game:

    push ecx                        ; save the value in ecx

    xor byte [board + 19], 1        ; player_number is turned to its opposite (1 -> 0 or 0 -> 1)
    mov eax, 4                      ; SYS_WRITE board
    mov ebx, 1
    mov ecx, board
    mov edx, 19
    int 0x80

    mov eax, 3                      ; SYS_READ user_input
    mov ebx, 2
    mov ecx, board + 20
    mov edx, 2
    int 0x80

    sub byte [board + 20], 49       ; user_input is converted from ascii to equivalent integer and lowered by 1 (it is lowered so that input is 1-9 and not 0-8)
    mov eax, board + 7              ; board's address moved into eax register
    add al, [board + 20]            ; adjust address based on user_input

    cmp al, 10                      ; since the board has two new-lines in it, this adjusts the address based on them. (AL starts at 00 for the first address in .data)
    jl n
    inc al
    cmp al, 14
    jl n
    inc al

n:
    mov bl, [board + 19]            ; move player_number into bl, turn it into ascii, then place in the spot on the board that corresponds to player_input
    add bl, 48
    mov byte [eax], bl

    mov ecx, 8                      ; prepare horizontal loop

h:
    mov al, [board + ecx + 7]       ; adds horizontal spaces together and checks them against 144 and 147 (if they equal either one they are all the same)
    add al, [board + ecx + 8]
    add al, [board + ecx + 9]
    cmp al, 144
    je exit
    cmp al, 147
    je exit

    sub ecx, 4                      ; horizontal loop
    cmp ecx, 0
    jge h

    mov ecx, 2                      ; prepare vertical loop

v:
    mov al, [board + ecx + 7]       ; same as previous but for vertical
    add al, [board + ecx + 11]
    add al, [board + ecx + 15]
    cmp al, 144
    je e
    cmp al, 147
    je e

    dec ecx                         ; vertical loop
    cmp ecx, 0
    jge v

    mov al, [board + 7]             ; checks first diagonal
    add al, [board + 12]
    add al, [board + 17]
    cmp al, 144
    je e
    cmp al, 147
    je e

    mov al, [board + 9]             ; checks second diagonal
    add al, [board + 12]
    add al, [board + 15]
    cmp al, 144
    je e
    cmp al, 147
    je e

    pop ecx                         ; loop
    inc cl
    cmp cl, 9
    jl g
exit:
    mov eax, 0x1    ; sys_exit
    xor ebx, ebx
    int 0x80
section .data
    board db 27,"[H",27,"[2J___",10,"___",10,"___",10,1,1

    ; 27,"[H",27,"[2J" is the code for a console clear. Having it at the start effectively clears the console each time the board is displayed
    ; "___",10,"___",10,"___",10 is the board
    ; 1,1 are 'variables' (player_number and user_input). Normally they would be in the .bss section, but to conserve space, I made them .data