org 100h
jmp start
s_size equ 7
snake dw s_size dup(0)
tail dw ?
left equ 4bh
right equ 4dh
up equ 48h
down equ 50h
cur_dir db right
wait_time dw 0
msg1 db " Snake game", 0dh,0ah,0ah
db " Yilani on oklari ile kontrol et.", 0dh,0ah,0ah
db " Duvarlara degersen yanarsin!!!", 0dh,0ah, 0ah
db " Esc programi sonlandirir.", 0dh,0ah,0ah,0ah
db " Baslamak icin bir tusa bas.$"
msg3 db "", 0dh,0ah, 0ah,0ah, 0ah,0ah,0ah, 0ah,0ah,0ah, 0ah,0ah,0ah, 0ah,0ah, 0ah, 0ah, 0ah,
db " !!GAME OVER!!", 0dh,0ah,0ah, 0ah, 0ah, 0ah,0ah, 0ah,0ah,
db " $"
start:
; print welcome message:
mov dx, offset msg1
mov ah, 9
int 21h
; wait for any key:
mov ah, 00h
int 16h
mov ax, 0xB800 ; Video memory segment
mov es, ax ; Set ES segment to video memory
es: mov [09b4h],'?'
es: mov [0848h],'0'
es: mov [06b0h],'0'
es: mov [01E8h],'0'
; hide text cursor:
mov ah, 1
mov ch, 2bh
mov cl, 0bh
int 10h
game_loop:
; === select first video page
mov al, 0
mov ah, 05h
int 10h
mov dx, snake[0]
; set cursor at dl,dh
mov ah, 02h
int 10h
; print 'o' at the location:
mov al, 'o'
mov ah, 09h
mov bl, 0eh
mov cx, 1
int 10h
; === keep the tail:
mov ax, snake[s_size * 2 - 2]
mov tail, ax
call move_snake
; === hide old tail:
mov dx, tail
; set cursor at dl,dh
mov ah, 02h
int 10h
; print '.' at the old location:
mov al, ' '
mov ah, 09h
mov bl, 0eh
mov cx, 1
int 10h
check_for_key:
; === check for player commands:
mov ah, 01h
int 16h
jz no_key
mov ah, 00h
int 16h
cmp al, 1bh ; esc - key?
je stop_game ;
mov cur_dir, ah
no_key:
; === wait a few moments here:
; get number of clock ticks
; (about 18 per second)
; since midnight into cx:dx
mov ah, 00h
int 1ah
cmp dx, wait_time
jb check_for_key
add dx, 4
mov wait_time, dx
; === eternal game loop:
jmp game_loop
stop_game:
; show cursor back:
mov ah, 1
mov ch, 0bh
mov cl, 0bh
int 10h
ret
move_snake proc near
; set es to bios info segment:
mov ax, 40h
mov es, ax
; point di to tail
mov di, s_size * 2 - 2
; move all body parts
; (last one simply goes away)
mov cx, s_size-1
move_array:
mov ax, snake[di-2]
mov snake[di], ax
sub di, 2
loop move_array
cmp cur_dir, left
je move_left
cmp cur_dir, right
je move_right
cmp cur_dir, up
je move_up
cmp cur_dir, down
je move_down
jmp stop_move ; no direction.
move_left:
mov al, b.snake[0]
dec al
mov b.snake[0], al
cmp al, -1
jne stop_move
mov al, es:[4ah] ; col number.
dec al
call game_over ; return to right.
jmp stop_move
move_right:
mov al, b.snake[0]
inc al
mov b.snake[0], al
cmp al, es:[09b4h]
cmp al, es:[4ah] ; col number.
jb stop_move
call game_over ; return to left.
jmp stop_move
move_up:
mov al, b.snake[1]
dec al
mov b.snake[1], al
cmp al, -1
jne stop_move
mov al, es:[84h] ; row number -1.
call game_over ; return to bottom.
jmp stop_move
move_down:
mov al, b.snake[1]
inc al
mov b.snake[1], al
cmp al, es:[84h] ; row number -1.
jbe stop_move
call game_over ; return to top.
jmp stop_move
stop_move:
ret
grow_snake:
ret
game_over:
mov dx, offset msg3
mov ah, 9
int 21h
; wait for any key:
mov ah, 00h
int 16h
move_snake endp
I tried to grow snake when it reaches to these memory locations:
es: mov [09b4h],'?'
es: mov [0848h],'0'
es: mov [06b0h],'0'
es: mov [01E8h],'0'
but i couldnt get it done. My first plan was check it in stop_game and call grow_snake in there but i didnt work no matter how i tried. But couldnt do anything about grow_snake part triend to inc s_size but it also doesnt work.
How am i gonna check if snake reaches the memory location that i printed something and gro accordingly?
Thank you.
Update
If You don't mind I wrote CheckFood proc after printing snake's head on screen. Which translates head's X Y coords to offset in mem and search if there is same address in array targetInMem.
org 100h
jmp start
s_size equ 7
snake dw s_size dup(0)
tail dw ?
left equ 4bh
right equ 4dh
up equ 48h
down equ 50h
targetInMem dw 09b4h,0848h,06b0h,01E8h
cur_dir db right
wait_time dw 0
Food1 db "Food 1 ", 0dh,0ah,'$'
Food2 db "Food 2 ", 0dh,0ah,'$'
Food3 db "Food 3 ", 0dh,0ah,'$'
questMark db "Question mark", 0dh,0ah,'$'
msg1 db " Snake game",0dh,0ah,0ah
db " Yilani on oklari ile kontrolet.",0dh,0ah,0ah
db " Duvarlara degersen yanarsin!!!", 0dh,0ah, 0ah
db " Esc programi sonlandirir.", 0dh,0ah,0ah,0ah
db " Baslamak icin bir tusa bas.$"
msg3 db "", 0dh,0ah, 0ah,0ah, 0ah,0ah,0ah, 0ah,0ah,0ah, 0ah,0ah,0ah,
db " !!GAME OVER!!", 0dh, 0ah,
db 0ah, 0ah, 0ah, 0ah,0ah, 0ah,0ah," $"
start:
mov ax,0003h
int 10h
; print welcome message:
mov dx, offset msg1
mov ah, 9
int 21h
; wait for any key:
mov ah, 00h
int 16h
mov ax, 0xB800 ; Video memory segment
mov es, ax ; Set ES segment to video memory
es: mov [09b4h],'?'
es: mov [0848h],'1'
es: mov [06b0h],'2'
es: mov [01E8h],'3'
; hide text cursor:
mov ah, 1
mov ch, 2bh
mov cl, 0bh
int 10h
game_loop:
; === select first video page
mov al, 0
mov ah, 05h
int 10h
mov dx, snake[0]
; set cursor at dl,dh
mov ah, 02h
int 10h
; print 'o' at the location:
mov al, 'o'
mov ah, 09h
mov bl, 0eh
mov cx, 1
int 10h
call CheckFood
; === keep the tail:
mov ax, snake[s_size * 2 - 2]
mov tail, ax
call move_snake
; === hide old tail:
mov dx, tail
; set cursor at dl,dh
mov ah, 02h
int 10h
; print '.' at the old location:
mov al, ' '
mov ah, 09h
mov bl, 0eh
mov cx, 1
int 10h
check_for_key:
; === check for player commands:
mov ah, 01h
int 16h
jz no_key
mov ah, 00h
int 16h
cmp al, 1bh ; esc - key?
je stop_game ;
mov cur_dir, ah
no_key:
; === wait a few moments here:
; get number of clock ticks
; (about 18 per second)
; since midnight into cx:dx
mov ah, 00h
int 1ah
cmp dx, wait_time
jb check_for_key
add dx, 4
mov wait_time, dx
; === eternal game loop:
jmp game_loop
stop_game:
; show cursor back:
mov ah, 1
mov ch, 0bh
mov cl, 0bh
int 10h
ret
move_snake proc near
; set es to bios info segment:
mov ax, 40h
mov es, ax
; point di to tail
mov di, s_size * 2 - 2
; move all body parts
; (last one simply goes away)
mov cx, s_size-1
move_array:
mov ax, snake[di-2]
mov snake[di], ax
sub di, 2
loop move_array
cmp cur_dir, left
je move_left
cmp cur_dir, right
je move_right
cmp cur_dir, up
je move_up
cmp cur_dir, down
je move_down
jmp stop_move ; no direction.
move_left:
mov al, b.snake[0]
dec al
mov b.snake[0], al
cmp al, -1
jne stop_move
mov al, es:[4ah] ; col number.
dec al
call game_over ; return to right.
jmp stop_move
move_right:
mov al, b.snake[0]
inc al
mov b.snake[0], al
cmp al, es:[09b4h]
cmp al, es:[4ah] ; col number.
jb stop_move
call game_over ; return to left.
jmp stop_move
move_up:
mov al, b.snake[1]
dec al
mov b.snake[1], al
cmp al, -1
jne stop_move
mov al, es:[84h] ; row number -1.
call game_over ; return to bottom.
jmp stop_move
move_down:
mov al, b.snake[1]
inc al
mov b.snake[1], al
cmp al, es:[84h] ; row number -1.
jbe stop_move
call game_over ; return to top.
jmp stop_move
stop_move:
ret
grow_snake:
ret
CheckFood:
pusha
xor ax,ax ;calculate head position
mov al,dh;[yPos]
mov cl,80
mul cl
xor cx,cx
mov cl,dl;[xPos]
add ax,cx ; ax offset in mem
mov cx,2
mul cx
mov bx, offset targetInMem
mov cx,4
push dx
MemSearch: ;search array, what snake eat
mov dx,[bx]
cmp dx,ax
jz PrintMsg
add bx,2
loop MemSearch
jmp NoFood
PrintMsg:
; set cursor at dl,dh
mov ah, 2
mov bh,0
mov dx, 1010h
int 10h
cmp cx,4
jz msgFood1
cmp cx,3
jz msgFood2
cmp cx,2
jz msgFood3
cmp cx,1
jz qMark
jmp NoFood
msgFood1:
mov dx, offset questMark
mov ah, 9
int 21h
jmp NoFood
msgFood2:
mov dx, offset Food1
mov ah, 9
int 21h
jmp NoFood
msgFood3:
mov dx, offset Food2
mov ah, 9
int 21h
jmp NoFood
qMark:
mov dx, offset Food3
mov ah, 9
int 21h
NoFood:
pop dx
popa
ret
game_over:
mov dx, offset msg3
mov ah, 9
int 21h
; wait for any key:
mov ah, 00h
int 16h
move_snake endp
I don't know if this will be Your answer. This is just an example. Screen coords translate to video memory offset.
xor ax,ax ;calculate head position mov al,[yPos] mov cl,80 mul cl xor cx,cx mov cl,[xPos] add ax,cx mov cx,2 mul cx mov cx,[targetInMem] cmp cx,ax jz game_over
And Example below
org 100h
jmp start
s_size equ 7
snake dw s_size dup(0)
tail dw ?
Head db 79
KeyNumber db ?
xPos db 2 ;cursor x position on screen
yPos db 2 ;cursor y position on screen
targetX db 13
targetY db 3
targetInMem dw 01fah
msg1 db "Use arrows. $"
msg2 db "Target reached!$"
msg3 db "!!GAME OVER!!$"
;;;Macros
SetCharAttrib MACRO char,attr
push bx
push ax
push dx
push cx
mov ah,9
mov al,char
mov cx,1
;mov dl,y
;mov dh,x
mov bh,0
mov bl,attr
int 10h
pop cx
pop dx
pop ax
pop bx
ENDM
SetCursor MACRO x,y
push bx
push ax
push dx
push cx
mov ah,02h
mov dl,x
mov dh,y
mov bh, 00h
int 10h
pop cx
pop dx
pop ax
pop bx
ENDM
start:
mov ax,0003h
int 10h
mov ax, 0xB800 ; Video memory segment
mov es, ax ; Set ES segment to video memory
es: mov [01fah],'X' ;506
; print welcome message:
mov dx, offset msg1
mov ah, 9
int 21h
; hide text cursor:
mov ah, 1
mov ch, 2bh
mov cl, 0bh
int 10h
;set cursor position
SetCursor [xPos],[yPos]
SetCharAttrib 79,14
game_loop:
; wait for any key:
call CheckKey
cmp al,27 ;Esc, exit program
jz stop_game
;SetCursor [xPos]+12,[yPos]
call BoardAction
SetCharAttrib 0,0
SetCursor [xPos],[yPos]
SetCharAttrib 79,14
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;; Translate from screen coords
;;;; to video mem adress
xor ax,ax ;calculate head position
mov al,[yPos]
mov cl,80
mul cl
xor cx,cx
mov cl,[xPos]
add ax,cx
mov cx,2
mul cx
mov cx,[targetInMem]
cmp cx,ax
jz game_over
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
; === eternal game loop:
jmp game_loop
stop_game:
; show cursor back:
mov ah, 1
mov ch, 0bh
mov cl, 0bh
int 10h
jmp game_over
CheckKey Proc
mov ah,0
int 16h
cmp al,0
jz Extended
jmp Normal
Extended:
mov [KeyNumber], ah
mov al,ah
jmp NextTurn
Normal:
mov [KeyNumber], al
NextTurn:
ret
CheckKey Endp
BoardAction Proc
cmp al,77 ;right arrow
jz moveRight
cmp al,75 ;left arrow
jz moveLeft
cmp al,72 ;up arrow
jz moveUp
cmp al,80 ;down arrow
jz moveDown
cmp al,32 ;Space, place X,O on Board
jmp BoardEdge
moveRight:
mov al,[xPos]
cmp al,15
jz BoardEdge
add [xPos],1
jmp BoardEdge
moveLeft:
mov al,[xPos]
cmp al,2
jz BoardEdge
sub [xPos],1
jmp BoardEdge
moveUp:
mov al,[yPos]
cmp al,1
jz BoardEdge
sub [yPos],1
jmp BoardEdge
moveDown:
mov al,[yPos]
cmp al,5
jz BoardEdge
add [yPos],1
BoardEdge:
ret
BoardAction Endp
game_over:
mov dx, offset msg2
mov ah, 9
int 21h
mov ax, 4c00h
int 21h