Half ellipse geometry

GoJS
1

Hi @walter, please generate and share “half ellipse geometry String”, starting from left to rigth and other one from right to left

2

Do you mean something like the “HalfEllipse” figure in the GoJS Shapes sample?

That, along with all of those other shapes, are defined in https://gojs.net/latest/extensions/Figures.js

In that particular case, it’s:

var KAPPA = 4 * ((Math.sqrt(2) - 1) / 3);

go.Shape.defineFigureGenerator("HalfEllipse", function(shape, w, h) {
  return new go.Geometry()
         .add(new go.PathFigure(0, 0, true)
              .add(new go.PathSegment(go.PathSegment.Bezier, w, .5 * h, KAPPA * w, 0, w, (.5 - KAPPA / 2) * h))
              .add(new go.PathSegment(go.PathSegment.Bezier, 0, h, w, (.5 + KAPPA / 2) * h, KAPPA * w, h).close()))
         .setSpots(0, 0.156, 0.844, 0.844);
});

You can adapt this code to define figures for the other three directions.

3

Hi @walter thanks for reply

I was asking regarding this examples

https://gojs.net/latest/intro/geometry.html

I want to use half ellipse from left to right and othe half from right to left
So In this example go.js shape is showing based on geometryString, half ellipse geometryString I am unable to generate from left to right and from right to left
If it is possible please generate and share

Thanks

4

Just create a Shape of a desired size with that “HallfEllipse” Shape.figure and then get its Shape.geometryString.