btCapsuleShape.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_CAPSULE_SHAPE_H
#define BT_CAPSULE_SHAPE_H

#include "btConvexInternalShape.h"
#include "BulletCollision/BroadphaseCollision/btBroadphaseProxy.h" // for the types


ATTRIBUTE_ALIGNED16(class) btCapsuleShape : public btConvexInternalShape
{
protected:
        int     m_upAxis;

protected:
        btCapsuleShape() : btConvexInternalShape() {m_shapeType = CAPSULE_SHAPE_PROXYTYPE;};

public:
        
        BT_DECLARE_ALIGNED_ALLOCATOR();
        
        btCapsuleShape(btScalar radius,btScalar height);

        virtual void    calculateLocalInertia(btScalar mass,btVector3& inertia) const;

        virtual btVector3       localGetSupportingVertexWithoutMargin(const btVector3& vec)const;

        virtual void    batchedUnitVectorGetSupportingVertexWithoutMargin(const btVector3* vectors,btVector3* supportVerticesOut,int numVectors) const;
        
        virtual void setMargin(btScalar collisionMargin)
        {
                //don't override the margin for capsules, their entire radius == margin
                (void)collisionMargin;
        }

        virtual void getAabb (const btTransform& t, btVector3& aabbMin, btVector3& aabbMax) const
        {
                        btVector3 halfExtents(getRadius(),getRadius(),getRadius());
                        halfExtents[m_upAxis] = getRadius() + getHalfHeight();
                        btMatrix3x3 abs_b = t.getBasis().absolute();  
                        btVector3 center = t.getOrigin();
            btVector3 extent = halfExtents.dot3(abs_b[0], abs_b[1], abs_b[2]);
        
                        aabbMin = center - extent;
                        aabbMax = center + extent;
        }

        virtual const char*     getName()const 
        {
                return "CapsuleShape";
        }

        int     getUpAxis() const
        {
                return m_upAxis;
        }

        btScalar        getRadius() const
        {
                int radiusAxis = (m_upAxis+2)%3;
                return m_implicitShapeDimensions[radiusAxis];
        }

        btScalar        getHalfHeight() const
        {
                return m_implicitShapeDimensions[m_upAxis];
        }

        virtual void    setLocalScaling(const btVector3& scaling)
        {
                btVector3 unScaledImplicitShapeDimensions = m_implicitShapeDimensions / m_localScaling;
                btConvexInternalShape::setLocalScaling(scaling);
                m_implicitShapeDimensions = (unScaledImplicitShapeDimensions * scaling);
                //update m_collisionMargin, since entire radius==margin
                int radiusAxis = (m_upAxis+2)%3;
                m_collisionMargin = m_implicitShapeDimensions[radiusAxis];
        }

        virtual btVector3       getAnisotropicRollingFrictionDirection() const
        {
                btVector3 aniDir(0,0,0);
                aniDir[getUpAxis()]=1;
                return aniDir;
        }


        virtual int     calculateSerializeBufferSize() const;

        virtual const char*     serialize(void* dataBuffer, btSerializer* serializer) const;

        SIMD_FORCE_INLINE       void    deSerializeFloat(struct btCapsuleShapeData* dataBuffer);

};

class btCapsuleShapeX : public btCapsuleShape
{
public:

        btCapsuleShapeX(btScalar radius,btScalar height);
                
        //debugging
        virtual const char*     getName()const
        {
                return "CapsuleX";
        }

        

};

class btCapsuleShapeZ : public btCapsuleShape
{
public:
        btCapsuleShapeZ(btScalar radius,btScalar height);

                //debugging
        virtual const char*     getName()const
        {
                return "CapsuleZ";
        }

        
};

struct  btCapsuleShapeData
{
        btConvexInternalShapeData       m_convexInternalShapeData;

        int     m_upAxis;

        char    m_padding[4];
};

SIMD_FORCE_INLINE       int     btCapsuleShape::calculateSerializeBufferSize() const
{
        return sizeof(btCapsuleShapeData);
}

SIMD_FORCE_INLINE       const char*     btCapsuleShape::serialize(void* dataBuffer, btSerializer* serializer) const
{
        btCapsuleShapeData* shapeData = (btCapsuleShapeData*) dataBuffer;

        btConvexInternalShape::serialize(&shapeData->m_convexInternalShapeData,serializer);

        shapeData->m_upAxis = m_upAxis;

        // Fill padding with zeros to appease msan.
        shapeData->m_padding[0] = 0;
        shapeData->m_padding[1] = 0;
        shapeData->m_padding[2] = 0;
        shapeData->m_padding[3] = 0;

        return "btCapsuleShapeData";
}

SIMD_FORCE_INLINE       void    btCapsuleShape::deSerializeFloat(btCapsuleShapeData* dataBuffer)
{
        m_implicitShapeDimensions.deSerializeFloat(dataBuffer->m_convexInternalShapeData.m_implicitShapeDimensions);
        m_collisionMargin = dataBuffer->m_convexInternalShapeData.m_collisionMargin;
        m_localScaling.deSerializeFloat(dataBuffer->m_convexInternalShapeData.m_localScaling);
        //it is best to already pre-allocate the matching btCapsuleShape*(X/Z) version to match m_upAxis
        m_upAxis = dataBuffer->m_upAxis;
}

#endif //BT_CAPSULE_SHAPE_H