Event Message Pump and Intrinsic Result.done False

utwsoft

Hello, I've integrated Miniscript in Unity, and run into an issue. I have an intrinsic that I want to continue processing (i.e. Result.done = false) until a user invokes a "break", setting Result.done = true. The use-case is a dialogue box that waits for user input to advance the dialogue. I have this part working, but I wanted to expand on this by allowing an event handler from allowing to break the intrinsic by having the handler set Result.done to true.

The issue I have is that the event pump (as recommended by the Unity integration guide) is not getting processed while the intrinsic is processing in its "wait" loop. What's a good design to listen to event handlers while the intrinsic's Result.done is false?

jstrout

You can't — those are two fundamentally incompatible things going on. If an intrinsic sets Result.done to false, it completely blocks the script; that whole Interpreter can't do anything else until the intrinsic says it's done. So you can't block the script, and also have the event handler processing events.

It sounds like maybe you want the dialog to not block the script, but instead to run asynchronously. So then you'd need an intrinsic that starts the dialog, and probably other intrinsics to check its status or cancel it. And when the user dismisses it, perhaps it throws another event on the event queue?

Or else, let it block the script, and don't expect any other event-processing to go on. What sort of events did you have in mind that should cause the dialog to close? Are those things that can be processed without script?

utwsoft

jstrout My hope was to do something like this:

isDone = 0

onGameStart = function()
  Say("Hi!")
  Say("This is a tutorial!")
  Say("Click on this 3D in-world object", isDone)
  Say("Great! You clicked on it!")
end function

onObjectClicked = function(args)
   objId = args["objId"]
   if objId == 3 then
       isDone = 1
   end if
end function

I had a couple goals here, where a script author can implement Say() statements that would async (or block as it is) run until done, that way it somewhat makes sense when authoring.

I suppose I can support two Say intrinsics, for blocking and non-blocking, that's something I've been mulling over.

Ultimately, I think the answer is still to execute the Say() intrinsics, returning done=true, and have the dialogue in maybe a separate list, perhaps using the event queue like you suggested.

jstrout

You could make the async option a parameter on the Say call, and default to false. So then your script might look like:

obj3Clicked = false

onGameStart = function
  Say "Hi!"
  Say "This is a tutorial!"
  Say "Click on this 3D in-world object", true   // async, i.e. return immediately
  while not obj3Clicked; processEvents; end while
  Say "Great! You clicked on it!"
end function

onObjectClicked = function(args)
   if orgs.objId == 3 then obj3Clicked = true
end function

Something like that might work. If your script gets more complex, you do need to watch out for creating a tangled mess of event handlers calling processEvents, which invokes other event handlers... in real-life desktop apps, I've seen that become problematic. But for something simple like a tutorial, it's probably fine.

utwsoft

Thanks! This works great, and is clear enough for any script authors to write.