So, I want to make guards that have attached lights. I also want the light to have different collision properties than the guard. My solution involves making a collection with the guards having subordinate lights.
Now I want to continually spawn these “lightguards” as entities in the game, but am having trouble implementing the factories. I’m using them as I use normal factories, and the following code (please point out anything stupid, even unrelated):
local frequency = 0.5
local min_y = -40
local max_y = 680
local min_x = -60
local max_x = 1020
local temp = 0
function init(self)
self.timer = 1/frequency
local props = {}
– make the game deterministic
math.randomseed(0)
end
function update(self, dt)
self.timer = self.timer - dt
if self.timer <= 0 then
self.timer = 1/frequency
local p = go.get_position()
temp = math.random(4)
if temp == 1 then
p.y = -20
p.x = vmath.lerp(math.random(), min_x, max_x)
elseif temp == 2 then
p.y = 660
p.x = vmath.lerp(math.random(), min_x, max_x)
elseif temp == 3 then
p.x = -20
p.y = vmath.lerp(math.random(), min_y, max_y)
elseif temp == 4 then
p.x = 1020
p.y = vmath.lerp(math.random(), min_y, max_y)
end
local rot = vmath.quat_rotation_z(math.pi / temp)
local self.enemy_id = collectionfactory.create(“#lightguard_spawn”, p, rot, nil, 1)
end
end
The error I get is for
local self.enemy_id = collectionfactory.create(“#lightguard_spawn”, p, rot, nil, 1)
saying
unexpected symbol near ‘.’
I’m sure I’m just doing something obviously stupid, but I don’t get the engine well enough yet to say what.
Also, a quick note on collectionfactory.create. you will get a table mapping the id:s from the collection to the new instance id:s as return value. Good to know if you want to, for example, delete all the objects from the spawned collection later on.
Looking forward to seeing your game, happy jamming!
ERROR:SCRIPT: guard/guard_spawn.script:37: expected table at argument #4 to collectionfactory.create
stack traceback:
[C]: in function ‘create’
guard/guard_spawn.script:37: in function <guard/guard_spawn.script:17>
I tried putting an actual table in place by making props actually used
Does anything happen to props between you declared it and the call to collectionfactory.create? Try printing it right before collectionfactory.create to make sure it’s still a table.
Regarding using slash / or pound #, there is more info on how game objects and components are assigned addresses (URLs) here: http://www.defold.com/doc/message-passing
Ah I see. That’s what you use the ‘self’ for. That is supposed to carry the ‘state’ of your script, and you use it just like a table. Local variables only live inside the scope they are declared in, in this case your init-function. I agree that your fix works fine (creating the table at the point of spawning), but for documentation-purposes this would work:
is the only way to really know! You might have forgotten to assign it to that variable before. There is also a debugger called zerobrane that lets you inspect the code, but printing is usually the fastest way.
Is the problem related to the guard object not knowing about the spawner’s table? Is there another way for guards to destroy their flashlight, themselves and nothing else?
Ah I see, yes, the self value is bound to the specific script in question. They could directly adress the game objects they want to delete. In the guard script:
go.delete() – implicitly deletes “this” game object
go.delete(“light”) – assuming the light sprite is attached to a game object called “light” in the spawned collection
You might have forgotten to assign it to that variable before. There is also a debugger called zerobrane that lets you inspect the code, but printing is usually the fastest way.
