btCompoundShape.h

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/*
Bullet Continuous Collision Detection and Physics Library
Copyright (c) 2003-2009 Erwin Coumans  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_COMPOUND_SHAPE_H
#define BT_COMPOUND_SHAPE_H
 
#include "btCollisionShape.h"
 
#include "LinearMath/btVector3.h"
#include "LinearMath/btTransform.h"
#include "LinearMath/btMatrix3x3.h"
#include "btCollisionMargin.h"
#include "LinearMath/btAlignedObjectArray.h"
 
//class btOptimizedBvh;
struct btDbvt;
 
ATTRIBUTE_ALIGNED16(struct)
btCompoundShapeChild
{
    BT_DECLARE_ALIGNED_ALLOCATOR();
 
    btTransform m_transform;
    btCollisionShape* m_childShape;
    int m_childShapeType;
    btScalar m_childMargin;
    struct btDbvtNode* m_node;
};
 
SIMD_FORCE_INLINE bool operator==(const btCompoundShapeChild& c1, const btCompoundShapeChild& c2)
{
    return (c1.m_transform == c2.m_transform &&
            c1.m_childShape == c2.m_childShape &&
            c1.m_childShapeType == c2.m_childShapeType &&
            c1.m_childMargin == c2.m_childMargin);
}

ATTRIBUTE_ALIGNED16(class)
btCompoundShape : public btCollisionShape
{
protected:
    btAlignedObjectArray<btCompoundShapeChild> m_children;
    btVector3 m_localAabbMin;
    btVector3 m_localAabbMax;
 
    btDbvt* m_dynamicAabbTree;

    int m_updateRevision;
 
    btScalar m_collisionMargin;
 
    btVector3 m_localScaling;
 
public:
    BT_DECLARE_ALIGNED_ALLOCATOR();
 
    explicit btCompoundShape(bool enableDynamicAabbTree = true, const int initialChildCapacity = 0);
 
    virtual ~btCompoundShape();
 
    void addChildShape(const btTransform& localTransform, btCollisionShape* shape);

    virtual void removeChildShape(btCollisionShape * shape);
 
    void removeChildShapeByIndex(int childShapeindex);
 
    int getNumChildShapes() const
    {
        return int(m_children.size());
    }
 
    btCollisionShape* getChildShape(int index)
    {
        return m_children[index].m_childShape;
    }
    const btCollisionShape* getChildShape(int index) const
    {
        return m_children[index].m_childShape;
    }
 
    btTransform& getChildTransform(int index)
    {
        return m_children[index].m_transform;
    }
    const btTransform& getChildTransform(int index) const
    {
        return m_children[index].m_transform;
    }

    void updateChildTransform(int childIndex, const btTransform& newChildTransform, bool shouldRecalculateLocalAabb = true);
 
    btCompoundShapeChild* getChildList()
    {
        return &m_children[0];
    }

    virtual void getAabb(const btTransform& t, btVector3& aabbMin, btVector3& aabbMax) const;

    virtual void recalculateLocalAabb();
 
    virtual void setLocalScaling(const btVector3& scaling);
 
    virtual const btVector3& getLocalScaling() const
    {
        return m_localScaling;
    }
 
    virtual void calculateLocalInertia(btScalar mass, btVector3 & inertia) const;
 
    virtual void setMargin(btScalar margin)
    {
        m_collisionMargin = margin;
    }
    virtual btScalar getMargin() const
    {
        return m_collisionMargin;
    }
    virtual const char* getName() const
    {
        return "Compound";
    }
 
    const btDbvt* getDynamicAabbTree() const
    {
        return m_dynamicAabbTree;
    }
 
    btDbvt* getDynamicAabbTree()
    {
        return m_dynamicAabbTree;
    }
 
    void createAabbTreeFromChildren();

    void calculatePrincipalAxisTransform(const btScalar* masses, btTransform& principal, btVector3& inertia) const;
 
    int getUpdateRevision() const
    {
        return m_updateRevision;
    }
 
    virtual int calculateSerializeBufferSize() const;

    virtual const char* serialize(void* dataBuffer, btSerializer* serializer) const;
};
 
// clang-format off

struct btCompoundShapeChildData
{
    btTransformFloatData    m_transform;
    btCollisionShapeData    *m_childShape;
    int                     m_childShapeType;
    float                   m_childMargin;
};

struct  btCompoundShapeData
{
    btCollisionShapeData        m_collisionShapeData;
 
    btCompoundShapeChildData    *m_childShapePtr;
 
    int                         m_numChildShapes;
 
    float   m_collisionMargin;
 
};
 
// clang-format on
 
SIMD_FORCE_INLINE int btCompoundShape::calculateSerializeBufferSize() const
{
    return sizeof(btCompoundShapeData);
}
 
#endif  //BT_COMPOUND_SHAPE_H