PBDCollisionContainerSolverSimd.h

Go to the documentation of this file.

// Copyright Epic Games, Inc. All Rights Reserved.
#pragma once
 
#include "Chaos/CollisionResolutionTypes.h"
#include "Chaos/Collision/CollisionApplyType.h"
#include "Chaos/Collision/PBDCollisionSolverSimd.h"
#include "Chaos/Collision/PBDCollisionSolverSettings.h"
#include "Chaos/Evolution/SolverConstraintContainer.h"
 
namespace Chaos
{
    class FPBDCollisionConstraint;
    class FPBDCollisionConstraints;
    class FSolverBody;
    class FSolverBodyContainer;
 
    namespace Private
    {
        template<int TNumLanes>
        using TConstraintPtrSimd = TSimdValue<FPBDCollisionConstraint*, TNumLanes>;
 
        class FPBDCollisionContainerSolverSimd : public FConstraintContainerSolver
        {
        public:
            UE_NONCOPYABLE(FPBDCollisionContainerSolverSimd);
 
            FPBDCollisionContainerSolverSimd(const FPBDCollisionConstraints& InConstraintContainer, const int32 InPriority);
            ~FPBDCollisionContainerSolverSimd();
 
            virtual void Reset(const int32 InMaxCollisions) override final;
 
            virtual int32 GetNumConstraints() const override final { return NumConstraints; }
 
            //
            // IslandGroup API
            //
            virtual void AddConstraints() override final;
            virtual void AddConstraints(const TArrayView<Private::FPBDIslandConstraint*>& ConstraintHandles) override final;
            virtual void AddBodies(FSolverBodyContainer& SolverBodyContainer) override final;
            virtual void GatherInput(const FReal Dt) override final;
            virtual void GatherInput(const FReal Dt, const int32 BeginIndex, const int32 EndIndex) override final;
            virtual void ScatterOutput(const FReal Dt) override final;
            virtual void ScatterOutput(const FReal Dt, const int32 BeginIndex, const int32 EndIndex) override final;
            virtual void ApplyPositionConstraints(const FReal Dt, const int32 It, const int32 NumIts) override final;
            virtual void ApplyVelocityConstraints(const FReal Dt, const int32 It, const int32 NumIts) override final;
            virtual void ApplyProjectionConstraints(const FReal Dt, const int32 It, const int32 NumIts) override final;
 
            // Rows of collision constraints and solvers. 
            // We solve each row using SIMD. 
            // NumLanes is the width of a row and will be the same as the float SIMD register width (or less).
            template<int TNumLanes>
            struct FDataSimd
            {
                TSimdInt32<TNumLanes> SimdNumConstraints;
                TArray<TSolverBodyPtrPairSimd<TNumLanes>> SimdSolverBodies;
                TArray<TPBDCollisionSolverSimd<TNumLanes>> SimdSolvers;
                TArray<TPBDCollisionSolverManifoldPointsSimd<TNumLanes>> SimdManifoldPoints;
                TArray<TConstraintPtrSimd<TNumLanes>> SimdConstraints;
                FSolverBody DummySolverBody0[TNumLanes];
                FSolverBody DummySolverBody1[TNumLanes];
            };
 
            // Used to recover the solver for a constraint
            // @todo(chaos): this is only really needed for debug validation
            struct FConstraintSolverId
            {
                int32 SolverIndex;
                int32 LaneIndex;
            };
 
            // For testing
            const FConstraintSolverId& GetConstraintSolverId(const int32 ConstraintIndex) const { return ConstraintSolverIds[ConstraintIndex]; }
            const TPBDCollisionSolverSimd<4>& GetConstraintSolver(const int32 SolverIndex) const { return SimdData.SimdSolvers[SolverIndex]; }
            TArrayView<const TPBDCollisionSolverManifoldPointsSimd<4>> GetManifoldPointBuffer() const { return MakeArrayView(SimdData.SimdManifoldPoints); }
 
        private:
            int32 GetNumLanes() const { return 4; }
            void CreateSolvers();
            void UpdatePositionShockPropagation(const int32 It, const int32 NumIts, const FPBDCollisionSolverSettings& SolverSettings);
            void UpdateVelocityShockPropagation(const int32 It, const int32 NumIts, const FPBDCollisionSolverSettings& SolverSettings);
            void ApplyShockPropagation(const FSolverReal ShockPropagation);
            void UpdateCollisions(const FSolverReal InDt);
 
            const FPBDCollisionConstraints& ConstraintContainer;
 
            FDataSimd<4> SimdData;
            TArray<FConstraintSolverId> ConstraintSolverIds;
            int32 NumConstraints;
            FSolverReal AppliedShockPropagation;
            bool bPerIterationCollisionDetection;
        };
 
    }   // namespace Private
}   // namespace Chaos