Fix TPSimplifier endpoint removal indexing (#1059)

locationtech · Jun 14, 2024 · 586780f · 586780f
1 parent 1672c03
commit 586780f
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Showing 3 changed files with 17 additions and 2 deletions.
diff --git a/modules/core/src/main/java/org/locationtech/jts/simplify/TaggedLineString.java b/modules/core/src/main/java/org/locationtech/jts/simplify/TaggedLineString.java
@@ -133,13 +133,14 @@ private static Coordinate[] extractCoordinates(List<LineSegment> segs)
     return pts;
   }
 
-  void removeRingEndpoint()
+  LineSegment removeRingEndpoint()
   {
     LineSegment firstSeg = (LineSegment) resultSegs.get(0);
     LineSegment lastSeg = (LineSegment) resultSegs.get(resultSegs.size() - 1);
 
     firstSeg.p0 = lastSeg.p0;
     resultSegs.remove(resultSegs.size() - 1);
+    return firstSeg;
   }
 
 

diff --git a/modules/core/src/main/java/org/locationtech/jts/simplify/TaggedLineStringSimplifier.java b/modules/core/src/main/java/org/locationtech/jts/simplify/TaggedLineStringSimplifier.java
@@ -133,7 +133,14 @@ private void simplifyRingEndpoint(double distanceTolerance)
       Coordinate endPt = firstSeg.p0;
       if (simpSeg.distance(endPt) <= distanceTolerance
           && isTopologyValid(line, firstSeg, lastSeg, simpSeg)) {
-        line.removeRingEndpoint();
+        //-- don't know if segments are original or new, so remove from all indexes
+        inputIndex.remove(firstSeg);
+        inputIndex.remove(lastSeg);
+        outputIndex.remove(firstSeg);
+        outputIndex.remove(lastSeg);
+
+        LineSegment flatSeg = line.removeRingEndpoint();
+        outputIndex.add(flatSeg);
       }
     }
   }

diff --git a/...es/core/src/test/java/org/locationtech/jts/simplify/TopologyPreservingSimplifierTest.java b/...es/core/src/test/java/org/locationtech/jts/simplify/TopologyPreservingSimplifierTest.java
@@ -238,6 +238,13 @@ public void testPolygonIntersectingSegments() {
         "MULTIPOLYGON (((0.63 0.2, 0.35 0, 0.73 0.66, 0.63 0.2)), ((1.42 4.01, 3.45 0.7, 1.79 1.47, 0 0.57, 1.42 4.01)))");
   }
 
+  //-- test added in https://github.com/libgeos/geos/pull/1110
+  public void testRingEndpointRemoval() {
+    checkTPS("POLYGON ((-222601.33094265286 6299915.50260568, -222599.13611514607 6299917.747821213, -222599.09754554977 6299925.149899498, -222599.07870256738 6299925.234615005, -222595.52372420163 6299932.934861557, -222510 6300300, -221720.85158014414 6300132.680680807, -222448.77936063593 6299647.669870703, -222618.41756525903 6299886.966175825, -222618.40178141624 6299887.020684309, -222616.09648739762 6299892.144482262, -222601.33094265286 6299915.50260568), (-222456.68914400978 6299947.489843342, -222455.07603815367 6299939.772017001, -222455.07542453965 6299939.691595431, -222456.57057590774 6299931.950053182, -222462.75368034307 6299916.87367865, -222465.9575074078 6299911.582542387, -222465.99782740293 6299911.534645676, -222483.5296791599 6299864.079888968, -222484.09789251382 6299852.105440594, -222485.11401620077 6299846.692173677, -222485.13170293145 6299846.639453617, -222487.58585740798 6299841.7086228, -222490.56062790897 6299837.359974515, -222415.1394852571 6299926.6972160805, -222421.19226152284 6299963.389132584, -222467.0202338936 6299970.185860572, -222465.71145777934 6299968.200784476, -222465.69955208438 6299968.180154371, -222464.63560265294 6299966.053788407, -222456.68914400978 6299947.489843342))",
+        20,
+        "POLYGON ((-222618.41756525903 6299886.966175825, -222510 6300300, -221720.85158014414 6300132.680680807, -222448.77936063593 6299647.669870703, -222618.41756525903 6299886.966175825), (-222467.0202338936 6299970.185860572, -222456.57057590774 6299931.950053182, -222490.56062790897 6299837.359974515, -222415.1394852571 6299926.6972160805, -222421.19226152284 6299963.389132584, -222467.0202338936 6299970.185860572))");
+  }
+
   private void checkTPS(String wkt, double tolerance, String wktExpected) {
     Geometry geom = read(wkt);
     Geometry actual = TopologyPreservingSimplifier.simplify(geom, tolerance);