drawContours function

void drawContours(VARP img, List<List<Point>> contours, int contourIdx, Scalar color, { int thickness = 1, int lineType = LINE_8, })

Implementation

void drawContours(
  VARP img,
  List<List<Point>> contours,
  int contourIdx,
  Scalar color, {
  int thickness = 1,
  int lineType = LINE_8,
}) {
  final pContours = malloc<ffi.Pointer<c.mnn_cv_point_t>>(contours.length);
  final pInnerLength = malloc<ffi.Int32>(contours.length);
  pInnerLength.asTypedList(contours.length).setAll(0, contours.map((e) => e.length));
  for (int i = 0; i < contours.length; i++) {
    final pContour = malloc<c.mnn_cv_point_t>(contours[i].length);
    for (int j = 0; j < contours[i].length; j++) {
      pContour[j] = contours[i][j].ref;
    }
    pContours[i] = pContour;
  }
  c.mnn_cv_drawContours(
    img.ptr,
    pContours,
    pInnerLength.cast(),
    contours.length,
    contourIdx,
    color.ref,
    thickness,
    lineType,
  );
  for (int i = 0; i < contours.length; i++) {
    malloc.free(pContours[i]);
  }
  malloc.free(pContours);
  malloc.free(pInnerLength);
}