Fix voronoi centers (#708)

* better comments

* draw voronoi centers in the right place

* fix null

* optional show center

src/main/java/com/marginallyclever/convenience/voronoi/VoronoiTesselator2.java

@@ -21,7 +21,7 @@ public void setNumHulls(int numHulls) {
     }
 
     public void tessellate(List<VoronoiCell> points, Rectangle2D bounds, double tolerance) {
-        if(points.size()!=coordinates.length) setNumHulls(points.size());
+        if(coordinates==null || points.size()!=coordinates.length) setNumHulls(points.size());
 
         int i=0;
         for(VoronoiCell cell : points) {

src/main/java/com/marginallyclever/makelangelo/makeart/turtlegenerator/Generator_Voronoi.java

@@ -4,6 +4,7 @@
 import com.marginallyclever.convenience.voronoi.VoronoiCell;
 import com.marginallyclever.convenience.voronoi.VoronoiTesselator2;
 import com.marginallyclever.makelangelo.Translator;
+import com.marginallyclever.makelangelo.select.SelectBoolean;
 import com.marginallyclever.makelangelo.select.SelectInteger;
 import com.marginallyclever.makelangelo.turtle.Turtle;
 import org.locationtech.jts.geom.Coordinate;
@@ -19,6 +20,7 @@
  */
 public class Generator_Voronoi extends TurtleGenerator {
 	private static int numCells = 500;
+	private static boolean showCenters = false;
 
 	public Generator_Voronoi() {
 		super();
@@ -29,6 +31,13 @@ public Generator_Voronoi() {
 			setNumCells(Math.max(1,cells.getValue()));
 			generate();
 		});
+		SelectBoolean showCenterChoice;
+		add(showCenterChoice = new SelectBoolean("showCenters",Translator.get("Converter_Voronoi.ShowCenters"),false));
+		showCenterChoice.addPropertyChangeListener(evt->{
+			showCenters = showCenterChoice.isSelected();
+			generate();
+		});
+
 	}
 
 	@Override
@@ -48,18 +57,30 @@ public void generate() {
 		Turtle turtle = new Turtle();
 
 		Rectangle2D bounds = myPaper.getMarginRectangle();
+		List<VoronoiCell> points = seedRandomPoints(bounds);
+		// generate the voronoi diagram
+		VoronoiTesselator2 diagram = new VoronoiTesselator2();
+		diagram.tessellate(points,bounds,0.0001);
 
+		drawGraphEdges(turtle,diagram);
+		if(showCenters) drawCellCenters(turtle,points);
+		turtle.penUp();
+		notifyListeners(turtle);
+	}
+
+	// seed random points on the paper.
+	private List<VoronoiCell> seedRandomPoints(Rectangle2D bounds) {
 		List<VoronoiCell> points = new ArrayList<>();
 		for(int i=0;i<numCells;++i) {
 			points.add(new VoronoiCell(
-					Math.random()*bounds.getWidth() +bounds.getMinX(),
-					Math.random()*bounds.getHeight()+bounds.getMinY()));
+					Math.random()*bounds.getWidth()  + bounds.getMinX(),
+					Math.random()*bounds.getHeight() + bounds.getMinY()));
 		}
+		return points;
+	}
 
-		VoronoiTesselator2 diagram = new VoronoiTesselator2();
-		diagram.tessellate(points,bounds,0.0001);
-
-		// draw all the graph edges according to the cells.
+	// draw all the graph edges according to the cells.
+	private void drawGraphEdges(Turtle turtle, VoronoiTesselator2 diagram) {
 		for(int i=0;i<diagram.getNumHulls();++i) {
 			boolean first = true;
 			Polygon poly = diagram.getHull(i);
@@ -70,22 +91,23 @@ public void generate() {
 				} else turtle.moveTo(p.x, p.y);
 			}
 		}
+	}
 
+	private void drawCellCenters(Turtle turtle, List<VoronoiCell> points) {
 		// draw all the cell centers
 		turtle.setColor(new ColorRGB(0,0,255));
+
 		for( VoronoiCell p : points ) {
+			// jump to corner
+			turtle.jumpTo(p.center.x-0.5,p.center.y-0.5);
+			// box
+			for(int i=0;i<4;++i) {
+				turtle.forward(1);
+				turtle.turn(90);
+			}
+			// point in center
 			turtle.jumpTo(p.center.x,p.center.y);
-			turtle.forward(1);
-			turtle.turn(90);
-			turtle.forward(1);
-			turtle.turn(90);
-			turtle.forward(1);
-			turtle.turn(90);
-			turtle.forward(1);
+			turtle.forward(0.1);
 		}
-
-		turtle.penUp();
-
-		notifyListeners(turtle);
 	}
 }

src/main/java/com/marginallyclever/makelangelo/turtle/Turtle.java

@@ -152,7 +152,7 @@ public double getDiameter() {
 	}
 
 	/**
-	 * Absolute position change, make sure pen is up before move and put pen down after move.
+	 * Absolute position change. Raise the pen before move and lower pen after move.
 	 * @param x absolute x position
 	 * @param y absolute y position
 	 */
@@ -163,7 +163,7 @@ public void jumpTo(double x,double y) {
 	}
 
 	/**
-	 * Absolute position change, do not adjust pen status
+	 * Absolute position change, do not change current pen status
 	 * @param x relative x position
 	 * @param y relative y position
 	 */

src/main/resources/languages/english.xml

@@ -272,6 +272,7 @@
 	<string><key>Converter_VoronoiStippling.DotMin</key><value>Min dot size</value></string>
 	<string><key>Converter_VoronoiStippling.DrawBorders</key><value>Draw borders?</value></string>
 	<string><key>Converter_VoronoiStippling.Cutoff</key><value>Cutoff</value></string>
+	<string><key>Converter_Voronoi.ShowCenters</key><value>Show centers</value></string>
 
 	<string><key>SandyNoble.title</key><value>Sandy Noble Style</value></string>
 	<string><key>SandyNoble.rings</key><value>Rings</value></string>