Oh no. (I HAVEN'T EVEN LEARNT LUNALUA AND I'M ASKING HOW TO DO SOMETHING)

[erkyp3rky]

Hey, if you read the title, you might now know I've never used LunaLua because it's no secret to anybody that I can't code. Either that or I haven't really tried. Maybe both. I don't know. Anyways.

I've read in a few places that "Event fields" are possible in LunaLua, where you pass through a collision field and it triggers an event. I have no idea how to actually code, or code this. I also want it to happen once. This was supposed to be added in the new SMBX2 Beta 4 (I think.) but with the looks of that spreadsheet we'll be waiting until Half Life 3. for a while.

So, erm, who's first to step up and help a literal and metaphorical new-ster to coding?

[ElectriKong]

Currently using invisible axes with nogravity = 1 can be used (the event field NPC in beta 4 is intended to replace this) to do this without the use of lunalua. As for collision fields with LunaLua, I don't know.

If you want to be able to code though, then you can learn by following tutorials or taking online courses etc.

[Emral]

There's a pretty easy solution for this. It's not very flexible, but in small amounts this is a decent solution:

Code: Select all

local hasTriggeredMyEvent = false --make sure it only happens once

--edit these two
local triggerPosition = -199400 --position which needs to be passed. Imagine it as a vertical line.
local triggeredEvent = "myEvent" --name of the event

function onTickEnd() --check every frame after SMBX did its movement code
	if not hasTriggeredMyEvent then
		if player.x > triggerPosition then
			triggerEvent(triggeredEvent)
			hasTriggeredMyEvent = true
		end
	end
end

Essentially what this does is wait for the player to step past a certain boundary. If the boundary needs to be on seperate axes or a box, further checks can be added. Such as one for player.x < triggerPosition + triggerZoneWidth, or an equivalent to the two along the y-axis with seperate coordinates.
When doing that, though, it might be smart to wrap triggerPosition into a table:

Code: Select all

local myTrigger = {
	x=-199400,
	y=-200300,
	width=400,
	height=300,
	event="myEvent",
	triggered=false
}

function onTickEnd()
	if not myTrigger.triggered then
		if player.x + player.width > myTrigger.x
		and player.x < myTrigger.x + myTrigger.width
		and player.y + player.height > myTrigger.y
		and player.y < myTrigger.y + myTrigger.height
			then
			myTrigger.triggered = true
			triggerEvent(myTrigger.event)
		end
	end
end

You can even go a step further and automate it for an arbitrary number of trigger zones:

Code: Select all

local triggers = {}

local function addTrigger(x,y,w,h,event)
	return {
		x=x,
		y=y,
		width=w,
		height=h,
		event=event,
		triggered=false
	}
end

table.insert(triggers, addTrigger(-199400, -200300, 400, 300, "myEvent"))
table.insert(triggers, addTrigger(-192400, -209300, 800, 200, "myEvent2"))

function onTickEnd()
	for _, triggerZone in ipairs(triggers) do
		if not triggerZone.triggered then
			if player.x + player.width > triggerZone.x
			and player.x < triggerZone.x + triggerZone.width
			and player.y + player.height > triggerZone.y
			and player.y < triggerZone.y + triggerZone.height
				then
				triggerZone .triggered = true
				triggerEvent(triggerZone.event)
			end
		end
	end
end

That for loop will loop over any zones you have in the triggers table, and you just have to use the table.insert lines to add more.

The next more convenient step would be to make it so that the zones are defined through a placed sizeable which is set to hidden in onStart, but that requires a bit more lua knowledge and me just typing that out could get confusing very quickly. This should be good enough for now though.
If you have any questions about the code, don't hesitate to ask.

[erkyp3rky]

So, just double checking, where it specifies the event, do I put my event name in the speech marks?

Added in 2 hours 45 minutes 34 seconds:

There's a pretty easy solution for this. It's not very flexible, but in small amounts this is a decent solution:

Code: Select all

local hasTriggeredMyEvent = false --make sure it only happens once

--edit these two
local triggerPosition = -199400 --position which needs to be passed. Imagine it as a vertical line.
local triggeredEvent = "myEvent" --name of the event

function onTickEnd() --check every frame after SMBX did its movement code
	if not hasTriggeredMyEvent then
		if player.x > triggerPosition then
			triggerEvent(triggeredEvent)
			hasTriggeredMyEvent = true
		end
	end
end

Essentially what this does is wait for the player to step past a certain boundary. If the boundary needs to be on seperate axes or a box, further checks can be added. Such as one for player.x < triggerPosition + triggerZoneWidth, or an equivalent to the two along the y-axis with seperate coordinates.
When doing that, though, it might be smart to wrap triggerPosition into a table:

Code: Select all

local myTrigger = {
	x=-199400,
	y=-200300,
	width=400,
	height=300,
	event="myEvent",
	triggered=false
}

function onTickEnd()
	if not myTrigger.triggered then
		if player.x + player.width > myTrigger.x
		and player.x < myTrigger.x + myTrigger.width
		and player.y + player.height > myTrigger.y
		and player.y < myTrigger.y + myTrigger.height
			then
			myTrigger.triggered = true
			triggerEvent(myTrigger.event)
		end
	end
end

You can even go a step further and automate it for an arbitrary number of trigger zones:

Code: Select all

local triggers = {}

local function addTrigger(x,y,w,h,event)
	return {
		x=x,
		y=y,
		width=w,
		height=h,
		event=event,
		triggered=false
	}
end

table.insert(triggers, addTrigger(-199400, -200300, 400, 300, "myEvent"))
table.insert(triggers, addTrigger(-192400, -209300, 800, 200, "myEvent2"))

function onTickEnd()
	for _, triggerZone in ipairs(triggers) do
		if not triggerZone.triggered then
			if player.x + player.width > triggerZone.x
			and player.x < triggerZone.x + triggerZone.width
			and player.y + player.height > triggerZone.y
			and player.y < triggerZone.y + triggerZone.height
				then
				triggerZone .triggered = true
				triggerEvent(triggerZone.event)
			end
		end
	end
end

That for loop will loop over any zones you have in the triggers table, and you just have to use the table.insert lines to add more.

The next more convenient step would be to make it so that the zones are defined through a placed sizeable which is set to hidden in onStart, but that requires a bit more lua knowledge and me just typing that out could get confusing very quickly. This should be good enough for now though.
If you have any questions about the code, don't hesitate to ask.

The first one half works, however the event activates straight away. I don't have "autostart" ticked or anything like that either.

[Emral]

So, just double checking, where it specifies the event, do I put my event name in the speech marks?

Added in 2 hours 45 minutes 34 seconds:

long quote applause

The first one half works, however the event activates straight away. I don't have "autostart" ticked or anything like that either.

Have you replaced triggerPosition with the position you would like? You can grab a reliable position by right-clicking a block on the X-coordinate you want and going to "Copy Preferences -> Position X,Y". Then you can paste that into the triggerPosition variable and remove everything that isn't the x-coordinate.
Just to have this said too: the first one assumes that you're moving from left to right (as seen through the use of the ">" symbol). If you want your player to approach the x-coordinate where the trigger happens from the right, you'll need "<".
Also keep in mind that Section 1 is the leftmost section, while Section 21 is naturally further right than any other. If that's the problem but you still want the player to trigger it by approaching it from the left, you can add a section check (or use the third code snippit where you'd need to define entire bounding boxes).

With added section check:

Spoiler: show

Code: Select all

local hasTriggeredMyEvent = false --make sure it only happens once

--edit these two
local triggerPosition = -199400 --position which needs to be passed. Imagine it as a vertical line.
local triggeredEvent = "myEvent" --name of the event
local triggerSection = 0 --0 is Section 1, 1 is Section 2, 2 is Section 3 .... 20 is Section 21.

function onTickEnd() --check every frame after SMBX did its movement code
	if player.section == triggerSection and not hasTriggeredMyEvent then
		if player.x > triggerPosition then
			triggerEvent(triggeredEvent)
			hasTriggeredMyEvent = true
		end
	end
end

[erkyp3rky]

Got it to work. Thanks!

Added in 1 minute 2 seconds:
Just checking in, with the Width and Height segments, does 1 block amount to 100 or 1?

[Emral]

Got it to work. Thanks!

Added in 1 minute 2 seconds:
Just checking in, with the Width and Height segments, does 1 block amount to 100 or 1?

Width and height are measured in pixels, so the standard block dimensions are a width and height of 32. Long slopes have 64 width, loooooong slopes have 128, etc.

[erkyp3rky]

Got it to work. Thanks!

Added in 1 minute 2 seconds:
Just checking in, with the Width and Height segments, does 1 block amount to 100 or 1?

Width and height are measured in pixels, so the standard block dimensions are a width and height of 32. Long slopes have 64 width, loooooong slopes have 128, etc.

Thank you so much, works like a charm.