int main()

in source/rig/RigSimulator.cpp [658:777]
103 lines of code
14 McCabe index (conditional complexity)

int main(int argc, char** argv) {
  system_util::initDep(argc, argv, kUsageMessage);

  CHECK_NE(FLAGS_mode, "");
  CHECK_NE(FLAGS_skybox_path, "");

  // load skybox
  cv::Mat_<cv::Vec3b> skybox = imreadExceptionOnFail(FLAGS_skybox_path, cv::IMREAD_COLOR);

  // construct scene of triangles
  std::vector<Triangle> triangles;
  if (FLAGS_scene == "icosahedron") {
    makeIcosahedronScene(triangles);
  } else if (FLAGS_scene == "cube") {
    makeCubesScene(triangles);
  } else if (FLAGS_scene == "ground_plane") {
    makeGroundPlaneScene(triangles);
  } else {
    CHECK(false) << "unexpected scene: " << FLAGS_scene;
  }

  // bind indices of triangles. we need these to know how to color them after
  // finding the ray-bvh intersection.
  for (int i = 0; i < int(triangles.size()); ++i) {
    triangles[i].selfIdx = i;
  }

  // build bounding volume hierarchy
  LOG(INFO) << "building BVH";
  const static int kBVHStopNumTrianglesInLeaf = 20;
  const static int kBVHSplitK = 5;
  const static int kBVHMaxDepth = 50;
  BoundingVolumeHierarchy bvh = BoundingVolumeHierarchy::makeBVH(
      triangles,
      kBVHStopNumTrianglesInLeaf,
      kBVHSplitK,
      0, // start at depth = 0
      kBVHMaxDepth);

  if (FLAGS_mode == "mono_eqr") {
    CHECK_NE(FLAGS_dest_mono, "");
    CHECK_NE(FLAGS_dest_mono_depth, "");

    cv::Mat_<cv::Vec3f> monoEquirect;
    cv::Mat_<float> monoEquirectInvDepth;
    std::tie(monoEquirect, monoEquirectInvDepth) =
        renderMonoEquirect(triangles, bvh, FLAGS_eqr_width, FLAGS_eqr_height, skybox);
    imwriteExceptionOnFail(FLAGS_dest_mono, monoEquirect);
    imwriteExceptionOnFail(FLAGS_dest_mono_depth, monoEquirectInvDepth * 255.0);

  } else if (FLAGS_mode == "stereo_eqr") {
    CHECK_NE(FLAGS_dest_left, "");
    CHECK_NE(FLAGS_dest_right, "");
    CHECK_NE(FLAGS_dest_stereo, "");

    std::pair<cv::Mat_<cv::Vec3f>, cv::Mat_<cv::Vec3f>> eqrLeftRight =
        renderStereoEquirect(triangles, bvh, FLAGS_eqr_width, FLAGS_eqr_height, skybox);
    cv::Mat_<cv::Vec3f> stereoPair;
    vconcat(eqrLeftRight.first, eqrLeftRight.second, stereoPair);
    imwriteExceptionOnFail(FLAGS_dest_left, eqrLeftRight.first);
    imwriteExceptionOnFail(FLAGS_dest_right, eqrLeftRight.second);
    imwriteExceptionOnFail(FLAGS_dest_stereo, stereoPair);

  } else {
    std::vector<Camera> cameras;
    if (FLAGS_mode == "pinhole_ring") {
      cameras = makeHorizontalRingOfPinholeCameras(
          FLAGS_num_cams_in_ring,
          FLAGS_rig_radius,
          FLAGS_pinhole_width,
          FLAGS_pinhole_height,
          FLAGS_pinhole_fov_horizontal,
          FLAGS_pinhole_aspect_ratio);
    } else if (FLAGS_mode == "ftheta_ring") {
      cameras = makeHorizontalRingOfFThetaCameras(
          FLAGS_num_cams_in_ring,
          FLAGS_rig_radius,
          FLAGS_ftheta_width,
          FLAGS_ftheta_height,
          FLAGS_ftheta_image_circle_radius,
          FLAGS_ftheta_image_circle_fov);
      // add top camera, too
      addTopCamera(
          cameras,
          FLAGS_ftheta_width,
          FLAGS_ftheta_height,
          FLAGS_ftheta_image_circle_radius,
          FLAGS_ftheta_image_circle_fov);
    } else if (FLAGS_mode == "dodecahedron") {
      cameras = makeDodecahedronOfFThetaCameras(
          FLAGS_rig_radius,
          FLAGS_ftheta_width,
          FLAGS_ftheta_height,
          FLAGS_ftheta_image_circle_radius,
          FLAGS_ftheta_image_circle_fov);
    } else if (FLAGS_mode == "icosahedron") {
      cameras = makeIcosahedronOfFThetaCameras(
          FLAGS_rig_radius,
          FLAGS_ftheta_width,
          FLAGS_ftheta_height,
          FLAGS_ftheta_image_circle_radius,
          FLAGS_ftheta_image_circle_fov);
    } else if (FLAGS_mode == "rig_from_json") {
      CHECK_NE(FLAGS_rig_in, "");
      cameras = Camera::loadRig(FLAGS_rig_in);
    } else {
      CHECK(false) << "unexpected mode: " << FLAGS_mode;
    }
    if (!FLAGS_rig_out.empty()) {
      const std::vector<std::string> comments = {};
      const int doubleNumDigits = 10;
      Camera::saveRig(FLAGS_rig_out, cameras, comments, doubleNumDigits);
    }
    if (!FLAGS_dest_cam_images.empty()) {
      renderCamerasThreaded(skybox, triangles, bvh, cameras, FLAGS_dest_cam_images);
    }
  }

  return EXIT_SUCCESS;
}