Fix `View.pickObjectAt()`

[mathieuLivebardon]

Description

pickObjectAt returns an empty array if parameter where is an empty array.

Motivation and Context

where is a parameter of pickObjectAt to specify the layers to perform a pick. The problem: If where is an empty array, the function picks on all layers by default.

const intersects = view.pickObjectsAt(
  event,
  0,
  view.getLayers().filter((el) => el.isC3DTilesLayer)
);

Here, if the application had dynamic layers¹ and no C3DTilesLayers in the View, intersects should be an empty array.

¹ remove/add layers at runtime

[ketourneau]

I think your PR can cause some trouble for people who use the pickObjectAt and want method to use all layers if where condition is an empty array.

In your case, why not simply check empty array before call pickObjectsAt ?

const layers = view.getLayers().filter((el) => el.isC3DTilesLayer);
let intersects = [];
if (layers.length > 0) {
  intersects = view.pickObjectsAt(event, 0, ayers);
}

[jailln]

I agree with @ketourneau, and how it works currently seems more intuitive to me. Would the solution proposed by @ketourneau work in your context?

[mathieuLivebardon]

Fine, I'll close this PR and use @ketourneau's solution. Thanks for your answers.