Brush-like mesh faces selection during GetPoint

Rhino Developer
1

Hello,

I have implemented a brush-like selection of mesh faces inside a GetPoint, with the final purpose of splitting a mesh into specific parts.

The result I got so far is this:

Following @jeff suggestions from another post, I draw the preview mesh as a shaded geometry with vertex colors (blue = unselected, yellow = selected).

The preview mesh would be much nicer if it showed also wires (with depth test filtering).

What I’m currently doing is drawing everything inside a custom GetPoint.DynamicDraw() method. I understand the DynamicDraw routine does not consider depth testing in any way (so it’s like a conduit’s DrawOverlay()), but I thought of using it to have e.CurrentPoint for free, without having to implement all mouse events.

public class GetPointDraggable : GetPoint
{
  public class CustomMouseCallback : MouseCallback
  {
    public bool DragFlag = false;

    public CustomMouseCallback() {
      Enabled = true;
    }

    protected override void OnMouseUp(MouseCallbackEventArgs e) {
      base.OnMouseUp(e);
      DragFlag = false;
    }

    protected override void OnMouseDown(MouseCallbackEventArgs e) {
      base.OnMouseDown(e);
      if (e.MouseButton == MouseButton.Left) {
        DragFlag = true;
      }
    }
  }

  public CustomMouseCallback Callback = new CustomMouseCallback();

  public HashSet<int> SelectedFaceIndices = new HashSet<int>();
  public Point3d? CurrentPoint = null;

  public GetPointDraggable() {
    MouseDown += (s, e) => {
      SelectedFaceIndices.Clear();
      CurrentPoint = null;
    };
    MouseMove += (s, e) => {
      if (Callback.DragFlag) {
        CurrentPoint = e.Point;
      }
    };
  }
}

But anyway, that was not actually true, because to know when the user is dragging I had to attach a MouseCallback to the GetPoint class…
(by the way, is there a reason why GetPoint allows you to override OnMouseDown / OnMouseMove but NOT OnMouseUp? I need to know when the mouse is released to understand when the drag operation is finished… that’s why I had to attach a MouseCallback instead).

I also tried to draw wires or unselected faces on a separate Conduit, but then I had a hard time synchronizing the conduit redraw and the selected faces draw from the DynamicDraw.

I think I messed up a little all the interactions :smiley:

So what approach would it be the best to draw a preview with mesh wires, over which the user can “paint” faces by dragging the mouse?

I you have any idea, it would be much appreciated.
Thanks

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