Help with the Timer() statement please...

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mbaucco

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Posted: 19th Jun 2007 21:09

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I am trying to rotate a cube at a constant rate using the following code:

+ Code Snippet

Rem Project: texture01
Rem Created: 6/19/2007 11:10:47 AM

Rem ***** Main Source File *****
Set Display Mode 1280, 1024, 32

nTime = Timer()

Load Image "textureWood.jpg", 1
Load Image "eyecol.jpg", 2

Make Object Cube 1, 40

Texture Object 1, 2

Position Object 1, 25, 0, 100

Do
   nElapsed = (Timer()- nTime)
   If nElapsed = 250
      Turn Object Left 1, 90.0
      nElapsed = 0
      nTime = Timer()
   Endif
Loop

End

For some reason this does nothing, but the same code without the 3d commands works fine. Can anyone help? Here is the code without the 3d:

+ Code Snippet

Set Display Mode 1280, 1024, 32

nTime = Timer()

Do
   nElapsed = (Timer()- nTime)
   If nElapsed = 250
      Print "tick"
      nElapsed = 0
      nTime = Timer()
   Endif
Loop

End

Thanks,
Matt

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TDK

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Posted: 19th Jun 2007 21:13

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Try updating the 3D screen with the Sync On and Sync commands.

TDK_Man

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Cloggy

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Posted: 19th Jun 2007 22:24 Edited at: 19th Jun 2007 22:24

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The problem is you are rotating the cube by 90 degrees each time so it never looks like it is moving.

Set it to 10.0 and you see it rotate.

+ Code Snippet

Rem Project: texture01
Rem Created: 6/19/2007 11:10:47 AM

Rem ***** Main Source File *****
Set Display Mode 1280, 1024, 32

nTime = Timer()

Load Image "textureWood.jpg", 1
Load Image "eyecol.jpg", 2

Make Object Cube 1, 40

`Texture Object 1, 2

Position Object 1, 25, 0, 100

Do
   nElapsed = (Timer()- nTime)
   If nElapsed = 250
      Turn Object Left 1, 10.0
      nElapsed = 0
      nTime = Timer()
   Endif
Loop

End

D3DFunc - Superfast Antialiased text & much much more

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mbaucco

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Posted: 19th Jun 2007 22:49

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Thanks for the replies but neither suggestion helped I'm afraid. I just don't understand why the code would work without the 3d commands but not work with them in it.

Thanks,
Matt

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Gil Galvanti

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Posted: 20th Jun 2007 00:47

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Change "If nElapsed = 250" to "If nElapsed => 250", because the timer won't always (and rarely will) be exactly equal to 250 at the time it hits that if statement.

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Cloggy

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Posted: 20th Jun 2007 01:27

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Maybe you should try a completely different tack. This has code borrowed from someone else (Nicholas Thompson I think).

It is a much better method for timer based movement.

+ Code Snippet

Rem Project: texture01
Rem Created: 6/19/2007 11:10:47 AM

Rem ***** Main Source File *****
Set Display Mode 1280, 1024, 32

Load Image "textureWood.jpg", 1
Load Image "eyecol.jpg", 2

Make Object Cube 1, 40

`Texture Object 1, 2

Position Object 1, 25, 0, 100

frameTime# = 1.0
startTime = timer()

do
   frameTime# = (frameTime# * 0.8) + ((timer() - startTime) * 0.2)
   startTime = timer()
   Turn Object Left 1, .2*frameTime#
Loop

You multiply all your movements by frameTime#. That way they remain constant regardless of PC speed.

Hope this helps.

D3DFunc - Superfast Antialiased text & much much more

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Cash Curtis II

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Posted: 20th Jun 2007 09:59 Edited at: 20th Jun 2007 10:03

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Here is a method that takes less math per loop.

+ Code Snippet

sync on

Make Object Cube 1, 40


timeStamp#=0
Rem 10 is degrees per second, we divide by 1000 to get degrees per millisecond
speed#=100.0/1000.0	
do
   time=timer()

    timeFrame#=timeStamp#*speed#
    Turn Object Left 1, timeFrame#
   
   set cursor 0,10:print screen fps():print "Space to slow down framerate but maintain speed":if spacekey() then wait 3
   sync
   timeStamp#=timer()-time
Loop

It's set up to spin the cube 100 degrees per second.

Come see the WIP!

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mbaucco

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Posted: 20th Jun 2007 17:32

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Thank you all very much for the help! I ended up using the solution Cash offered and it works perfectly.

-Matt

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Cash Curtis II

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Posted: 21st Jun 2007 04:22

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Cool

Be sure and put this

Quote: "timeStamp#=timer()-time"

under your Sync statement or it won't work right. Also, I made 'timeStamp#' a global variable so that I can access it anywhere in the program.

I use timer control for everything - movement, rotation, animation. I'd never do it any other way.

Come see the WIP!

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Cash Curtis II

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Posted: 21st Jun 2007 16:20

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@WindowsKiller -
Yes, I am well aware of that. If you look at the line that it's used, it's used with all floating point numbers. I can recast it once, when I calculate timeStamp#, or I can recast it every single time I use it in an equation. I use it hundreds of times per loop, hundreds of integer to float casts wouldn't be very smart.

Come see the WIP!

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jason p sage

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Posted: 25th Jun 2007 05:01

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Timer Based is THE ONLY way to go.

I just got back into DBPro and my first halfway decent creation was pretty - mechanical - decent - BUT with the lack of timer based stuff through out - I totally rethought the whole scenario - and started again. The results - Much smoother - and all things that move do just as much action /distance etc regardless of PC speed! Very Cool!

Now if I could code my media loading routines to do a trick like that! hahah

Jason

Know way to many languages - Master of none

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Code Dragon

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Posted: 28th Jun 2007 14:29

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WindowsKiller, if he used timeStamp# 100s of times per loop, it would be faster. You wouldn't make it an integer because while it may be faster at this very moment, you'd lose more and more speed every time you use timeStamp#

I would never optimize if it meant that I couldn't add new code without defeating the purpose of the optimization.

You never really know a person until you look at their google autocomplete entries.

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jason p sage

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Posted: 28th Jun 2007 19:31

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Why would using a FLOAT (something#) get slower each loop? Is Dark Basic Sloppy with Floats or something?

Thanx - Just trying to prevent writing mucky code. Hard enough without creating new problems

thank you in advance.

Know way too many languages - Master of none

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IanM

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Posted: 28th Jun 2007 22:10

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Quote: "Why would using a FLOAT (something#) get slower each loop?"

It wouldn't, but converting and integer to a float 100 times is slower than converting once and reusing the result - that's what was meant.

However, they are each only seeing their own side of the picture. IF the amount of time used by these calculations is large enough to have a noticeable effect on the speed of the code, and IF there is a mixture of floating and integer maths that needs the timings, THEN MAYBE it might be worthwhile to store the timer difference in BOTH float AND integer format so that you can use the appropriate one at each place in the code.

For free Plug-ins and source code
http://www.matrix1.demon.co.uk
New Utility plugins collection

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jason p sage

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Posted: 28th Jun 2007 23:02

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I agree with that sort of thinking. In fact - If I can "foresee" needing a calulated result of anykind over and over - OR - (usually) see a pattern after entering a few times - I'll try to make the "math" part create a "base" result I can use over and over and save the repetition.

Thanks for clarifying what was meant

Jason

Know way too many languages - Master of none

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Cash Curtis II

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Posted: 29th Jun 2007 10:40 Edited at: 29th Jun 2007 10:42

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Quote: "only made it a float to save one cast when calculating timeFrame#"

In a game that uses timer based movement and animation, you'll access timeStamp# lots of times, hundreds in my case.

Everything in DBP that involves angles, position, or animation frames uses floating point math. If you use integers with any of these commands you risk making everything look choppy. Having to typecast every time is much slower than type casting once. Every single time you pass an integer to a float parameter DBP has to type cast it.

If you're going to make a program, you should do it right the first time so that it is expandable and efficient. I created that code snippet so that no matter how he used it, it would be as fast as possible.

I don't know why you're trying to argue WindowsKiller, my logic is sound and I am very experienced with timer based operations and I am a stickler for efficiency.

Come see the WIP!

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vibe runner

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Posted: 29th Jun 2007 15:55

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As an aside, let me plug the M1 plug-ins http://www.matrix1.demon.co.uk/

One of the functions is HITIMER(), highly accurate, unlike the standard TIMER()

Moreover, you will find, unlike *so* many other plug-in suites, that there are many useful plugins. Check them out, you won't be sorry.

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IanM

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Posted: 29th Jun 2007 23:57

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Actually, the utility plug-ins are best picked up from the DLL forum (they replace all commands in the old utility plug-in, and provide a whole lot more).

The array, data and map plug-ins can be picked up from my site until I roll them into the utility set - sadly, I'm taking far too long to do it

BTW, I'll be releasing the latest updates later this weekend. I need to include something new in addition to the few fixes that have been required.

For free Plug-ins and source code
http://www.matrix1.demon.co.uk
New Utility plugins collection

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Attila

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Posted: 30th Jun 2007 15:04

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If the rotation is regular but can although be frame based try this code, it will work in DB and DBPro:

+ Code Snippet

cls
backdrop on : color backdrop rgb(0,0,64)
sync on : hide mouse
autocam off
make object cube 1, 10
position object 1,20,0,20
position camera 0,15,0
point camera 20,0,20

Rotation=0
do
   Rotation=Rotation+2
   yrotate object 1, wrapvalue(Rotation)
   sync

loop
end

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