Class SoEllipseScreenDrawer

  • All Implemented Interfaces:

    public class SoEllipseScreenDrawer
    extends SoPolyLineScreenDrawer
    Interactively draw an ellipse in normalized screen space. This class can be used to interactively draw an ellipse on screen.

    When the ellipse is finished, an event is raised to notify the application (see SoPolyLineScreenDrawer.onFinish ). Points are returned as normalized coordinates in the range -1..1, which is conveniently the default view volume for an SoOrthographicCamera node.

    The line color is specified by the color field in the parent class SoPolyLineScreenDrawer.

    Please see SoPolyLineScreenDrawer for general notes and code example.

    Ellipse specific notes:

    • The ellipse can be specified by the 2 corners of its bounding box (default) or by its center and one corner of its bounding box (see CreationMethod).
    • The simplificationThreshold field does not apply to this node. The number of points in the ellipse is specified using the nbPoint field.
    • The isClosed field does apply to this node (but false is not very useful).
    • If user finishes an ellipse, then the next click will automatically clear the polyline (begin a new ellipse).
    • SbEventHandlers:
      • OnStart : Triggered on LeftMouseDown input event.
      • OnMove : Triggered on MouseMove input events (after Start).
      • OnFinish : Triggered on LeftMouseUp input event.


    • Press and drag left mouse to draw the ellipse.
    • Release to finish the ellipse.
    • Press Escape to cancel construction of the ellipse.

    File format/default:

    EllipseScreenDrawer {

      point []
      color 1 0 0
      simplificationThreshold 0
      isClosed true
      method CORNER_CORNER
      nbPoint 16

    See Also:
    SoLassoScreenDrawer, SoPolyLineScreenDrawer, SoPolygonScreenDrawer, SoRectangleScreenDrawer
    • Constructor Detail

      • SoEllipseScreenDrawer

        public SoEllipseScreenDrawer()