From 120c92eeb36db76d06da6ef765e27565aa91cce9 Mon Sep 17 00:00:00 2001
From: Mike Barry <msb5014@gmail.com>
Date: Sat, 26 Oct 2024 07:08:08 -0400
Subject: [PATCH] accessor on feature

---
 .../planetiler/reader/SourceFeature.java      | 27 ++++++++++++---
 .../planetiler/FeatureCollectorTest.java      | 33 +++++++++++++++++++
 2 files changed, 55 insertions(+), 5 deletions(-)

diff --git a/planetiler-core/src/main/java/com/onthegomap/planetiler/reader/SourceFeature.java b/planetiler-core/src/main/java/com/onthegomap/planetiler/reader/SourceFeature.java
index 10a04a6a7f..f2d51fb197 100644
--- a/planetiler-core/src/main/java/com/onthegomap/planetiler/reader/SourceFeature.java
+++ b/planetiler-core/src/main/java/com/onthegomap/planetiler/reader/SourceFeature.java
@@ -43,7 +43,8 @@ public abstract class SourceFeature implements WithTags, WithGeometryType, WithS
   private Geometry validPolygon = null;
   private double area = Double.NaN;
   private double length = Double.NaN;
-  private double size = Double.NaN;
+  private double areaMeters = Double.NaN;
+  private double lengthMeters = Double.NaN;
   private LineSplitter lineSplitter;
 
   /**
@@ -283,7 +284,7 @@ public final Geometry validatedPolygon() throws GeometryException {
    * {@code 1} means the area of the entire planet.
    */
   public double area() throws GeometryException {
-    return Double.isNaN(area) ? (area = canBePolygon() ? polygon().getArea() : 0) : area;
+    return Double.isNaN(area) ? (area = canBePolygon() ? Math.abs(polygon().getArea()) : 0) : area;
   }
 
   /**
@@ -297,11 +298,27 @@ public double length() throws GeometryException {
   }
 
   /**
-   * Returns and caches sqrt of {@link #area()} if polygon or {@link #length()} if a line string.
+   * Returns the sqrt of {@link #area()} if polygon or {@link #length()} if a line string.
    */
   public double size() throws GeometryException {
-    return Double.isNaN(size) ? (size = canBePolygon() ? Math.sqrt(Math.abs(area())) : canBeLine() ? length() : 0) :
-      size;
+    return canBePolygon() ? Math.sqrt(Math.abs(area())) : canBeLine() ? length() : 0;
+  }
+
+  /** Returns and caches the approximate area of the geometry in square meters. */
+  public double areaMeters() throws GeometryException {
+    return Double.isNaN(areaMeters) ? (areaMeters =
+      (isPoint() || canBePolygon() || canBeLine()) ? GeoUtils.areaInMeters(latLonGeometry()) : 0) : areaMeters;
+  }
+
+  /** Returns and caches the approximate length of the geometry in meters. */
+  public double lengthMeters() throws GeometryException {
+    return Double.isNaN(lengthMeters) ? (lengthMeters =
+      (isPoint() || canBePolygon() || canBeLine()) ? GeoUtils.lengthInMeters(latLonGeometry()) : 0) : lengthMeters;
+  }
+
+  /** Returns the sqrt of {@link #areaMeters()} if polygon or {@link #lengthMeters()} if a line string. */
+  public double sizeMeters() throws GeometryException {
+    return canBePolygon() ? Math.sqrt(Math.abs(areaMeters())) : canBeLine() ? lengthMeters() : 0;
   }
 
   /** Returns the ID of the source that this feature came from. */
diff --git a/planetiler-core/src/test/java/com/onthegomap/planetiler/FeatureCollectorTest.java b/planetiler-core/src/test/java/com/onthegomap/planetiler/FeatureCollectorTest.java
index 799e2ae81f..8fa6e39449 100644
--- a/planetiler-core/src/test/java/com/onthegomap/planetiler/FeatureCollectorTest.java
+++ b/planetiler-core/src/test/java/com/onthegomap/planetiler/FeatureCollectorTest.java
@@ -890,4 +890,37 @@ void testPointAlongLine() {
 
     assertFalse(iter.hasNext());
   }
+
+
+  @Test
+  void testSizeInMetersOfLine() throws GeometryException {
+    var sourceLine = newReaderFeature(newLineString(
+      0, 0,
+      1, 0
+    ), Map.of());
+
+    assertEquals(111_195, sourceLine.lengthMeters(), 1d);
+    assertEquals(111_195, sourceLine.sizeMeters(), 1d);
+    assertEquals(0, sourceLine.areaMeters());
+  }
+
+
+  @Test
+  void testSizeInMetersOfPolygon() throws GeometryException {
+    var sourceLine = newReaderFeature(rectangle(0, 1), Map.of());
+
+    assertEquals(0, sourceLine.lengthMeters());
+    assertEquals(111192, sourceLine.sizeMeters(), 1d);
+    assertEquals(Math.pow(111192.25757749, 2), sourceLine.areaMeters(), 1d);
+  }
+
+
+  @Test
+  void testSizeInMetersOfPoint() throws GeometryException {
+    var sourceLine = newReaderFeature(newPoint(0, 1), Map.of());
+
+    assertEquals(0, sourceLine.lengthMeters());
+    assertEquals(0, sourceLine.sizeMeters());
+    assertEquals(0, sourceLine.areaMeters());
+  }
 }