( cards.tal )

( CARD LAYOUT )
( )
( cards are stored as 16-bit values. )
( the high byte holds the flags. )
( the low byte holds the card id. )
( )
( NOTE: this layout predates the one used by kodiak.tal )
(       so, that file has functions to convert from its )
(       card representation to this one for looking up tiles. )
( )
( FLAGS )
(   bit 1:    flipping, #80 face down, #00 face up )
(   bits 2-6: unused )
(   bits 7-8: rotation, #00 north, #01 east, #02 south, #03 west )
( )
( IDENTIFIER )
(   00: ace of spades )
(   01: two of spades )
(   ... )
(   0c: king of spades )
(   0d: ace of hearts )
(   0e: two of hearts )
(   ... )
(   19: king of hearts )
(   1a: ace of diamonds )
(   1b: two of diamonds )
(   ... )
(   26: king of diamonds )
(   27: ace of clubs )
(   28: two of clubs )
(   33: king of clubs )

@set-fg ( -> ) #40 ,set-sprite/layer STR JMP2r
@set-bg ( -> ) #00 ,set-sprite/layer STR JMP2r

@set-sprite ( byte^ -> )
    LIT [ &layer 00 ] ORA .Screen/sprite DEO JMP2r

@set-sprite-3x ( byte^ -> )
    ,set-sprite/layer LDR ORA .Screen/sprite DEOk DEOk DEO JMP2r

@draw-background ( -> )
    #01 .Screen/auto DEO
    #0000 .Screen/y DEO2
    ;tiles #0200 ADD2 .Screen/addr DEO2
    .height LDZ2 #03 SFT2 #0000 &yloop
    #0000 .Screen/x DEO2
    .width LDZ2 #03 SFT2 #0000 &xloop
    #81 .Screen/sprite DEO
    INC2 GTH2k ?&xloop
    POP2 POP2
    .Screen/y DEI2 #0008 ADD2 .Screen/y DEO2
    INC2 GTH2k ?&yloop
    POP2 POP2 JMP2r

@draw-spot-down ( -> )
    #16 .Screen/auto DEO        ( ; draw 2 tiles, increment x and addr )
    ;masks #0100 ADD2 .Screen/addr DEO2
    #8d set-sprite-3x
    JMP2r

( assumes x/y already set )
@draw-mask-down ( -> )
    #16 .Screen/auto DEO        ( ; draw 2 tiles, increment x and addr )
    ;masks #0100 ADD2 .Screen/addr DEO2
    #86 set-sprite-3x ( TODO fixme )
    JMP2r

( assumes x/y already set )
@draw-face-down ( -> )
    #16 .Screen/auto DEO        ( ; draw 2 tiles, increment x and addr )
    ;tiles #0100 ADD2 .Screen/addr DEO2
    #81 set-sprite-3x
    JMP2r

@card-is-red ( idx* -> bool^ )
    #000c DIV2
    NIP #03 MUL #02 AND JMP2r ( [q*3]&2 )

@find-middle-addr ( idx* -> addr* )
    #000d DIV2k STH2k MUL2 SUB2 ( r* [q*] )
    DUP2 #000a LTH2 ?&normal
    DUP2 #000a NEQ2 ?&not-j POP2 #0200 !&face
    &not-j #000b NEQ2 ?&not-q #0100 !&face
    &not-q #0000
    &face ;tiles ADD2 #00c0 ADD2
    STH2r card-is-red ?&is-red JMP2r
    &is-red #0020 ADD2 JMP2r
    &normal POP2 POP2r ;tiles #0020 ADD2 JMP2r

( assumes x/y already set )
@draw-mask-up ( idx* -> )
    #16 .Screen/auto DEO        ( ; draw 2 tiles, increment x and addr )
    #00ff AND2                  ( idx* ; remove rotation/flip info for now )
    DUP2                        ( idx* idx* )
    #000d DIV2k STH2k MUL2 SUB2 ( idx* r* [q*] )
    #0100 MUL2 ;masks #0300 ADD2 ( idx* 128r* card+384* [q*] )
    ADD2 STH2r #0020 MUL2 ADD2  ( idx* a=card+384+128r+16q* )
    STH2k .Screen/addr DEO2     ( idx* [a*] )
    #86 set-sprite      ( idx* [a*] ; draw top of card )
    find-middle-addr            ( mid* [a*] )
    ;tiles SUB2 ;masks ADD2
    .Screen/addr DEO2           ( [a*] )
    #86 set-sprite      ( [a*] ; draw middle of card )
    STH2r DUP2 #0010 ADD2       ( a* a+8* )
    SWP2 #0008 .Screen/x DEI2 ADD2 .Screen/x DEO2
    .Screen/addr DEO2           ( )
    #01 .Screen/auto DEO        ( ; draw 1 tile, increment x )
    #b6 set-sprite      ( ; draw bottom left of card )
    .Screen/addr DEO2           ( )
    #b6 set-sprite      ( ; draw bottom right of card )
    JMP2r

( assumes x/y already set )
@draw-face-up ( idx* -> )
    #16 .Screen/auto DEO        ( ; draw 2 tiles, increment x and addr )
    #00ff AND2                  ( idx* ; remove rotation/flip info for now )
    DUP2                        ( idx* idx* )
    #000d DIV2k STH2k MUL2 SUB2 ( idx* r* [q*] )
    #0100 MUL2 ;tiles #0300 ADD2 ( idx* 256r* card+768* [q*] )
    ADD2 STH2r #0020 MUL2 ADD2  ( idx* a=card+768+256r+32q* )
    STH2k .Screen/addr DEO2     ( idx* [a*] )
    #81 set-sprite      ( idx* [a*] ; draw top of card )
    find-middle-addr            ( mid* [a*] )
    .Screen/addr DEO2           ( [a*] )
    #81 set-sprite      ( [a*] ; draw middle of card )
    STH2r DUP2 #0010 ADD2       ( a* a+16* )
    SWP2 #0008 .Screen/x DEI2 ADD2 .Screen/x DEO2
    .Screen/addr DEO2           ( )
    #01 .Screen/auto DEO        ( ; draw 1 tile, increment x )
    #b1 set-sprite      ( ; draw bottom left of card )
    .Screen/addr DEO2           ( )
    #b1 set-sprite      ( ; draw bottom right of card )
    JMP2r

@init-rng-from-datetime ( -> )
    #00 .DateTime/dow #5180 MUL2
    #00 .DateTime/hr DEI #0e10 MUL2 ADD2
    #00 .DateTime/min DEI #003c MUL2 ADD2
    #00 .DateTime/sec DEI ADD2 ( s* )
    DUP2 .DateTime/doy DEI2 EOR2 ( s* sdoy* )
    #0001 ROT2 OVR2             ( y* 1* x* 1* )
    ORA2 ;rng-x STA2            ( y* 1* )
    ORA2 ;rng-x STA2 JMP2r      ( )

@random ( -> x* )
    ;rng-x LDA2 DUP2 #50 SFT2 EOR2 ( t=x^[x<<5]* )
    ;rng-y LDA2 DUP2 ;rng-x STA2   ( t* y* ; x<-y )
    DUP2 #01 SFT2 EOR2             ( t* u=y^[y>>1]* )
    SWP2 DUP2 #03 SFT2 EOR2        ( u* v=t^[t>>3]* )
    EOR2 DUP2 ;rng-y STA2 JMP2r    ( u^v* ; y<-u^v )

( 52 cards x 4 bytes per card = 208 bytes )
( each card has: )
( )
( - byte 1: flags )
( - byte 2: card suit/value )
( - byte 3: x position )
( - byte 4: y position )

( @rng &x $2 &y $2 )
@rng-x $2
@rng-y $2

( each tile is 16 bytes: a 2-bit 8x8 image )
@tiles ~card-sprites.tal

( each mask tile is 16 bytes: a 2-bit 8x8 image )
@masks ~mask2.tal