FastR Grid: distinguish filled polygon and polylines

com.oracle.truffle.r.library/src/com/oracle/truffle/r/library/fastrGrid/GridLinesNode.java

@@ -121,7 +121,7 @@ public abstract class GridLinesNode extends Node {
         void drawPolylines(GridDevice dev, DrawingContext drawingCtx, double[] yy, double[] xx, int start, int length) {
             xx[start + length] = xx[start];
             yy[start + length] = yy[start];
-            dev.drawPolyLines(drawingCtx, xx, yy, start, length + 1);
+            dev.drawPolygon(drawingCtx, xx, yy, start, length + 1);
         }
     }
 }

com.oracle.truffle.r.library/src/com/oracle/truffle/r/library/fastrGrid/device/BufferedJFrameDevice.java

@@ -101,6 +101,14 @@ public class BufferedJFrameDevice implements GridDevice {
         }
     }
 
+    @Override
+    public void drawPolygon(DrawingContext ctx, double[] x, double[] y, int startIndex, int length) {
+        inner.drawPolygon(ctx, x, y, startIndex, length);
+        if (buffer != null) {
+            drawActions.add(() -> inner.drawPolygon(ctx, x, y, startIndex, length));
+        }
+    }
+
     @Override
     public void drawCircle(DrawingContext ctx, double centerX, double centerY, double radius) {
         inner.drawCircle(ctx, centerX, centerY, radius);

com.oracle.truffle.r.library/src/com/oracle/truffle/r/library/fastrGrid/device/GridDevice.java

@@ -54,6 +54,15 @@ public interface GridDevice {
      */
     void drawPolyLines(DrawingContext ctx, double[] x, double[] y, int startIndex, int length);
 
+    /**
+     * Version of {@link #drawPolyLines(DrawingContext, double[], double[], int, int)}, which should
+     * fill in the area bounded by the lines. Note that it is responsibility of the caller to
+     * connect the first and the last point if the caller wishes to draw actual polygon.
+     *
+     * @see DrawingContext#getFillColor()
+     */
+    void drawPolygon(DrawingContext ctx, double[] x, double[] y, int startIndex, int length);
+
     void drawCircle(DrawingContext ctx, double centerX, double centerY, double radius);
 
     /**

com.oracle.truffle.r.library/src/com/oracle/truffle/r/library/fastrGrid/device/JFrameDevice.java

@@ -23,6 +23,7 @@
 package com.oracle.truffle.r.library.fastrGrid.device;
 
 import static com.oracle.truffle.r.library.fastrGrid.device.DrawingContext.INCH_TO_POINTS_FACTOR;
+import static java.awt.geom.Path2D.WIND_EVEN_ODD;
 
 import java.awt.BasicStroke;
 import java.awt.BorderLayout;
@@ -89,17 +90,18 @@ public class JFrameDevice implements GridDevice {
 
     @Override
     public void drawPolyLines(DrawingContext ctx, double[] x, double[] y, int startIndex, int length) {
-        assert startIndex >= 0 && startIndex < x.length && startIndex < y.length : "startIndex out of bounds";
-        assert length > 0 && (startIndex + length) <= Math.min(x.length, y.length) : "length out of bounds";
+        Path2D.Double path = getPath2D(x, y, startIndex, length);
         setContext(ctx);
-        Path2D.Double path = new Path2D.Double();
-        path.moveTo(x[startIndex], y[startIndex]);
-        for (int i = startIndex + 1; i < length; i++) {
-            path.lineTo(x[i], y[i]);
-        }
         graphics.draw(path);
     }
 
+    @Override
+    public void drawPolygon(DrawingContext ctx, double[] x, double[] y, int startIndex, int length) {
+        Path2D.Double path = getPath2D(x, y, startIndex, length);
+        setContext(ctx);
+        drawShape(ctx, path);
+    }
+
     @Override
     public void drawCircle(DrawingContext ctx, double centerX, double centerY, double radius) {
         setContext(ctx);
@@ -166,6 +168,17 @@ public class JFrameDevice implements GridDevice {
         graphics.setRenderingHint(RenderingHints.KEY_STROKE_CONTROL, RenderingHints.VALUE_STROKE_PURE);
     }
 
+    private Path2D.Double getPath2D(double[] x, double[] y, int startIndex, int length) {
+        assert startIndex >= 0 && startIndex < x.length && startIndex < y.length : "startIndex out of bounds";
+        assert length > 0 && (startIndex + length) <= Math.min(x.length, y.length) : "length out of bounds";
+        Path2D.Double path = new Path2D.Double(WIND_EVEN_ODD, x.length);
+        path.moveTo(x[startIndex], y[startIndex]);
+        for (int i = startIndex + 1; i < length; i++) {
+            path.lineTo(x[i], y[i]);
+        }
+        return path;
+    }
+
     private void drawShape(DrawingContext drawingCtx, Shape shape) {
         Paint paint = graphics.getPaint();
         graphics.setPaint(fromGridColor(drawingCtx.getFillColor()));