Multisprite kernel color hack (WIP)

[+Al_Nafuur]

I am currently modifying the bB multisprite kernel, so that different colors can be used for player0 and missile0 if missile0 is above the player (shooting up situation).

 

The color switch does not work on the lines where in addition to the color change there would also be a repositioning of a player1. I am currently looking for the needed 6/12 cpu cycles in the repo-kernel, but it looks like I have to sacrifice the rendering of the ball, either in the situation where all (color change, ball and repositioning) meet in one scanline or ball and repositioning meet.

 

Attached my current version, which also includes a "pfscore" hack so one side of the playfield score bars can be deactivated to used the 6lives mini kernel (without statusbar) too.

multisprite_kernel.asm

 

Here is a test ROM of 1942 bB using this kernel with red missile0 and yellow player0:

1942 color hack NTSC.bas.bin

(This is just a test ROM and not an "offficial" WIP release of 1942 bB !)

[+Al_Nafuur]

I managed to make the adjustments at least to the point where they were sufficient for my purposes (1942 bB).

 

The customized multisprite_kernel is here in the GIT:

https://github.com/Al-Nafuur/PlusROM-Hacks/blob/main/bBasic/1942/multisprite_kernel.asm

 

To use the split colors for player0/missile0 the constant "switch_player_0_color" has to be set in batari Basic and one variable has to be reserved for the player0 color "Player0SwitchColor"

   const switch_player_0_color = 1

   dim Player0SwitchColor     = a

 

You can set "Player0SwitchColor" once or change it for player0 explosion. You have to set the missile color by setting COLUP0 every frame and the kernel switches COLUP0 to the "Player0SwitchColor" up to three scan lines before rendering the player0. So your missile will have the player0 color if it is too near to the player.