source: code/branches/physics/src/bullet/BulletCollision/CollisionShapes/btConeShape.h @ 1983

/*
Bullet Continuous Collision Detection and Physics Library
Copyright (c) 2003-2006 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 CONE_MINKOWSKI_H
#define CONE_MINKOWSKI_H

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

///The btConeShape implements a cone shape primitive, centered around the origin and aligned with the Y axis. The btConeShapeX is aligned around the X axis and btConeShapeZ around the Z axis.
class btConeShape : public btConvexInternalShape

{

        btScalar m_sinAngle;
        btScalar m_radius;
        btScalar m_height;
        int             m_coneIndices[3];
        btVector3 coneLocalSupport(const btVector3& v) const;


public:
        btConeShape (btScalar radius,btScalar height);
        
        virtual btVector3       localGetSupportingVertex(const btVector3& vec) const;
        virtual btVector3       localGetSupportingVertexWithoutMargin(const btVector3& vec) const;
        virtual void    batchedUnitVectorGetSupportingVertexWithoutMargin(const btVector3* vectors,btVector3* supportVerticesOut,int numVectors) const;

        btScalar getRadius() const { return m_radius;}
        btScalar getHeight() const { return m_height;}


        virtual void    calculateLocalInertia(btScalar mass,btVector3& inertia) const
        {
                btTransform identity;
                identity.setIdentity();
                btVector3 aabbMin,aabbMax;
                getAabb(identity,aabbMin,aabbMax);

                btVector3 halfExtents = (aabbMax-aabbMin)*btScalar(0.5);

                btScalar margin = getMargin();

                btScalar lx=btScalar(2.)*(halfExtents.x()+margin);
                btScalar ly=btScalar(2.)*(halfExtents.y()+margin);
                btScalar lz=btScalar(2.)*(halfExtents.z()+margin);
                const btScalar x2 = lx*lx;
                const btScalar y2 = ly*ly;
                const btScalar z2 = lz*lz;
                const btScalar scaledmass = mass * btScalar(0.08333333);

                inertia = scaledmass * (btVector3(y2+z2,x2+z2,x2+y2));

//              inertia.x() = scaledmass * (y2+z2);
//              inertia.y() = scaledmass * (x2+z2);
//              inertia.z() = scaledmass * (x2+y2);
        }


                virtual const char*     getName()const 
                {
                        return "Cone";
                }
                
                ///choose upAxis index
                void    setConeUpIndex(int upIndex);
                
                int     getConeUpIndex() const
                {
                        return m_coneIndices[1];
                }
};

///btConeShape implements a Cone shape, around the X axis
class btConeShapeX : public btConeShape
{
        public:
                btConeShapeX(btScalar radius,btScalar height);
};

///btConeShapeZ implements a Cone shape, around the Z axis
class btConeShapeZ : public btConeShape
{
        public:
                btConeShapeZ(btScalar radius,btScalar height);
};
#endif //CONE_MINKOWSKI_H