From b3186691ef4361d30621ca69dbb26bddf1c3dfb1 Mon Sep 17 00:00:00 2001
From: Mike Barry <msb5014@gmail.com>
Date: Sun, 3 Nov 2024 06:08:37 -0500
Subject: [PATCH] more realistic lines

---
 .../benchmarks/BenchmarkLineMerge.java        | 65 ++++++++++---------
 1 file changed, 36 insertions(+), 29 deletions(-)

diff --git a/planetiler-benchmarks/src/main/java/com/onthegomap/planetiler/benchmarks/BenchmarkLineMerge.java b/planetiler-benchmarks/src/main/java/com/onthegomap/planetiler/benchmarks/BenchmarkLineMerge.java
index 7b6ff96675..c85691cc99 100644
--- a/planetiler-benchmarks/src/main/java/com/onthegomap/planetiler/benchmarks/BenchmarkLineMerge.java
+++ b/planetiler-benchmarks/src/main/java/com/onthegomap/planetiler/benchmarks/BenchmarkLineMerge.java
@@ -1,18 +1,20 @@
 package com.onthegomap.planetiler.benchmarks;
 
+import com.onthegomap.planetiler.geo.GeoUtils;
 import com.onthegomap.planetiler.util.Format;
 import com.onthegomap.planetiler.util.LoopLineMerger;
 import java.time.Duration;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
+import java.util.Random;
 import java.util.function.Function;
+import org.locationtech.jts.geom.Coordinate;
 import org.locationtech.jts.geom.CoordinateXY;
 import org.locationtech.jts.geom.Geometry;
 import org.locationtech.jts.geom.GeometryFactory;
 import org.locationtech.jts.geom.LineString;
 import org.locationtech.jts.operation.linemerge.LineMerger;
-import org.locationtech.jts.util.GeometricShapeFactory;
 
 public class BenchmarkLineMerge {
 
@@ -20,38 +22,39 @@ public static void main(String[] args) {
     for (int i = 0; i < 10; i++) {
       System.err.println(
         " JTS line merger (/s):\t" +
-          timeJts(10) + "\t" +
-          timeJts(1_000) + "\t" +
-          timeJts(10_000) + "\t" +
-          timeJts(100_000));
+          timeJts(10, 10) + "\t" +
+          timeJts(10, 100) + "\t" +
+          timeJts(1000, 10) + "\t" +
+          timeJts(1000, 1000));
       System.err.println(
         "loop line merger (/s):\t" +
-          timeLoop(10) + "\t" +
-          timeLoop(1_000) + "\t" +
-          timeLoop(10_000) + "\t" +
-          timeLoop(100_000));
+          timeLoop(10, 10) + "\t" +
+          timeLoop(10, 100) + "\t" +
+          timeLoop(1000, 10));
+      // TODO currently this does not finish:
+      // + "\t" + timeLoop(1000, 1000));
       System.err.println();
     }
   }
 
-  private static String timeLoop(int parts) {
-    return time(parts, geom -> {
+  private static String timeLoop(int lines, int parts) {
+    return time(lines, parts, geom -> {
       var merger = new LoopLineMerger();
       merger.add(geom);
       return merger.getMergedLineStrings(0.1, 0.1);
     });
   }
 
-  private static String timeJts(int parts) {
-    return time(parts, geom -> {
+  private static String timeJts(int lines, int parts) {
+    return time(lines, parts, geom -> {
       var merger = new LineMerger();
       merger.add(geom);
       return merger.getMergedLineStrings();
     });
   }
 
-  private static String time(int parts, Function<Geometry, Collection<LineString>> fn) {
-    Geometry multiLinestring = makeCircles(parts);
+  private static String time(int lines, int parts, Function<Geometry, Collection<LineString>> fn) {
+    Geometry multiLinestring = makeLines(lines, parts);
     long start = System.nanoTime();
     long end = start + Duration.ofSeconds(1).toNanos();
     int num = 0;
@@ -63,19 +66,23 @@ private static String time(int parts, Function<Geometry, Collection<LineString>>
       .numeric(Math.round(num * 1d / ((System.nanoTime() - start) * 1d / Duration.ofSeconds(1).toNanos())), true);
   }
 
-  private static Geometry makeCircles(int parts) {
-    var factory = new GeometricShapeFactory();
-    factory.setCentre(new CoordinateXY(0, 0));
-    factory.setSize(2);
-    factory.setNumPoints(parts);
-    List<LineString> lines = new ArrayList<>();
-    lines.add(factory.createArc(0, Math.PI * 2));
-    factory.setCentre(new CoordinateXY(1, 0));
-    lines.add(factory.createArc(0, Math.PI * 2));
-    factory.setCentre(new CoordinateXY(1, 1));
-    lines.add(factory.createArc(0, Math.PI * 2));
-    factory.setCentre(new CoordinateXY(0, 1));
-    lines.add(factory.createArc(0, Math.PI * 2));
-    return new GeometryFactory().createMultiLineString(lines.toArray(LineString[]::new));
+  private static Geometry makeLines(int lines, int parts) {
+    List<LineString> result = new ArrayList<>();
+    var random = new Random(0);
+    for (int i = 0; i < lines; i++) {
+      Coordinate[] coords = new Coordinate[parts];
+      double x = random.nextInt(100);
+      double y = random.nextInt(100);
+      double dx = random.nextInt(-3, 3);
+      double dy = random.nextInt(-3, 3);
+      for (int j = 0; j < parts; j++) {
+        coords[j] = new CoordinateXY(
+          x += dx,
+          y += dy
+        );
+      }
+      result.add(GeoUtils.JTS_FACTORY.createLineString(coords));
+    }
+    return new GeometryFactory().createMultiLineString(result.toArray(LineString[]::new));
   }
 }