AGA 64Px sprites with more colours.

[shoestring]

Sorry if this has been discussed but I'm wondering if this is possible.

I have 2 playfields, both 4bpl (16 cols ea ) and using large 64px sprites to display a logo, I can display 16 col sprites easily. Both playfields are built using tiles from data I dumped directly from MAME.

I'm basically trying to reproduce the title screen of an arcade game I used to play as a youngster.

First screenshot is the Amiga screen from UAE and second is the arcade, the logo on the arcade is 35 colours, black for transparency. Fmode x 4 for sprites and bitmap data. Image is 256x240, so 4 x 64px sprites total.

My copper list for the sprites look like this.

.
.
dc.w BPLCON4,%00110010
.
.


spritePalette:
; Bank 1 - Colors

dc.w BPLCON3,%0011000001000000 ; CLR BANK1 - PF2OF16 - LOCT0 - LORES SPR
dc.w $0180,$0000,$0182,$0226,$0184,$0448
dc.w $0186,$0555,$0188,$0559,$018a,$0666,$018c,$066a
dc.w $018e,$0777,$0190,$077b,$0192,$0888,$0194,$088c
dc.w $0196,$099d,$0198,$0aae,$019a,$0bbf,$019c,$0ccf
dc.w $019e,$0ddd

The problem is I cannot use attached sprites that have more than 4 bpl ( using Piccon to convert from iff to raw ). Is it possible to change/cycle the colours on the fly, using multiple copper lists for the sprites ( I will need at least 3 x 16 cols ) and different colour banks ?

Thanks in advance.

[ross]

Originally Posted by shoestring

The problem is I cannot use attached sprites that have more than 4 bpl ( using Piccon to convert from iff to raw ). Is it possible to change/cycle the colours on the fly, using multiple copper lists for the sprites ( I will need at least 3 x 16 cols ) and different colour banks ?

Thanks in advance.

Sure you can.

Change with copper, on the right positions, on the fly, OSPRM bits in BPLCON4 register (a color bank selector for sprite, in your case in 16 colors).

[shoestring]

Thanks, I totally forgot about BPLCON4. I'll give that a try.

[shoestring]

Finally figured it out. I did something like this where I switched banks in my copper list and made changes to the colours to match the arcade.

This was quite tedious work, are there any visual tools available that might make this process a little easier ?


titleScreenTweaks:
dc.w $5c0f,$ff00
dc.w BPLCON3,%0100110001000000 ;COLOR BANK2 - PF2OF8
dc.w BPLCON4,%0000000000110100
dc.w $0192,$0337
...
...
dc.w $6b0f,$ff00
dc.w BPLCON3,%0110110001000000 ;COLOR BANK3
dc.w BPLCON4,%0000000000110110
...
...
dc.w $8c0f,$ff00
dc.w BPLCON3,%1000110001000000 ; COLOR BANK4
dc.w BPLCON4,%0000000000111000
...

[ross]

Not that I know, but it would be really useful to have some visual tools (possibly in cross-development) for the management of the real-time color changes made with the copper on the tile/bitmap/sprite map.

Just look at the spectacular Metro-Siege what has managed to do with a similar technique (well, in fact with the colors bank switcher on AGA it is really very simple, but the concept could also be expanded by the direct change of colors).