Enum-like node inputs / outputs

[rsaccon]

For a 3d modeling app I have different data types like Solid, Surface, Curve. Now I want to have some nodes for 3d transformations like translation, rotation and scaling. These nodes should accept one input which can have data type of Solid, Surface or Curve. And the output data type will be the same. Now I am wondering how something like that could be implemented.

Maybe having inputs / outputs for each data type, but after user has connected an input (or output), disable all the other inputs / outputs which have different data type.

Or having only one input / output which accepts several data types ? But that would require changes at the egui_node_graph library itself.

Or use separate transformation nodes for each data type ? That is easy to implement but confusing to the user (lots of different nodes for the same operation).

Maybe somebody has ran into the same issue and come up with a smart approach how to handle this.

[mxgrey]

I presented some ideas here that I think could be relevant.

If we imagine that the changes I recommend in 1. Function instead of Eq for testing data compatibility are finished, then you could define a data type whose fn is_compatible implementation knows that your transformation node's input is capable of connecting to Solid, Surface, or Curve input types.

After that things get trickier. I'm just learning the egui_node_graph code base right now so I'm not clear if there's a better option, but if there were a way to listen for add_connection events, then you could have your system listen for cases where your input port has this flexible type. When that flexible type gets connected to Solid, Surface, or Curve, then you modify the node that the input port belongs to so that the type of output port on the node is consistent with the incoming data type.

[mxgrey]

It seems that draw_graph_editor should have information about connection events that have taken place in the last cycle, so I think you could listen for ConnectEventEnded from that to have your node react to the connection.