A First Program

C++C

As an example of a simple HOOPS Access application the following program illustrates reading the node coordinates from an SDRC Universal file. The program uses the DataSource interface to open and read the file.

Once the file is opened successfully using openFile(), we load the finite element model data into a Model object using loadModel(). The Model object encapsulates all objects which define an entire finite element model, including the mesh data. We then extract the Mesh object from the model using getMesh(), which manages all data related to the finite element mesh, particularly the node coordinates.

After obtaining the Mesh object, we query the total number of nodes in the model using getEntityCount() and print the coordinates of the first and last nodes using getCoordinates(). This demonstrates basic mesh traversal and coordinate access functionality.

The following program is a listing of the “A First Program” in C++ language bindings.

#include "samcpp/core/core.h"
#include "samcpp/access/access.h"
#include "sam/hoops_license.h"

#include <iostream>
#include <iomanip>

/*----------------------------------------------------------------------
            Read and Print Finite Element Node Coordinates
----------------------------------------------------------------------*/
int
main(int argc, char** argv)
{
    char inputFile[cae::core::MAX_NAME_LENGTH] = {};
    // Check input arguments
    if (argc < 2) {
        std::cerr << "Usage: " << argv[0] << " inputfile\n";
        std::cerr << " inputfile is blank, 'bumper.unv' is assumed\n";
        strcpy(inputFile, "bumper.unv");
    }
    else {
        strcpy(inputFile, argv[1]);
    }

    cae::core::license::validate(HOOPS_LICENSE);

    // Open file
    cae::access::DataSource dataSource;
    cae::core::Status status = dataSource.openFile(inputFile, nullptr);

    // Check for error
    if (!status) {
        std::cerr << "Error: opening file " << inputFile << '\n';
        exit(1);
    }

    // Load Model object with finite element model
    cae::core::Model model;
    dataSource.loadModel(&model);

    // Get Mesh object created in Model
    cae::core::MeshPtr mesh;
    status = model.getMesh(mesh);

    // Check for errors
    if (!status) {
        std::cerr << "Error: Unable to get connect object from model\n";
        exit(1);
    }

    // Get number of nodes
    int nodeCount = 0;
    mesh->getEntityCount(cae::core::EntityType::NODE, &nodeCount);

    // Print first and last node coordinates
    std::cout << "Node Coordinates\n";

    double coordinates[1][3] = {{0.0, 0.0, 0.0}};
    std::cout << std::fixed << std::setprecision(6);

    // Print first node
    int nodeId = 1;
    mesh->getCoordinates(1, &nodeId, coordinates);
    std::cout << std::setw(10) << 1 << ' ' << std::setw(12) << coordinates[0][0] << ' ' << std::setw(12) << coordinates[0][1]
              << ' ' << std::setw(12) << coordinates[0][2] << '\n';

    // Print last node
    mesh->getCoordinates(1, &nodeCount, coordinates);
    std::cout << std::setw(10) << nodeCount << ' ' << std::setw(12) << coordinates[0][0] << ' ' << std::setw(12)
              << coordinates[0][1] << ' ' << std::setw(12) << coordinates[0][2] << '\n';

    return 0;
}

The output of this example program appears below.

Node Coordinates
      1    30.826799     3.968360    -1.003940
    652   -47.007900    15.984300    -2.007870