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107 | /*
Written by Xuchen Han <xuchenhan2015@u.northwestern.edu>
Bullet Continuous Collision Detection and Physics Library
Copyright (c) 2019 Google Inc. http://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 BT_DEFORMABLE_GRAVITY_FORCE_H
#define BT_DEFORMABLE_GRAVITY_FORCE_H
#include "btDeformableLagrangianForce.h"
class btDeformableGravityForce : public btDeformableLagrangianForce
{
public:
typedef btAlignedObjectArray<btVector3> TVStack;
btVector3 m_gravity;
btDeformableGravityForce(const btVector3& g) : m_gravity(g)<--- Class 'btDeformableGravityForce' has a constructor with 1 argument that is not explicit. [+]Class 'btDeformableGravityForce' has a constructor with 1 argument that is not explicit. Such constructors should in general be explicit for type safety reasons. Using the explicit keyword in the constructor means some mistakes when using the class can be avoided.
{
}
virtual void addScaledForces(btScalar scale, TVStack& force)<--- Function in derived class
{
addScaledGravityForce(scale, force);
}
virtual void addScaledExplicitForce(btScalar scale, TVStack& force)<--- Function in derived class
{
addScaledGravityForce(scale, force);
}
virtual void addScaledDampingForce(btScalar scale, TVStack& force)<--- Function in derived class
{
}
virtual void addScaledElasticForceDifferential(btScalar scale, const TVStack& dx, TVStack& df)<--- Function in derived class
{
}
virtual void addScaledDampingForceDifferential(btScalar scale, const TVStack& dv, TVStack& df)<--- Function in derived class
{
}
virtual void buildDampingForceDifferentialDiagonal(btScalar scale, TVStack& diagA){}<--- Function in derived class
virtual void addScaledGravityForce(btScalar scale, TVStack& force)
{
int numNodes = getNumNodes();
btAssert(numNodes <= force.size());
for (int i = 0; i < m_softBodies.size(); ++i)
{
btSoftBody* psb = m_softBodies[i];
if (!psb->isActive())
{
continue;
}
for (int j = 0; j < psb->m_nodes.size(); ++j)
{
btSoftBody::Node& n = psb->m_nodes[j];
size_t id = n.index;
btScalar mass = (n.m_im == 0) ? 0 : 1. / n.m_im;
btVector3 scaled_force = scale * m_gravity * mass;
force[id] += scaled_force;
}
}
}
virtual btDeformableLagrangianForceType getForceType()<--- Function in derived class
{
return BT_GRAVITY_FORCE;
}
// the gravitational potential energy
virtual double totalEnergy(btScalar dt)<--- Function in derived class
{
double e = 0;
for (int i = 0; i<m_softBodies.size();++i)
{
btSoftBody* psb = m_softBodies[i];
if (!psb->isActive())
{
continue;
}
for (int j = 0; j < psb->m_nodes.size(); ++j)
{
const btSoftBody::Node& node = psb->m_nodes[j];
if (node.m_im > 0)
{
e -= m_gravity.dot(node.m_q)/node.m_im;
}
}
}
return e;
}
};
#endif /* BT_DEFORMABLE_GRAVITY_FORCE_H */
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