Drawing Polygons in OpenCV?

Question

What am I doing wrong here?

vector <vector<Point> > contourElement;

for (int counter = 0; counter < contours -> size (); counter ++)
{   
    contourElement.push_back (contours -> at (counter));

    const Point *elementPoints [1] = {contourElement.at (0)};
    int numberOfPoints [] = {contourElement.at (0).size ()};

    fillPoly (contourMask, elementPoints, numberOfPoints, 1, Scalar (0, 0, 0), 8);

I keep getting an error on the const Point part. The compiler says

error: cannot convert 'std::vector<cv::Point_<int>, std::allocator<cv::Point_<int> > >' to 'const cv::Point*' in initialization

What am I doing wrong? (PS: Obviously ignore the missing bracket at the end of the for loop due to this being only part of my code)

Answer 1

Just for the record (and because the opencv docu is very sparse here) a more reduced snippet using the c++ API:

  std::vector<cv::Point> fillContSingle;
  [...]
  //add all points of the contour to the vector
  fillContSingle.push_back(cv::Point(x_coord,y_coord));
  [...]

  std::vector<std::vector<cv::Point> > fillContAll;
  //fill the single contour 
  //(one could add multiple other similar contours to the vector)
  fillContAll.push_back(fillContSingle);
  cv::fillPoly( image, fillContAll, cv::Scalar(128));