reimplement cornerrounding

Author: micycle1

CHANGELOG.md

@@ -5,6 +5,17 @@ All notable changes to PGS will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html). Dates are *YYYY-MM-DD*.
 
+## **2.1** *(2025-xx-xx)*
+
+### Added
+
+### Changes
+
+### Fixed
+Fixed invalid results given by `PGS_Morphology.rounding()`.
+
+### Removed
+
 ## **2.0** *(2025-01-11)*
 
 **NOTE: Beginning at v2.0, PGS is built with Java 17.**

pom.xml

@@ -4,7 +4,7 @@
 	<modelVersion>4.0.0</modelVersion>
 	<groupId>micycle</groupId>
 	<artifactId>PGS</artifactId>
-	<version>2.0</version>
+	<version>2.1-SNAPSHOT</version>
 	<name>Processing Geometry Suite</name>
 	<description>Geometric algorithms for Processing</description>
 
@@ -88,7 +88,7 @@
 		<profile>
 			<id>uber-jar</id>
 			<build>
-			<finalName>${fatJarName}</finalName>
+				<finalName>${fatJarName}</finalName>
 				<plugins>
 					<plugin>
 						<groupId>org.apache.maven.plugins</groupId>

resources/morphology/round.gif

@@ -1486,14 +1486,18 @@ public static PShape fromArray(double[][] shape, boolean close) {
 
 	/**
 	 * Flattens a collection of PShapes into a single GROUP PShape which has the
-	 * input shapes as its children.
+	 * input shapes as its children. If the collection contains only one shape, it
+	 * is directly returned.
 	 *
 	 * @since 1.2.0
 	 * @see #flatten(PShape...)
 	 */
 	public static PShape flatten(Collection<PShape> shapes) {
 		PShape group = new PShape(GROUP);
 		shapes.forEach(group::addChild);
+		if (group.getChildCount() == 1) {
+			return group.getChild(0);
+		}
 		return group;
 	}
 
@@ -1990,8 +1994,9 @@ public static class PShapeData {
 		 * Apply this shapedata to a given PShape.
 		 *
 		 * @param other
+		 * @return other (fluent interface)
 		 */
-		public void applyTo(PShape other) {
+		public PShape applyTo(PShape other) {
 			if (other.getFamily() == GROUP) {
 				getChildren(other).forEach(c -> applyTo(c));
 			}
@@ -2000,6 +2005,8 @@ public void applyTo(PShape other) {
 			other.setStroke(stroke);
 			other.setStroke(strokeColor);
 			other.setStrokeWeight(strokeWeight);
+
+			return other;
 		}
 
 		@Override

src/main/java/micycle/pgs/PGS_Conversion.java

@@ -37,6 +37,7 @@
 import micycle.pgs.color.Colors;
 import micycle.pgs.commons.ChaikinCut;
 import micycle.pgs.commons.CornerRounding;
+import micycle.pgs.commons.CornerRounding.RoundingStyle;
 import micycle.pgs.commons.DiscreteCurveEvolution;
 import micycle.pgs.commons.DiscreteCurveEvolution.DCETerminationCallback;
 import micycle.pgs.commons.EllipticFourierDesc;
@@ -546,19 +547,23 @@ public static PShape smoothEllipticFourier(PShape shape, int descriptors) {
 
 	/**
 	 * Modifies the corners of a specified shape by replacing each angular corner
-	 * with a smooth, circular arc. The radius of each arc is determined
-	 * proportionally to the shorter of the two lines forming the corner.
+	 * with a smooth, circular arc.
 	 * 
-	 * @param shape  The original PShape object whose corners are to be rounded.
-	 * @param extent Specifies the degree of corner rounding, with a range from 0 to
-	 *               1. A value of 0 corresponds to no rounding, whereas a value of
-	 *               1 yields maximum rounding while still maintaining the validity
-	 *               of the shape. Values above 1 are accepted but may produce
-	 *               unpredictable results.
+	 * @param shape  A polygonal PShape, or GROUP shape having polygonal children.
+	 * @param radius The radius of the circular arc used to round each corner. This
+	 *               determines how much a circle of the given radius "cuts into"
+	 *               the corner. The effective radius is bounded by the lengths of
+	 *               the edges forming the corner: If the radius is larger than half
+	 *               the length of either edge, it is clamped to the smaller of the
+	 *               two half-lengths to prevent overlapping or invalid geometry.
 	 * @return A new PShape object with corners rounded to the specified extent.
 	 */
-	public static PShape round(PShape shape, double extent) {
-		return CornerRounding.round(shape, extent);
+	public static PShape round(PShape shape, double radius) {
+		return PGS_Processing.transform(shape, s -> {
+			var styling = PGS_Conversion.getShapeStylingData(shape);
+			var t = CornerRounding.roundCorners(s, radius, RoundingStyle.CIRCLE);
+			return styling.applyTo(t);
+		});
 	}
 
 	/**