btSoftRigidDynamicsWorld.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 "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();
}