BatchedMesh: add method to check if geometry can be added

[marwie]

Description

How should i detect if my BufferGeometry can be added to a BatchedMesh before calling addGeometry?

I know there's _validateGeometry - but this method seems not meant to be part of the public API. I'd need a way to detect if calling addGeometry is safe.

Solution

Expose _validateGeometry - not sure if it should throw however - perhaps it could return an object or string containing a reason for why it can't be added (and then the addGeometry call could still throw)

Alternatives

Calling _validateGeometry (this is very slow) - but an official API method would be preferred

Additional context

No response

[gkjohnson]

Of course you can currently use a try / catch block to test if adding the geometry is successful, but I understand it's not ideal.

Calling _validateGeometry (this is very slow)

In what way is this slow? I'm looking at the code and it doesn't look like it should take an unreasonable amount of time if it just returned success or not.

[marwie]

Perhaps something else in the code was causing the performance issue - I can't say for sure right now, sorry for implying.

What do you think about officially exposing the method or adding a public method for testing which returns information if (and if not) the object can be added: { success:boolean; reason?:string }

[gkjohnson]

What would you plan to do with the "reason" string? An API structured such that you can do the following feels best:

if ( mesh.canAddGeometry( geometry ) ) {

  const id = mesh.addGeometry( geometry );
  // ...

}

[marwie]

The reason for this object return type was just so that it could also be called internally (and replace __validateGeometry) and then throw with the reason given to the Error.

[gkjohnson]

The reason for this object return type was just so that it could also be called internally (and replace __validateGeometry) and then throw with the reason given to the Error.

Got it - I think this can be achieved with an internal function while retaining a simple public facing function that can be used like above.