// Jolt Physics Library (https://github.com/jrouwe/JoltPhysics)
// SPDX-FileCopyrightText: 2021 Jorrit Rouwe
// SPDX-License-Identifier: MIT
#pragma once
#include <Jolt/Physics/Body/BodyInterface.h>
#include <Jolt/Physics/Collision/NarrowPhaseQuery.h>
#include <Jolt/Physics/Collision/ContactListener.h>
#include <Jolt/Physics/Constraints/ContactConstraintManager.h>
#include <Jolt/Physics/Constraints/ConstraintManager.h>
#include <Jolt/Physics/IslandBuilder.h>
#include <Jolt/Physics/LargeIslandSplitter.h>
#include <Jolt/Physics/PhysicsUpdateContext.h>
#include <Jolt/Physics/PhysicsSettings.h>
JPH_NAMESPACE_BEGIN
class JobSystem;
class StateRecorder;
class TempAllocator;
class PhysicsStepListener;
class SoftBodyContactListener;
class SimShapeFilter;
/// The main class for the physics system. It contains all rigid bodies and simulates them.
///
/// The main simulation is performed by the Update() call on multiple threads (if the JobSystem is configured to use them). Please refer to the general architecture overview in the Docs folder for more information.
class JPH_EXPORT PhysicsSystem : public NonCopyable
{
public:
JPH_OVERRIDE_NEW_DELETE
/// Constructor / Destructor
PhysicsSystem() : mContactManager(mPhysicsSettings) JPH_IF_ENABLE_ASSERTS(, mConstraintManager(&mBodyManager)) { }
~PhysicsSystem();
/// The maximum value that can be passed to Init for inMaxBodies.
static constexpr uint cMaxBodiesLimit = BodyID::cMaxBodyIndex + 1;
/// The maximum value that can be passed to Init for inMaxBodyPairs.
/// Note you should really use a lower value, using this value will cost a lot of memory!
/// On a 32 bit platform, you'll run out of memory way before you reach this limit.
static constexpr uint cMaxBodyPairsLimit = ContactConstraintManager::cMaxBodyPairsLimit;
/// The maximum value that can be passed to Init for inMaxContactConstraints.
/// Note you should really use a lower value, using this value will cost a lot of memory!
/// On a 32 bit platform, you'll run out of memory way before you reach this limit.
static constexpr uint cMaxContactConstraintsLimit = ContactConstraintManager::cMaxContactConstraintsLimit;
/// Initialize the system.
/// @param inMaxBodies Maximum number of bodies to support.
/// @param inNumBodyMutexes Number of body mutexes to use. Should be a power of 2 in the range [1, 64], use 0 to auto detect.
/// @param inMaxBodyPairs Maximum amount of body pairs to process (anything else will fall through the world), this number should generally be much higher than the max amount of contact points as there will be lots of bodies close that are not actually touching.
/// @param inMaxContactConstraints Maximum amount of contact constraints to process (anything else will fall through the world).
/// @param inBroadPhaseLayerInterface Information on the mapping of object layers to broad phase layers. Since this is a virtual interface, the instance needs to stay alive during the lifetime of the PhysicsSystem.
/// @param inObjectVsBroadPhaseLayerFilter Filter callback function that is used to determine if an object layer collides with a broad phase layer. Since this is a virtual interface, the instance needs to stay alive during the lifetime of the PhysicsSystem.
/// @param inObjectLayerPairFilter Filter callback function that is used to determine if two object layers collide. Since this is a virtual interface, the instance needs to stay alive during the lifetime of the PhysicsSystem.
void Init(uint inMaxBodies, uint inNumBodyMutexes, uint inMaxBodyPairs, uint inMaxContactConstraints, const BroadPhaseLayerInterface &inBroadPhaseLayerInterface, const ObjectVsBroadPhaseLayerFilter &inObjectVsBroadPhaseLayerFilter, const ObjectLayerPairFilter &inObjectLayerPairFilter);
/// Listener that is notified whenever a body is activated/deactivated
void SetBodyActivationListener(BodyActivationListener *inListener) { mBodyManager.SetBodyActivationListener(inListener); }
BodyActivationListener * GetBodyActivationListener() const { return mBodyManager.GetBodyActivationListener(); }
/// Listener that is notified whenever a contact point between two bodies is added/updated/removed.
/// You can't change contact listener during PhysicsSystem::Update but it can be changed at any other time.
void SetContactListener(ContactListener *inListener) { mContactManager.SetContactListener(inListener); }
ContactListener * GetContactListener() const { return mContactManager.GetContactListener(); }
/// Listener that is notified whenever a contact point between a soft body and another body
void SetSoftBodyContactListener(SoftBodyContactListener *inListener) { mSoftBodyContactListener = inListener; }
SoftBodyContactListener * GetSoftBodyContactListener() const { return mSoftBodyContactListener; }
/// Set the function that combines the friction of two bodies and returns it
/// Default method is the geometric mean: sqrt(friction1 * friction2).
void SetCombineFriction(ContactConstraintManager::CombineFunction inCombineFriction) { mContactManager.SetCombineFriction(inCombineFriction); }
ContactConstraintManager::CombineFunction GetCombineFriction() const { return mContactManager.GetCombineFriction(); }
/// Set the function that combines the restitution of two bodies and returns it
/// Default method is max(restitution1, restitution1)
void SetCombineRestitution(ContactConstraintManager::CombineFunction inCombineRestitution) { mContactManager.SetCombineRestitution(inCombineRestitution); }
ContactConstraintManager::CombineFunction GetCombineRestitution() const { return mContactManager.GetCombineRestitution(); }
/// Set/get the shape filter that will be used during simulation. This can be used to exclude shapes within a body from colliding with each other.
/// E.g. if you have a high detail and a low detail collision model, you can attach them to the same body in a StaticCompoundShape and use the ShapeFilter
/// to exclude the high detail collision model when simulating and exclude the low detail collision model when casting rays. Note that in this case
/// you would need to pass the inverse of inShapeFilter to the CastRay function. Pass a nullptr to disable the shape filter.
/// The PhysicsSystem does not own the ShapeFilter, make sure it stays alive during the lifetime of the PhysicsSystem.
void SetSimShapeFilter(const SimShapeFilter *inShapeFilter) { mSimShapeFilter = inShapeFilter; }
const SimShapeFilter * GetSimShapeFilter() const { return mSimShapeFilter; }
/// Advanced use only: This function is similar to CollisionDispatch::sCollideShapeVsShape but only used to collide bodies during simulation.
/// inBody1 The first body to collide.
/// inBody2 The second body to collide.
/// inCenterOfMassTransform1 The center of mass transform of the first body (note this will not be the actual world space position of the body, it will be made relative to some position so we can drop down to single precision).
/// inCenterOfMassTransform2 The center of mass transform of the second body.
/// ioCollideShapeSettings Settings that control the collision detection. Note that the implementation can freely overwrite the shape settings if needed, the caller provides a temporary that will not be used after the function returns.
/// ioCollector The collector that will receive the contact points.
/// inShapeFilter The shape filter that can be used to exclude shapes from colliding with each other.
using SimCollideBodyVsBody = std::function<void(const Body &inBody1, const Body &inBody2, Mat44Arg inCenterOfMassTransform1, Mat44Arg inCenterOfMassTransform2, CollideShapeSettings &ioCollideShapeSettings, CollideShapeCollector &ioCollector, const ShapeFilter &inShapeFilter)>;
/// Advanced use only: Set the function that will be used to collide two bodies during simulation.
/// This function is expected to eventually call CollideShapeCollector::AddHit all contact points between the shapes of body 1 and 2 in their given transforms.
void SetSimCollideBodyVsBody(const SimCollideBodyVsBody &inBodyVsBody) { mSimCollideBodyVsBody = inBodyVsBody; }
const SimCollideBodyVsBody &GetSimCollideBodyVsBody() const { return mSimCollideBodyVsBody; }
/// Advanced use only: Default function that is used to collide two bodies during simulation.
static void sDefaultSimCollideBodyVsBody(const Body &inBody1, const Body &inBody2, Mat44Arg inCenterOfMassTransform1, Mat44Arg inCenterOfMassTransform2, CollideShapeSettings &ioCollideShapeSettings, CollideShapeCollector &ioCollector, const ShapeFilter &inShapeFilter);
/// Control the main constants of the physics simulation
void SetPhysicsSettings(const PhysicsSettings &inSettings) { mPhysicsSettings = inSettings; }
const PhysicsSettings & GetPhysicsSettings() const { return mPhysicsSettings; }
/// Access to the body interface. This interface allows to to create / remove bodies and to change their properties.
const BodyInterface & GetBodyInterface() const { return mBodyInterfaceLocking; }
BodyInterface & GetBodyInterface() { return mBodyInterfaceLocking; }
const BodyInterface & GetBodyInterfaceNoLock() const { return mBodyInterfaceNoLock; } ///< Version that does not lock the bodies, use with great care!
BodyInterface & GetBodyInterfaceNoLock() { return mBodyInterfaceNoLock; } ///< Version that does not lock the bodies, use with great care!
/// Access to the broadphase interface that allows coarse collision queries
const BroadPhaseQuery & GetBroadPhaseQuery() const { return *mBroadPhase; }
/// Interface that allows fine collision queries against first the broad phase and then the narrow phase.
const NarrowPhaseQuery & GetNarrowPhaseQuery() const { return mNarrowPhaseQueryLocking; }
const NarrowPhaseQuery & GetNarrowPhaseQueryNoLock() const { return mNarrowPhaseQueryNoLock; } ///< Version that does not lock the bodies, use with great care!
/// Add constraint to the world
void AddConstraint(Constraint *inConstraint) { mConstraintManager.Add(&inConstraint, 1); }
/// Remove constraint from the world
void RemoveConstraint(Constraint *inConstraint) { mConstraintManager.Remove(&inConstraint, 1); }
/// Batch add constraints.
void AddConstraints(Constraint **inConstraints, int inNumber) { mConstraintManager.Add(inConstraints, inNumber); }
/// Batch remove constraints.
void RemoveConstraints(Constraint **inConstraints, int inNumber) { mConstraintManager.Remove(inConstraints, inNumber); }
/// Get a list of all constraints
Constraints GetConstraints() const { return mConstraintManager.GetConstraints(); }
/// Optimize the broadphase, needed only if you've added many bodies prior to calling Update() for the first time.
/// Don't call this every frame as PhysicsSystem::Update spreads out the same work over multiple frames.
/// If you add many bodies through BodyInterface::AddBodiesPrepare/AddBodiesFinalize and if the bodies in a batch are
/// in a roughly unoccupied space (e.g. a new level section) then a call to OptimizeBroadPhase is also not needed
/// as batch adding creates an efficient bounding volume hierarchy.
/// Don't call this function while bodies are being modified from another thread or use the locking BodyInterface to modify bodies.
void OptimizeBroadPhase();
/// Adds a new step listener
void AddStepListener(PhysicsStepListener *inListener);
/// Removes a step listener
void RemoveStepListener(PhysicsStepListener *inListener);
/// Simulate the system.
/// The world steps for a total of inDeltaTime seconds. This is divided in inCollisionSteps iterations.
/// Each iteration consists of collision detection followed by an integration step.
/// This function internally spawns jobs using inJobSystem and waits for them to complete, so no jobs will be running when this function returns.
/// The temp allocator is used, for example, to store the list of bodies that are in contact, how they form islands together
/// and data to solve the contacts between bodies. At the end of the Update call, all allocated memory will have been freed.
EPhysicsUpdateError Update(float inDeltaTime, int inCollisionSteps, TempAllocator *inTempAllocator, JobSystem *inJobSystem);
/// Saving state for replay
void SaveState(StateRecorder &inStream, EStateRecorderState inState = EStateRecorderState::All, const StateRecorderFilter *inFilter = nullptr) const;
/// Restoring state for replay. Returns false if failed.
bool RestoreState(StateRecorder &inStream, const StateRecorderFilter *inFilter = nullptr);
/// Saving state of a single body.
void SaveBodyState(const Body &inBody, StateRecorder &inStream) const;
/// Restoring state of a single body.
void RestoreBodyState(Body &ioBody, StateRecorder &inStream);
#ifdef JPH_DEBUG_RENDERER
// Drawing properties
static bool sDrawMotionQualityLinearCast; ///< Draw debug info for objects that perform continuous collision detection through the linear cast motion quality
/// Draw the state of the bodies (debugging purposes)
void DrawBodies(const BodyManager::DrawSettings &inSettings, DebugRenderer *inRenderer, const BodyDrawFilter *inBodyFilter = nullptr) { mBodyManager.Draw(inSettings, mPhysicsSettings, inRenderer, inBodyFilter); }
/// Draw the constraints only (debugging purposes)
void DrawConstraints(DebugRenderer *inRenderer) { mConstraintManager.DrawConstraints(inRenderer); }
/// Draw the constraint limits only (debugging purposes)
void DrawConstraintLimits(DebugRenderer *inRenderer) { mConstraintManager.DrawConstraintLimits(inRenderer); }
/// Draw the constraint reference frames only (debugging purposes)
void DrawConstraintReferenceFrame(DebugRenderer *inRenderer) { mConstraintManager.DrawConstraintReferenceFrame(inRenderer); }
#endif // JPH_DEBUG_RENDERER
/// Set gravity value
void SetGravity(Vec3Arg inGravity) { mGravity = inGravity; }
Vec3 GetGravity() const { return mGravity; }
/// Returns a locking interface that won't actually lock the body. Use with great care!
inline const BodyLockInterfaceNoLock & GetBodyLockInterfaceNoLock() const { return mBodyLockInterfaceNoLock; }
/// Returns a locking interface that locks the body so other threads cannot modify it.
inline const BodyLockInterfaceLocking & GetBodyLockInterface() const { return mBodyLockInterfaceLocking; }
/// Broadphase layer filter that decides if two objects can collide, this was passed to the Init function.
const ObjectVsBroadPhaseLayerFilter &GetObjectVsBroadPhaseLayerFilter() const { return *mObjectVsBroadPhaseLayerFilter; }
/// Object layer filter that decides if two objects can collide, this was passed to the Init function.
const ObjectLayerPairFilter &GetObjectLayerPairFilter() const { return *mObjectLayerPairFilter; }
/// Get an broadphase layer filter that uses the default pair filter and a specified object layer to determine if broadphase layers collide
DefaultBroadPhaseLayerFilter GetDefaultBroadPhaseLayerFilter(ObjectLayer inLayer) const { return DefaultBroadPhaseLayerFilter(*mObjectVsBroadPhaseLayerFilter, inLayer); }
/// Get an object layer filter that uses the default pair filter and a specified layer to determine if layers collide
DefaultObjectLayerFilter GetDefaultLayerFilter(ObjectLayer inLayer) const { return DefaultObjectLayerFilter(*mObjectLayerPairFilter, inLayer); }
/// Gets the current amount of bodies that are in the body manager
uint GetNumBodies() const { return mBodyManager.GetNumBodies(); }
/// Gets the current amount of active bodies that are in the body manager
uint32 GetNumActiveBodies(EBodyType inType) const { return mBodyManager.GetNumActiveBodies(inType); }
/// Get the maximum amount of bodies that this physics system supports
uint GetMaxBodies() const { return mBodyManager.GetMaxBodies(); }
/// Helper struct that counts the number of bodies of each type
using BodyStats = BodyManager::BodyStats;
/// Get stats about the bodies in the body manager (slow, iterates through all bodies)
BodyStats GetBodyStats() const { return mBodyManager.GetBodyStats(); }
/// Get copy of the list of all bodies under protection of a lock.
/// @param outBodyIDs On return, this will contain the list of BodyIDs
void GetBodies(BodyIDVector &outBodyIDs) const { return mBodyManager.GetBodyIDs(outBodyIDs); }
/// Get copy of the list of active bodies under protection of a lock.
/// @param inType The type of bodies to get
/// @param outBodyIDs On return, this will contain the list of BodyIDs
void GetActiveBodies(EBodyType inType, BodyIDVector &outBodyIDs) const { return mBodyManager.GetActiveBodies(inType, outBodyIDs); }
/// Get the list of active bodies, use GetNumActiveBodies() to find out how long the list is.
/// Note: Not thread safe. The active bodies list can change at any moment when other threads are doing work. Use GetActiveBodies() if you need a thread safe version.
const BodyID * GetActiveBodiesUnsafe(EBodyType inType) const { return mBodyManager.GetActiveBodiesUnsafe(inType); }
/// Check if 2 bodies were in contact during the last simulation step. Since contacts are only detected between active bodies, so at least one of the bodies must be active in order for this function to work.
/// It queries the state at the time of the last PhysicsSystem::Update and will return true if the bodies were in contact, even if one of the bodies was moved / removed afterwards.
/// This function can be called from any thread when the PhysicsSystem::Update is not running. During PhysicsSystem::Update this function is only valid during contact callbacks:
/// - During the ContactListener::OnContactAdded callback this function can be used to determine if a different contact pair between the bodies was active in the previous simulation step (function returns true) or if this is the first step that the bodies are touching (function returns false).
/// - During the ContactListener::OnContactRemoved callback this function can be used to determine if this is the last contact pair between the bodies (function returns false) or if there are other contacts still present (function returns true).
bool WereBodiesInContact(const BodyID &inBody1ID, const BodyID &inBody2ID) const { return mContactManager.WereBodiesInContact(inBody1ID, inBody2ID); }
/// Get the bounding box of all bodies in the physics system.
/// Deprecated: Use GetBroadPhaseQuery().GetBounds() instead.
AABox GetBounds() const { return mBroadPhase->GetBounds(); }
#ifdef JPH_TRACK_BROADPHASE_STATS
/// Trace the accumulated broadphase stats to the TTY
void ReportBroadphaseStats() { mBroadPhase->ReportStats(); }
#endif // JPH_TRACK_BROADPHASE_STATS
#if defined(JPH_TRACK_SIMULATION_STATS) && defined(JPH_PROFILE_ENABLED)
/// Dump the per body simulation stats to the TTY
void ReportSimulationStats() { mBodyManager.ReportSimulationStats(); }
#endif
private:
using CCDBody = PhysicsUpdateContext::Step::CCDBody;
// Various job entry points
void JobStepListeners(PhysicsUpdateContext::Step *ioStep);
void JobDetermineActiveConstraints(PhysicsUpdateContext::Step *ioStep) const;
void JobApplyGravity(const PhysicsUpdateContext *ioContext, PhysicsUpdateContext::Step *ioStep);
void JobSetupVelocityConstraints(float inDeltaTime, PhysicsUpdateContext::Step *ioStep) const;
void JobBuildIslandsFromConstraints(PhysicsUpdateContext *ioContext, PhysicsUpdateContext::Step *ioStep);
void JobFindCollisions(PhysicsUpdateContext::Step *ioStep, int inJobIndex);
void JobFinalizeIslands(PhysicsUpdateContext *ioContext);
void JobBodySetIslandIndex();
void JobSolveVelocityConstraints(PhysicsUpdateContext *ioContext, PhysicsUpdateContext::Step *ioStep);
void JobPreIntegrateVelocity(PhysicsUpdateContext *ioContext, PhysicsUpdateContext::Step *ioStep);
void JobIntegrateVelocity(const PhysicsUpdateContext *ioContext, PhysicsUpdateContext::Step *ioStep);
void JobPostIntegrateVelocity(PhysicsUpdateContext *ioContext, PhysicsUpdateContext::Step *ioStep) const;
void JobFindCCDContacts(const PhysicsUpdateContext *ioContext, PhysicsUpdateContext::Step *ioStep);
void JobResolveCCDContacts(PhysicsUpdateContext *ioContext, PhysicsUpdateContext::Step *ioStep);
void JobContactRemovedCallbacks(const PhysicsUpdateContext::Step *ioStep);
void JobSolvePositionConstraints(PhysicsUpdateContext *ioContext, PhysicsUpdateContext::Step *ioStep);
void JobSoftBodyPrepare(PhysicsUpdateContext *ioContext, PhysicsUpdateContext::Step *ioStep);
void JobSoftBodyCollide(PhysicsUpdateContext *ioContext) const;
void JobSoftBodySimulate(PhysicsUpdateContext *ioContext, uint inThreadIndex) const;
void JobSoftBodyFinalize(PhysicsUpdateContext *ioContext);
/// Tries to spawn a new FindCollisions job if max concurrency hasn't been reached yet
void TrySpawnJobFindCollisions(PhysicsUpdateContext::Step *ioStep) const;
#ifdef JPH_TRACK_SIMULATION_STATS
/// Gather stats from the islands and distribute them over the bodies
void GatherIslandStats();
#endif
using ContactAllocator = ContactConstraintManager::ContactAllocator;
/// Process narrow phase for a single body pair
void ProcessBodyPair(ContactAllocator &ioContactAllocator, const BodyPair &inBodyPair);
/// This helper batches up bodies that need to put to sleep to avoid contention on the activation mutex
class BodiesToSleep;
/// Called at the end of JobSolveVelocityConstraints to check if bodies need to go to sleep and to update their bounding box in the broadphase
void CheckSleepAndUpdateBounds(uint32 inIslandIndex, const PhysicsUpdateContext *ioContext, const PhysicsUpdateContext::Step *ioStep, BodiesToSleep &ioBodiesToSleep);
/// Number of constraints to process at once in JobDetermineActiveConstraints
static constexpr int cDetermineActiveConstraintsBatchSize = 64;
/// Number of constraints to process at once in JobSetupVelocityConstraints, we want a low number of threads working on this so we take fairly large batches
static constexpr int cSetupVelocityConstraintsBatchSize = 256;
/// Number of bodies to process at once in JobApplyGravity
static constexpr int cApplyGravityBatchSize = 64;
/// Number of active bodies to test for collisions per batch
static constexpr int cActiveBodiesBatchSize = 16;
/// Number of active bodies to integrate velocities for
static constexpr int cIntegrateVelocityBatchSize = 64;
/// Number of contacts that need to be queued before another narrow phase job is started
static constexpr int cNarrowPhaseBatchSize = 16;
/// Number of continuous collision shape casts that need to be queued before another job is started
static constexpr int cNumCCDBodiesPerJob = 4;
/// Broadphase layer filter that decides if two objects can collide
const ObjectVsBroadPhaseLayerFilter *mObjectVsBroadPhaseLayerFilter = nullptr;
/// Object layer filter that decides if two objects can collide
const ObjectLayerPairFilter *mObjectLayerPairFilter = nullptr;
/// The body manager keeps track which bodies are in the simulation
BodyManager mBodyManager;
/// Body locking interfaces
BodyLockInterfaceNoLock mBodyLockInterfaceNoLock { mBodyManager };
BodyLockInterfaceLocking mBodyLockInterfaceLocking { mBodyManager };
/// Body interfaces
BodyInterface mBodyInterfaceNoLock;
BodyInterface mBodyInterfaceLocking;
/// Narrow phase query interface
NarrowPhaseQuery mNarrowPhaseQueryNoLock;
NarrowPhaseQuery mNarrowPhaseQueryLocking;
/// The broadphase does quick collision detection between body pairs
BroadPhase * mBroadPhase = nullptr;
/// The soft body contact listener
SoftBodyContactListener * mSoftBodyContactListener = nullptr;
/// The shape filter that is used to filter out sub shapes during simulation
const SimShapeFilter * mSimShapeFilter = nullptr;
/// The collision function that is used to collide two shapes during simulation
SimCollideBodyVsBody mSimCollideBodyVsBody = &sDefaultSimCollideBodyVsBody;
/// Simulation settings
PhysicsSettings mPhysicsSettings;
/// The contact manager resolves all contacts during a simulation step
ContactConstraintManager mContactManager;
/// All non-contact constraints
ConstraintManager mConstraintManager;
/// Keeps track of connected bodies and builds islands for multithreaded velocity/position update
IslandBuilder mIslandBuilder;
/// Will split large islands into smaller groups of bodies that can be processed in parallel
LargeIslandSplitter mLargeIslandSplitter;
/// Mutex protecting mStepListeners
Mutex mStepListenersMutex;
/// List of physics step listeners
using StepListeners = Array<PhysicsStepListener *>;
StepListeners mStepListeners;
/// This is the global gravity vector
Vec3 mGravity = Vec3(0, -9.81f, 0);
/// Previous frame's delta time of one sub step to allow scaling previous frame's constraint impulses
float mPreviousStepDeltaTime = 0.0f;
};
JPH_NAMESPACE_END