pausing messing up bullet acceleration

[ITISITHEBKID]

Pausing in my game messes up bullet acceleration. I know why, but I'm not sure how to fix it. It is happening because I calculate acceleration by using the formula (love.timer.getTime() - bullets creation time), but while the game is paused, love.Timer.getTime is still increasing, leading to bullets zooming away as soon as the game is unpaused. What can I do about this problem? I am using love 11.0. Included are useful code snippets and the .love file for my game.

Pausing the game:

Code: Select all

function love.keypressed(key)
	if key == "escape" then 
		if gamestate == "paused" then 
			gamestate = "playing"
		else
			gamestate = "paused"
		end
	end
end

Bullet acceleration code:

Code: Select all

for i=#bullets,1,-1 do
		b = bullets[i]
		local timedif = love.timer.getTime() - b.creation_time
		if gamestate == "playing" then 
			b.x = math.round(b.x + (b.dx * dt)* (timedif/3+0.6))
			b.y = math.round(b.y + (b.dy * dt)* (timedif/3+0.6))
		end
end

Note: when running the .love file you can use f1 to spawn more enemies

[ITISITHEBKID]

I accidentally uploaded this to general and not support and development, but I am not allowed to delete it. I apologize for this inconvenience.

[zorg]

You could try passing dt from love.update into your bullet acceleration code through the code path, and in that case, you'd just need to edit love.update to include something like this:

Code: Select all

function love.update(dt)
    if gamestate == 'paused' then return end
    -- do normal processing
    updateBullets()
    -- ...etc.
end

[ITISITHEBKID]

You could try passing dt from love.update into your bullet acceleration code through the code path, and in that case, you'd just need to edit love.update to include something like this:

Code: Select all

function love.update(dt)
    if gamestate == 'paused' then return end
    -- do normal processing
    updateBullets()
    -- ...etc.
end

This did not work for me, as love.timer.getTime() still increases

[pgimeno]

Using love.timer.getTime() is a weird way to go about this. But if you really want to do it that way, you could subtract the total pause time from the time, to compensate (untested):

Code: Select all

local pauseTime
local totalPauseTime = 0

function love.keypressed(key)
	if key == "escape" then 
		if gamestate == "paused" then 
			gamestate = "playing"
			totalPauseTime = totalPauseTime + (love.timer.getTime() - pauseTime)
		else
			gamestate = "paused"
			pauseTime = love.timer.getTime()
		end
	end
end

...

for i=#bullets,1,-1 do
		b = bullets[i]
		local timedif = love.timer.getTime() - totalPauseTime - b.creation_time
		if gamestate == "playing" then 
			b.x = math.round(b.x + (b.dx * dt)* (timedif/3+0.6))
			b.y = math.round(b.y + (b.dy * dt)* (timedif/3+0.6))
		end
end

[ITISITHEBKID]

Using love.timer.getTime() is a weird way to go about this. But if you really want to do it that way, you could subtract the total pause time from the time, to compensate (untested):

I only used love.timer.getTime() because it's what I thought of. A better way to do it would be great!

[zorg]

This did not work for me, as love.timer.getTime() still increases

Of course it does.

Apologies, it seems i missed the most important statement in my previous post;

Instead of using love.timer.getTime, You could try passing dt from love.update into your bullet acceleration code through the code path, and in that case, you'd just need to edit love.update to include something like this: <Code from my previous post>

Because the dt parameter in love.update is basically the same value you get from love.timer.getTime; if you don't call update code there, nothing will change, which is what you want... more or less.

[pgimeno]

I have taken a look at the full code and I'm finding it difficult to understand what you're trying to do with the different patterns. At first sight it appears that it's intended to apply an acceleration to the bullets, as if they were missiles. Is that it?

If so, the simplest way to apply acceleration is to add the acceleration times dt to the velocity. Something of this kind (which is just schematic, not adapted to your code):

Code: Select all

  vx = vx + ax * dt
  vy = vy + ay * dt
  x = x + vx * dt
  y = y + vy * dt

To adapt that to your code, you probably need to add a current acceleration variable in the bullets, which should have the same direction (cos/sin) times an acceleration that depends on the pattern.

[ITISITHEBKID]

I have taken a look at the full code and I'm finding it difficult to understand what you're trying to do with the different patterns. At first sight it appears that it's intended to apply an acceleration to the bullets, as if they were missiles. Is that it?

Yes, bullets have acceleration. I am implementing your changes now.

[ITISITHEBKID]

I have implemented the changes, but it still does not work properly.