fix polygon

Author: mikebarkmin

CHANGELOG.md

@@ -4,6 +4,10 @@ index: 4
 lang: en
 ---
 
+## 4.24.1
+
+- Fix wrong implemention of Polygon.
+
 ## 4.24.0
 
 Move towards supporting Java modules. Therefore we added the shape extension

pom.xml

@@ -5,7 +5,7 @@
 
     <groupId>org.openpatch</groupId>
     <artifactId>scratch</artifactId>
-    <version>4.24.0</version>
+    <version>4.24.1</version>
     <packaging>jar</packaging>
 
     <name>Scratch for Java</name>

src/main/java/org/openpatch/scratch/extensions/shape/Polygon.java

@@ -1,14 +1,19 @@
 package org.openpatch.scratch.extensions.shape;
 
 import java.awt.geom.Path2D;
+import java.awt.geom.Point2D;
+import java.util.ArrayList;
+import java.util.List;
 
 /**
  * Represents a polygon shape defined by its vertices.
  */
 public class Polygon extends Shape {
 
+  private final List<Point2D.Double> points = new ArrayList<>();
+
   /**
-   * Creates a polygon with no points.
+   * Creates an empty polygon.
    */
   public Polygon() {
     this.awtShape = new Path2D.Double();
@@ -17,34 +22,44 @@ public Polygon() {
   /**
    * Creates a polygon with the specified vertices.
    *
-   * @param xPoints an array of x-coordinates of the polygon's vertices
-   * @param yPoints an array of y-coordinates of the polygon's vertices
+   * @param xPoints an array of x-coordinates
+   * @param yPoints an array of y-coordinates
    */
   public Polygon(double[] xPoints, double[] yPoints) {
     if (xPoints.length != yPoints.length) {
-      throw new IllegalArgumentException("xPoints and yPoints must have same length");
+      throw new IllegalArgumentException("xPoints and yPoints must have the same length");
     }
-    var awtPath = new Path2D.Double();
-    awtPath.moveTo(xPoints[0], yPoints[0]);
-    for (int i = 1; i < xPoints.length; i++) {
-      awtPath.lineTo(xPoints[i], yPoints[i]);
+    this.awtShape = new Path2D.Double();
+    for (int i = 0; i < xPoints.length; i++) {
+      addPoint(xPoints[i], yPoints[i]);
     }
-    awtPath.closePath();
-
-    this.awtShape = awtPath;
   }
 
   /**
    * Adds a point to the polygon.
    *
-   * @param x the x-coordinate of the point
-   * @param y the y-coordinate of the point
+   * @param x the x-coordinate
+   * @param y the y-coordinate
    */
   public void addPoint(double x, double y) {
-    if (this.awtShape instanceof Path2D path) {
-      path.lineTo(x, y);
-    } else {
-      throw new IllegalStateException("Shape is not a Path2D");
+    points.add(new Point2D.Double(x, y));
+    rebuildPath();
+  }
+
+  /**
+   * Rebuilds the Path2D from the stored points.
+   */
+  private void rebuildPath() {
+    Path2D.Double path = new Path2D.Double();
+    if (!points.isEmpty()) {
+      Point2D.Double first = points.get(0);
+      path.moveTo(first.x, first.y);
+      for (int i = 1; i < points.size(); i++) {
+        Point2D.Double p = points.get(i);
+        path.lineTo(p.x, p.y);
+      }
+      path.closePath();
     }
+    this.awtShape = path;
   }
 }