Allow multiple collision listeners per entity, for all instances, regardless of old ent:PhysicsCollide()

[legokidlogan]

Similar to #1865, but allows entities that already have :PhysicsCollide() from glua to still have starfall collision listeners. Also allows for different chip instances to have their own listeners on the same entity.

Bonus side effect due to how addCollisions() was reworked: previously, if two entities had collision listeners, any time either of them made a collision, it would call both listeners, resulting in callbacks being called for the collisions of entities they weren't associated with. This issue is now resolved with the rewrite.

[legokidlogan]

@thegrb93 I've left a TODO note commenting on addCollisions(). Do we really need a one-tick delay before any and all processing collision listeners, and if so, why?

I know that using SetVelocity on players can result in no change and creating entities can result in collisions regardless of group, if either are done from inside the collision listener, but is there a crash exploit or some other critical issue the delay fixes? Or is it to guarantee a 1-tick delay so that players don't encounter and fix those aforementioned odd behaviors themselves?

[thegrb93]

This needs to be coalesced into a class. The current implementation is way too fragmented and messy.

[thegrb93]

Should also co-author @proton0va

[thegrb93]

I have time to class-ify it right now, so I can do that.

[thegrb93]

It's working now. Mind testing it out?

[legokidlogan]

starfall/libs_sv/entities.lua:144: attempt to call method 'exists' (a nil value)
stack traceback:
	starfall/libs_sv/entities.lua:144: in function 'add'
	starfall/libs_sv/entities.lua:525: in function 'addCollisionListener'
	SF:main:14: in main chunk

[legokidlogan]

Using these to test:

--@name 1
--@author
--@server

--prop.setPropClean( false )

local ent = prop.create( chip():getPos() + Vector( 0, 0, 50 ), Angle(), "models/hunter/blocks/cube025x025x025.mdl", false )
ent:setColor( Color( 255, 0, 0, 255 ) )

ent:addCollisionListener( function()
    print( "1 listener a" )
end, "a" )

ent:addCollisionListener( function()
    print( "1 listener b" )
end, "b" )

ent:addCollisionListener( function()
    print( "1 listener ?1" )
end )

ent:addCollisionListener( function()
    print( "1 listener ?2" )
end )


timer.simple( 1.5, function()
    print( "1 removed b" )

    ent:removeCollisionListener( "b" )
    ent:getPhysicsObject():setVelocity( Vector( 0, 0, 100 ) )
    
    timer.simple( 1.5, function()
        print( "1 removed all" )
    
        ent:removeCollisionListener()
        ent:getPhysicsObject():setVelocity( Vector( 0, 0, 100 ) )
        
        timer.simple( 1.5, function()
            print( "1 added a" )
        
            ent:addCollisionListener( function()
                print( "1 listener a" )
            end, "a" )

            ent:getPhysicsObject():setVelocity( Vector( 0, 0, 100 ) )
        end )
    end )
end )

--@name 2
--@author
--@server

local ent = find.byModel( "models/hunter/blocks/cube025x025x025.mdl" )[1]
ent:setColor( Color( 0, 255, 0, 255 ) )

ent:addCollisionListener( function()
    print( "2 listener a" )
end, "a" )

ent:addCollisionListener( function()
    print( "2 listener b" )
end, "b" )

ent:addCollisionListener( function()
    print( "2 listener ?1" )
end )

ent:addCollisionListener( function()
    print( "2 listener ?2" )
end )


timer.simple( 1.5, function()
    print( "2 removed b" )

    ent:removeCollisionListener( "b" )
    ent:getPhysicsObject():setVelocity( Vector( 0, 0, 100 ) )
    
    timer.simple( 1.5, function()
        print( "2 removed all" )
    
        ent:removeCollisionListener()
        ent:getPhysicsObject():setVelocity( Vector( 0, 0, 100 ) )
        
        timer.simple( 1.5, function()
            print( "2 added a" )
        
            ent:addCollisionListener( function()
                print( "2 listener a" )
            end, "a" )

            ent:getPhysicsObject():setVelocity( Vector( 0, 0, 100 ) )
        end )
    end )
end )

[thegrb93]

Did you 'git pull'? The exists function was added in sflib.lua

[legokidlogan]

Yes, I did. You never defined exists in the listener metatable.

[legokidlogan]

Never mind, the copy in my addons folder was out of date across the other files.

[legokidlogan]

Everything seems to be working except for ent:removeCollisionListener() with no arguments. It correctly removes unnamed listeners, but not the named ones.

[legokidlogan]

Also, adding an unnmaed listener will incorrectly override existing unnamed listeners, instead of adding to the list.

[thegrb93]

I changed the behavior so that calling without a name argument uses '""' instead adding/removing an array of listeners. This behavior is easier to manage.

[legokidlogan]

Ah. Alright then.