Frame Rate Questions

[MarekkPie]

Depending on his system speed, just flooring dt might skip or repeat frames and whatnot. For example, an average dt of 1.5 would give him:

You know, if dt is 1.5, you have an FPS of 0.67. Skipping frames is not your worst problem then.

It's a made up number to illustrate a point.

[Robin]

And I used math to show the point is moot.

[MarekkPie]

Well, flooring a number less than 1 would also give you a problem as an index. That is unless we really like the first frame.

[Robin]

Not really, look at what I wrote earlier:

You could use dt.

Code: Select all

function A()
  return array[math.floor(index)] -- this is the trick that makes it work
  -- it rounds index to the nearest smaller-or-equal integer.
end

function love.update(dt)
  index = index + dt * speed
end

See math.floor for more information.

It is not stored as an integer, this works. Everyone uses this, all the time.

[MarekkPie]

From my understanding of his initial question, he has an array that represents the images of his jump animation (either as individual images or quads for spritesheets). He needs to cycle through that array in numerical order, and he needs to have the index change every time dt appears (aka once every call of love.update(dt)).

Code: Select all

index = 0
speed = -- whatever

function love.update(dt)
  index = index + speed * dt
  print(math.floor(index))
end

Clearly this doesn't update the array after every update call. It will update the array, it may even do it in numerical order, but it doesn't do every time love.update(dt) is called.

Again, like I said in another post, my brains hurting due to RL issues, so I may have misunderstood the question, or maybe your method of calculating the jump frames is better. But I think that method won't work for my understanding of his question.

[Nixola]

I think you have understood the question, but if someone on a fast PC plays this without dt, he may not see the animation or see it too quick, and I may see it veeeery slow; that's why delta has to be called, and that's why LÖVE developers put delta in LÖVE

[MarekkPie]

Oh...duh...

/hides

[Nixola]

You don't have to hide , he asked how to do it without dt

[MarekkPie]

I'm hiding because I made a very similar point on these forums to someone else and I fall into the same trap.

[verilog]

Hey guys,
Thanks for your posts; the matter is looking much clearer to me now. However, I’ve one final question. If I lock the FPS speed, wouldn’t that set a fixed execution speed for the game regardless of the user's CPU speed?