Need to make a gradually speeding up loop. [SOLVED]

Solar2D Lua Language
#1

Hi! I’m making my first project with corona right now. I have everything working so far, but I just need to find out one thing: how can I make a slowly speeding up loop? I just need any kind of loop that executes a function , and it keeps happening faster and faster.

For instance, it will execute the function every 3000 ms. Every time it executes, though, it goes down by 10 ms.

I’ve made a sleep function from code online but all that does is freezes the program, which I don’t want. I’ve also tried timer.performWithDelay using “enterFrame” but that instantly reaches huge speeds.

Can anyone help me? 

#2

This code prints out using timer.performWithDelay() starting at every 1000ms delay and dropping to 100 and exiting at 0:

local tm = {count=0} local function handleit(event) print(event.name..event.time) tm.count = tm.count + 1 if tm.count == 10 then print"timer reset" tm.count = 0 tm["timer"]= nil tm:set\_timer() end end function tm:set\_timer() if self.speed == nil then self.speed = 1000 print("timer start speed 1000") elseif self.speed == 0 then print "done" return else self.speed = self.speed - 100 print("new timer speed: "..self.speed) end self["timer"] = timer.performWithDelay(self.speed, handleit, 10) end tm:set\_timer()

Edit: 

I cleaned up the code a little.

I made sure to set the expired timer table entry to nil before creating a new one.  

I think without that there might have been a memory leak.  

#3

Here is another method. This one uses two timers. 

The first timer called print_timer acts as the loop and prints the event.name and event.time to the console. 

The second timer called speed_timer is used to gradually decrease the delay in print_timer causing it to fire events faster. 

local print\_timer = nil local speed\_timer = {speed = 1010} local function handle\_print\_timer(event) print(event.name.." "..event.time) end local function handle\_speed\_timer(event) speed\_timer.speed = speed\_timer.speed - 10 if speed\_timer.speed \<=0 then timer.cancel(speed\_timer["timer"]) speed\_timer["timer"] = nil speed\_timer.speed = 1 print("Maximum speed set") end if print\_timer ~= nil then timer.cancel(print\_timer) print\_timer = nil end print\_timer = timer.performWithDelay(speed\_timer.speed, handle\_print\_timer, 1000) print("Speed changed to: "..speed\_timer.speed) end speed\_timer["timer"] = timer.performWithDelay(2000, handle\_speed\_timer, 1000 )

In the code I have set a maximum iterations for each timer. This is only so it didn’t run constantly during testing.   

The speed timer is set to change the speed every 2 seconds. 

The print timer begins printing events at a rate of 1 per second. So you will see two printed timer events between speed changes until the delay drops to about 650. Then the print timer will start printing 3 events for every speed change. And then obviously this grows as the delay drops.  

When the delay drops below 0, I set the print timer speed to 1 and remove the speed timer.  This will give you maximum speed from the timer. 

#4

Not wanting to miss out, this is my 2-cents.

local resetOnMin = true local maxPeriod = 5000 local minPeriod = 60 local periodDelta = 100 local lastT = system.getTimer() local curPeriod = maxPeriod local function work() print("Period: " .. tostring(curPeriod) .. " @ " .. tostring(system.getTimer()) ) end local function enterFrame() local curT = system.getTimer() local dt = curT - lastT -- if( dt \< curPeriod ) then return end lastT = curT -- work() -- curPeriod = curPeriod - periodDelta if( curPeriod \< minPeriod ) then if( resetOnMin ) then curPeriod = maxPeriod else curPeriod = minPeriod end end end; Runtime:addEventListener( "enterFrame", enterFrame )
#5

And a timer variant:
 

local proxy = {} proxy.resetOnMin = true proxy.maxPeriod = 5000 proxy.minPeriod = 60 proxy.periodDelta = 100 proxy.curPeriod = maxPeriod local function work() print("Period: " .. tostring(proxy.curPeriod) .. " @ " .. tostring(system.getTimer()) ) end function proxy.timer( self ) work() -- self.curPeriod = self.curPeriod - self.periodDelta -- if( self.curPeriod \< self.minPeriod ) then if( self.resetOnMin ) then self.curPeriod = self.maxPeriod else self.curPeriod = self.minPeriod end end timer.performWithDelay( self.curPeriod, self ) end; timer.performWithDelay( proxy.curPeriod, proxy )
#6

Thank you both so much for the help! I’ve been waiting a month to get this project done, I had a great idea and I couldn’t finish this without the loop. 

#7

This code prints out using timer.performWithDelay() starting at every 1000ms delay and dropping to 100 and exiting at 0:

local tm = {count=0} local function handleit(event) print(event.name..event.time) tm.count = tm.count + 1 if tm.count == 10 then print"timer reset" tm.count = 0 tm["timer"]= nil tm:set\_timer() end end function tm:set\_timer() if self.speed == nil then self.speed = 1000 print("timer start speed 1000") elseif self.speed == 0 then print "done" return else self.speed = self.speed - 100 print("new timer speed: "..self.speed) end self["timer"] = timer.performWithDelay(self.speed, handleit, 10) end tm:set\_timer()

Edit: 

I cleaned up the code a little.

I made sure to set the expired timer table entry to nil before creating a new one.  

I think without that there might have been a memory leak.  

#8

Here is another method. This one uses two timers. 

The first timer called print_timer acts as the loop and prints the event.name and event.time to the console. 

The second timer called speed_timer is used to gradually decrease the delay in print_timer causing it to fire events faster. 

local print\_timer = nil local speed\_timer = {speed = 1010} local function handle\_print\_timer(event) print(event.name.." "..event.time) end local function handle\_speed\_timer(event) speed\_timer.speed = speed\_timer.speed - 10 if speed\_timer.speed \<=0 then timer.cancel(speed\_timer["timer"]) speed\_timer["timer"] = nil speed\_timer.speed = 1 print("Maximum speed set") end if print\_timer ~= nil then timer.cancel(print\_timer) print\_timer = nil end print\_timer = timer.performWithDelay(speed\_timer.speed, handle\_print\_timer, 1000) print("Speed changed to: "..speed\_timer.speed) end speed\_timer["timer"] = timer.performWithDelay(2000, handle\_speed\_timer, 1000 )

In the code I have set a maximum iterations for each timer. This is only so it didn’t run constantly during testing.   

The speed timer is set to change the speed every 2 seconds. 

The print timer begins printing events at a rate of 1 per second. So you will see two printed timer events between speed changes until the delay drops to about 650. Then the print timer will start printing 3 events for every speed change. And then obviously this grows as the delay drops.  

When the delay drops below 0, I set the print timer speed to 1 and remove the speed timer.  This will give you maximum speed from the timer. 

#9

Not wanting to miss out, this is my 2-cents.

local resetOnMin = true local maxPeriod = 5000 local minPeriod = 60 local periodDelta = 100 local lastT = system.getTimer() local curPeriod = maxPeriod local function work() print("Period: " .. tostring(curPeriod) .. " @ " .. tostring(system.getTimer()) ) end local function enterFrame() local curT = system.getTimer() local dt = curT - lastT -- if( dt \< curPeriod ) then return end lastT = curT -- work() -- curPeriod = curPeriod - periodDelta if( curPeriod \< minPeriod ) then if( resetOnMin ) then curPeriod = maxPeriod else curPeriod = minPeriod end end end; Runtime:addEventListener( "enterFrame", enterFrame )
#10

And a timer variant:
 

local proxy = {} proxy.resetOnMin = true proxy.maxPeriod = 5000 proxy.minPeriod = 60 proxy.periodDelta = 100 proxy.curPeriod = maxPeriod local function work() print("Period: " .. tostring(proxy.curPeriod) .. " @ " .. tostring(system.getTimer()) ) end function proxy.timer( self ) work() -- self.curPeriod = self.curPeriod - self.periodDelta -- if( self.curPeriod \< self.minPeriod ) then if( self.resetOnMin ) then self.curPeriod = self.maxPeriod else self.curPeriod = self.minPeriod end end timer.performWithDelay( self.curPeriod, self ) end; timer.performWithDelay( proxy.curPeriod, proxy )
#11

Thank you both so much for the help! I’ve been waiting a month to get this project done, I had a great idea and I couldn’t finish this without the loop.