from/toWKB file IO

other small things

CHANGELOG.md

@@ -63,6 +63,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 * `align()` to `PGS_Transformation`. Aligns one polygon shape to another, by finding the optimal transformation.
 * `extractInnerEdges()` to `PGS_Meshing`. Extracts all inner edges from a mesh.
 * `centerLine()` to `PGS_Contour`. Determines the longest center line passing through a given shape.
+* Additional signatures for `PGS_Conversion.toWKB()` and `.fromWKB()` that write/read the binary shape representation into a file.
 
 ### Changed
 * Reimplemented `PGS_Processing.equalParition()`. New algorithm is ~2x faster. Also removed `precise` parameter from method signature (no longer necessary).

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

@@ -11,6 +11,7 @@
 import java.awt.Shape;
 import java.awt.geom.AffineTransform;
 import java.awt.geom.PathIterator;
+import java.io.File;
 import java.io.IOException;
 import java.io.OutputStream;
 import java.io.PrintStream;
@@ -30,6 +31,7 @@
 import java.util.Set;
 import java.util.stream.Collectors;
 
+import org.apache.commons.io.FileUtils;
 import org.jgrapht.alg.drawing.IndexedFRLayoutAlgorithm2D;
 import org.jgrapht.alg.drawing.LayoutAlgorithm2D;
 import org.jgrapht.alg.drawing.model.Box2D;
@@ -1093,6 +1095,25 @@ public static byte[] toWKB(PShape shape) {
 		return writer.write(fromPShape(shape));
 	}
 
+	/**
+	 * Converts a shape into <i>Well-Known Binary</i> format and writes the bytes to
+	 * a file.
+	 * 
+	 * @param shape    shape to process
+	 * @param filename Absolute file path (with filename and extension). Prefix with
+	 *                 "./" for a relative path.
+	 * @since 1.3.1
+	 */
+	public static void toWKB(PShape shape, String filename) {
+		WKBWriter writer = new WKBWriter();
+		byte[] bytes = writer.write(fromPShape(shape));
+		try {
+			FileUtils.writeByteArrayToFile(new File(filename), bytes);
+		} catch (IOException e) {
+			e.printStackTrace();
+		}
+	}
+
 	/**
 	 * Converts a geometry in <i>Well-Known Binary</i> format into a PShape.
 	 *
@@ -1110,6 +1131,27 @@ public static PShape fromWKB(byte[] shapeWKB) {
 		}
 	}
 
+	/**
+	 * Reads a shape from a (binary) file containing the <i>Well-Known Binary</i>
+	 * representation of it.
+	 * 
+	 * @param filename Absolute file path (with filename and extension). Prefix with
+	 *                 "./" for a relative path.
+	 * @return a PShape specified by the WKB in the file
+	 */
+	public static PShape fromWKB(String filename) {
+		byte[] shapeWKB;
+		try {
+			shapeWKB = FileUtils.readFileToByteArray(new File(filename));
+			WKBReader reader = new WKBReader();
+			return toPShape(reader.read(shapeWKB));
+		} catch (IOException | ParseException e) {
+			e.printStackTrace();
+			return new PShape();
+		}
+
+	}
+
 	/**
 	 * Writes a shape into the hexadecimal string representation of its
 	 * <i>Well-Known Binary</i> format.

src/main/java/micycle/pgs/PGS_SegmentSet.java

@@ -20,7 +20,10 @@
 import org.locationtech.jts.geom.Coordinate;
 import org.locationtech.jts.geom.Geometry;
 import org.locationtech.jts.geom.LineSegment;
+import org.locationtech.jts.geom.LineString;
 import org.locationtech.jts.geom.Location;
+import org.locationtech.jts.geom.util.LineStringExtracter;
+import org.locationtech.jts.geom.util.LinearComponentExtracter;
 import org.locationtech.jts.noding.MCIndexSegmentSetMutualIntersector;
 import org.locationtech.jts.noding.NodedSegmentString;
 import org.locationtech.jts.noding.SegmentIntersector;
@@ -409,6 +412,9 @@ public static PShape toPShape(Collection<PEdge> segments, @Nullable Integer stro
 	 */
 	public static PShape dissolve(Collection<PEdge> segments) {
 		Geometry g = SegmentStringUtil.toGeometry(fromPEdges(segments), PGS.GEOM_FACTORY);
+		if (g.isEmpty()) {
+			return new PShape();
+		}
 		Geometry dissolved = LineDissolver.dissolve(g);
 		return PGS_Conversion.toPShape(dissolved);
 	}
@@ -419,25 +425,30 @@ public static PShape dissolve(Collection<PEdge> segments) {
 	 * This method iterates through all the child shapes of the input shape,
 	 * creating PEdge segments for each pair of consecutive vertices.
 	 *
-	 * @param shape shape from which to extract the edges.
-	 * @return list of unique PEdge segments representing the edges of the input
+	 * @param shape The shape from which to extract the edges. Supports holes and
+	 *              GROUP shapes.
+	 * @return A list of unique PEdge segments representing the edges of the input
 	 *         shape and its child shapes.
 	 * @since 1.3.1
 	 */
 	public static List<PEdge> fromPShape(PShape shape) {
-		Set<PEdge> edges = new HashSet<>(shape.getVertexCount() / 2);
-		for (PShape child : PGS_Conversion.getChildren(shape)) {
-			for (int i = 0; i < child.getVertexCount(); i++) {
-				final PVector a = child.getVertex(i);
-				final PVector b = child.getVertex((i + 1) % child.getVertexCount());
+		List<PEdge> edges = new ArrayList<>(shape.getFamily() != PShape.GROUP ? shape.getVertexCount() : shape.getChildCount() * 4);
+		@SuppressWarnings("unchecked")
+		List<LineString> strings = LinearComponentExtracter.getLines(PGS_Conversion.fromPShape(shape));
+		strings.forEach(s -> {
+			Coordinate[] coords = s.getCoordinates();
+			boolean closed = coords[0].equals2D(coords[coords.length - 1]);
+			for (int i = 0; i < coords.length - (closed ? 0 : 1); i++) {
+				Coordinate a = coords[i];
+				Coordinate b = coords[(i + 1) % coords.length];
 				if (a.equals(b)) {
 					continue;
 				}
-				final PEdge e = new PEdge(a, b);
+				final PEdge e = new PEdge(a.x, a.y, b.x, b.y);
 				edges.add(e);
 			}
-		}
-		return new ArrayList<>(edges);
+		});
+		return edges;
 	}
 
 	/**

src/main/java/micycle/pgs/PGS_Transformation.java

@@ -460,7 +460,7 @@ public static PShape align(PShape sourceShape, PShape transformShape) {
 	public static PShape align(PShape alignShape, PShape baseShape, double alignmentRatio) {
 		final Geometry g1 = fromPShape(alignShape);
 		final Geometry g2 = fromPShape(baseShape);
-		if (g1.getGeometryType() != Geometry.TYPENAME_POLYGON || g2.getGeometryType() != Geometry.TYPENAME_POLYGON) {
+		if (!g1.getGeometryType().equals(Geometry.TYPENAME_POLYGON) || !g2.getGeometryType().equals(Geometry.TYPENAME_POLYGON)) {
 			throw new IllegalArgumentException("Inputs to align() must be polygons.");
 		}
 		if (((Polygon) g1).getNumInteriorRing() > 0 || ((Polygon) g2).getNumInteriorRing() > 0) {

src/main/java/micycle/pgs/commons/AreaMerge.java

@@ -139,7 +139,8 @@ private static <V, E> void mergeVertices(Graph<V, E> graph, V keep, V remove) {
 	static class FaceGroup implements Comparable<FaceGroup> {
 
 		private double area;
-		private Map<PShape, Double> faces; // faces comprising this group (and their areas)
+		/** A map of faces comprising this group and their respective areas. */
+		private Map<PShape, Double> faces;
 		private Set<PShape> neighborFaces; // union of neighbors of each face - faces themselves
 		private final NeighborCache<PShape, DefaultEdge> neighborCache;