Adapting Movement to Delta-time

[Chrille]

I've decided to implement delta-time to my game, but I can't think of a good way to adapt my current movement system to it and was hoping someone might have a solution.

My character moves in a straight line from the starting point to the destination, the movement time is calculated by distance/character speed. Here's what the code for setting the screen coordinates look like:

Always:
X = starting point.X + (moveDistance.X * (step / moveTime))
Y = starting point.Y + (moveDistance.Y * (step / moveTime))
step ++

I went for this half-assed solution in lack of any better ideas:

+ Always:
- Counter = Counter + (30 * deltaTime)
- X = starting point.X + (moveDistance.X * (step / moveTime))
- Y = starting point.Y + (moveDistance.Y * (step / moveTime))

+ Counter is greater than 1
- step ++
- Counter = 0

That solution works as long as I don't set the frame rate too low, but it doesn't feel like right way to go. Very grateful for any suggestions.

[J3sseM]

The way I do it is that I have two global values, one I call: deltaspeed and one is deltatime.

Always -> set deltatime to (deltaspeed/1.0)/(framerate/1.0)
Basically I can now adjust the speed of the game with deltaspeed (as long as I use deltatime in my code)

My character has a value pos_x and I have an event:

Always -> set position x to pos_x

And when I move I simply do: Add 3*(deltatime*60) to pos_x

My framerate is 60. This works really well even with LOW fps as it always adds to value.

Not sure if you can use this somehow but thought I'd share it anyway!

[Chrille]

Thanks for sharing. I use an example that tompa shared, with the formula of:

+ Always
- deltatime = (timer - timerLastValue) * 0.001
- timerLastValue = timer

I realised I could use "step = step + (deltatime *30)" instead. Well, I had some problems since I'm storing all the values in an array, and it doesn't support float variables. I had to multiply the value added by 1000 when writing, and dividing by 1000 when reading. It works quite well now, but it still chops along quite inconsistently at lower frame rates. Not that I'm aiming for it to ever drop down below 20