Port JTS locationtech/jts#756 to match

IsValidReason more closely to historic reasons for self-intersecting polygons.
libgeos · Jul 13, 2021 · 1bfc5b2 · 1bfc5b2
1 parent 917aeec
commit 1bfc5b2
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Showing 3 changed files with 66 additions and 3 deletions.
diff --git a/src/operation/valid/PolygonIntersectionAnalyzer.cpp b/src/operation/valid/PolygonIntersectionAnalyzer.cpp
@@ -68,6 +68,8 @@ PolygonIntersectionAnalyzer::findInvalidIntersection(
         return TopologyValidationError::oNoInvalidIntersection;
     }
 
+    bool isSameSegString = (ss0 == ss1);
+
     /**
      * Check for an intersection in the interior of both segments.
      * Collinear intersections by definition contain an interior intersection.
@@ -89,7 +91,6 @@ PolygonIntersectionAnalyzer::findInvalidIntersection(
      * (since they are not collinear).
      * This is valid.
      */
-    bool isSameSegString = ss0 == ss1;
     bool isAdjacentSegments = isSameSegString && isAdjacentInRing(ss0, segIndex0, segIndex1);
     // Assert: intersection is an endpoint of both segs
     if (isAdjacentSegments) return TopologyValidationError::oNoInvalidIntersection;
@@ -99,7 +100,7 @@ PolygonIntersectionAnalyzer::findInvalidIntersection(
      * So the intersection is invalid.
      */
     if (isSameSegString && ! isInvertedRingValid) {
-        return TopologyValidationError::eSelfIntersection;
+        return TopologyValidationError::eRingSelfIntersection;
     }
 
     /**

diff --git a/tests/unit/capi/GEOSisValidDetailTest.cpp b/tests/unit/capi/GEOSisValidDetailTest.cpp
@@ -116,7 +116,7 @@ void object::test<4>
     geom1_ = GEOSGeomFromWKT("POLYGON((0 1, -10 10, 10 10, 0 1, 4 6, -4 6, 0 1))");
     int r = GEOSisValidDetail(geom1_, 0, &reason_, &loc_);
     ensure_equals(r, 0); // invalid
-    ensure_equals(std::string(reason_), std::string("Self-intersection"));
+    ensure_equals(std::string(reason_), std::string("Ring Self-intersection"));
     ensure_equals(toWKT(loc_), "POINT (0 1)");
 }
 

diff --git a/tests/unit/operation/valid/IsValidOpTest.cpp b/tests/unit/operation/valid/IsValidOpTest.cpp
@@ -188,6 +188,16 @@ void object::test<8> ()
         "POLYGON ((10 90, 90 10, 90 90, 10 10, 10 90))");
 }
 
+// testInvalidPolygonInverted
+template<>
+template<>
+void object::test<22> ()
+{
+    checkInvalid(
+        TopologyValidationError::eRingSelfIntersection,
+        "POLYGON ((70 250, 40 500, 100 400, 70 250, 80 350, 60 350, 70 250))");
+}
+
 // testSimplePolygonHole
 template<>
 template<>
@@ -309,6 +319,58 @@ void object::test<21> ()
         "MULTIPOLYGON (((20 380, 420 380, 420 20, 20 20, 20 380), (220 340, 180 240, 60 200, 140 100, 340 60, 300 240, 220 340)), ((60 200, 340 60, 220 340, 60 200)))");
 }
 
+// testLineString
+template<>
+template<>
+void object::test<23> ()
+{
+    checkInvalid(
+        "LINESTRING(0 0, 0 0)");
+}
+
+// testLinearRingTriangle
+template<>
+template<>
+void object::test<24> ()
+{
+    checkValid(
+        "LINEARRING (100 100, 150 200, 200 100, 100 100)");
+}
+
+// testLinearRingSelfCrossing
+template<>
+template<>
+void object::test<25> ()
+{
+    checkInvalid(TopologyValidationError::eRingSelfIntersection,
+        "LINEARRING (150 100, 300 300, 100 300, 350 100, 150 100)");
+}
+
+// testLinearRingSelfCrossing2
+template<>
+template<>
+void object::test<26> ()
+{
+    checkInvalid(TopologyValidationError::eRingSelfIntersection,
+        "LINEARRING (0 0, 100 100, 100 0, 0 100, 0 0)");
+}
+
+//
+template<>
+template<>
+void object::test<27> ()
+{
+    checkInvalid(TopologyValidationError::eRingSelfIntersection,
+        "POLYGON ((70 250, 40 500, 100 400, 70 250, 80 350, 60 350, 70 250))");
+}
+
+template<>
+template<>
+void object::test<28> ()
+{
+    checkInvalid(TopologyValidationError::eSelfIntersection,
+        "POLYGON ((70 250, 70 500, 80 400, 40 400, 70 250))");
+}
 
 
 } // namespace tut