Simple Parallax Background

[SilverSpook]

Is there a way to just have an object frozen in the background (for example a distant mountain)?  Basically, I want the object to never move in the player's screen, even when the rest of the room scrolls left and right.  I saw the parallax module but I was wondering if there was some simpler way to keep an object frozen in place. 

Thanks

[Crimson Wizard]

Easy:

Code: ags

function repeatedly_execute_always()
{
   oObj.X = GetViewportX();
   oObj.Y = GetViewportY();
}

[SilverSpook]

Thanks!

One thing though: it seems when the view scrolls, the unmoving object is always one frame behind everything else?  So when the player starts / stops, the background lags a little bit, then jerks into place.  Is there a way to smooth the transition out so you don't get the jerking?  Right now I have "repeatedly_execute_always" in the room's script.

[Ali]

If I recall correctly,  that jerkiness is inevitable unless you use DX9.

[Monsieur OUXX]

One thing though: it seems when the view scrolls, the unmoving object is always one frame behind everything else?

I'm not expert enough to tell the reason for sure, but I know that what you say is plausible, because when you update obj.X (resp. Y) you do it during your game cycle, whereas Viewport's X (resp. Y) was given to you from the previous game cycle.
I can't think of a solution from the top of my head, so I'll just say that you should use the SmoothScrolling module, which also allows parallax.

BOOM: just when I mention smoothscrolling, Ali pops in.

EDIT: if the jerkiness is inevitable, then another workaround would be not to do a perfectly still background, but instead a background that has a very slight scrolling/parallax effect. This way, nobody will notice.

[Crimson Wizard]

Which version of AGS are you using?
I made this experimental engine version for Snarky, it's based on AGS 3.3.3 and supports "late_repeatedly_execute_always()" function that is run after new game state is calculated.
http://www.mediafire.com/download/jd86vdw6jxr6n5y/acwin_3.3.3--laterepexec.zip

[Monsieur OUXX]

late_repeatedly_execute_always()

Oh boy oh boy oh boy. I didn't know the existence of this. I'm excited.

[SilverSpook]

I'm using AGS 3.4 unfortunately.  I need the free aspect ratio feature cause I'm working in 1366 x 768

Thanks for the support though!

[Snarky]

If you script the room scrolling yourself instead of relying on the built-in one, it will all happen in user-script and should sync up correctly.

[SilverSpook]

Hm, how would you disable the scrolling so to script it yourself?

[Snarky]

The function is called setviewport or lockviewport or something like that. Search the manual for "viewport" and you should find it.