Add a fill_region method to the AStarGrid2D

[Chaosus]

Closes godotengine/godot-proposals#7276 by adding a property default_solid_enabled to the AStarGrid2D - after the user set it to true, the next call of update method will make all points solid. Adds the fill_region method to assign the solid flag and weight_scale to the specified region on the gird.

[dalexeev]

Maybe it should be an optional argument to the update() method instead?

Or we can add a fill_region() method that would fill the specified region (must be a sub-region of the current region) with the specified value. In my opinion, this is better, as it can be used in more cases (for batch operations). The main complaint of the linked proposal is that you have to use a loop, but that's just 3 lines of code. So there is a concern about GDScript performance?

[Chaosus]

@dalexeev I think fill_region is the neat idea! Thanks!

[dalexeev]

I forgot to remind you about this check, sorry. The rest of the code and approach looks good to me. Not sure how much the GDScript loop is less performant though. Probably worth asking the proposal author, perhaps they meant some other problem?

[dalexeev]

For consistency, the following should be added to the description of the methods:

[b]Note:[/b] Calling [method update] is not needed after the call of this function.

Also I'm a bit worried that there is no error/warning if the specified region is outside the grid region boundaries.

[smix8]

I am not really involved with the AStar classes but looks useful and fine.

[akien-mga]

Thanks!

[2fd5]

Thank you for implementing this and everyone involved