Method createHalfEdgeStructure

src/collision/ConvexMesh.cpp:117–182

Create the half-edge structure of the mesh This method returns true if the mesh is valid or false otherwise

// Create the half-edge structure of the mesh
/// This method returns true if the mesh is valid or false otherwise
bool ConvexMesh::createHalfEdgeStructure(const PolygonVertexArray& polygonVertexArray, std::vector<Message>& errors) {

    bool isValid = true;

    // For each vertex of the mesh
    const uint32 nbVertices = polygonVertexArray.getNbVertices();
    for (uint32 v=0; v < nbVertices; v++) {
        mHalfEdgeStructure.addVertex(v);
    }

    uint32 nbEdges = 0;

    // For each polygon face of the mesh
    const uint32 nbFaces = polygonVertexArray.getNbFaces();
    for (uint32 f=0; f < nbFaces; f++) {

        // Get the polygon face
        PolygonVertexArray::PolygonFace* face = polygonVertexArray.getPolygonFace(f);

        Array<uint32> faceVertices(mMemoryAllocator, face->nbVertices);

        // For each vertex of the face
        for (uint32 v=0; v < face->nbVertices; v++) {
            faceVertices.add(polygonVertexArray.getVertexIndexInFace(f, v));
        }

        nbEdges += face->nbVertices;

        // If the face has less than three vertices
        if (faceVertices.size() < 3) {

            // Create a new error
            errors.push_back(Message(std::string("The face with index " + std::to_string(f) + " has less than three vertices")));

            isValid = false;

            RP3D_LOG("PhysicsCommon", Logger::Level::Error, Logger::Category::PhysicCommon,
                     "Error when creating a ConvexMesh: Mesh has a face with less than three vertices.",  __FILE__, __LINE__);
        }

        // Addd the face into the half-edge structure
        mHalfEdgeStructure.addFace(faceVertices);
    }

    nbEdges /= 2;

    // If the mesh is not valid (check Euler formula V + F - E = 2) (has duplicated vertices)
    if (2 + nbEdges - polygonVertexArray.getNbFaces() != polygonVertexArray.getNbVertices()) {

        RP3D_LOG("PhysicsCommon", Logger::Level::Error, Logger::Category::PhysicCommon,
                 "Error when creating a ConvexMesh: input PolygonVertexArray is not valid. Mesh with duplicated vertices is not supported.",  __FILE__, __LINE__);

        // Create a new error
        errors.push_back(Message(std::string("Convex Mesh might have duplicated vertices (invalid Euler formula)")));

        isValid = false;
    }