hallo, ich suche immer noch ein asm-beispiel für spriteähnliche gebilde auf dem cpc. habe ein beispiel in asm gefunden, das flackert aber dermaßen, das es unbrauchbar sit.
weiterhin habe ich noch keine vernünftige lösung für ein forth-porgramm gefunden.
mfg
Kuckste mal in die CPCAI 8/9 1992 da hat Elmar Krieger nen Artikel über Spriteprogrammierung gemacht.
Zitat
CPCAI 8/9 1992
schick mal ein ausführlichn link rüber.
danke.
mfg
Muß ich erstmal scannen. Hab momentan keinen Scanner da, wenn ich an einen ramkomme, scann ich den Artikel gerne.
Sorry, I just want to help you but I don't speak german language, so if you speak in english, i will probably help you... Are tou speaking about Cpc+ Sprite or Cpc Sprite coding way ?
hello, thanks you. i'm Cpc Sprite coding !!! have you her code sprite whis cpc ?
mfg peter
No problem ! What do you want to know exactly ? How to plot a sprite on the screen ?
hello, yes. with asm-code!
ps: I can only very little English.
thanks.
mfg peter
So, enter in sprite's world :
The most simply method is :
LD HL,Data ; Sprite's datas
LD DE,Screen ; Screen Adress where the sprite will be displayed
LD B,NbLines ; Sprite's numbers lines
bouc PUSH BC ; Save BC register 'coz B is already used ;-)
LDI
LDI
LDI
LDI ; Number of Bytes (In this example -> 4 Bytes will be displayed!)
POP BC ;
EX DE,HL ; HL became DE.... DE became HL
CALL &BC26 ; Calcul next line in HL ... HL=HL+&800...
; At the 8th line HL=HL+&50
EX DE,HL ; Invert HL & DE
DJNZ LOOP ; Come back to the loop instead of b<>0
RET ; Return....I Hope I could help you in your quest... For more explanation... ask me ![/code]
hello, thanks.
mfg peter
Sorry but i've just seen an error :
you must read :
LOOP instead of BOUC ; a french translation... Sorry for this big mistake !
Zitat von "AsT"Alles anzeigenSo, enter in sprite's world :
The most simply method is :
CodeAlles anzeigenLD HL,Data ; Sprite's datas LD DE,Screen ; Screen Adress where the sprite will be displayed LD B,NbLines ; Sprite's numbers lines bouc PUSH BC ; Save BC register 'coz B is already used ;-) LDI LDI LDI LDI ; Number of Bytes (In this example -> 4 Bytes will be displayed!) POP BC ; EX DE,HL ; HL became DE.... DE became HL CALL &BC26 ; Calcul next line in HL ... HL=HL+&800... ; At the 8th line HL=HL+&50 EX DE,HL ; Invert HL & DE DJNZ LOOP ; Come back to the loop instead of b<>0 RET ; Return....
I Hope I could help you in your quest... For more explanation... ask me ![/code]
The next easiest thing to do is to repeat this for every byte :
ld a,(de) ; get sprite graphics
xor (hl) ; XOR with screen graphics
ld (hl),a ; write back to screen
inc de ; increment sprite graphics pointer
inc hl ; increment screen pointerAbove code becomes:
LD DE,Data ; Sprite's datas
LD HL,Screen ; Screen Adress where the sprite will be displayed
LD B,NbLines ; Sprite's numbers lines
bouc PUSH BC ; Save BC register 'coz B is already used ;-)
;; 4 times = 4 bytes
ld a,(de)
xor (hl)
ld (hl),a
inc de
inc hl
ld a,(de)
xor (hl)
ld (hl),a
inc de
inc hl
ld a,(de)
xor (hl)
ld (hl),a
inc de
inc hl
ld a,(de)
xor (hl)
ld (hl),a
inc de
inc hl
POP BC ;
CALL &BC26 ; Calcul next line in HL ... HL=HL+&800...
; At the 8th line HL=HL+&50
DJNZ LOOP ; Come back to the loop instead of b<>0
RET ; Return....Notice I changed the function of DE and HL.
If you use this routine you will see the sprite will change colour if it moves over background, but the same routine can be used to erase the sprite from the screen.
For more optization you can use :
INC L instead of INC HL
and
INC E instead of INC DE...
you'll win 2 nops per bytes so in this example you'll win 2x4 nops -> 8 Nops for each lines...
hello, thanks for the info.
mfg
