Game Loop Speed on Different Machines

In my game loop, I have it Sleep for 50ms on each loop so the speed is appropriate for my machine. However, when I install in on other machines, 50ms may be too fast or too slow.

I realize I can give the user a speed up/slow down capability, but my game really needs to be a "standard" speed, so it looks the same on each machine -- otherwise the game dynamic is thrown off.

So anyone have a recommended, tried and true way to do this before I start experimenting?

It depends on how many game ticks you want in a second, it seems that you want 20 (1000 / 50) so here's the code for that:

VB Code:

'Declare Function GetTickCount()
A = GetTickCount
Do
    B = GetTickCount
    If B - A >= 50 Then
        UpdateStuff
        A = GetTickCount
    End If
    DrawStuff
Loop

to help confuse matters you can use the below code for simple games:

Private Sub Form_Load()
Dim count As Double ' set up count
count2 = Timer ' count2 = timer function
For count = 1 To 1000000 ' count from 1 to 1000000
Next count ' then
Inter = Timer - count2 ' take count2 from timer and store it as tmrInterval
Inter = Inter * 400 ' times tmrInterval by 400
Timer1.Interval = Inter
MsgBox ("Game speed = " & Inter)
MsgBox ("player 1 controls = d:up c:down x:left v:right")
MsgBox ("player 2 controls = up:up down:down left:left right:right")
End Sub

The attatched file is a game i made for a pal to help him through his course!

My code is built for a DDraw loop..

Might wanna put that DrawStuff call into the If block. No need to redraw if nothing's been refreshed yet, and redrawing too often tends to slow yer comp a bit.. ;[

Actually that may slow down the program more. :/

And might I add this is direct draw (probably full-screen exclusive!!) so you redraw as quickly as you can.

Oh, I was thinking of BitBlt, which is what I'm using until I get off my lazy arse and learn DX X]

That's the verbose name for it. ^_^

Simply redraw as fast as you can, and in your game loop, do something like this:

Static LastTick as Long
Dim CurrentTick as Long, NextTime as Long, Framerate as Long
Framerate = 60 ' 60fps
CurrentTick = GetTickCount
If LastTick = 0 Then LastTick = CurrentTick
NextTime = LastTick + (1000 / (Framerate))
If CurrentTick >= NextTime Then
LastTick = CurrentTick
UpdateData ' Move all your sprites and stuff.
End If
Redraw ' Redraw.

Hi Janus

I see that you got my message on the RPGMaker forums (if you are that Janus :rolleyes: )

Thanks everyone! I only now have seen your replies since for some reason I no longer seem to get email notifications.

Hey Sas, you said RPGMaker forums? The web page doesn't seem to work, so I can't get to them :)

Can you give me a link or something?