game Lua scripting - using couroutine or polling? - lua

Question

I am starting to learn how to use Lua scripting for different game profile with logitech software.
First I tried to use onevent (I know it isn't very advanced) and created this attack combo script
function OnEvent(event, arg)
if event == "MOUSE_BUTTON_PRESSED" and arg == 1 then --set flag for mb1
mb1_pressed = true
elseif event == "MOUSE_BUTTON_RELEASED" and arg == 1 then --set flag for mb1=false
mb1_pressed = false
end
end
if mb1_pressed then --using flags to determine whether to start attack or not
repeat
presskey("A")
Sleep(50)
releasekey("A")
Sleep(100)
--if MB1 is release, it will also break script. if i only tap mb1, this will only execute the first line of attack without the rest below
if not (**argument**, can be MB1/ismouse1) then break end
presskey("S")
Sleep(50)
releasekey("")
Sleep(120)
presskey("A")
Sleep(50)
releasekey("A")
Sleep(200)
if not (**argument**, can be MB1/ismouse1) then break end --if MB1 is release, it will also break script. this point will prevent script from looping from start if mb1 release
until not (**argument**, i use ismouse1) --end the loop of script
end
So I am trying to bind this to G6 button of my logiech mouse (using mouse_button_press == 6)
Setting a flag with MB6 works, but ending a loop/breaking a loop cannot be triggered by MB6
After some research on SDK/Lua forum of logitech support, it seems that there is a problem with my script
Flags cannot be used/detect as an argument while a script is performing a loop sequence
IsMouseButtonPressed (reads windows keypress) can be used in place or arguments
Windows only detects MB1-5, so binding to G6 is not possible (registers as 6th button)
I read that using couroutine.yield() or polling can be used for stopping repeat scripts in loop. But I cannot find a tutorial for beginners online.
Sorry for the noobish question!

Answer 1

I don't know anything about Logitech mice so I will try to explain things using a simplified, pure Lua example. Lets model the autoattack script as a loop that prints "A" and "B" alternatively. The "A" corresponds to the first part of your loop (press and release A) and the "B" represents the second part (press and release S and A).
function autoattack()
while true do
print("A")
print("B")
end
end
autoattack()
So far we are OK but the loop will obviously run forever and we need to add a way to stop it. I think what you are trying to do is something along the lines of:
local autoattacking = false
function autoattack()
autoattacking = true
while true do
print("A")
if not autoattacking then break end
print("B")
if not autoattacking then break end
end
end
function stop_autoattack()
autoattacking = false
end
autoattack()
stop_autoattack()
However, since autoattack is an infinite loop, stop_autoattack never runs and the autoattacking flag never gets updated. How can we fix this?
Polling
Instead of calling a function and setting a flag to stop the loop, what if we could call some code to see if the loop should be stopped or not?
function continue_autoattack()
print("continue autoattacking? y/n")
return (io.read("*l") == "y")
end
function autoattack()
while true do
print("A")
if not continue_autoattack() then break end
print("B")
if not continue_autoattack() then break end
end
end
autoattack()
In your mouse this would probably mean using some sort of isKeyPressed function, if its available in the API. Its also important to note that the autoattack loop is still an infinite loop - its just that we changed it so it is in control of its stopping condition.
Coroutines
If we want to keep the code to stop the loop outside the loop we will need a way to run the autoattack loop one step at a time. Here is an example:
local state = 1
function autoattack_step()
if state == 1 then
print("A")
state = 2
elseif state == 2
print("B")
state = 1
elseif state == 3
print("STOPPED")
--state remains as 3
else
error("bad state") -- defensive programming; I hate if/elseif without an else
end
end
function stop_autoattack()
state = 3
end
autoattack_step()
autoattack_step()
autoattack_step()
stop_autoattack()
autoattack_step()
Since we broke up the autoattack loop, we now have a chance to call stop_autoattack between calls to autoattack_step. To do this in your mouse script, I think stop_autoattack can go in "release button" handlers but I dont know where I would put the autoattack_step calls. Maybe the API includes something similar to setTimeout or setInterval in Javascript.
As for coroutines, where do they come in? Did you notice how we needed to do some substantial code refactoring to break the loop into single step chunks for autoattack_step? Coroutines are a Lua feature that lets you write code using loops while still being able to run them "one step at a time". When a coroutine reaches a coroutine.yield, it returns back to its caller. The thing is that when you call coroutine.resume again the coroutine will continue executing from where it stopped instead of going back to the start like a normal function would.
local autoattacking = true
autoattack = coroutine.create(function()
while true do
print("A")
coroutine.yield()
if not autoattacking then break end
print("B")
coroutine.yield()
if not autoattacking then break end
end
end)
function stop_autoattack()
autoattacking = false
end
coroutine.resume(autoattack)
coroutine.resume(autoattack)
coroutine.resume(autoattack)
stop_autoattack()
coroutine.resume(autoattack)
coroutine.resume(autoattack)
Very often, coroutines let you keep code more readable, without turning inside out with lots of explicit "state" variables. We still need to have some "higher up" code calling coroutine.resume though, just like we needed to have some higher level code calling autoattack_step.

Answer 2

Ok, so specific to Logitech's implementation of lua in the Logitech Gaming Software suite, you need to use polling.
Once you press a G-key (mouse, pad or keyboard) the OnEvent() function is called. Once inside on event no new OnEvent() events can be called until you exit, your process will become 'stuck' in any loop (as it can't exit the loop, it can't exit the OnEvent() call.
What you need is an interrupt to poll for.
There are three:- IsMouseButtonPressed( button), IsMKeyPressed( key ), IsModifierPressed( modifier ).
If you want your routiene to run while you hold the (any specified) mouse button, you can use IsMouseButtonPressed(n) thus:-
while IsMouseButtonPressed(n) do
doStuff()
end
If you wish to to say, have a toggle switch to start firing (ie: to auto-press a mouse button), then you have to use one of the other two available interrupts, ie:-
PressMouseButton(n);
while not IsModifierPressed("ctrl") do
doStuff()
end
Here your loop will run until you hold down the ctrl key. So not a puristic toggle switch (a G-key to turn on and ctrl to turn off), but passable I believe.
Note:- after further playing, er, testing, I have found IsMouseButtonPressed(n) is independent of PressMouseButton(n), rather this is read from the i/o device, so you can use IsMouseButtonPressed as the interrupt for auto-mouse pressing.
Using a G-Key to kick the action off and a mouse click to interrupt (end) the action , (or you could use both mouse and/or modifier).