godot/thirdparty/bullet/Bullet3Dynamics/ConstraintSolver/b3SolverBody.h

/*
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.
*/

#ifndef B3_SOLVER_BODY_H
#define B3_SOLVER_BODY_H

#include "Bullet3Common/b3Vector3.h"
#include "Bullet3Common/b3Matrix3x3.h"

#include "Bullet3Common/b3AlignedAllocator.h"
#include "Bullet3Common/b3TransformUtil.h"

///Until we get other contributions, only use SIMD on Windows, when using Visual Studio 2008 or later, and not double precision
#ifdef B3_USE_SSE
#define USE_SIMD 1
#endif  //

#ifdef USE_SIMD

struct b3SimdScalar
{
	B3_FORCE_INLINE b3SimdScalar()
	{
	}

	B3_FORCE_INLINE b3SimdScalar(float fl)
		: m_vec128(_mm_set1_ps(fl))
	{
	}

	B3_FORCE_INLINE b3SimdScalar(__m128 v128)
		: m_vec128(v128)
	{
	}
	union {
		__m128 m_vec128;
		float m_floats[4];
		float x, y, z, w;
		int m_ints[4];
		b3Scalar m_unusedPadding;
	};
	B3_FORCE_INLINE __m128 get128()
	{
		return m_vec128;
	}

	B3_FORCE_INLINE const __m128 get128() const
	{
		return m_vec128;
	}

	B3_FORCE_INLINE void set128(__m128 v128)
	{
		m_vec128 = v128;
	}

	B3_FORCE_INLINE operator __m128()
	{
		return m_vec128;
	}
	B3_FORCE_INLINE operator const __m128() const
	{
		return m_vec128;
	}

	B3_FORCE_INLINE operator float() const
	{
		return m_floats[0];
	}
};

///@brief Return the elementwise product of two b3SimdScalar
B3_FORCE_INLINE b3SimdScalar
operator*(const b3SimdScalar& v1, const b3SimdScalar& v2)
{
	return b3SimdScalar(_mm_mul_ps(v1.get128(), v2.get128()));
}

///@brief Return the elementwise product of two b3SimdScalar
B3_FORCE_INLINE b3SimdScalar
operator+(const b3SimdScalar& v1, const b3SimdScalar& v2)
{
	return b3SimdScalar(_mm_add_ps(v1.get128(), v2.get128()));
}

#else
#define b3SimdScalar b3Scalar
#endif

///The b3SolverBody is an internal datastructure for the constraint solver. Only necessary data is packed to increase cache coherence/performance.
B3_ATTRIBUTE_ALIGNED16(struct)
b3SolverBody
{
	B3_DECLARE_ALIGNED_ALLOCATOR();
	b3Transform m_worldTransform;
	b3Vector3 m_deltaLinearVelocity;
	b3Vector3 m_deltaAngularVelocity;
	b3Vector3 m_angularFactor;
	b3Vector3 m_linearFactor;
	b3Vector3 m_invMass;
	b3Vector3 m_pushVelocity;
	b3Vector3 m_turnVelocity;
	b3Vector3 m_linearVelocity;
	b3Vector3 m_angularVelocity;

	union {
		void* m_originalBody;
		int m_originalBodyIndex;
	};

	int padding[3];

	void setWorldTransform(const b3Transform& worldTransform)
	{
		m_worldTransform = worldTransform;
	}

	const b3Transform& getWorldTransform() const
	{
		return m_worldTransform;
	}

	B3_FORCE_INLINE void getVelocityInLocalPointObsolete(const b3Vector3& rel_pos, b3Vector3& velocity) const
	{
		if (m_originalBody)
			velocity = m_linearVelocity + m_deltaLinearVelocity + (m_angularVelocity + m_deltaAngularVelocity).cross(rel_pos);
		else
			velocity.setValue(0, 0, 0);
	}

	B3_FORCE_INLINE void getAngularVelocity(b3Vector3 & angVel) const
	{
		if (m_originalBody)
			angVel = m_angularVelocity + m_deltaAngularVelocity;
		else
			angVel.setValue(0, 0, 0);
	}

	//Optimization for the iterative solver: avoid calculating constant terms involving inertia, normal, relative position
	B3_FORCE_INLINE void applyImpulse(const b3Vector3& linearComponent, const b3Vector3& angularComponent, const b3Scalar impulseMagnitude)
	{
		if (m_originalBody)
		{
			m_deltaLinearVelocity += linearComponent * impulseMagnitude * m_linearFactor;
			m_deltaAngularVelocity += angularComponent * (impulseMagnitude * m_angularFactor);
		}
	}

	B3_FORCE_INLINE void internalApplyPushImpulse(const b3Vector3& linearComponent, const b3Vector3& angularComponent, b3Scalar impulseMagnitude)
	{
		if (m_originalBody)
		{
			m_pushVelocity += linearComponent * impulseMagnitude * m_linearFactor;
			m_turnVelocity += angularComponent * (impulseMagnitude * m_angularFactor);
		}
	}

	const b3Vector3& getDeltaLinearVelocity() const
	{
		return m_deltaLinearVelocity;
	}

	const b3Vector3& getDeltaAngularVelocity() const
	{
		return m_deltaAngularVelocity;
	}

	const b3Vector3& getPushVelocity() const
	{
		return m_pushVelocity;
	}

	const b3Vector3& getTurnVelocity() const
	{
		return m_turnVelocity;
	}

	////////////////////////////////////////////////
	///some internal methods, don't use them

	b3Vector3& internalGetDeltaLinearVelocity()
	{
		return m_deltaLinearVelocity;
	}

	b3Vector3& internalGetDeltaAngularVelocity()
	{
		return m_deltaAngularVelocity;
	}

	const b3Vector3& internalGetAngularFactor() const
	{
		return m_angularFactor;
	}

	const b3Vector3& internalGetInvMass() const
	{
		return m_invMass;
	}

	void internalSetInvMass(const b3Vector3& invMass)
	{
		m_invMass = invMass;
	}

	b3Vector3& internalGetPushVelocity()
	{
		return m_pushVelocity;
	}

	b3Vector3& internalGetTurnVelocity()
	{
		return m_turnVelocity;
	}

	B3_FORCE_INLINE void internalGetVelocityInLocalPointObsolete(const b3Vector3& rel_pos, b3Vector3& velocity) const
	{
		velocity = m_linearVelocity + m_deltaLinearVelocity + (m_angularVelocity + m_deltaAngularVelocity).cross(rel_pos);
	}

	B3_FORCE_INLINE void internalGetAngularVelocity(b3Vector3 & angVel) const
	{
		angVel = m_angularVelocity + m_deltaAngularVelocity;
	}

	//Optimization for the iterative solver: avoid calculating constant terms involving inertia, normal, relative position
	B3_FORCE_INLINE void internalApplyImpulse(const b3Vector3& linearComponent, const b3Vector3& angularComponent, const b3Scalar impulseMagnitude)
	{
		//if (m_originalBody)
		{
			m_deltaLinearVelocity += linearComponent * impulseMagnitude * m_linearFactor;
			m_deltaAngularVelocity += angularComponent * (impulseMagnitude * m_angularFactor);
		}
	}

	void writebackVelocity()
	{
		//if (m_originalBody>=0)
		{
			m_linearVelocity += m_deltaLinearVelocity;
			m_angularVelocity += m_deltaAngularVelocity;

			//m_originalBody->setCompanionId(-1);
		}
	}

	void writebackVelocityAndTransform(b3Scalar timeStep, b3Scalar splitImpulseTurnErp)
	{
		(void)timeStep;
		if (m_originalBody)
		{
			m_linearVelocity += m_deltaLinearVelocity;
			m_angularVelocity += m_deltaAngularVelocity;

			//correct the position/orientation based on push/turn recovery
			b3Transform newTransform;
			if (m_pushVelocity[0] != 0.f || m_pushVelocity[1] != 0 || m_pushVelocity[2] != 0 || m_turnVelocity[0] != 0.f || m_turnVelocity[1] != 0 || m_turnVelocity[2] != 0)
			{
				//	b3Quaternion orn = m_worldTransform.getRotation();
				b3TransformUtil::integrateTransform(m_worldTransform, m_pushVelocity, m_turnVelocity * splitImpulseTurnErp, timeStep, newTransform);
				m_worldTransform = newTransform;
			}
			//m_worldTransform.setRotation(orn);
			//m_originalBody->setCompanionId(-1);
		}
	}
};

#endif  //B3_SOLVER_BODY_H