
        }
};
 
void btSoftRigidDynamicsWorld::rayTest(const btVector3& rayFromWorld, const btVector3& rayToWorld, RayResultCallback& resultCallback) const
{
        BT_PROFILE("rayTest");
        btSoftSingleRayCallback rayCB(rayFromWorld, rayToWorld, this, resultCallback);
 
#ifndef USE_BRUTEFORCE_RAYBROADPHASE
        m_broadphasePairCache->rayTest(rayFromWorld, rayToWorld, rayCB);
#else
        for (int i = 0; i < this->getNumCollisionObjects(); i++)
        {
                rayCB.process(m_collisionObjects[i]->getBroadphaseHandle());
        }
#endif  //USE_BRUTEFORCE_RAYBROADPHASE
}
 
void btSoftRigidDynamicsWorld::rayTestSingle(const btTransform& rayFromTrans, const btTransform& rayToTrans,
                                                                                         btCollisionObject* collisionObject,
                                                                                         const btCollisionShape* collisionShape,
                                                                                         const btTransform& colObjWorldTransform,
                                                                                         RayResultCallback& resultCallback)
{
        if (collisionShape->isSoftBody())
        {
                btSoftBody* softBody = btSoftBody::upcast(collisionObject);
                if (softBody)
                {
                        btSoftBody::sRayCast softResult;
                        if (softBody->rayTest(rayFromTrans.getOrigin(), rayToTrans.getOrigin(), softResult))
                        {
                                if (softResult.fraction <= resultCallback.m_closestHitFraction)
                                {
                                        btCollisionWorld::LocalShapeInfo shapeInfo;
                                        shapeInfo.m_shapePart = 0;
                                        shapeInfo.m_triangleIndex = softResult.index;
                                        // get the normal
                                        btVector3 rayDir = rayToTrans.getOrigin() - rayFromTrans.getOrigin();
                                        btVector3 normal = -rayDir;
                                        normal.normalize();
 
                                        if (softResult.feature == btSoftBody::eFeature::Face)
                                        {
                                                normal = softBody->m_faces[softResult.index].m_normal;
                                                if (normal.dot(rayDir) > 0)
                                                {
                                                        // normal always point toward origin of the ray
                                                        normal = -normal;
                                                }
                                        }
 
                                        btCollisionWorld::LocalRayResult rayResult(collisionObject,
                                                                                                                           &shapeInfo,
                                                                                                                           normal,
                                                                                                                           softResult.fraction);
                                        bool normalInWorldSpace = true;
                                        resultCallback.addSingleResult(rayResult, normalInWorldSpace);
                                }
                        }
                }
        }
        else
        {
                btCollisionWorld::rayTestSingle(rayFromTrans, rayToTrans, collisionObject, collisionShape, colObjWorldTransform, resultCallback);
        }
}
 
void btSoftRigidDynamicsWorld::serializeSoftBodies(btSerializer* serializer)
{
        int i;
        //serialize all collision objects
        for (i = 0; i < m_collisionObjects.size(); i++)
        {
                btCollisionObject* colObj = m_collisionObjects[i];
                if (colObj->getInternalType() & btCollisionObject::CO_SOFT_BODY)
                {
                        int len = colObj->calculateSerializeBufferSize();
                        btChunk* chunk = serializer->allocate(len, 1);
                        const char* structType = colObj->serialize(chunk->m_oldPtr, serializer);
                        serializer->finalizeChunk(chunk, structType, BT_SOFTBODY_CODE, colObj);
                }
        }
}
 
void btSoftRigidDynamicsWorld::serialize(btSerializer* serializer)
{
        serializer->startSerialization();
 
        serializeDynamicsWorldInfo(serializer);
 
        serializeSoftBodies(serializer);
 
        serializeRigidBodies(serializer);
 
        serializeCollisionObjects(serializer);
 
        serializer->finishSerialization();
}