code: def _tilt(c, direction:uniform_int, magnitude:uniform=0, invert=False):
      "Tilt `c` field with random `direction` and `magnitude`."
      orig_pts = [[-1,-1], [-1,1], [1,-1], [1,1]]
      if direction == 0:   targ_pts = [[-1,-1], [-1,1], [1,-1-magnitude], [1,1+magnitude]]
      elif direction == 1: targ_pts = [[-1,-1-magnitude], [-1,1+magnitude], [1,-1], [1,1]]
      elif direction == 2: targ_pts = [[-1,-1], [-1-magnitude,1], [1,-1], [1+magnitude,1]]
      elif direction == 3: targ_pts = [[-1-magnitude,-1], [-1,1], [1+magnitude,-1], [1,1]]
      coeffs = _find_coeffs(targ_pts, _orig_pts) if invert else _find_coeffs(_orig_pts, targ_pts)
      return _apply_perspective(c, coeffsf _tilt(c, direction:uniform_int, magnitude:uniform=0, invert=False):
      "Tilt `c` field with random `direction` and `magnitude`."
      orig_pts = [[-1,-1], [-1,1], [1,-1], [1,1]]
      if direction == 0:   targ_pts = [[-1,-1], [-1,1], [1,-1-magnitude], [1,1+magnitude]]
      elif direction == 1: targ_pts = [[-1,-1-magnitude], [-1,1+magnitude], [1,-1], [1,1]]
      elif direction == 2: targ_pts = [[-1,-1], [-1-magnitude,1], [1,-1], [1+magnitude,1]]
      elif direction == 3: targ_pts = [[-1-magnitude,-1], [-1,1], [1+magnitude,-1], [1,1]]
      coeffs = _find_coeffs(targ_pts, _orig_pts) if invert else _find_coeffs(_orig_pts, targ_pts)
      return _apply_perspective(c, coeffs)
docs: Tilt `c` field with random `direction` and `magnitude`.