C++ Parse relative coordinates without using CRhinoGetPoint

Rhino Developer
,
1

I am creating a custom Move command which asks for a CRhinoGetObjet using the point_object filter.

Then I want to ask the user for a new point position, which has to be inputted as x,y,z coordinates.

I don’t want to accept mouse click as input.
I don’t want the mouse crosshair to be transformed to a cross, like it does with the CRhinoGetPoint::GetPoint(and which can handle relative coordinates and other formats).

Basically I want what the CRhinoGetNumber::GetNumber does. However this only accepts numbers and I want to accept all the coordinate formats listed on this page Entering Numbers | Rhino 3-D modeling

My current code:

CRhinoCommand::result RunCommand(const CRhinoCommandContext &context) {
	CRhinoGetObject point{};
	point.SetCommandPrompt(L"Select a point");
	point.SetGeometryFilter(CRhinoGetObject::point_object);

	const CRhinoGet::result result = point.GetObjects(1, 1);
	const CRhinoCommand::result command_result = point.CommandResult();

	if (command_result != CRhinoCommand::result::success) {
		RhinoApp().Print(L"Command failed. Bad selection?\n");
	}

	if (result != CRhinoGet::object) {
		RhinoApp().Print(L"This was not a point.\n");
	}


	CRhinoGetNumber try_new_pos {};
	try_new_pos.SetCommandPrompt(L"Input new coordinates");
	// This will fail because x,y,z format from user is not CRhinoGet::number
	if (not (try_new_pos.GetNumber() == CRhinoGet::number)) {
		RhinoApp().Print("Not a number, exiting.\n");
		return CRhinoCommand::result::failure;
	}

	double new_pos = try_new_pos.Number();
	const CRhinoObject *old_point = point.Object(0).Object();
	CRhinoPointObject *new_point = new CRhinoPointObject();

	if (new_point == nullptr) {
		RhinoApp().Print("Memory allocation failed\n");
		return CRhinoCommand::result::failure;
	}

	ON_3dPoint p {new_pos}; // This fails of course. new_pos typed as @5,0,0
	*new_point = p;

	if (!context.m_doc.ReplaceObject(CRhinoObjRef {old_point}, new_point, true)) {
		RhinoApp().Print("Rhino failed to modify the point\n");
		delete new_point;
		return CRhinoCommand::result::failure;
	}

	context.Document()->Redraw();
	return CRhinoCommand::success;
}
2

You can use RhinoGetString and then call RhinoParsePoint to attempt to convert the input into a 3d point.

3

Hi Steve. RhinoParsePoint can only parse absolute x,y,z coordinates, optionally delimited by whitespace if multiple points. It cannot handle relative notation liker1,2,3 and the like.

It seems my only two options are to use CRhinoGetPoint or write my own parser.

4

Hi @John_Dough,

The handling of special characters used in accurate drawing are built in to CRhinoGetPoint.

If at all possible, you should just use this class.

– Dale

5

It is pretty clear to me now what my options are and what is the intended way to handle the special characters.

Thanks Dale and Steve.