Background kernel option

[lord_mike]

I'm trying to figure out how to use the background kernel option... supposedly, this option works like pfcolors, only it changes the background color for each playfield line... the problem is, this kernel option is mentioned in the manual, but it completely undocumented... There is some reference to backgroundchange in the source code, but that is all I can figure out this late at night...

 

I'm trying to bypass the pfheights with pfcolors "one time only" define restriction by using this kernel option instead to create a dynamic multicolored background... I tried the following with no success:

 

 
 set kernel_options player1colors pfheights background

 pfheights:
 8
 3
 4
 5
 6
 7
 8
 9
 10
 13
 15
end

 playfield:
 ................................
 ............X..X................
 ...........X....X...............
 ..........X......X..............
 .........X........X.............
 ........X..........X............
 .......X............X...........
 ......X..............X..........
 .....X................X.........
 ....X..................X........
 ...X....................X.......
end

 COLUPF=203

 background:
 144
 146
 148
 152
 154
 156
 158
 160
 162
 164
 166
end

gameloop

 drawscreen
 goto gameloop

end

 

It says that the background keyword does not exist.... I haven't seen this issue brought up before, so I don't know where to turn for answers...

 

Any help would be greatly appreciated!

 

Thanks,

 

Mike

Edited August 22, 2007 by lord_mike

[+batari]

The compiler should not allow that combination of kernel options:

 
 set kernel_options player1colors pfheights background

But obviously it is, so you've found a bug. I'm hoping the command reference doesn't claim this is valid as well

 

The issue is that the background option simply takes the pfcolor table and writes to the background instead of the playfield color register. Therefore, the background kernel option must include pfcolors.

 

IIRC, the timing for the background color write is a little off. That was the reason why I didn't document it very well (aside from laziness.)

[lord_mike]

Thank you for replying, Batari!

 

The compiler should not allow that combination of kernel options:

 
 set kernel_options player1colors pfheights background

But obviously it is, so you've found a bug. I'm hoping the command reference doesn't claim this is valid as well

 

I actually got that combo straight from the manual:

 

Acceptable combinations:

 

pfcolors pfheights

pfcolors pfheights background

pfcolors no_blank_lines

pfcolors no_blank_lines background

player1colors no_blank_lines

player1colors pfcolors

player1colors pfheights

player1colors pfcolors pfheights

player1colors pfcolors background

player1colors pfheights background

player1colors pfcolors pfheights background

player1colors no_blank_lines readpaddle

player1colors no_blank_lines pfcolors

player1colors no_blank_lines pfcolors background

playercolors player1colors pfcolors

playercolors player1colors pfheights

playercolors player1colors pfcolors pfheights

playercolors player1colors pfcolors background

playercolors player1colors pfheights background

playercolors player1colors pfcolors pfheights background

no_blank_lines readpaddle

 

The issue is that the background option simply takes the pfcolor table and writes to the background instead of the playfield color register. Therefore, the background kernel option must include pfcolors.

 

Ah, yes.. now it works with the pfcolors keyword!

 

IIRC, the timing for the background color write is a little off. That was the reason why I didn't document it very well (aside from laziness.)

 

I see... it doesn't look too bad in Stella, though.. the effect is pretty stunning, actually.... now, I have to figure out a hack to make it change colors dynamically... Curtis addressed something similar in another thread... we'll see if it's doable!

 

Thanks, Batari for such a great product! I've noticed that you haven't updated your blog recently. Have you stopped working on BBasic?

 

Thanks,

 

Mike

Edited August 22, 2007 by lord_mike

[lord_mike]

Thanks, Batari for such a great product! I've noticed that you haven't updated your blog recently. Have you stopped working on BBasic? icon_confused.gif

 

Never mind... I saw that you answered that question in another thread!

 

Thanks,

 

Mike