Ultimate Amiga

Network Boards => AMOS Programming Environment => AMOS Factory => AMOS BASIC => Topic started by: Lee DaBee on March 28, 2019, 09:10:24 PM

Title: Multiple screes
Post by: Lee DaBee on March 28, 2019, 09:10:24 PM

Hello,

How can i have two screens where the background can be seen through the foreground screen.

Ie the background is scrolling while the foreground screen has all the bobs etc.

Or if that can't be done then how do you keep bobs in place while the screen is scrolling

Thanks

Title: Re: Multiple screes
Post by: Volvo_0ne on March 29, 2019, 10:04:20 PM

Quote from: Lee DaBee on March 28, 2019, 09:10:24 PM

Hello,

How can i have two screens where the background can be seen through the foreground screen.

Ie the background is scrolling while the foreground screen has all the bobs etc.

Or if that can't be done then how do you keep bobs in place while the screen is scrolling

Thanks

You need to look at the "Dual Playfield" instruction in the AMOS manual

It has a few restrictions in format and colour palette, but it works quite well.

Experiment with it a while and it should do what you want.

Title: Re: Multiple screes
Post by: Lee DaBee on March 29, 2019, 11:33:22 PM

Thanks I'll have a fiddle around with that

Title: Dual Playfield
Post by: Lee DaBee on March 30, 2019, 07:15:22 PM

Hello,
I've used the Dual Playfield command, which works in giving me the see through screen at the front, but the background screen which is scrolling using Amal, becomes split horizontally with each half being a copy of the other, also the display starts to creep up vertically too.

Title: Re: Dual Playfield
Post by: Volvo_0ne on April 01, 2019, 06:25:11 PM

Quote from: Lee DaBee on March 30, 2019, 07:15:22 PM

Hello,
I've used the Dual Playfield command, which works in giving me the see through screen at the front, but the background screen which is scrolling using Amal, becomes split horizontally with each half being a copy of the other, also the display starts to creep up vertically too.

I think this is a "feature" of Amiga screen handling, if you research the problem I've seen s few discussions on the subject, but never used any.

Try typing "amiga corkscrew scroller" into a search engine, to see if anyone has a suitable solution.

Regards
V1

Title: Re: Dual Playfield
Post by: Lonewolf10 on April 28, 2019, 07:48:14 PM

Quote from: Lee DaBee on March 30, 2019, 07:15:22 PM

Hello,
I've used the Dual Playfield command, which works in giving me the see through screen at the front, but the background screen which is scrolling using Amal, becomes split horizontally with each half being a copy of the other,

Can you post a screenshot to illustrate this?

Quote from: Lee DaBee on March 30, 2019, 07:15:22 PM

so the display starts to creep up vertically too.

That happens because you are scrolling the screen continuously and not resetting the X position to 0.
Consider a screen that is 320 pixels wide and set the x position to -320. It has now been scrolled 1.0 screens to the left and will have moved up by 1 pixel.

Title: Re: Dual Playfield
Post by: Volvo_0ne on May 08, 2019, 08:50:18 PM

Quote from: Lonewolf10 on April 28, 2019, 07:48:14 PM

That happens because you are scrolling the screen continuously and not resetting the X position to 0.
Consider a screen that is 320 pixels wide and set the x position to -320. It has now been scrolled 1.0 screens to the left and will have moved up by 1 pixel.

To be fair, it shouldn't happen, but it does, that's the way it is, so ALWAYS reset the X position and you'll be ok.