Return the direction toward to the line from via to target from starting :param starting: The starting point via: The via point target: The target point :return: the Direction Examples: >>> check_direction((1,1), (2,2), (3,3)) Direction.straight >>> c
(
starting: tuple[int, int], via: tuple[int, int], target: tuple[int, int]
)
| 49 | |
| 50 | |
| 51 | def check_direction( |
| 52 | starting: tuple[int, int], via: tuple[int, int], target: tuple[int, int] |
| 53 | ) -> Direction: |
| 54 | """Return the direction toward to the line from via to target from starting |
| 55 | |
| 56 | :param starting: The starting point |
| 57 | via: The via point |
| 58 | target: The target point |
| 59 | :return: the Direction |
| 60 | |
| 61 | Examples: |
| 62 | >>> check_direction((1,1), (2,2), (3,3)) |
| 63 | Direction.straight |
| 64 | |
| 65 | >>> check_direction((60,1), (-50,199), (30,2)) |
| 66 | Direction.left |
| 67 | |
| 68 | >>> check_direction((0,0), (5,5), (10,0)) |
| 69 | Direction.right |
| 70 | """ |
| 71 | x0, y0 = starting |
| 72 | x1, y1 = via |
| 73 | x2, y2 = target |
| 74 | via_angle = degrees(atan2(y1 - y0, x1 - x0)) |
| 75 | via_angle %= 360 |
| 76 | target_angle = degrees(atan2(y2 - y0, x2 - x0)) |
| 77 | target_angle %= 360 |
| 78 | # t- |
| 79 | # \ \ |
| 80 | # \ v |
| 81 | # \| |
| 82 | # s |
| 83 | # via_angle is always lower than target_angle, if direction is left. |
| 84 | # If they are same, it means they are on a same line of convex hull. |
| 85 | if target_angle > via_angle: |
| 86 | return Direction.left |
| 87 | elif target_angle == via_angle: |
| 88 | return Direction.straight |
| 89 | else: |
| 90 | return Direction.right |
| 91 | |
| 92 | |
| 93 | def graham_scan(points: list[tuple[int, int]]) -> list[tuple[int, int]]: |