Vendor thirdparty Bullet source for upcoming physics server backend

1 files changed, 241 insertions, 0 deletions

diff --git a/thirdparty/bullet/src/LinearMath/btTransformUtil.h b/thirdparty/bullet/src/LinearMath/btTransformUtil.h
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+++ b/thirdparty/bullet/src/LinearMath/btTransformUtil.h
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+/*
+Copyright (c) 2003-2006 Gino van den Bergen / 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.
+*/
+
+
+#ifndef BT_TRANSFORM_UTIL_H
+#define BT_TRANSFORM_UTIL_H
+
+#include "btTransform.h"
+#define ANGULAR_MOTION_THRESHOLD btScalar(0.5)*SIMD_HALF_PI
+
+
+
+
+SIMD_FORCE_INLINE btVector3 btAabbSupport(const btVector3& halfExtents,const btVector3& supportDir)
+{
+	return btVector3(supportDir.x() < btScalar(0.0) ? -halfExtents.x() : halfExtents.x(),
+      supportDir.y() < btScalar(0.0) ? -halfExtents.y() : halfExtents.y(),
+      supportDir.z() < btScalar(0.0) ? -halfExtents.z() : halfExtents.z()); 
+}
+
+
+
+
+
+
+/// Utils related to temporal transforms
+class btTransformUtil
+{
+
+public:
+
+	static void integrateTransform(const btTransform& curTrans,const btVector3& linvel,const btVector3& angvel,btScalar timeStep,btTransform& predictedTransform)
+	{
+		predictedTransform.setOrigin(curTrans.getOrigin() + linvel * timeStep);
+//	#define QUATERNION_DERIVATIVE
+	#ifdef QUATERNION_DERIVATIVE
+		btQuaternion predictedOrn = curTrans.getRotation();
+		predictedOrn += (angvel * predictedOrn) * (timeStep * btScalar(0.5));
+		predictedOrn.safeNormalize();
+	#else
+		//Exponential map
+		//google for "Practical Parameterization of Rotations Using the Exponential Map", F. Sebastian Grassia
+
+		btVector3 axis;
+		btScalar	fAngle2 = angvel.length2();
+        	btScalar    fAngle = 0;
+        	if (fAngle2>SIMD_EPSILON)
+        	{
+            		fAngle = btSqrt(fAngle2);
+        	}
+
+		//limit the angular motion
+		if (fAngle*timeStep > ANGULAR_MOTION_THRESHOLD)
+		{
+			fAngle = ANGULAR_MOTION_THRESHOLD / timeStep;
+		}
+
+		if ( fAngle < btScalar(0.001) )
+		{
+			// use Taylor's expansions of sync function
+			axis   = angvel*( btScalar(0.5)*timeStep-(timeStep*timeStep*timeStep)*(btScalar(0.020833333333))*fAngle*fAngle );
+		}
+		else
+		{
+			// sync(fAngle) = sin(c*fAngle)/t
+			axis   = angvel*( btSin(btScalar(0.5)*fAngle*timeStep)/fAngle );
+		}
+		btQuaternion dorn (axis.x(),axis.y(),axis.z(),btCos( fAngle*timeStep*btScalar(0.5) ));
+		btQuaternion orn0 = curTrans.getRotation();
+
+		btQuaternion predictedOrn = dorn * orn0;
+		predictedOrn.safeNormalize();
+	#endif
+		if (predictedOrn.length2()>SIMD_EPSILON)
+		{
+			predictedTransform.setRotation(predictedOrn);
+		}
+		else
+		{
+			predictedTransform.setBasis(curTrans.getBasis());
+		}
+	}
+
+	static void	calculateVelocityQuaternion(const btVector3& pos0,const btVector3& pos1,const btQuaternion& orn0,const btQuaternion& orn1,btScalar timeStep,btVector3& linVel,btVector3& angVel)
+	{
+		linVel = (pos1 - pos0) / timeStep;
+		btVector3 axis;
+		btScalar  angle;
+		if (orn0 != orn1)
+		{
+			calculateDiffAxisAngleQuaternion(orn0,orn1,axis,angle);
+			angVel = axis * angle / timeStep;
+		} else
+		{
+			angVel.setValue(0,0,0);
+		}
+	}
+
+	static void calculateDiffAxisAngleQuaternion(const btQuaternion& orn0,const btQuaternion& orn1a,btVector3& axis,btScalar& angle)
+	{
+		btQuaternion orn1 = orn0.nearest(orn1a);
+		btQuaternion dorn = orn1 * orn0.inverse();
+		angle = dorn.getAngle();
+		axis = btVector3(dorn.x(),dorn.y(),dorn.z());
+		axis[3] = btScalar(0.);
+		//check for axis length
+		btScalar len = axis.length2();
+		if (len < SIMD_EPSILON*SIMD_EPSILON)
+			axis = btVector3(btScalar(1.),btScalar(0.),btScalar(0.));
+		else
+			axis /= btSqrt(len);
+	}
+
+	static void	calculateVelocity(const btTransform& transform0,const btTransform& transform1,btScalar timeStep,btVector3& linVel,btVector3& angVel)
+	{
+		linVel = (transform1.getOrigin() - transform0.getOrigin()) / timeStep;
+		btVector3 axis;
+		btScalar  angle;
+		calculateDiffAxisAngle(transform0,transform1,axis,angle);
+		angVel = axis * angle / timeStep;
+	}
+
+	static void calculateDiffAxisAngle(const btTransform& transform0,const btTransform& transform1,btVector3& axis,btScalar& angle)
+	{
+		btMatrix3x3 dmat = transform1.getBasis() * transform0.getBasis().inverse();
+		btQuaternion dorn;
+		dmat.getRotation(dorn);
+
+		///floating point inaccuracy can lead to w component > 1..., which breaks 
+		dorn.normalize();
+		
+		angle = dorn.getAngle();
+		axis = btVector3(dorn.x(),dorn.y(),dorn.z());
+		axis[3] = btScalar(0.);
+		//check for axis length
+		btScalar len = axis.length2();
+		if (len < SIMD_EPSILON*SIMD_EPSILON)
+			axis = btVector3(btScalar(1.),btScalar(0.),btScalar(0.));
+		else
+			axis /= btSqrt(len);
+	}
+
+};
+
+
+///The btConvexSeparatingDistanceUtil can help speed up convex collision detection 
+///by conservatively updating a cached separating distance/vector instead of re-calculating the closest distance
+class	btConvexSeparatingDistanceUtil
+{
+	btQuaternion	m_ornA;
+	btQuaternion	m_ornB;
+	btVector3	m_posA;
+	btVector3	m_posB;
+	
+	btVector3	m_separatingNormal;
+
+	btScalar	m_boundingRadiusA;
+	btScalar	m_boundingRadiusB;
+	btScalar	m_separatingDistance;
+
+public:
+
+	btConvexSeparatingDistanceUtil(btScalar	boundingRadiusA,btScalar	boundingRadiusB)
+		:m_boundingRadiusA(boundingRadiusA),
+		m_boundingRadiusB(boundingRadiusB),
+		m_separatingDistance(0.f)
+	{
+	}
+
+	btScalar	getConservativeSeparatingDistance()
+	{
+		return m_separatingDistance;
+	}
+
+	void	updateSeparatingDistance(const btTransform& transA,const btTransform& transB)
+	{
+		const btVector3& toPosA = transA.getOrigin();
+		const btVector3& toPosB = transB.getOrigin();
+		btQuaternion toOrnA = transA.getRotation();
+		btQuaternion toOrnB = transB.getRotation();
+
+		if (m_separatingDistance>0.f)
+		{
+			
+
+			btVector3 linVelA,angVelA,linVelB,angVelB;
+			btTransformUtil::calculateVelocityQuaternion(m_posA,toPosA,m_ornA,toOrnA,btScalar(1.),linVelA,angVelA);
+			btTransformUtil::calculateVelocityQuaternion(m_posB,toPosB,m_ornB,toOrnB,btScalar(1.),linVelB,angVelB);
+			btScalar maxAngularProjectedVelocity = angVelA.length() * m_boundingRadiusA + angVelB.length() * m_boundingRadiusB;
+			btVector3 relLinVel = (linVelB-linVelA);
+			btScalar relLinVelocLength = relLinVel.dot(m_separatingNormal);
+			if (relLinVelocLength<0.f)
+			{
+				relLinVelocLength = 0.f;
+			}
+	
+			btScalar	projectedMotion = maxAngularProjectedVelocity +relLinVelocLength;
+			m_separatingDistance -= projectedMotion;
+		}
+	
+		m_posA = toPosA;
+		m_posB = toPosB;
+		m_ornA = toOrnA;
+		m_ornB = toOrnB;
+	}
+
+	void	initSeparatingDistance(const btVector3& separatingVector,btScalar separatingDistance,const btTransform& transA,const btTransform& transB)
+	{
+		m_separatingDistance = separatingDistance;
+
+		if (m_separatingDistance>0.f)
+		{
+			m_separatingNormal = separatingVector;
+			
+			const btVector3& toPosA = transA.getOrigin();
+			const btVector3& toPosB = transB.getOrigin();
+			btQuaternion toOrnA = transA.getRotation();
+			btQuaternion toOrnB = transB.getRotation();
+			m_posA = toPosA;
+			m_posB = toPosB;
+			m_ornA = toOrnA;
+			m_ornB = toOrnB;
+		}
+	}
+
+};
+
+
+#endif //BT_TRANSFORM_UTIL_H
+