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Forums > C64 Coding > convert between MC sprite data and MC Font data?

2006-08-05 14:51

Trifox
Account closed

Registered: Mar 2006
Posts: 108

convert between MC sprite data and MC Font data?

hi2all, unfortunately i crossed a problem, when doing sprite multicolor graphics and font multicolor graphics, the problem is, i cant use the same sprite data in my MC Font data, the problem is:
color index in MC Text mode is determined by
"00": Background color 0 ($d021)
"01": Background color 1 ($d022)
"10": Background color 2 ($d023)
"11": Color from bits 8-10 of c-data

the dynamic color code is "11" and for sprite data it is

"00": Transparent
"01": Sprite multicolor 0 ($d025)
"10": Sprite color ($d027 - $d02e)
"11": Sprite multicolor 1 ($d026)

the dynamic color code is here "10", what a pitty, now i need a fast method of converting all "10"'s to "11"'s and vice versa, do i need to shift around and create the other bitcombination, or is there a faster method?

2006-08-05 15:20

tlr

Registered: Sep 2003
Posts: 1790

A 256 byte lookup table would be fast, i.e similar to:

ldx fontbyte
lda lut,x
sta spritebyte

Even faster would be store another copy of the charset, preconverted. ;)

What is it supposed to be used for?

2006-08-05 15:41

Trifox
Account closed

Registered: Mar 2006
Posts: 108

oh, its just for my little game i am actually on, i am first experimenting with font multicolor mode, but ran into this problem, i think i will build a complete lookuptable, its fast and easy .. ;) ii have written a routine for doing that with register a ... so, building a table can be quite easy

2006-08-05 16:34

Hein

Registered: Apr 2004
Posts: 954

or use

lda fontbyte
eor #%01010101
sta spritebyte

but you'd have to make $d022 your background colour and $d021 becomes object colour 1 (for instance a happy mushroom).

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