import numpy as np
import matplotlib.pyplot as plt
from matplotlib.transforms import Bbox
from matplotlib.path import Path

# Fixing random state for reproducibility
np.random.seed(19680801)


left, bottom, width, height = (-1, -1, 2, 2)
rect = plt.Rectangle((left, bottom), width, height, facecolor="#aaaaaa")

fig, ax = plt.subplots()
ax.add_patch(rect)

bbox = Bbox.from_bounds(left, bottom, width, height)

for i in range(12):
  vertices = (np.random.random((2, 2)) - 0.5) * 6.0
  path = Path(vertices)
  if path.intersects_bbox(bbox):
    color = 'r'
  else:
    color = 'b'
  ax.plot(vertices[:, 0], vertices[:, 1], color=color)

plt.show()