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LuaSurface::find_entity returns no-collision entity
Posted: Sun Mar 05, 2017 9:41 am
by Mooncat
Request:
LuaSurface::find_entity can find entities that have zero-sized collision box (collision_box = {{0, 0}, {0, 0}}), e.g. item-request-proxy
This thing has bugged me for quite some time: we have to use LuaSurface::find_entities_filtered to get the entity that we know its name and exact position, but LuaSurface::find_entity cannot get it for us.
At the end, we have to do this
Code: Select all
local x = position.x
local y = position.y
local arr = surface.find_entities_filtered{area = {{x - 0.1, y - 0.1}, {x + 0.1, y + 0.1}}, name = "item-request-proxy", force = force, limit = 1}
if #arr > 0 then
local item_request_proxy = arr[1]
-- We can finally work on the proxy!!
instead of the expected, clean way
Code: Select all
local item_request_proxy = surface.find_entity("item-request-proxy", position)
if item_request_proxy then
-- blah blah blah
end
We do this not just for item-request-proxy, but most of the time, we do this for our custom entities (e.g. combinator) with zero-sized collision box so players cannot select them in normal way.
Re: LuaSurface::find_entity returns no-collision entity
Posted: Sun Mar 05, 2017 7:36 pm
by Rseding91
You can't have both. An entity with zero sized collision box never collides with a single point (or anything else for that matter) and find_entity only searches a single point.
Either it does collide or it can't be found with entity_search.
Re: LuaSurface::find_entity returns no-collision entity
Posted: Mon Mar 06, 2017 12:42 pm
by Mooncat
Rseding91 wrote:You can't have both. An entity with zero sized collision box never collides with a single point (or anything else for that matter) and find_entity only searches a single point.
Either it does collide or it can't be found with entity_search.
hm... so find_entity(position) searches entity by checking collision... but why does find_entities(area) work?
I'm thinking of an API that really checks the positions of entities rather than collision for searching. Don't know whether it is possible on your side.
Re: LuaSurface::find_entity returns no-collision entity
Posted: Mon Mar 06, 2017 1:05 pm
by posila
Hm, I find to be strange inconsistency.
Entity has two collide() overloads:
Code: Select all
virtual bool collide(const BoundingBox& boundingBox) const
{
if (this->boundingBox.isZero())
return boundingBox.collide(this->position);
return this->boundingBox.collide(boundingBox);
}
Code: Select all
virtual bool collide(const RealPosition& position) const
{
return this->boundingBox.collide(position);
}
The second overload doesn't check for empty bounding box, but there might be some good reason for it.
Re: LuaSurface::find_entity returns no-collision entity
Posted: Fri Mar 24, 2017 6:21 pm
by Mooncat
Sorry to bother, but is someone investigating the inconsistency mentioned by Posila? Just asking.
Re: LuaSurface::find_entity returns no-collision entity
Posted: Fri Mar 24, 2017 6:47 pm
by Rseding91
Not currently.
Re: LuaSurface::find_entity returns no-collision entity
Posted: Fri Mar 24, 2017 7:12 pm
by Mooncat
OK. Will keep my eye on any update about this.
