computes intersection between two rectangles

intersection.py

# Assuming the origin is in the top left corner
# x axis facing right
# y axis facing downwards

# r.x, r.y -- are top left corners of the rectangle
# with corresponding r.height and r.width

def intersection_area(r_1, r_2):
  intersection = 0.0

  left_x   = max( r_1.x, r_2.x )
  right_x  = min( r_1.x + r_1.width, r_2.x + r_2.width )
  top_y    = max( r_1.y, r_2.y )
  bottom_y = min( r_1.y + r_1.height, r_2.y + r_2.height )

  if left_x < right_x && top_y < bottom_y:
    intersection = (right_x - left_x) * (bottom_y - top_y)
  
  return intersection