code: def rbox2poly_np(rboxes):
      """
      rboxes:[x_ctr,y_ctr,w,h,angle]
      to
      poly:[x0,y0,x1,y1,x2,y2,x3,y3]
      """
      polys = []
      for i in range(len(rboxes)):
          x_ctr, y_ctr, width, height, angle = rboxes[i][:5]
          tl_x, tl_y, br_x, br_y = (
              -width / 2,
              -height / 2,
              width / 2,
              height / 2,
          )
          rect = np.array(
              [[tl_x, br_x, br_x, tl_x], [tl_y, tl_y, br_y, br_y]]
          )
          R = np.array(
              [
                  [np.cos(angle), -np.sin(angle)],
                  [np.sin(angle), np.cos(angle)],
              ]
          )
          poly = R.dot(rect)
          x0, x1, x2, x3 = poly[0, :4] + x_ctr
          y0, y1, y2, y3 = poly[1, :4] + y_ctr
          poly = np.array(
              [x0, y0, x1, y1, x2, y2, x3, y3], dtype=np.float32
          )
          poly = get_best_begin_point_single(poly)
          polys.append(poly)
      polys = np.array(polys)
      return polys
  
file_path: PaddleDetection/ppdet/modeling/rbox_utils.py
imports: import math
  import paddle
  import numpy
  import cv2
label_desc: Use image node_id 7 for calling a global function with example usage: rbox2poly_np(rboxes) and returns: polys