Do Functions Play Nice with Banks?

[+Gemintronic]

So, I'm trying to convert Game Maker 5 constants, subroutines and functions over to Batari BASIC. I'm trying to keep my library of routines in the second bank. How do functions work with multi-banked games? Do they at all?

Edited August 12, 2010 by theloon

[SeaGtGruff]

So, I'm trying to convert Game Maker 5 constants, subroutines and functions over to Batari BASIC. I'm trying to keep my library of routines in the second bank. How do functions work with multi-banked games? Do they at all?

Functions are like subroutines, so I think there would be a problem calling them if they're in a different bank. This is a good question, and I don't have a good answer, but it might be necessary to create a multibanked version of user functions. Otherwise, you'd probably need to find a way to work around the problem of calling them from different banks. Like I said, I don't have an answer. If I can think of something, I'll let you know.

 

Michael

[+Random Terrain]

I was playing with batari's platformer source code not that long ago and it used 2 banks. He put his functions in the last bank:

 

http://www.atariage.com/forums/topic/166826-so-far-so-good/page__view__findpost__p__2065923

[+Gemintronic]

Thanks for the replies so far. I'd like to use functions multi-bank if possible.

 

I noticed Batari's Platformer example seems to only call the functions from the same bank. So it still doesn't prove functions can work across banks.

 

Workaround seems to be setting aside a variable or two as arguments and then calling a gosub that uses those variables.

Edited August 13, 2010 by theloon

[+batari]

Thanks for the replies so far. I'd like to use functions multi-bank if possible.

 

I noticed Batari's Platformer example seems to only call the functions from the same bank. So it still doesn't prove functions can work across banks.

 

Workaround seems to be setting aside a variable or two as arguments and then calling a gosub that uses those variables.

You can make a cross-bank wrapper to do this.

 

For example, if this function is in bank 2 (note this is modified a bit from the platformer source - the return is used to go back to the calling bank):

 function blockread
 temp1=temp1-16:temp1=temp1/4
 temp2=temp2+1
 temp2=temp2/4-3
 temp1=romPFpixel(temp1,temp2)
 return

To call it from bank 1, do something like this in bank 1:

 

  function blockread_bank1_wrapper
 goto blockread bank2

 

Untested, but I think this will work. If it does not, let me know.

 

That said, cross-bank subroutines should be minimized as they use perhaps 30-60 more cycles than in-bank subroutines.

Edited August 18, 2010 by batari