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berberberber · 2012-06-17 00:45:03

I have seen users like AB3 and Wes64 use this, but I don't understand the mechanics. I know it has to do with stamping, but I don't know how to program it. Can someone help?
Thanks!

SciTecCf · 2012-06-17 04:59:29

Okay, you're going to need a variable called xscroll for the scrolling amount. Then, you need to do this:

when  clicked
hide
The stamping will do all of the work.
forever
clear
Remove all previous stamps or pen marks.
if key left arrow ▼
 pressed?
 and scrollx
 < 0
change scrollx ▼
 by 1
You can change this to 2, 3, 4, or 6.
if key right arrow ▼
 pressed?
 and scrollx
 > -480
Limits scrolling to 480 pixels, or 2 backgrounds.
change scrollx ▼
 by -1
The same as above, but negative.
switch to costume costume1 ▼
The first background.
if scrollx
 < 480
If the first background will be in the screen.
go to x: scrollx
 y: 0
stamp
switch to costume costume2 ▼
The second background.
if scrollx
 > 0
If the second background will be in the screen.
go to x: scrollx
 + 480
 * 1
 y: 0
stamp

That's a very basic 2-background scroller. If you want it to be longer, I'll post a solution to that.

berberberber · 2012-06-17 11:29:44

Could you tell me how to extend it?

SciTecCf · 2012-06-17 12:09:20

berberberber wrote:
Could you tell me how to extend it?

Okay!

You start with this:

when  clicked
hide
forever
clear
if key left arrow ▼
 pressed?
 and scrollx
 < 0
change scrollx ▼
 by 1
You can change this to 2, 3, 4, or 6.
if key right arrow ▼
 pressed?
 and scrollx
 < 960
Set this number to ((your amount of backgrounds minus 1) times 480)
change scrollx ▼
 by -1
The same as above, but negative.

Okay, now, the first one's scripts:


switch to costume costume1 ▼
Your first background.
if scrollx
 < -480
go to x: scrollx
 y: 0
stamp

Add that at the end of the forever loop.
Now, for each of the other ones (except the last one), we need to add this to the end of the forever loop:


switch to costume costume2 ▼
Set this to the correct one.
if scrollx
 < 0
 and scrollx
 > -960
Change these numbers by -480 for each background.
go to x: scrollx
 + 480
 * 1
 y: 0
Change the 1 by 1 for each background.
stamp

No, finally, for the last one. Just add this to the end of the forever loop:


switch to costume costume3 ▼
Your last background.
if scrollx
 > -480
Set this to (((amount of backgrounds minus 1) times 480) times -1)
go to x: scrollx
 + 480
 * 2
 y: 0
Set the 2 to the amount of backgrounds - 1.
stamp

All done! I'm sorry if I didn't explain it well. I hope this helps!

IMPORTANT: Test it in Presentation Mode.

Last edited by SciTecCf (2012-06-17 13:47:47)

AtomicBawm3 · 2012-06-17 15:33:52

If you want to extend it into infinite, you should use the "mod" block. Basically, the mod block gives you the remainder after dividing the first number by the second. You have to think about it a bit before it makes sense:
-you want 2 stamps/positions.
-each one must be able to travel from one side to the other and then loop around
next, get into the math:
-since each scene is a full screen (480 pixels long) and the screen is 480 pixels long, in order for it to completely exit the screen on both sides, it must travel from x=480 to x=-480
-480*2=960 is thus the number we will use for the modulus or mod block.

so far we have:


go to x: scrollx
 mod 960
 y: 0

but this will make our sprite travel from 960 to 0 and then loop back to 960, so we have to make it:


go to x: scrollx
 mod 960
-480
 y: 0

instead.
There's one of the scenes done, but we need a second in order to keep the screen filled the whole time. Right now we've got one that's going to -480 when scrollx = 0 so you need one going to 0 when scrollx = 0 but also cycles from 480 to -480:


go to x: scrollx
+480
 mod 960
-480
 y: 0

should do the trick.

Last edited by AtomicBawm3 (2012-06-17 15:34:46)

berberberber · 2012-06-17 16:11:27

Thanks, but could you sho me the whole script, AB3?

AtomicBawm3 · 2012-06-17 16:34:58

berberberber wrote:
Thanks, but could you sho me the whole script, AB3?

Sure:

when  clicked
set sx ▼
 to 0
forever
switch to costume
go to x: sx
 * -1
 + 480
 mod 960
 - 480
 y: 0
stamp
switch to costume
go to x: sx
*-1
 mod 960
 - 480
 y: 0
stamp

This is what I used for Dark and Light.

Sorry...You can't see the math for the costume numbers:
just odds:
(round(sx/960)*2)+1
Just evens:
(round((sx+480)/960)-1)*2)+2

Last edited by AtomicBawm3 (2012-06-17 16:38:29)

mythbusteranimator · 2012-06-17 17:41:41

Is it something like this?

When  clicked
forever
switch to costume 1 ▼
go to x: cos1 x
 y: cos1 y
stamp
if 
change cos1x ▼
 by 1
if 
change cos1 y
 by -1

And then you just do as many costumes and sensing scripts as you need?

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archived forums

#1 2012-06-17 00:45:03

1 Sprite Scrolling

#2 2012-06-17 04:59:29

Re: 1 Sprite Scrolling

#3 2012-06-17 11:29:44

Re: 1 Sprite Scrolling

#4 2012-06-17 12:09:20

Re: 1 Sprite Scrolling

berberberber wrote:

#5 2012-06-17 15:33:52

Re: 1 Sprite Scrolling

#6 2012-06-17 16:11:27

Re: 1 Sprite Scrolling

#7 2012-06-17 16:34:58

Re: 1 Sprite Scrolling

berberberber wrote:

#8 2012-06-17 17:41:41

Re: 1 Sprite Scrolling

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