topic Invalid argument from GeometryEngine when drawing an ellipse in Java Maps SDK Questions

Invalid argument from GeometryEngine when drawing an ellipse

Tone — Thu, 09 Dec 2021 15:11:12 GMT

Hi,

I'm fairly new to ArcGIS, I do a bit of testing to see if we could use it for our application. I have a basic application displaying a map, and I want to draw an ellipse on it. I managed to draw circles, but for whatever reason I can't figure out, I have an arcGISRuntimeException : Invalid argument from the GeometryEngine when I run it with my ellipse.

Here is my code (without my API key):

public class App extends Application { private MapView mapView; public static void main(String[] args) { Application.launch(args); } @Override public void start(Stage stage) { stage.setTitle("Carto App"); stage.setWidth(800); stage.setHeight(700); stage.show(); StackPane stackPane = new StackPane(); Scene scene = new Scene(stackPane); stage.setScene(scene); String yourApiKey = ""; ArcGISRuntimeEnvironment.setApiKey(yourApiKey); mapView = new MapView(); stackPane.getChildren().add(mapView); ArcGISMap map = new ArcGISMap(BasemapStyle.ARCGIS_IMAGERY); mapView.setMap(map); GraphicsOverlay graphicsOverlay = new GraphicsOverlay(); mapView.getGraphicsOverlays().add(graphicsOverlay); EllipseFigure ellipse = new EllipseFigure(new Point(0, 0), 100, 100, 0, 0xFF00FF00); Graphic graphic = new Graphic(ellipse.getGeometry(), ellipse.getSymbol()); graphicsOverlay.getGraphics().add(graphic); } /** * Stops and releases all resources used in application. */ @Override public void stop() { if (mapView != null) { mapView.dispose(); } } }

public class EllipseFigure { private final double semiMajorAxis; private final double semiMinorAxis; private Point center; private double rotAngle; private int color; public EllipseFigure(Point center, double semiMajorAxis, double semiMinorAxis, double rotAngle, int color) { this.center = center; this.semiMajorAxis = semiMajorAxis; this.rotAngle = rotAngle; this.semiMinorAxis = semiMinorAxis; this.color = color; } public Geometry getGeometry() { GeodesicEllipseParameters params = new GeodesicEllipseParameters(center, semiMajorAxis, semiMinorAxis); params.setAngularUnit(new AngularUnit(AngularUnitId.RADIANS)); params.setAxisDirection(rotAngle); return GeometryEngine.ellipseGeodesic(params); } public Symbol getSymbol() { return new SimpleLineSymbol(SimpleLineSymbol.Style.SOLID, color, 3); } }

I'd really appreciate if someone could help me figure out what's going on here.

Re: Invalid argument from GeometryEngine when drawing an ellipse

MarkBaird — Fri, 10 Dec 2021 13:41:19 GMT

Hi @Tone

The ellipseGeodesic method is very fussy about its parameters. You need to make sure you set them all and you also need to pass in a center point which has a known spatial reference.

I've created an example ellipse method which should help you:

private Polygon makeEllipse() { // create parameters and set all the parameters GeodesicEllipseParameters parameters = new GeodesicEllipseParameters(); parameters.setCenter(new Point(3,14, SpatialReferences.getWebMercator())); // Note the spatial reference parameters.setGeometryType(GeometryType.POLYGON); parameters.setSemiAxis1Length(100); parameters.setSemiAxis2Length(200); parameters.setAxisDirection(45); parameters.setMaxPointCount(100); parameters.setAngularUnit(new AngularUnit(AngularUnitId.DEGREES)); parameters.setLinearUnit(new LinearUnit(LinearUnitId.METERS)); parameters.setMaxSegmentLength(20); Polygon ellipsePoly = (Polygon) GeometryEngine.ellipseGeodesic(parameters); return ellipsePoly; }

This is how I used the resulting geometry:

SimpleLineSymbol lineSymbol = new SimpleLineSymbol(SimpleLineSymbol.Style.SOLID, 0xFF0063FF, 1); SimpleFillSymbol fillSymbol = new SimpleFillSymbol(SimpleFillSymbol.Style.SOLID, 0xFF00FF00, lineSymbol); Graphic graphic = new Graphic(makeEllipse(), fillSymbol); graphicsOverlay.getGraphics().add(graphic);

Looks like this:

Let me know if this helps

Mark

Re: Invalid argument from GeometryEngine when drawing an ellipse

Tone — Mon, 13 Dec 2021 08:54:00 GMT

Ah, I knew I had a problem with the parameters but couldn't figure out what it was.

Thank you @MarkBaird !