Re: 3D Chess 2K18
Posted: Tue Jul 10, 2018 1:03 pm
Nope, not lost interest at all. I would love to see a full blown Chess game created with it though.
Paddy
Paddy
The community forum for all Sinclair users
https://spectrumcomputing.co.uk/forums/
Code: Select all
;Chess 2K18 Version 2A 002
;
;July 2018 Arkannoyed-JES
;
;Significant changes to the way the data is constructed have allowed the
;code to become much faster and more efficient, also allowing the gfx
;data to vastly reduce in size.
;
;standard lines consist of 4 bits of data and a length of C (Black or White) infill
;data lines consist of 4 types
;1. long lines. These are lines of 18, 20 or 22 bits length, where the additional 6 bits over 16
;are stored within the index (first) byte, followed by 4 bytes of BWBW arranged data
;2. mini lines. Lines of 8 bits length or less, where left and right bytes are mirrored, so the
;4 bits are stored in the low 4 bits of the index byte.
;3. BLR-WLR lines. The Black and White versions of the line are different, but their Right and Left sides
;are mirrored versions of each other, where the low 5 bits of the index byte hold a XOR overlay to create
; the Black version from the White data. If the XOR ooverlay is 00000 then there is no change applied.
;4. BWR-BWL lines. These lines are non-mirrored, but Black and White are the same, so the low 5 bits in the
;index are added to the Left side to create the Right.
;
;the line Buffers are HL and DE where the MSB is the innermost and they are written outwards right for DE
; and left for HL.
;The last bit in the buffer is always '1' and is inverted to '0' and written, then the printing ends.
;
;Currently this isn't a very fast method for longer lines, however needs no mask as such.
; Work is progressing to auto-mask the printing byte-wise instead, probably speeding things up and
; possibly saving space too.
;
;
org 0fd00h
gfx_data:
db 00h ;these 3x00h bytes ensure the piece
db 00h ;prints after 3 lines of the board square
db 00h ;have been printed.
db 81h ;base
db 0a0h,0f2h
db 0e4h,0feh,0eh,0feh,0eh
db 0f6h,0ffh,05h,0f9h,01h
db 3fh
db 5fh
db 3fh
db 5fh
db 0dbh,1fh,0e3h,1ch,0e0h
db 0dbh,0e3h,1dh,0e2h,1ch
db 0f6h,0fch,0bh,0f5h,01h
db 0e4h,0feh,02eh,0eah,02h ;40b
db 5ch ;king 28 ;28 Pawn & Knight switch
db 5bh
db 2bh
db 5bh
db 2bh
db 2ah
db 5ah
db 2ah
db 5ah
db 19h ;31 = Castle switch
db 29h
db 19h
db 29h
db 19h
db 9eh,0ech
db 1bh
db 1ch
db 1ch
db 9fh,0c6h
db 9eh,3ch
db 11h
db 1ah
db 2ah
db 12h ;42 = Bishop switch
db 5bh
db 0a0h,1eh ;44 = Queen switch
db 0a0h,0e3h
db 0a0h,7eh
db 0a0h,0b4h
db 89h
db 8fh
db 8fh
db 8ah
db 88h ;41 HT 31
db 0a0h,0b6h ;queen 51
db 0a0h,57h
db 0a0h,6bh
db 0a0h,0b2h
db 8dh
db 8ch
db 88h ;11 HT 2f
db 0c0h,0fch,0ech,0cch,0ch ;bishop 5C
db 0aah,0bch
db 0b0h,98h
db 0aah,48h
db 83h
db 8bh
db 86h
db 8ch
db 88h ;16 HT 31
db 2bh ;pawn 6C
db 2ah
db 5ah
db 19h
db 29h
db 19h
db 9eh,0ech
db 1bh
db 1ch
db 1ch
db 0c0h,3eh,0deh,26h,0d6h
db 0ach,54h
db 29h
db 2ah
db 1ah
db 2ah
db 1ah
db 19h
db 0a0h,38h
db 8dh
db 84h ;28 HT 24
db 9eh,0ech ;castle 88
db 1bh
db 1ch
db 1ch
db 9fh,0c6h
db 98h,1ch
db 5bh
db 5ch
db 2ch
db 5ch
db 2ch
db 5ch
db 0a0h,67h
db 0a0h,0a7h
db 0a0h,9bh
db 0a0h,92h
db 81h ;24 HT 29
db 5bh ;knight A0
db 2bh
db 2ah
db 1ah
db 9eh,0ech
db 1bh
db 1ch
db 1ch
db 9fh,0c6h
db 1ah
db 0c0h,0fch,5ch,0a6h,06h
db 0c0h,0feh,2eh,0d3h,03h
db 3ch
db 5ch
db 0e0h,0ffh,1eh,0a3h,03h
db 0e0h,0ffh,0bh,46h,06h
db 0e0h,7fh,17h,8ch,0ch
db 0e0h,0bfh,0bh,31h,31h
db 0e4h,7fh,07h,43h,43h
db 0e6h,3fh,0bh,9dh,9dh
db 0e3h,9fh,85h,7dh,61h
db 0c3h,0bfh,8bh,0feh,82h
db 0c6h,7fh,17h,0fdh,00h
db 0c4h,0feh,0eh,0fbh,03h
db 0c0h,0feh,2eh,9dh,65h
db 0c0h,0fch,5ch,3ch,0dch
db 0c0h,0f8h,38h,0e8h,68h
db 0a6h,70h
db 0ach,60h
db 0b8h,0c0h
db 88h ;96 HT 2E
;256 bytes 134 lines
chess_2018A:
rra ;test B/W BIT 0
sbc a,a ;
ld c,a ;set B/W component, Black=FF, White=00
continue:
ld a,(ix+00h) ;get gfx byte
inc ixl ;this INC must be here to avoid blanking repetition
test_line:
add a,a ;test BIT 7
ret z ;if 00 then its a blanking line, so RET
push hl ;save the screen address for later
push hl ;again
push hl ;...and again!
ld hl,0c000h ;initialise HL
ld e,l ;E=00h
ld b,0e0h ;ensure the counter is over max piece height.
jr c,data_line ;if type '1' line then jump to data_line builder
standard_line:
ld d,a ;save temp
and 0fh ;mask counter
ld b,a ;B=counter
ld a,c ;temp back into A
xor d ;add in b/w component
and 0f0h ;mask upper 4 bits F0h
or 0ch ;add-in the '10'
ld d,a ;data into D
ld a,c ;bw byte into A
st_lp0:
rlca ;propagate bw bit
rr h ;
rr l ;into HL
ex de,hl ;swap sides
st_lp1:
djnz st_lp0 ;loop
inc l ;set marker
ex de,hl ;swap buffers
adjust:
add hl,hl ;get bit
rr d ;into
rr e ;DE
jr c,adjust ;repeat if marker found (BIT = 1)
inc c ;test C
jr z,print_line ;if it was 00(White) then swap buffers
ex de,hl ;
adj_skp:
jr print_line ;jump to printing line
data_line:
ld d,(ix+00h) ;pre load D
cp 1fh ;
jr c,bit6_test ;
inc ixl ;
bit6_test:
add a,a ;test BIT 6
jr nc,bit5_test ;next if '0'
long_line:
ld l,a ;remainder of A into L - 6 bits
and b ;mask upper 3 bits E0h
add hl,hl ;
add hl,hl ;
add hl,hl ;
ld e,a ;
ll_lp0:
inc c ;B=FF to 00, W=00 to 01
jr z,blk1 ;if black, jump to get black2
wht1:
ld d,(ix+00h) ;get White R
blk1:
inc ix ;point to Black L
jr z,blk2
wht2:
ld h,(ix+01h) ;get Black L
jr blk3
blk2:
ld h,(ix+00h)
blk3:
inc ixl
inc ixl
jr print_line
bit5_test:
add a,a ;test BIT 5
jr nc,bit4_test ;
bit5_set:
add a,d ;get Left switch data in A then add it to Right buffer byte t ocreate the H byte
jr bit4_res+1 ;
bit4_test:
add a,a ;test BIT 4
jr nc,bit4_res ;if bit ='0' then the data for BWRL is in the 4 bits remaining in A
bit4_set:
rra ;re-use bit to fill BIT 7, creating a left orientated mask
and c ;mask with C BW byte to create 5 bit overlay mask of ccccc000
xor d ;create the Black or White Left and Right buffer bytes
bit4_res:
ld d,a ;load Right buffer
ld h,a ;load Left buffer
print_line:
ex (sp),hl ;put HL Left buffer on stack and retrieve screen address
ex de,hl ;swap register pair, DE=screen address, HL=buffer
ld c,80h ;bit mask R&L
right:
call place_bit ;
rrc c ;right bit mask move
jr nc,ovr21 ;
inc e ;
ovr21:
djnz right ;rpt if not 00
rst_left:
ld c,80h
pop hl ;LHS data retrieve
pop de ;reset screen address
left:
rlc c ;next left bit
jr nc,ovr22 ;
dec e ;
ovr22:
call place_bit ;
djnz left ;repeat
pop hl ;restore screen address
ld a,ixl ;test for switch line
switch:
cp 00h ;line to test for
ret nz ;
set_jump:
ex af,af' ;retrieve jump line
ld ixl,a ;update IX
ret ;finish (33)
place_bit:
ld a,h ;test whether HL contains 8000h
or l ;
sub 80h ;
jr nz,ovr20 ;
ld h,a ;if so, zero the register and
ld b,01h ;set the counter to finish on this pass
ovr20:
add hl,hl ;get data bit
sbc a,a ;
ex de,hl ;swap to screen addr
xor (hl) ;
and c ;
xor (hl) ;
ld (hl),a ;place BIT
ex de,hl ;swap back to data register
ret ;RET
;(149)
data_17:
db 05h,07h,09h,0bh,0dh,09h,07h,05h
db 03h,03h,03h,03h,03h,03h,03h,03h;01h(use BC op-code) ;17 bytes
chess_builder:
ld bc,00c0h ;start address of board
main_loop:
ld ix,gfx_data ;IX reset address
ld d,b ;D=00h
dec b ;B=FFh
ld a,(bc) ;get piece occupying square into A
ld (main_call+1),a ;store piece no.
get_piece_height:
ld hl,piece_sizes-2 ;piece sizes & positions table base address
rra ;find piece data
ld b,a ;/2 into L
add a,a ;X2
add a,b ;+L = X3 = Trigger line, jump line, piece height
add a,l ;
ld l,a ;
ld a,(hl) ;this byte determines which index line we make the jump at
ld (switch+1),a ;
inc l ;
jump_to:
ld a,(hl) ;
ex af,af' ;this is the index line to jump to.
inc l ;
set_height:
ld b,(hl) ;this is the piece height
calc_square_addr:
ld a,c
ld hl,2822h ;HL=square 00 address
ld e,l ;DE=0022h
csa_lp1:
rra ;get lsb into carry
jr nc,csa_ovr ;
add hl,de ;
csa_ovr:
rl e ;E x 2
jr nc,csa_lp2 ;
ld e,1eh ;2nd part E value
csa_lp2:
or a
jr nz,csa_lp1 ;loop if not found
csa_lp3:
sla h ;H x 8
jr nc,csa_lp3 ;
ld e,80h ;set the add line BIT mask to 80h
get_len:
push de ;save line
push bc ;save height + current square no.
current_square:
ld a,c ;c=curent square
and 09h ;
jp pe,main_call ;if white square, jump to main call
;change to JP PO to effectively rotate the board
;90 degrees.
new_calc_line:
ld a,d ;D=current line
sub 11h ;are we above the height of the board square?
jr nc,main_call ;if so, skip drawing the line
adc a,d ;
jr nc,ovr_e ;
jr z,skp1 ;
dec a ;
skp1:
cpl ;
ovr_e:
and 0fh ;
inc a ;
ld b,a ;line length /2 in B
add_line_in:
ld d,l ;save HL position
addl_lp1:
rlc e ;next bit left
jr nc,addl_ovr1 ;
dec l ;update HL if theres a carry
addl_ovr1:
djnz addl_lp1 ;loop
draw_line:
add a,a ;x2 to get line length
ld b,a ;into B again
addl_lp2:
ld a,(hl) ;
or e ;
ld (hl),a ;merge bit with screen content
rrc e ;next right bit
jr nc,addl_ovr2 ;
inc l ;update HL if carry occurs
addl_ovr2:
djnz addl_lp2 ;
ld l,d ;restore HL
main_call:
ld a,00h ;piece occupying the current square
or a ;is it empty?
call nz,chess_2018A ;call main build routine if a piece occupies the square
next_line_up:
ld a,h ;fairly standard stuff
dec h ;I'm sure we're all
and 07h ;familiar with!
jr nz,nlu_end ;
ld a,l ;
add a,0e0h ;
ld l,a ;
sbc a,a ;
and 08h ;
add a,h ;
ld h,a ;
nlu_end:
pop bc ;B=height C=current square
pop de ;current line
inc d ;
djnz get_len ;inner loop for pieces
end_check_board:
inc c ;next square
jr nz,main_loop ;repeat if needed
ret ;ret
initialise_board:
ld de,0ffc0h
ld b,d
ld c,d
ld hl,data_17
ib_loop1:
ld a,(hl)
dec a
ld (bc),a
ldi
jr nz,ib_loop1
dec e
ld b,20h
ib_loop2:
ld (de),a
inc e
djnz ib_loop2
ret ;23 bytes (+17 data)
piece_sizes:
; SW JL HT
db 11h ;square only - will use 2 previous bytes unimportant.
db 28h,6ch,24h ;pawn
db 31h,88h,29h ;castle
db 28h,0a0h,2eh ;knight
db 42h,5ch,2fh ;bishop
db 44h,51h,2fh ;queen
db 28h,28h,31h ;king
Way back a couple of years ago when I first began trying to compress the whole thing from the original sprites created in the early 90's, which were 4000 bytes alone!, I envisaged needing at least 400 bytes free out of 1k in order to produce some sort of basic GUI and Chess logic. Well, I do now seem to have reached that tipping point, so I think as soon as I get it below 600 bytes, then I will begin the next phase of trying to make it actually playable somehow.
Would 1k chess engine for zx81 be helpful?arkannoyed wrote: ↑Tue Jul 10, 2018 1:18 pmWay back a couple of years ago when I first began trying to compress the whole thing from the original sprites created in the early 90's, which were 4000 bytes alone!, I envisaged needing at least 400 bytes free out of 1k in order to produce some sort of basic GUI and Chess logic. Well, I do now seem to have reached that tipping point, so I think as soon as I get it below 600 bytes, then I will begin the next phase of trying to make it actually playable somehow.
Reduce the pieces’ dimensions.arkannoyed wrote: ↑Sun Jul 15, 2018 9:06 am I’ve no idea how I might achieve that though as we’re at 593, which is 81 bytes too big!