Line Sweep Alorithmus mit Test

lib/linesweep.py

@@ -0,0 +1,48 @@
+from bisect import bisect_left, bisect_right
+import unittest
+
+
+def find_intersections(horizontal_segments, vertical_segments, epsilon=0.0):
+    horizontal_segments.sort(key=lambda h: h[0][1])  # sortiere nach y
+
+    horizontal_ys = []
+    horizontal_x_ranges = []
+    for (x1, y), (x2, _) in horizontal_segments:
+        if x1 > x2:
+            x1, x2 = x2, x1
+        horizontal_ys.append(y)
+        horizontal_x_ranges.append((x1, x2))
+
+    intersections = []
+
+    for (x, y1), (_, y2) in vertical_segments:
+        if y1 > y2:
+            y1, y2 = y2, y1
+
+        for idx, y in enumerate(horizontal_ys):
+            if y1 - epsilon <= y <= y2 + epsilon:
+                x_start, x_end = horizontal_x_ranges[idx]
+                if x_start - epsilon <= x <= x_end + epsilon:
+                    intersections.append((x, y))
+
+    return intersections
+
+class TestStringMethods(unittest.TestCase):
+
+    def test_sweep(self):
+        horizontal = [((1, 2), (5, 2)), ((3, 4), (7, 4))]
+        vertical = [((4, 1), (4, 5)), ((6, 3), (6, 6))]
+
+        a = find_intersections(horizontal, vertical)
+        self.assertEqual( [(4,2),(4,4),(6,4)], a) 
+
+    def test_tol(self):
+        horizontal = [((0, 0), (10, 0))]
+        vertical = [((4, 0.6), (4, 5)), ((6, 0.2), (6, 6)),((8,-0.2),(8, 4))]
+
+        b = find_intersections(horizontal, vertical, 0.5)
+        self.assertEqual( length(b), 2) 
+
+
+if __name__  == '__main__':
+    unittest.main()