[geos-commits] [SCM] GEOS branch main updated. f67563f307264544fb390528315511ab772386d0
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Mon Feb 10 17:19:37 PST 2025
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- Log -----------------------------------------------------------------
commit f67563f307264544fb390528315511ab772386d0
Author: Martin Davis <mtnclimb at gmail.com>
Date: Mon Feb 10 17:19:14 2025 -0800
Add Orientation Index stress test (#1237)
diff --git a/benchmarks/algorithm/CMakeLists.txt b/benchmarks/algorithm/CMakeLists.txt
index cf89a52e5..3b8f867a5 100644
--- a/benchmarks/algorithm/CMakeLists.txt
+++ b/benchmarks/algorithm/CMakeLists.txt
@@ -18,6 +18,9 @@ target_link_libraries(perf_unaryunion_segments geos)
if (BUILD_BENCHMARKS)
+add_executable(stress_orientation OrientationIndexStressTest.cpp)
+target_link_libraries(stress_orientation geos)
+
if (benchmark_FOUND)
add_executable(perf_orientation OrientationIndexPerfTest.cpp
${PROJECT_SOURCE_DIR}/src/algorithm/CGAlgorithmsDD.cpp
diff --git a/benchmarks/algorithm/OrientationIndexStressTest.cpp b/benchmarks/algorithm/OrientationIndexStressTest.cpp
new file mode 100644
index 000000000..af9e6be66
--- /dev/null
+++ b/benchmarks/algorithm/OrientationIndexStressTest.cpp
@@ -0,0 +1,221 @@
+/**********************************************************************
+ *
+ * GEOS - Geometry Engine Open Source
+ * http://geos.osgeo.org
+ *
+ * Copyright (C) 2025 Martin Davis
+ *
+ * This is free software; you can redistribute and/or modify it under
+ * the terms of the GNU Lesser General Public Licence as published
+ * by the Free Software Foundation.
+ * See the COPYING file for more information.
+ *
+ **********************************************************************/
+
+/*--------------------------------------------------------------
+Stress test for the Orientation Index implementation.
+
+Usage: stress_orientation [ -v ] [ -d ]
+ -d - run diagonal line segment tests
+ -v - displays the input and results from each test
+
+A robust orientation index implementation should be internally consistent
+- i.e. it should produce the same result for the 3 possible
+permutations of the input coordinates which have the same orientation:
+
+p0-p1 / p2 p1-p2 / p0 p2-p0 / p1
+
+Also, the reverse orientations should themselves be consistent,
+and be opposite in sign to the forward orientation.
+
+The robust implementation uses DoubleDouble arithmetic and a filter to improve computation time.
+It is compared to the simple Floating-Point orientation computation, which is not robust.
+
+Two kinds of test generators are provided:
+- random line segments with midpoints
+- points at increasing decimal intervals along a diagonal line segment LINESTRING(2 0, 0 2)
+--------------------------------------------------------------*/
+
+#include <geos/algorithm/Orientation.h>
+#include <geos/geom/Coordinate.h>
+#include <geos/geom/LineSegment.h>
+#include <geos/io/WKTWriter.h>
+
+#include <iomanip>
+
+using namespace geos::algorithm;
+using namespace geos::geom;
+using namespace geos::io;
+
+int
+orientationIndexFP(const Coordinate& p1, const Coordinate& p2,const Coordinate& q){
+ double dx1 = p2.x-p1.x;
+ double dy1 = p2.y-p1.y;
+ double dx2 = q.x-p2.x;
+ double dy2 = q.y-p2.y;
+ double det = dx1 * dy2 - dx2 * dy1;
+ if (det > 0.0) return 1;
+ if (det < 0.0) return-1;
+ return 0;
+}
+
+bool isVerbose = false;
+bool isDiagonalTest = false;
+
+std::size_t count;
+std::size_t failDD;
+std::size_t failFP;
+
+void parseFlag(char* arg) {
+ char flag = arg[1];
+ switch (flag) {
+ case 'v':
+ isVerbose = true; break;
+ case 'd':
+ isDiagonalTest = true; break;
+ }
+}
+
+void parseArgs(int argc, char** argv) {
+ if (argc <= 1) return;
+ int i = 1;
+ //-- parse flags
+ while (i < argc && argv[i][0] == '-' && isalpha(argv[i][1])) {
+ parseFlag(argv[i]);
+ i++;
+ }
+}
+
+char orientSym(int orientationIndex) {
+ if (orientationIndex < 0) return '-';
+ if (orientationIndex > 0) return '+';
+ return '0';
+}
+
+bool isConsistent(std::string tag, Coordinate p0, Coordinate p1, Coordinate p2,
+ std::function<int(Coordinate p0, Coordinate p1, Coordinate p2)> orientFunc )
+{
+ int orient0 = orientFunc(p0, p1, p2);
+ int orient1 = orientFunc(p1, p2, p0);
+ int orient2 = orientFunc(p2, p0, p1);
+ bool isConsistentForward = orient0 == orient1 && orient0 == orient2;
+
+ int orientRev0 = orientFunc(p1, p0, p2);
+ int orientRev1 = orientFunc(p0, p2, p1);
+ int orientRev2 = orientFunc(p2, p1, p0);
+ bool isConsistentRev = orientRev0 == orientRev1 && orientRev0 == orientRev2;
+
+ bool isConsistent = isConsistentForward && isConsistentRev;
+ if (isConsistent) {
+ bool isOpposite = orient0 == -orientRev0;
+ isConsistent &= isOpposite;
+ }
+
+ if (isVerbose) {
+ std::string consistentInd = isConsistent ? " " : "<!";
+ std::cout << tag << ": "
+ << orientSym(orient0) << orientSym(orient1) << orientSym(orient2) << " "
+ << orientSym(orientRev0) << orientSym(orientRev1) << orientSym(orientRev2) << " "
+ << " " << consistentInd << " ";
+ }
+ return isConsistent;
+}
+
+bool isConsistentDD(Coordinate p0, Coordinate p1, Coordinate p2)
+{
+ return isConsistent("DD", p0, p1, p2,
+ [](Coordinate p0, Coordinate p1, Coordinate p2) -> int {
+ return Orientation::index(p0, p1, p2);
+ });
+}
+
+bool isConsistentFP(Coordinate p0, Coordinate p1, Coordinate p2)
+{
+ return isConsistent("FP", p0, p1, p2,
+ [](Coordinate p0, Coordinate p1, Coordinate p2) -> int {
+ return orientationIndexFP(p0, p1, p2);
+ });
+}
+
+Coordinate randomCoord() {
+ double x = (10.0 * random()) / RAND_MAX;
+ double y = (10.0 * random()) / RAND_MAX;
+ return Coordinate(x, y);
+}
+
+void checkTest(Coordinate p0, Coordinate p1, Coordinate p2)
+{
+ bool isCorrectDD = isConsistentDD(p0, p1, p2);
+ bool isCorrectFP = isConsistentFP(p0, p1, p2);
+
+ if (isVerbose) {
+ std::cout << std::setprecision(20) << " "
+ << "LINESTRING ( " << p0.x << " " << p0.y << ", " << p1.x << " " << p1.y << " )"
+ << " - " << "POINT ( " << p2.x << " " << p2.y << " )"
+ << std::endl;
+ }
+
+ count++;
+ if (! isCorrectDD) failDD++;
+ if (! isCorrectFP) failFP++;
+}
+
+void reportStats(std::string tag = "") {
+ std::cout << tag << "Num tests: " << count
+ << " DD fail = " << failDD << " (" << round((100.0 * failDD / (double) count)) << "%)"
+ << " FP fail = " << failFP << " (" << round((100.0 * failFP / (double) count)) << "%)"
+ << std::endl;
+}
+
+void runDiagonalTests()
+{
+ const int DIAG_SIZE = 2;
+ Coordinate p0 = Coordinate(DIAG_SIZE, 0);
+ Coordinate p1 = Coordinate(0, DIAG_SIZE);
+
+ const int MAX_PRECISION = 3;
+ int d = 10;
+ for (int i = 0; i < MAX_PRECISION; i++) {
+ int num_points = DIAG_SIZE * d;
+ for (int ix = 0; ix <= num_points; ix++) {
+ int iy = num_points - ix;
+ double x = ix / (double) d;
+ double y = iy / (double) d;
+ Coordinate p2 = Coordinate(x, y);
+ checkTest(p0, p1, p2);
+ }
+ d *= 10;
+ reportStats();
+ }
+}
+
+void runRandomTests()
+{
+ srand (static_cast <unsigned> (time(0)));
+
+ const size_t MAX_ITER = 10'000'000;
+
+ for (size_t i = 1 ; i <= MAX_ITER; i++) {
+ Coordinate p0 = randomCoord();
+ Coordinate p1 = randomCoord();
+ Coordinate p2 = Coordinate(LineSegment::midPoint(p0, p1));
+ checkTest(p0, p1, p2);
+
+ if (i % 10'000 == 0) {
+ reportStats();
+ }
+ }
+}
+
+int main(int argc, char** argv) {
+ if (argc > 1) {
+ parseArgs(argc, argv);
+ }
+ if (isDiagonalTest) {
+ runDiagonalTests();
+ }
+ else {
+ runRandomTests();
+ }
+ reportStats("Final: ");
+}
\ No newline at end of file
-----------------------------------------------------------------------
Summary of changes:
benchmarks/algorithm/CMakeLists.txt | 3 +
.../algorithm/OrientationIndexStressTest.cpp | 221 +++++++++++++++++++++
2 files changed, 224 insertions(+)
create mode 100644 benchmarks/algorithm/OrientationIndexStressTest.cpp
hooks/post-receive
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