OpenCV's RotatedRect angle does not provide enough information

Question

From my experiments, the angle returned by RotatedRect\'s angle variable goes from -90 to 0 degrees, which is not sufficient to determine if the object is leaned to the left

Answer 1

After learning from Sebastian Schmitz and Michael Burdinov answers this is how I solved it:

RotatedRect rotated_rect = minAreaRect(contour);
float blob_angle_deg = rotated_rect.angle;
if (rotated_rect.size.width < rotated_rect.size.height) {
  blob_angle_deg = 90 + blob_angle_deg;
}
Mat mapMatrix = getRotationMatrix2D(center, blob_angle_deg, 1.0);

So, in fact, RotatedRect's angle does not provide enough information for knowing an object's angle, you must also use RotatedRect's size.width and size.height.