bonus_p1_renderScene

void renderScene() {
    // ...
    //trimesh.draw();

    // get time passed
    system_clock::duration t = system_clock::now() - startTime;

    // bonus (make objects move)
    switch (modelType) {
    case ModelType::DELPHIN:
        // swim like a delphin
        glRotatef(t.count() * 0.00001, 1, 0, 0);
        glTranslatef(0, 2, 5);
        trimesh.draw();
        val += 0.01f;
        break;
    case ModelType::BRACH:
        // swim around the y-axis
        glRotatef(t.count() * 0.00001, 0, 1, 0);
        glTranslatef(0, 0, -5);
        glRotatef(-90, 0, 1, 0);
        glTranslatef(0, 0, 5);
        trimesh.draw();
        break;
    case ModelType::BALLON:
        // fly up, land, fly up again
        glTranslatef(0, 5 + cos(t.count() * 0.0000001) * 5, 0);
        trimesh.draw();
        break;
    case ModelType::FORD:
        // appear disappear
        glTranslatef(sin(t.count() * 0.00000001) * 5, 3.5f, tan(t.count() * 0.0000001) * 2);
        glRotatef(180, 0, 1, 0);    // 3. rotate around y-axis (so that car looks in our direction)
        glRotatef(-90, 1, 0, 0);    // 2. rotate around x-axis (so that car stands on wheels)
        glTranslatef(0, 0, 2);      // 1. translate to origin
        trimesh.draw();
        break;
    case NONE:
    default:
        //std::cout << "Unknown model type -- do a normal draw() call" << std::endl;
        trimesh.draw();
        break;
    }

  // swap buffers
    glutSwapBuffers();
    // force rendering
    glutPostRedisplay();
}