How to change playfield background on the fly..

[+Gemintronic]

So, I noticed I can change the first playfield row background color with COLUBK with these kernel settings enabled:

set kernel_options pfcolors pfheights background

 

Is there a way to change other playfield rows similar to this?

 

rem Compiler options
set smartbranching on
set kernel_options pfcolors pfheights background
set romsize 4k

rem Declare constants
 const true = 1
 const false = 0
 const pfscore=1
scorecolor = $33

pfheights:
8
13
13
13
13
13
13
2
2
2
2
end
pfcolors:
$00
$E2
$E4
$E6
$E8
$EA
$09
$00
$00
$00
$00
end
playfield:
......X.........................
..............X.................
................................
....................X...........
........X.......................
............X...................
..................X.............
.X.X.XX...X.X.XX..XX...X..XXX.X.
X..X.X.X.X..X.X.X.X.X.X.X..X..X.
X..X.X.X.X..X.X.X.X.X.XXX..X..X.
.X.X.X.X..X.X.X.X.X.X.X.X..X..X.
end
player0:
%100010
%010100
%011000
%111100
%111111
%111100
%011000
%010100
%100010
end
player1:
%010001
%001010
%000110
%001111
%111111
%001111
%000110
%001010
%010001
end

player0x = 4
player0y = 79
player1x = 148
player1y = 66
score = 123456
main
gosub draw_event
if joy0up && player0y > 11 then player0y = player0y - 1
if joy0down && player0y < 85 then player0y = player0y +1
if joy0left then player0x = player0x - 1
if joy0right then player0x = player0x +1
if joy1up && player1y > 11 then player1y = player1y - 1
if joy1down && player1y < 85 then player1y = player1y +1
goto main
draw_event
REFP0 = 0
COLUP0 = $47
NUSIZ0 = $30
COLUP1 = $AA
COLUPF = $0E
COLUBK = rand
drawscreen
return

Edited March 26, 2012 by theloon

[SeaGtGruff]

I think Random Terrain's guide explains the bug regarding the top row's color and how to fix it.

 

If you use pfcolors and pfheights together, you can't change the pfcolors and pfheights after you set them-- under normal circumstances. If I remember correctly, I wrote a demo program a couple of years ago that shows how to move them into RAM so you can change the pfcolors and pfheights on the fly. It's in one of the threads here...

 

Edit: Found it... http://www.atariage.com/forums/topic/112423-pfcolors-and-pfheights-together-in-ram/

Edited March 27, 2012 by SeaGtGruff

[+Gemintronic]

I think Random Terrain's guide explains the bug regarding the top row's color and how to fix it.

 

If you use pfcolors and pfheights together, you can't change the pfcolors and pfheights after you set them-- under normal circumstances. If I remember correctly, I wrote a demo program a couple of years ago that shows how to move them into RAM so you can change the pfcolors and pfheights on the fly. It's in one of the threads here...

 

Edit: Found it... http://www.atariage....ogether-in-ram/

 

Thanks for the reply man! If you're talking about the repeating color issue with the top row.. I know about (and experience frequently) that bug. What I didn't expect is that COLUBK actually changes the color on-the-fly for the top rows of my code above. I just hoped someone knew how to access the other playfields rows like that (with the standard kernel).

 

You custom kernel modifications look mind bogglingly jawsome but I'd like to avoid using anything but the latest stable version of bB.

 

UPDATE: I did a search on "top row" in the command refernce and found this indeed was already documented - not just the color bleeding onto other rows. Drat! I thought I found something new

toprowch.bin

Edited March 28, 2012 by theloon