I have a problem with lag

[matu]

First of all, i have not a perfect english, so sorry for my posible mistakes.

Hello, i'm new at Lua and LOVE2d and i'm starting with a practice (here's how i learn ) and when i was ending i programmed an animated background and when i started the game it was very lag(more than the last way i started the game). I used this codes for the animation:

Code: Select all

 function love.load()

 stageTime = 0
 stageState = "0"
 stage = none

 end
 function love.update(dt)
 
 --Animation's time--
 
 stageTime = stageTime + 1

  if stageState == 30 then
   stageState = 0 --This is cause i only made 30 pictures for the animation--
  end
  

--Animation's conf--

  if stageTime == 30 then
   stageState = stageState + 1
   stageTime = 0
  end

  stage = love.graphics.newImage("graphics/stage/stage"..tostring(stageState)..".png") --This line is that lags--

 end
 function love.draw()
--Animation drawing--
  love.graphics.draw(stage,0,0,0,0)

end

Can anyone tell me how to remove the lag please ?

[zorg]

Hi and welcome to the forums!

The gigantic yellow warning box on the page for love.graphics.newImage should tell you your mistake.

Also, do use the dt variable so that your thing runs consistently with regards to time.

[pgimeno]

And please use the support forum to post questions!

[sphyrth]

Woohoo! Now time for me to provide a sample solution of what to do instead:

Code: Select all

 function love.load()
  stageTime = 0
  stageState = "1"

  -- I'm replacing your "stage = none" with this:
  -- Step 1: (A table of stages)
  stages = {}
 
  -- Step 2: Insert all your 30 images in that table.
  for i = 1, 30 do
   table.insert(stages, love.graphics.newImage("graphics/stage/stage" .. tostring(i) .. ".png")
  end
 end

 function love.update(dt)
 
  --Animation's time--
  stageTime = stageTime + 1

  if stageState == 30 then
   stageState = 1 --This is cause i only made 30 pictures for the animation--
  end

  --Animation's conf--
  if stageTime == 30 then
   stageState = stageState + 1
   stageTime = 0
  end

  -- Now you no longer have to use this laggy thing:
  -- stage = love.graphics.newImage("graphics/stage/stage"..tostring(stageState)..".png")
  -- Instead, look at love.draw()
 end
 
 function love.draw()
  --Animation drawing--
  love.graphics.draw(stages[stageState],0,0,0,0)
 end

NOTE: I started with 1 instead of 0 because tables don't reference 0 values. So I guess you have to rename the images starting from "1" instead of "0".

[zorg]

And now that that happened, i can fix the above code so it:
- uses dt like it should
- uses locals like it should
- uses 0-based indexing so we can microoptimize a branch out (and you don't need to rename anything)

Code: Select all

local frameDelay, frameTime, currentFrame

function love.load()
	frameDelay   = 1/30 -- Animate with 30 frames per second
	frameTime    = 0.0
	currentFrame = 0 -- Start on the first frame

	-- A table of frames
	frame = {}

	-- Insert all 30 images into that table
	for i = 0, 29 do
		frame[i] = love.graphics.newImage("graphics/stage/stage" .. tostring(i) .. ".png")
	end
end

function love.update(dt)

	-- Time the animation
	frameTime = frameTime + dt

	if frameTime >= frameDelay then
		-- Wrap around the end
		currentFrame = (currentFrame + 1) % 30 -- number of frames
		-- Decrease time by the frame time
		frameTime = frameTime - frameDelay
	end

end

function love.draw()
	love.graphics.draw(frame[currentFrame],0,0,0,0)
end

NOTE: I started with 1 instead of 0 because tables don't reference 0 values. So I guess you have to rename the images starting from "1" instead of "0".

table methods indeed usually ignore what's at the 0th key (#, ipairs, etc. won't give "correct" results), but it's still fine to use it, both in terms of speed (thanks to luaJIT handling that) and the fact that there are ways to code around such limitations.

[matu]

Hi and welcome to the forums!

The gigantic yellow warning box on the page for love.graphics.newImage should tell you your mistake.

Also, do use the dt variable so that your thing runs consistently with regards to time.

I don't know how i haven't seen this.

[matu]

Woohoo! Now time for me to provide a sample solution of what to do instead:

Code: Select all

 function love.load()
  stageTime = 0
  stageState = "1"

  -- I'm replacing your "stage = none" with this:
  -- Step 1: (A table of stages)
  stages = {}
 
  -- Step 2: Insert all your 30 images in that table.
  for i = 1, 30 do
   table.insert(stages, love.graphics.newImage("graphics/stage/stage" .. tostring(i) .. ".png")
  end
 end

 function love.update(dt)
 
  --Animation's time--
  stageTime = stageTime + 1

  if stageState == 30 then
   stageState = 1 --This is cause i only made 30 pictures for the animation--
  end

  --Animation's conf--
  if stageTime == 30 then
   stageState = stageState + 1
   stageTime = 0
  end

  -- Now you no longer have to use this laggy thing:
  -- stage = love.graphics.newImage("graphics/stage/stage"..tostring(stageState)..".png")
  -- Instead, look at love.draw()
 end
 
 function love.draw()
  --Animation drawing--
  love.graphics.draw(stages[stageState],0,0,0,0)
 end

NOTE: I started with 1 instead of 0 because tables don't reference 0 values. So I guess you have to rename the images starting from "1" instead of "0".

Thanks, I know I'm supposed to know certain things about Lua (which I don't quite know) to start with love2d so thanks for the explicit information.

[matu]

NOTE: I started with 1 instead of 0 because tables don't reference 0 values. So I guess you have to rename the images starting from "1" instead of "0".

table methods indeed usually ignore what's at the 0th key (#, ipairs, etc. won't give "correct" results), but it's still fine to use it, both in terms of speed (thanks to luaJIT handling that) and the fact that there are ways to code around such limitations.

Thanks for clarifying that it is not necessary to rename the files, you saved me a lot of time.

[milon]

Hi and welcome to the forums!

The gigantic yellow warning box on the page for love.graphics.newImage should tell you your mistake.

Also, do use the dt variable so that your thing runs consistently with regards to time.

I don't know how i haven't seen this.

Are you referring to the dt variable, or love.graphics.newImage? Do you still have questions about it?

Thanks, I know I'm supposed to know certain things about Lua (which I don't quite know) to start with love2d so thanks for the explicit information.

I started that way too - jumping into Love without knowing Lua. It's okay - the people on this forum are awesome at helping out! Keep asking questions! You'll learn lots.