From cdb37db2a2cf4d9fa5dc4d3a9a65d51f6ae544bd Mon Sep 17 00:00:00 2001
From: wqy <wqyuyu@outlook.com>
Date: Sat, 16 Sep 2023 15:47:50 +0800
Subject: [PATCH] Fix slope calculation

---
 api/s32_region_util.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/api/s32_region_util.py b/api/s32_region_util.py
index 3830776..d95862b 100644
--- a/api/s32_region_util.py
+++ b/api/s32_region_util.py
@@ -142,7 +142,10 @@ def _angle_of_node_link(node: str, link: str, nodes, links) -> float:
     n2 = links[link]['node1'] if n1 == links[link]['node2'] else links[link]['node2']
     x1, y1 = nodes[n1]['x'], nodes[n1]['y']
     x2, y2 = nodes[n2]['x'], nodes[n2]['y']
-    v = _normal((x2 - x1, y2 - y1))
+    if y1 == y2:
+        v = ((x2 - x1) / abs(x2 - x1), 0.0)
+    else:
+        v = _normal((x2 - x1, y2 - y1))
     return _angle(v)