BulletIntegration: conversion of Magnum mesh data into Bullet collision mesh [snippet] about magnum-integration HOT 3 OPEN

    std::optional<Trade::MeshData3D> meshData = ...;

    if(!meshData || meshData->primitive() != MeshPrimitive::Triangles) {
        Error() << "Cannot load collision mesh, skipping";
        return;
    }

    /* this is a collision mesh, convert to bullet mesh */
    btIndexedMesh bulletMesh;
    bulletMesh.m_numTriangles = meshData->indices().size()/3;
    bulletMesh.m_triangleIndexBase = reinterpret_cast<const unsigned char *>(meshData->indices().data());
    bulletMesh.m_triangleIndexStride = 3 * sizeof(UnsignedInt);
    bulletMesh.m_numVertices = meshData->positions(0).size();
    bulletMesh.m_vertexBase = reinterpret_cast<const unsigned char *>(meshData->positions(0).data());
    bulletMesh.m_vertexStride = sizeof(Vector3);
    bulletMesh.m_indexType = PHY_INTEGER;
    bulletMesh.m_vertexType = PHY_FLOAT;

    btCollisionShape* shape = nullptr;
    auto tivArray = new btTriangleIndexVertexArray());
    tivArray->addIndexedMesh(bulletMesh, PHY_INTEGER);
    if(shapeType == "TriangleMeshShape") {
        /* exact shape, but worse performance */
        shape = new btBvhTriangleMeshShape(tivArray, true);
    } else {
        /* convex hull, but better performance */
        shape = new btConvexTriangleMeshShape(tivArray, true);
    } /* btConvexHullShape can be even more performant */