Why does this snippet of code eat my CPU?

[zwzsg]

I can see how mouse press can be get by event, but not how you can add your own time's up event.

[aegis]

Code: Select all

local pressed = -1
function widget:MousePress()
    pressed = clock()
end
function widget:MouseRelease()
    pressed = -1
end
function widget:Update()
    if (pressed >= 0) and (clock() - pressed > 0.25) then
        fire()
        -- option 1: don't shoot until clicked again
        pressed = -1
        -- option 2: shoot again after timeout
        -- pressed = clock()
    end
end

[zwzsg]

So that widget:Update() is not a polling?

[aegis]

it's not polling the mouse state I don't think spring has an event for "x amount of time passed"

compare my code to regret's. mine pretty much doesn't do *anything* unless a single variable is set.

his full polling method uses four lasting variables, calls GetMouseState to set five variables, then runs through a mess of if statements <_<

[Regret]

Code: Select all

local pressed = -1
function widget:MousePress()
    pressed = clock()
end
function widget:MouseRelease()
    pressed = -1
end
function widget:Update()
    if (pressed >= 0) and (clock() - pressed > 0.25) then
        fire()
        -- option 1: don't shoot until clicked again
        pressed = -1
        -- option 2: shoot again after timeout
        -- pressed = clock()
    end
end

You forgot specific mouse button checks

Also polling in this case has ~0 impact on performance, as do the 2 extra ifs and/or variables used, but yea congratulations.

[aegis]

was an example for zwzsg, not for caydr
the point was cleanness

[Caydr]

Code: Select all

local midclicktimer --placeholder
local pm1,pm2,pm3 --placeholder
function widget:Update()
	local _,_,m1,m2,m3 = Spring.GetMouseState() --get mouse button status
	if (m2 and (not pm2)) then --is pressed and was not pressed before == was pressed right now
		midclicktimer = os.clock() + 0.25 --initialize timer
	end
	if (midclicktimer ~= nil) then --timer initialized?
		if (m2) then --is button still pressed?
			if (os.clock() >= midclicktimer) then --enough time passed?
				midclicktimer = nil --reset timer
				yourfunction() --do shit
			end
		else --nope
			midclicktimer = nil --reset timer
		end
	end
	pm1,pm2,pm3 = m1,m2,m3 --remember last mouse state
end

I think this is exactly what I needed, I'll give it a try later. Thanks as always.

I think that basically the brick wall I was hitting was my assumption that widgets are run parallel, as would seem pretty sensible. But that's just me, the guy that thinks a "wait" shouldn't be interpreted as "stall user's computer" and the game shouldn't allow sloppy programming to be able to damage my hardware.

[aegis]

we said several times that widgets didn't run in parallel and sleeping blocks the main thread

[zerver]

ye, polling is only good if there is no suitable interrupt, or if the interrupt is 'unreliable'

[lurker]

While loops are not waits, calls to sleep() are waits.

Just think about if for a bit and you see that spring has to let gadgets complete to not desync, spring has to let widgets in draw calls complete or corrupt the screen, spring has to not change while lua is doing anything with a loop of units or they'll crash horribly on random days, there is just no way to make lua wait without an explicit sleep() function. sleep could be added, but it's not at all what you were doing.