reactphysics3d/src/collision/shapes/ConvexMeshShape.h

 /********************************************************************************
* ReactPhysics3D physics library, http://www.reactphysics3d.com                 *
* Copyright (c) 2010-2016 Daniel Chappuis                                       *
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#ifndef REACTPHYSICS3D_CONVEX_MESH_SHAPE_H
#define REACTPHYSICS3D_CONVEX_MESH_SHAPE_H

// Libraries
#include "ConvexPolyhedronShape.h"
#include "engine/CollisionWorld.h"
#include "mathematics/mathematics.h"
#include "collision/TriangleMesh.h"
#include "collision/PolyhedronMesh.h"
#include "collision/narrowphase/GJK/GJKAlgorithm.h"
#include <vector>
#include <set>
#include <map>

/// ReactPhysics3D namespace
namespace reactphysics3d {

// Declaration
class CollisionWorld;

// Class ConvexMeshShape
/**
 * This class represents a convex mesh shape. In order to create a convex mesh shape, you
 * need to indicate the local-space position of the mesh vertices. The center of mass
 * of the shape will be at the origin of the local-space geometry that you use to create
 * the mesh.
 */
class ConvexMeshShape : public ConvexPolyhedronShape {

    protected :

        // -------------------- Attributes -------------------- //

        /// Polyhedron structure of the mesh
        PolyhedronMesh* mPolyhedronMesh;

        /// Mesh minimum bounds in the three local x, y and z directions
        Vector3 mMinBounds;

        /// Mesh maximum bounds in the three local x, y and z directions
        Vector3 mMaxBounds;

        // -------------------- Methods -------------------- //

        /// Recompute the bounds of the mesh
        void recalculateBounds();

        /// Return a local support point in a given direction without the object margin.
        virtual Vector3 getLocalSupportPointWithoutMargin(const Vector3& direction) const override;

        /// Return true if a point is inside the collision shape
        virtual bool testPointInside(const Vector3& localPoint, ProxyShape* proxyShape) const override;

        /// Raycast method with feedback information
        virtual bool raycast(const Ray& ray, RaycastInfo& raycastInfo, ProxyShape* proxyShape) const override;

        /// Return the number of bytes used by the collision shape
        virtual size_t getSizeInBytes() const override;

    public :

        // -------------------- Methods -------------------- //

        /// Constructor
        ConvexMeshShape(PolyhedronMesh* polyhedronMesh);

        /// Destructor
        virtual ~ConvexMeshShape() override = default;

        /// Deleted copy-constructor
        ConvexMeshShape(const ConvexMeshShape& shape) = delete;

        /// Deleted assignment operator
        ConvexMeshShape& operator=(const ConvexMeshShape& shape) = delete;

        /// Set the scaling vector of the collision shape
        virtual void setLocalScaling(const Vector3& scaling) override;

        /// Return the local bounds of the shape in x, y and z directions
        virtual void getLocalBounds(Vector3& min, Vector3& max) const override;

        /// Return the local inertia tensor of the collision shape.
        virtual void computeLocalInertiaTensor(Matrix3x3& tensor, decimal mass) const override;

        /// Return the number of faces of the polyhedron
        virtual uint getNbFaces() const override;

        /// Return a given face of the polyhedron
        virtual HalfEdgeStructure::Face getFace(uint faceIndex) const override;

        /// Return the number of vertices of the polyhedron
        virtual uint getNbVertices() const override;

        /// Return a given vertex of the polyhedron
        virtual HalfEdgeStructure::Vertex getVertex(uint vertexIndex) const override;

        /// Return the number of half-edges of the polyhedron
        virtual uint getNbHalfEdges() const override;

        /// Return a given half-edge of the polyhedron
        virtual HalfEdgeStructure::Edge getHalfEdge(uint edgeIndex) const override;

        /// Return the position of a given vertex
        virtual Vector3 getVertexPosition(uint vertexIndex) const override;

        /// Return the normal vector of a given face of the polyhedron
        virtual Vector3 getFaceNormal(uint faceIndex) const override;

        /// Return the centroid of the polyhedron
        virtual Vector3 getCentroid() const override;
};

/// Set the scaling vector of the collision shape
inline void ConvexMeshShape::setLocalScaling(const Vector3& scaling) {
    ConvexShape::setLocalScaling(scaling);
    recalculateBounds();
}

// Return the number of bytes used by the collision shape
inline size_t ConvexMeshShape::getSizeInBytes() const {
    return sizeof(ConvexMeshShape);
}

// Return the local bounds of the shape in x, y and z directions
/**
 * @param min The minimum bounds of the shape in local-space coordinates
 * @param max The maximum bounds of the shape in local-space coordinates
 */
inline void ConvexMeshShape::getLocalBounds(Vector3& min, Vector3& max) const {
    min = mMinBounds;
    max = mMaxBounds;
}

// Return the local inertia tensor of the collision shape.
/// The local inertia tensor of the convex mesh is approximated using the inertia tensor
/// of its bounding box.
/**
* @param[out] tensor The 3x3 inertia tensor matrix of the shape in local-space
*                    coordinates
* @param mass Mass to use to compute the inertia tensor of the collision shape
*/
inline void ConvexMeshShape::computeLocalInertiaTensor(Matrix3x3& tensor, decimal mass) const {
    decimal factor = (decimal(1.0) / decimal(3.0)) * mass;
    Vector3 realExtent = decimal(0.5) * (mMaxBounds - mMinBounds);
    assert(realExtent.x > 0 && realExtent.y > 0 && realExtent.z > 0);
    decimal xSquare = realExtent.x * realExtent.x;
    decimal ySquare = realExtent.y * realExtent.y;
    decimal zSquare = realExtent.z * realExtent.z;
    tensor.setAllValues(factor * (ySquare + zSquare), 0.0, 0.0,
                        0.0, factor * (xSquare + zSquare), 0.0,
                        0.0, 0.0, factor * (xSquare + ySquare));
}

// Return true if a point is inside the collision shape
inline bool ConvexMeshShape::testPointInside(const Vector3& localPoint,
                                             ProxyShape* proxyShape) const {

    // Use the GJK algorithm to test if the point is inside the convex mesh
    return proxyShape->mBody->mWorld.mCollisionDetection.
           mNarrowPhaseGJKAlgorithm.testPointInside(localPoint, proxyShape);
}

// Return the number of faces of the polyhedron
inline uint ConvexMeshShape::getNbFaces() const {
    return mPolyhedronMesh->getHalfEdgeStructure().getNbFaces();
}

// Return a given face of the polyhedron
inline HalfEdgeStructure::Face ConvexMeshShape::getFace(uint faceIndex) const {
    assert(faceIndex < getNbFaces());
    return mPolyhedronMesh->getHalfEdgeStructure().getFace(faceIndex);
}

// Return the number of vertices of the polyhedron
inline uint ConvexMeshShape::getNbVertices() const {
    return mPolyhedronMesh->getHalfEdgeStructure().getNbVertices();
}

// Return a given vertex of the polyhedron
inline HalfEdgeStructure::Vertex ConvexMeshShape::getVertex(uint vertexIndex) const {
    assert(vertexIndex < getNbVertices());
    return mPolyhedronMesh->getHalfEdgeStructure().getVertex(vertexIndex);
}

// Return the number of half-edges of the polyhedron
inline uint ConvexMeshShape::getNbHalfEdges() const {
    return mPolyhedronMesh->getHalfEdgeStructure().getNbHalfEdges();
}

// Return a given half-edge of the polyhedron
inline HalfEdgeStructure::Edge ConvexMeshShape::getHalfEdge(uint edgeIndex) const {
    assert(edgeIndex < getNbHalfEdges());
    return mPolyhedronMesh->getHalfEdgeStructure().getHalfEdge(edgeIndex);
}

// Return the position of a given vertex
inline Vector3 ConvexMeshShape::getVertexPosition(uint vertexIndex) const {
    assert(vertexIndex < getNbVertices());
    return mPolyhedronMesh->getVertex(vertexIndex) * mScaling;
}

// Return the normal vector of a given face of the polyhedron
inline Vector3 ConvexMeshShape::getFaceNormal(uint faceIndex) const {
    assert(faceIndex < getNbFaces());
    return mPolyhedronMesh->getFaceNormal(faceIndex);
}

// Return the centroid of the polyhedron
inline Vector3 ConvexMeshShape::getCentroid() const {
    return mPolyhedronMesh->getCentroid() * mScaling;
}

}

#endif