Re: A85: Memory Loading
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Re: A85: Memory Loading
Here's the main chunks of where the bug is...
Board = TEXT_MEM ;where the board is stored in text mem
;b = x-coordinates
;c = y-coordinates
;e = row XOR mask
;hl = row in board
ld bc,0 ;PutSprite position
ld e,128 ;for position mask in Draw_XOR_Block
ld hl,Board ;load board mem to hl
PlaceMove: ;if 2nd was pressed inside game loop...
push bc
push de
push hl
ld a,b ;load x-cord into a
or a ;is it zero?
jr z,InvertCurrentPos ;if yes, goto InvertCurrentPos
ld a,b ;get the x-cord from b
sub 8 ;decrease by 8 (get to left position)
ld b,a ;load it back to b
rlc e ;Memory:
ld a,(hl) ; o
xor e ; xoo
ld (hl),a ; o
call &Draw_Block ;draw it
ld a,b ;get x-cord from b
add a,8 ;increase by 8 (get back to center
position)
ld b,a ;x-cord back to b
rrc e ;get memory back to center position
InvertCurrentPos:
ld a,(hl) ;get byte from board
xor e ;invert current position in memory
ld (hl),a ;load it back to hl
call &Draw_XOR_Block ;back to origional block
call &Draw_Block ;invert it
call &Draw_XOR_Block ;back to XOR masked block
InvertRight:
ld a,b ;get x-cord to a
cp 56 ;is it 56?
jr z,InvertUp ;if yes, go to InvertUp
ld a,b ;get x-cord to a
add a,8 ;increase by 8 (get to right position)
ld b,a ;load x-cord back to b
rrc e ;rotate memory byte right
ld a,(hl) ;get byte from board
xor e ;invert it in memory
ld (hl),a ;load it back into hl
call &Draw_Block ;invert block
ld a,b ;x-cord into a
sub 8 ;get center position
ld b,a ;x-cord back to b
rlc e ;rotate memory byte left
InvertUp:
ld a,c ;y-cord to a
or a ;zero?
jr z,InvertDown ;if yes, go to InvertDown
ld a,c ;y-cord to a
sub 8 ;go to top position
ld c,a ;y-cord back to c
dec hl ;get to previous row
ld a,(hl) ;get byte from board
xor e ;invert top position
ld (hl),a ;load it back into hl
call &Draw_Block ;invert block
ld a,c ;y-cord to a
add a,8 ;go to center position
ld c,a ;y-cord back to c
inc hl ;next row down
InvertDown:
ld a,c ;y-cord to c
cp 56 ;is it 56?
jr z,InvertDone ;if yes, go to InvertDone
ld a,c ;y-cord to a
add a,8 ;increase it by 8 (get bottom position)
ld c,a ;y-cord back to c
pop de ;de should be the way it was going into
PlaceMove but without these two
push de ;lines the keypressing is all messed up.
Go figure...
inc hl ;hl points to next row
ld a,(hl) ;get byte from board
xor e ;invert bottom position
ld (hl),a ;load it back into hl
call &Draw_Block ;invert block
InvertDone:
pop hl ;load hl
pop de ;load de
pop bc ;load bc
jp &GameLoop
Block:
.db 8,8
.db %01111100
.db %11000010
.db %10111110
.db %10111110
.db %10111110
.db %10111110
.db %01111100
.db %00000000
XOR_Block:
.db 8,8
.db %01111100
.db %11111110
.db %11111110
.db %11111110
.db %11111110
.db %11111110
.db %01111100
.db %00000000
.end
Yeah this is probably horribly unoptomized but this is my first Z80 asm
program and plus I haven't gotten to the optimization stage yet. You'll
have to forgive the messed up spacing... it was made in DOS Edit.
First off, this is part of the LightsOut game I'm making (for those of
you who've played it before... rather like Toggles but with multiple
levels). The Board var uses the first eight bytes of the text mem for
the board storage (8x8 board, each block is 8x8 more or less). HL
points to the current board row, BC are the x and y coordinates
respectively, and E is the XOR mask for the current row (like say you
are at the 2nd from the left position in a row. E now contains binary
01000000 so it can be used to invert the positions it needs to.
What I'm having trouble with is that when you call PlaceMove from the
gameloop, everything shows up OK on the screen but it never changes the
Board memory. There may be a few more bugs in there too but this is the
one I'm trying to kill now. Any help whatsoever would be greatly
appreciated!
- Jim
btw, I hope I don't come across as a freeloader trying to get everyone
else to write my code for me but I've been working on this little sucker
for months =)
References: