godot/thirdparty/bullet/BulletCollision/Gimpact/btGImpactShape.h

/*! \file btGImpactShape.h
\author Francisco Len Nßjera
*/
/*
This source file is part of GIMPACT Library.

For the latest info, see http://gimpact.sourceforge.net/

Copyright (c) 2007 Francisco Leon Najera. C.C. 80087371.
email: projectileman@yahoo.com


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 GIMPACT_SHAPE_H
#define GIMPACT_SHAPE_H

#include "BulletCollision/CollisionShapes/btCollisionShape.h"
#include "BulletCollision/CollisionShapes/btTriangleShape.h"
#include "BulletCollision/CollisionShapes/btStridingMeshInterface.h"
#include "BulletCollision/CollisionShapes/btCollisionMargin.h"
#include "BulletCollision/CollisionDispatch/btCollisionWorld.h"
#include "BulletCollision/CollisionShapes/btConcaveShape.h"
#include "BulletCollision/CollisionShapes/btTetrahedronShape.h"
#include "LinearMath/btVector3.h"
#include "LinearMath/btTransform.h"
#include "LinearMath/btMatrix3x3.h"
#include "LinearMath/btAlignedObjectArray.h"

#include "btGImpactQuantizedBvh.h"  // box tree class

//! declare Quantized trees, (you can change to float based trees)
typedef btGImpactQuantizedBvh btGImpactBoxSet;

enum eGIMPACT_SHAPE_TYPE
{
	CONST_GIMPACT_COMPOUND_SHAPE = 0,
	CONST_GIMPACT_TRIMESH_SHAPE_PART,
	CONST_GIMPACT_TRIMESH_SHAPE
};

//! Helper class for tetrahedrons
class btTetrahedronShapeEx : public btBU_Simplex1to4
{
public:
	btTetrahedronShapeEx()
	{
		m_numVertices = 4;
	}

	SIMD_FORCE_INLINE void setVertices(
		const btVector3& v0, const btVector3& v1,
		const btVector3& v2, const btVector3& v3)
	{
		m_vertices[0] = v0;
		m_vertices[1] = v1;
		m_vertices[2] = v2;
		m_vertices[3] = v3;
		recalcLocalAabb();
	}
};

//! Base class for gimpact shapes
class btGImpactShapeInterface : public btConcaveShape
{
protected:
	btAABB m_localAABB;
	bool m_needs_update;
	btVector3 localScaling;
	btGImpactBoxSet m_box_set;  // optionally boxset

	//! use this function for perfofm refit in bounding boxes
	//! use this function for perfofm refit in bounding boxes
	virtual void calcLocalAABB()
	{
		lockChildShapes();
		if (m_box_set.getNodeCount() == 0)
		{
			m_box_set.buildSet();
		}
		else
		{
			m_box_set.update();
		}
		unlockChildShapes();

		m_localAABB = m_box_set.getGlobalBox();
	}

public:
	btGImpactShapeInterface()
	{
		m_shapeType = GIMPACT_SHAPE_PROXYTYPE;
		m_localAABB.invalidate();
		m_needs_update = true;
		localScaling.setValue(1.f, 1.f, 1.f);
	}

	//! performs refit operation
	/*!
	Updates the entire Box set of this shape.
	\pre postUpdate() must be called for attemps to calculating the box set, else this function
		will does nothing.
	\post if m_needs_update == true, then it calls calcLocalAABB();
	*/
	SIMD_FORCE_INLINE void updateBound()
	{
		if (!m_needs_update) return;
		calcLocalAABB();
		m_needs_update = false;
	}

	//! If the Bounding box is not updated, then this class attemps to calculate it.
	/*!
    \post Calls updateBound() for update the box set.
    */
	void getAabb(const btTransform& t, btVector3& aabbMin, btVector3& aabbMax) const
	{
		btAABB transformedbox = m_localAABB;
		transformedbox.appy_transform(t);
		aabbMin = transformedbox.m_min;
		aabbMax = transformedbox.m_max;
	}

	//! Tells to this object that is needed to refit the box set
	virtual void postUpdate()
	{
		m_needs_update = true;
	}

	//! Obtains the local box, which is the global calculated box of the total of subshapes
	SIMD_FORCE_INLINE const btAABB& getLocalBox()
	{
		return m_localAABB;
	}

	virtual int getShapeType() const
	{
		return GIMPACT_SHAPE_PROXYTYPE;
	}

	/*!
	\post You must call updateBound() for update the box set.
	*/
	virtual void setLocalScaling(const btVector3& scaling)
	{
		localScaling = scaling;
		postUpdate();
	}

	virtual const btVector3& getLocalScaling() const
	{
		return localScaling;
	}

	virtual void setMargin(btScalar margin)
	{
		m_collisionMargin = margin;
		int i = getNumChildShapes();
		while (i--)
		{
			btCollisionShape* child = getChildShape(i);
			child->setMargin(margin);
		}

		m_needs_update = true;
	}

	//! Subshape member functions
	//!@{

	//! Base method for determinig which kind of GIMPACT shape we get
	virtual eGIMPACT_SHAPE_TYPE getGImpactShapeType() const = 0;

	//! gets boxset
	SIMD_FORCE_INLINE const btGImpactBoxSet* getBoxSet() const
	{
		return &m_box_set;
	}

	//! Determines if this class has a hierarchy structure for sorting its primitives
	SIMD_FORCE_INLINE bool hasBoxSet() const
	{
		if (m_box_set.getNodeCount() == 0) return false;
		return true;
	}

	//! Obtains the primitive manager
	virtual const btPrimitiveManagerBase* getPrimitiveManager() const = 0;

	//! Gets the number of children
	virtual int getNumChildShapes() const = 0;

	//! if true, then its children must get transforms.
	virtual bool childrenHasTransform() const = 0;

	//! Determines if this shape has triangles
	virtual bool needsRetrieveTriangles() const = 0;

	//! Determines if this shape has tetrahedrons
	virtual bool needsRetrieveTetrahedrons() const = 0;

	virtual void getBulletTriangle(int prim_index, btTriangleShapeEx& triangle) const = 0;

	virtual void getBulletTetrahedron(int prim_index, btTetrahedronShapeEx& tetrahedron) const = 0;

	//! call when reading child shapes
	virtual void lockChildShapes() const
	{
	}

	virtual void unlockChildShapes() const
	{
	}

	//! if this trimesh
	SIMD_FORCE_INLINE void getPrimitiveTriangle(int index, btPrimitiveTriangle& triangle) const
	{
		getPrimitiveManager()->get_primitive_triangle(index, triangle);
	}

	//! Retrieves the bound from a child
	/*!
    */
	virtual void getChildAabb(int child_index, const btTransform& t, btVector3& aabbMin, btVector3& aabbMax) const
	{
		btAABB child_aabb;
		getPrimitiveManager()->get_primitive_box(child_index, child_aabb);
		child_aabb.appy_transform(t);
		aabbMin = child_aabb.m_min;
		aabbMax = child_aabb.m_max;
	}

	//! Gets the children
	virtual btCollisionShape* getChildShape(int index) = 0;

	//! Gets the child
	virtual const btCollisionShape* getChildShape(int index) const = 0;

	//! Gets the children transform
	virtual btTransform getChildTransform(int index) const = 0;

	//! Sets the children transform
	/*!
	\post You must call updateBound() for update the box set.
	*/
	virtual void setChildTransform(int index, const btTransform& transform) = 0;

	//!@}

	//! virtual method for ray collision
	virtual void rayTest(const btVector3& rayFrom, const btVector3& rayTo, btCollisionWorld::RayResultCallback& resultCallback) const
	{
		(void)rayFrom;
		(void)rayTo;
		(void)resultCallback;
	}

	//! Function for retrieve triangles.
	/*!
	It gives the triangles in local space
	*/
	virtual void processAllTriangles(btTriangleCallback* callback, const btVector3& aabbMin, const btVector3& aabbMax) const
	{
		(void)callback;
		(void)aabbMin;
		(void)aabbMax;
	}

	//! Function for retrieve triangles.
	/*!
	It gives the triangles in local space
	*/
	virtual void processAllTrianglesRay(btTriangleCallback* /*callback*/, const btVector3& /*rayFrom*/, const btVector3& /*rayTo*/) const
	{
	}

	//!@}
};

//! btGImpactCompoundShape allows to handle multiple btCollisionShape objects at once
/*!
This class only can manage Convex subshapes
*/
class btGImpactCompoundShape : public btGImpactShapeInterface
{
public:
	//! compound primitive manager
	class CompoundPrimitiveManager : public btPrimitiveManagerBase
	{
	public:
		virtual ~CompoundPrimitiveManager() {}
		btGImpactCompoundShape* m_compoundShape;

		CompoundPrimitiveManager(const CompoundPrimitiveManager& compound)
			: btPrimitiveManagerBase()
		{
			m_compoundShape = compound.m_compoundShape;
		}

		CompoundPrimitiveManager(btGImpactCompoundShape* compoundShape)
		{
			m_compoundShape = compoundShape;
		}

		CompoundPrimitiveManager()
		{
			m_compoundShape = NULL;
		}

		virtual bool is_trimesh() const
		{
			return false;
		}

		virtual int get_primitive_count() const
		{
			return (int)m_compoundShape->getNumChildShapes();
		}

		virtual void get_primitive_box(int prim_index, btAABB& primbox) const
		{
			btTransform prim_trans;
			if (m_compoundShape->childrenHasTransform())
			{
				prim_trans = m_compoundShape->getChildTransform(prim_index);
			}
			else
			{
				prim_trans.setIdentity();
			}
			const btCollisionShape* shape = m_compoundShape->getChildShape(prim_index);
			shape->getAabb(prim_trans, primbox.m_min, primbox.m_max);
		}

		virtual void get_primitive_triangle(int prim_index, btPrimitiveTriangle& triangle) const
		{
			btAssert(0);
			(void)prim_index;
			(void)triangle;
		}
	};

protected:
	CompoundPrimitiveManager m_primitive_manager;
	btAlignedObjectArray<btTransform> m_childTransforms;
	btAlignedObjectArray<btCollisionShape*> m_childShapes;

public:
	btGImpactCompoundShape(bool children_has_transform = true)
	{
		(void)children_has_transform;
		m_primitive_manager.m_compoundShape = this;
		m_box_set.setPrimitiveManager(&m_primitive_manager);
	}

	virtual ~btGImpactCompoundShape()
	{
	}

	//! if true, then its children must get transforms.
	virtual bool childrenHasTransform() const
	{
		if (m_childTransforms.size() == 0) return false;
		return true;
	}

	//! Obtains the primitive manager
	virtual const btPrimitiveManagerBase* getPrimitiveManager() const
	{
		return &m_primitive_manager;
	}

	//! Obtains the compopund primitive manager
	SIMD_FORCE_INLINE CompoundPrimitiveManager* getCompoundPrimitiveManager()
	{
		return &m_primitive_manager;
	}

	//! Gets the number of children
	virtual int getNumChildShapes() const
	{
		return m_childShapes.size();
	}

	//! Use this method for adding children. Only Convex shapes are allowed.
	void addChildShape(const btTransform& localTransform, btCollisionShape* shape)
	{
		btAssert(shape->isConvex());
		m_childTransforms.push_back(localTransform);
		m_childShapes.push_back(shape);
	}

	//! Use this method for adding children. Only Convex shapes are allowed.
	void addChildShape(btCollisionShape* shape)
	{
		btAssert(shape->isConvex());
		m_childShapes.push_back(shape);
	}

	//! Gets the children
	virtual btCollisionShape* getChildShape(int index)
	{
		return m_childShapes[index];
	}

	//! Gets the children
	virtual const btCollisionShape* getChildShape(int index) const
	{
		return m_childShapes[index];
	}

	//! Retrieves the bound from a child
	/*!
    */
	virtual void getChildAabb(int child_index, const btTransform& t, btVector3& aabbMin, btVector3& aabbMax) const
	{
		if (childrenHasTransform())
		{
			m_childShapes[child_index]->getAabb(t * m_childTransforms[child_index], aabbMin, aabbMax);
		}
		else
		{
			m_childShapes[child_index]->getAabb(t, aabbMin, aabbMax);
		}
	}

	//! Gets the children transform
	virtual btTransform getChildTransform(int index) const
	{
		btAssert(m_childTransforms.size() == m_childShapes.size());
		return m_childTransforms[index];
	}

	//! Sets the children transform
	/*!
	\post You must call updateBound() for update the box set.
	*/
	virtual void setChildTransform(int index, const btTransform& transform)
	{
		btAssert(m_childTransforms.size() == m_childShapes.size());
		m_childTransforms[index] = transform;
		postUpdate();
	}

	//! Determines if this shape has triangles
	virtual bool needsRetrieveTriangles() const
	{
		return false;
	}

	//! Determines if this shape has tetrahedrons
	virtual bool needsRetrieveTetrahedrons() const
	{
		return false;
	}

	virtual void getBulletTriangle(int prim_index, btTriangleShapeEx& triangle) const
	{
		(void)prim_index;
		(void)triangle;
		btAssert(0);
	}

	virtual void getBulletTetrahedron(int prim_index, btTetrahedronShapeEx& tetrahedron) const
	{
		(void)prim_index;
		(void)tetrahedron;
		btAssert(0);
	}

	//! Calculates the exact inertia tensor for this shape
	virtual void calculateLocalInertia(btScalar mass, btVector3& inertia) const;

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

	virtual eGIMPACT_SHAPE_TYPE getGImpactShapeType() const
	{
		return CONST_GIMPACT_COMPOUND_SHAPE;
	}
};

//! This class manages a sub part of a mesh supplied by the btStridingMeshInterface interface.
/*!
- Simply create this shape by passing the btStridingMeshInterface to the constructor btGImpactMeshShapePart, then you must call updateBound() after creating the mesh
- When making operations with this shape, you must call <b>lock</b> before accessing to the trimesh primitives, and then call <b>unlock</b>
- You can handle deformable meshes with this shape, by calling postUpdate() every time when changing the mesh vertices.

*/
class btGImpactMeshShapePart : public btGImpactShapeInterface
{
public:
	//! Trimesh primitive manager
	/*!
	Manages the info from btStridingMeshInterface object and controls the Lock/Unlock mechanism
	*/
	class TrimeshPrimitiveManager : public btPrimitiveManagerBase
	{
	public:
		btScalar m_margin;
		btStridingMeshInterface* m_meshInterface;
		btVector3 m_scale;
		int m_part;
		int m_lock_count;
		const unsigned char* vertexbase;
		int numverts;
		PHY_ScalarType type;
		int stride;
		const unsigned char* indexbase;
		int indexstride;
		int numfaces;
		PHY_ScalarType indicestype;

		TrimeshPrimitiveManager()
		{
			m_meshInterface = NULL;
			m_part = 0;
			m_margin = 0.01f;
			m_scale = btVector3(1.f, 1.f, 1.f);
			m_lock_count = 0;
			vertexbase = 0;
			numverts = 0;
			stride = 0;
			indexbase = 0;
			indexstride = 0;
			numfaces = 0;
		}

		TrimeshPrimitiveManager(const TrimeshPrimitiveManager& manager)
			: btPrimitiveManagerBase()
		{
			m_meshInterface = manager.m_meshInterface;
			m_part = manager.m_part;
			m_margin = manager.m_margin;
			m_scale = manager.m_scale;
			m_lock_count = 0;
			vertexbase = 0;
			numverts = 0;
			stride = 0;
			indexbase = 0;
			indexstride = 0;
			numfaces = 0;
		}

		TrimeshPrimitiveManager(
			btStridingMeshInterface* meshInterface, int part)
		{
			m_meshInterface = meshInterface;
			m_part = part;
			m_scale = m_meshInterface->getScaling();
			m_margin = 0.1f;
			m_lock_count = 0;
			vertexbase = 0;
			numverts = 0;
			stride = 0;
			indexbase = 0;
			indexstride = 0;
			numfaces = 0;
		}

		virtual ~TrimeshPrimitiveManager() {}

		void lock()
		{
			if (m_lock_count > 0)
			{
				m_lock_count++;
				return;
			}
			m_meshInterface->getLockedReadOnlyVertexIndexBase(
				&vertexbase, numverts,
				type, stride, &indexbase, indexstride, numfaces, indicestype, m_part);

			m_lock_count = 1;
		}

		void unlock()
		{
			if (m_lock_count == 0) return;
			if (m_lock_count > 1)
			{
				--m_lock_count;
				return;
			}
			m_meshInterface->unLockReadOnlyVertexBase(m_part);
			vertexbase = NULL;
			m_lock_count = 0;
		}

		virtual bool is_trimesh() const
		{
			return true;
		}

		virtual int get_primitive_count() const
		{
			return (int)numfaces;
		}

		SIMD_FORCE_INLINE int get_vertex_count() const
		{
			return (int)numverts;
		}

		SIMD_FORCE_INLINE void get_indices(int face_index, unsigned int& i0, unsigned int& i1, unsigned int& i2) const
		{
			if (indicestype == PHY_SHORT)
			{
				unsigned short* s_indices = (unsigned short*)(indexbase + face_index * indexstride);
				i0 = s_indices[0];
				i1 = s_indices[1];
				i2 = s_indices[2];
			}
			else if (indicestype == PHY_INTEGER)
			{
				unsigned int* i_indices = (unsigned int*)(indexbase + face_index * indexstride);
				i0 = i_indices[0];
				i1 = i_indices[1];
				i2 = i_indices[2];
			}
			else
			{
				btAssert(indicestype == PHY_UCHAR);
				unsigned char* i_indices = (unsigned char*)(indexbase + face_index * indexstride);
				i0 = i_indices[0];
				i1 = i_indices[1];
				i2 = i_indices[2];
			}
		}

		SIMD_FORCE_INLINE void get_vertex(unsigned int vertex_index, btVector3& vertex) const
		{
			if (type == PHY_DOUBLE)
			{
				double* dvertices = (double*)(vertexbase + vertex_index * stride);
				vertex[0] = btScalar(dvertices[0] * m_scale[0]);
				vertex[1] = btScalar(dvertices[1] * m_scale[1]);
				vertex[2] = btScalar(dvertices[2] * m_scale[2]);
			}
			else
			{
				float* svertices = (float*)(vertexbase + vertex_index * stride);
				vertex[0] = svertices[0] * m_scale[0];
				vertex[1] = svertices[1] * m_scale[1];
				vertex[2] = svertices[2] * m_scale[2];
			}
		}

		virtual void get_primitive_box(int prim_index, btAABB& primbox) const
		{
			btPrimitiveTriangle triangle;
			get_primitive_triangle(prim_index, triangle);
			primbox.calc_from_triangle_margin(
				triangle.m_vertices[0],
				triangle.m_vertices[1], triangle.m_vertices[2], triangle.m_margin);
		}

		virtual void get_primitive_triangle(int prim_index, btPrimitiveTriangle& triangle) const
		{
			unsigned int indices[3];
			get_indices(prim_index, indices[0], indices[1], indices[2]);
			get_vertex(indices[0], triangle.m_vertices[0]);
			get_vertex(indices[1], triangle.m_vertices[1]);
			get_vertex(indices[2], triangle.m_vertices[2]);
			triangle.m_margin = m_margin;
		}

		SIMD_FORCE_INLINE void get_bullet_triangle(int prim_index, btTriangleShapeEx& triangle) const
		{
			unsigned int indices[3];
			get_indices(prim_index, indices[0], indices[1], indices[2]);
			get_vertex(indices[0], triangle.m_vertices1[0]);
			get_vertex(indices[1], triangle.m_vertices1[1]);
			get_vertex(indices[2], triangle.m_vertices1[2]);
			triangle.setMargin(m_margin);
		}
	};

protected:
	TrimeshPrimitiveManager m_primitive_manager;

public:
	btGImpactMeshShapePart()
	{
		m_box_set.setPrimitiveManager(&m_primitive_manager);
	}

	btGImpactMeshShapePart(btStridingMeshInterface* meshInterface, int part);
	virtual ~btGImpactMeshShapePart();

	//! if true, then its children must get transforms.
	virtual bool childrenHasTransform() const
	{
		return false;
	}

	//! call when reading child shapes
	virtual void lockChildShapes() const;
	virtual void unlockChildShapes() const;

	//! Gets the number of children
	virtual int getNumChildShapes() const
	{
		return m_primitive_manager.get_primitive_count();
	}

	//! Gets the children
	virtual btCollisionShape* getChildShape(int index)
	{
		(void)index;
		btAssert(0);
		return NULL;
	}

	//! Gets the child
	virtual const btCollisionShape* getChildShape(int index) const
	{
		(void)index;
		btAssert(0);
		return NULL;
	}

	//! Gets the children transform
	virtual btTransform getChildTransform(int index) const
	{
		(void)index;
		btAssert(0);
		return btTransform();
	}

	//! Sets the children transform
	/*!
	\post You must call updateBound() for update the box set.
	*/
	virtual void setChildTransform(int index, const btTransform& transform)
	{
		(void)index;
		(void)transform;
		btAssert(0);
	}

	//! Obtains the primitive manager
	virtual const btPrimitiveManagerBase* getPrimitiveManager() const
	{
		return &m_primitive_manager;
	}

	SIMD_FORCE_INLINE TrimeshPrimitiveManager* getTrimeshPrimitiveManager()
	{
		return &m_primitive_manager;
	}

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

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

	virtual eGIMPACT_SHAPE_TYPE getGImpactShapeType() const
	{
		return CONST_GIMPACT_TRIMESH_SHAPE_PART;
	}

	//! Determines if this shape has triangles
	virtual bool needsRetrieveTriangles() const
	{
		return true;
	}

	//! Determines if this shape has tetrahedrons
	virtual bool needsRetrieveTetrahedrons() const
	{
		return false;
	}

	virtual void getBulletTriangle(int prim_index, btTriangleShapeEx& triangle) const
	{
		m_primitive_manager.get_bullet_triangle(prim_index, triangle);
	}

	virtual void getBulletTetrahedron(int prim_index, btTetrahedronShapeEx& tetrahedron) const
	{
		(void)prim_index;
		(void)tetrahedron;
		btAssert(0);
	}

	SIMD_FORCE_INLINE int getVertexCount() const
	{
		return m_primitive_manager.get_vertex_count();
	}

	SIMD_FORCE_INLINE void getVertex(int vertex_index, btVector3& vertex) const
	{
		m_primitive_manager.get_vertex(vertex_index, vertex);
	}

	SIMD_FORCE_INLINE void setMargin(btScalar margin)
	{
		m_primitive_manager.m_margin = margin;
		postUpdate();
	}

	SIMD_FORCE_INLINE btScalar getMargin() const
	{
		return m_primitive_manager.m_margin;
	}

	virtual void setLocalScaling(const btVector3& scaling)
	{
		m_primitive_manager.m_scale = scaling;
		postUpdate();
	}

	virtual const btVector3& getLocalScaling() const
	{
		return m_primitive_manager.m_scale;
	}

	SIMD_FORCE_INLINE int getPart() const
	{
		return (int)m_primitive_manager.m_part;
	}

	virtual void processAllTriangles(btTriangleCallback* callback, const btVector3& aabbMin, const btVector3& aabbMax) const;
	virtual void processAllTrianglesRay(btTriangleCallback* callback, const btVector3& rayFrom, const btVector3& rayTo) const;
};

//! This class manages a mesh supplied by the btStridingMeshInterface interface.
/*!
Set of btGImpactMeshShapePart parts
- Simply create this shape by passing the btStridingMeshInterface to the constructor btGImpactMeshShape, then you must call updateBound() after creating the mesh

- You can handle deformable meshes with this shape, by calling postUpdate() every time when changing the mesh vertices.

*/
class btGImpactMeshShape : public btGImpactShapeInterface
{
	btStridingMeshInterface* m_meshInterface;

protected:
	btAlignedObjectArray<btGImpactMeshShapePart*> m_mesh_parts;
	void buildMeshParts(btStridingMeshInterface* meshInterface)
	{
		for (int i = 0; i < meshInterface->getNumSubParts(); ++i)
		{
			btGImpactMeshShapePart* newpart = new btGImpactMeshShapePart(meshInterface, i);
			m_mesh_parts.push_back(newpart);
		}
	}

	//! use this function for perfofm refit in bounding boxes
	virtual void calcLocalAABB()
	{
		m_localAABB.invalidate();
		int i = m_mesh_parts.size();
		while (i--)
		{
			m_mesh_parts[i]->updateBound();
			m_localAABB.merge(m_mesh_parts[i]->getLocalBox());
		}
	}

public:
	btGImpactMeshShape(btStridingMeshInterface* meshInterface)
	{
		m_meshInterface = meshInterface;
		buildMeshParts(meshInterface);
	}

	virtual ~btGImpactMeshShape()
	{
		int i = m_mesh_parts.size();
		while (i--)
		{
			btGImpactMeshShapePart* part = m_mesh_parts[i];
			delete part;
		}
		m_mesh_parts.clear();
	}

	btStridingMeshInterface* getMeshInterface()
	{
		return m_meshInterface;
	}

	const btStridingMeshInterface* getMeshInterface() const
	{
		return m_meshInterface;
	}

	int getMeshPartCount() const
	{
		return m_mesh_parts.size();
	}

	btGImpactMeshShapePart* getMeshPart(int index)
	{
		return m_mesh_parts[index];
	}

	const btGImpactMeshShapePart* getMeshPart(int index) const
	{
		return m_mesh_parts[index];
	}

	virtual void setLocalScaling(const btVector3& scaling)
	{
		localScaling = scaling;

		int i = m_mesh_parts.size();
		while (i--)
		{
			btGImpactMeshShapePart* part = m_mesh_parts[i];
			part->setLocalScaling(scaling);
		}

		m_needs_update = true;
	}

	virtual void setMargin(btScalar margin)
	{
		m_collisionMargin = margin;

		int i = m_mesh_parts.size();
		while (i--)
		{
			btGImpactMeshShapePart* part = m_mesh_parts[i];
			part->setMargin(margin);
		}

		m_needs_update = true;
	}

	//! Tells to this object that is needed to refit all the meshes
	virtual void postUpdate()
	{
		int i = m_mesh_parts.size();
		while (i--)
		{
			btGImpactMeshShapePart* part = m_mesh_parts[i];
			part->postUpdate();
		}

		m_needs_update = true;
	}

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

	//! Obtains the primitive manager
	virtual const btPrimitiveManagerBase* getPrimitiveManager() const
	{
		btAssert(0);
		return NULL;
	}

	//! Gets the number of children
	virtual int getNumChildShapes() const
	{
		btAssert(0);
		return 0;
	}

	//! if true, then its children must get transforms.
	virtual bool childrenHasTransform() const
	{
		btAssert(0);
		return false;
	}

	//! Determines if this shape has triangles
	virtual bool needsRetrieveTriangles() const
	{
		btAssert(0);
		return false;
	}

	//! Determines if this shape has tetrahedrons
	virtual bool needsRetrieveTetrahedrons() const
	{
		btAssert(0);
		return false;
	}

	virtual void getBulletTriangle(int prim_index, btTriangleShapeEx& triangle) const
	{
		(void)prim_index;
		(void)triangle;
		btAssert(0);
	}

	virtual void getBulletTetrahedron(int prim_index, btTetrahedronShapeEx& tetrahedron) const
	{
		(void)prim_index;
		(void)tetrahedron;
		btAssert(0);
	}

	//! call when reading child shapes
	virtual void lockChildShapes() const
	{
		btAssert(0);
	}

	virtual void unlockChildShapes() const
	{
		btAssert(0);
	}

	//! Retrieves the bound from a child
	/*!
    */
	virtual void getChildAabb(int child_index, const btTransform& t, btVector3& aabbMin, btVector3& aabbMax) const
	{
		(void)child_index;
		(void)t;
		(void)aabbMin;
		(void)aabbMax;
		btAssert(0);
	}

	//! Gets the children
	virtual btCollisionShape* getChildShape(int index)
	{
		(void)index;
		btAssert(0);
		return NULL;
	}

	//! Gets the child
	virtual const btCollisionShape* getChildShape(int index) const
	{
		(void)index;
		btAssert(0);
		return NULL;
	}

	//! Gets the children transform
	virtual btTransform getChildTransform(int index) const
	{
		(void)index;
		btAssert(0);
		return btTransform();
	}

	//! Sets the children transform
	/*!
	\post You must call updateBound() for update the box set.
	*/
	virtual void setChildTransform(int index, const btTransform& transform)
	{
		(void)index;
		(void)transform;
		btAssert(0);
	}

	virtual eGIMPACT_SHAPE_TYPE getGImpactShapeType() const
	{
		return CONST_GIMPACT_TRIMESH_SHAPE;
	}

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

	virtual void rayTest(const btVector3& rayFrom, const btVector3& rayTo, btCollisionWorld::RayResultCallback& resultCallback) const;

	//! Function for retrieve triangles.
	/*!
	It gives the triangles in local space
	*/
	virtual void processAllTriangles(btTriangleCallback* callback, const btVector3& aabbMin, const btVector3& aabbMax) const;

	virtual void processAllTrianglesRay(btTriangleCallback* callback, const btVector3& rayFrom, const btVector3& rayTo) const;

	virtual int calculateSerializeBufferSize() const;

	///fills the dataBuffer and returns the struct name (and 0 on failure)
	virtual const char* serialize(void* dataBuffer, btSerializer* serializer) const;
};

///do not change those serialization structures, it requires an updated sBulletDNAstr/sBulletDNAstr64
struct btGImpactMeshShapeData
{
	btCollisionShapeData m_collisionShapeData;

	btStridingMeshInterfaceData m_meshInterface;

	btVector3FloatData m_localScaling;

	float m_collisionMargin;

	int m_gimpactSubType;
};

SIMD_FORCE_INLINE int btGImpactMeshShape::calculateSerializeBufferSize() const
{
	return sizeof(btGImpactMeshShapeData);
}

#endif  //GIMPACT_MESH_SHAPE_H