A Snake game in Assembly language

;////////////////////SYSTEM PROGRAMMING TERM PROJECT///////////////////////////
;
; -This program is a snake game that programmed in 16-bit real-address mode in assembly language. It includes four edges which surround
; game area, a snake that moves consistently, a food which is created randomly, and two walls in the following level
; -Snake is a struct array that consists of x and y coordinates. To print the snake on the console, single 'o' character is used.
; -Food consists of 'x' character, and is created randomly on the screen. When the snake eat the food, it grows up and the food
; created again.0
; -Game is controlled with w,a,s,d. (w = north, a = west, s = south, d = east) w esc = exit the game
; a s d
; -

TITLE Snake

INCLUDE Irvine16.inc


snakeLength=15 ; Keep the max length of the snake
stones=4 ; Keep the length of the wall

up_=1 ; Up
down_=2 ; Down
left_=3 ; Left
right_=4 ; Right

true=5 ; boolean true
false=6 ; boolean false


;Data Segment____________________________________________________________
.data

; Struct of the snake
Snake_ STRUCT
x BYTE ?
y BYTE ?
Snake_ ENDS

; Struct of the stone
Stone_ STRUCT
xPos BYTE ?
yPos BYTE ?
Stone_ ENDS

;------------------------------------------------------------------------
;Procedures Prototype
PrintConsole PROTO
DuvarBas PROTO
Elemanlar PROTO, currX:BYTE,currY:BYTE
;------------------------------------------------------------------------

snake Snake_ snakeLength DUP()
wall Stone_ stones DUP()
wall2 Stone_ stones DUP()

;------------------------------------------------------------------------
; Coordinate variables
;------------------------------------------------------------------------
Xpos BYTE ?
Ypos BYTE ?
Xcu BYTE ?
Ycu BYTE ?
eatX BYTE ?
eatY BYTE ?
yStone BYTE 8
xStone BYTE 60
xStone2 BYTE 20
yStone2 BYTE 8

;------------------------------------------------------------------------
; Messages
;------------------------------------------------------------------------
s DWORD 9
char BYTE 'a'
message BYTE " GAME OVER ",0
messe BYTE " GAME OVER ",0
mes BYTE "CONGRATULATION, You win",0
mes2 BYTE "CONGRATULATION, You win",0
messa BYTE " WELCOME TO SNAKE GAME",0
messa2 BYTE " You can play the game by using",0
messa3 BYTE " w(up),a(left),s(down),d(right) and esc(exit) buttons",0
level2Message BYTE "Level 2 is beginning",0
isLevel byte 0
yourScore BYTE "Your Score :",0
eat BYTE ?
isMeal BYTE ?
t DWORD ?
Bonus DWORD 0
speed DWORD 2000
;________________________________________________________________________


;Code Segment____________________________________________________________
.code

main PROC
mov ax,@data
mov ds,ax

;-----------------------------------------------
;//////// Print the game start message \\\\\\\\\
mov dl,10
mov dh,10
call Gotoxy
mov edx,OFFSET messa
call WriteString
call Crlf
mov edx,OFFSET messa2
call WriteString
call Crlf
mov edx,OFFSET messa3
call WriteString
call Crlf
call WaitMsg

mov eax,0

begin_level:

mov eax,0

cmp isLevel,1
jne noLevel

mov ecx,0
mov esi,0
mov edi,0

mov ecx,stones
mov esi,OFFSET wall
mov al,0

DUVAR:
mov al,yStone
mov (wall[esi]).yPos,al
inc yStone
mov al,xStone
mov (wall[esi]).xPos,al

mov al,yStone2
mov (wall2[esi]).yPos,al
inc yStone2
mov al,xStone2
mov (wall2[esi]).xPos,al

add esi, TYPE wall
Loop DUVAR

mov esi,OFFSET snake

call DuvarBas
mov char,left_

noLevel:

mov Xpos,35
mov Ypos,12

mov isMeal,false
mov esi,OFFSET snake
mov ecx,s

;/////////////////The first length of snake//////////////////////
L2:
mov al,Xpos
mov (snake[esi]).x,al
mov al,Ypos
mov (snake[esi]).y,al
inc Xpos
add esi,TYPE snake

Loop L2
;/////////////////////////////////////////////////////////////

mov esi,OFFSET snake

;////////////////////// Game Loop \\\\\\\\\\\\\\\\\\\\\\
Game_Start:


call ClrScr

;////////////////////// isMeal
;////////////////////// Check the food is whether eaten or not
;////////////////////// If food is eaten (isMeal) is false then generate a new food
cmp isMeal,false
jne atla
mov eax,24
call RandomRange
mov dh,al ;ROW
mov eax,79
call RandomRange
mov dl, al ;Coloumn
call Gotoxy
mov eatY,dh
mov eatX,dl
jmp atla2

;////////////////////// If food has not eaten yet
; then print the food on screen with same coordinates
atla:
mov dh,eatY
mov dl,eatX
call Gotoxy

atla2:
mov ah,2
mov dl,15
int 21h
mov isMeal,true

;////////////////////// Check whether the food is eaten or not
;////////////////////// If it is eaten, then (isMeal) is false
mov al,(snake[esi]).x
cmp eatX,al
jne atla3
mov al,(snake[esi]).y
cmp eatY,al
jne atla3
inc s
add Bonus,2
mov isMeal,false

;////////////////////// Check the snake is long enough to win the level
cmp s,SnakeLength
je cik2

atla3:
;//////////////////////Accident/////Collision///

mov al,(snake[esi]).x
mov ah,(snake[esi]).y

mov ecx,s


kaza:

add esi,TYPE snake

cmp al,(snake[esi]).x
jne isKaza
cmp ah,(snake[esi]).y
je cik

isKaza:
Loop kaza

;////////////////////// Second Level \\\\\\\\\\\\\\\\\\\\\\
cmp isLevel,1
jne go1
mov esi,OFFSET snake

mov al,(snake[esi]).x
mov ah,(snake[esi]).y

mov esi,OFFSET wall
mov ecx,stones
;/////////////////////// Did snake crash the walls?
kaza2:
cmp al,(wall[esi]).xPos
jne git_
cmp ah,(wall[esi]).yPos
jne git_
jmp cik
;/////////////////////// Game Over
git_:
cmp al,(wall2[esi]).xPos
jne git2_
cmp ah,(wall2[esi]).yPos
jne git2_
jmp cik

git2_:
add esi,TYPE wall
Loop kaza2

mov esi,OFFSET snake

go1:

;////////////////////// Collision \\\\\\\\\\\\\\\\\\\\\\

mov esi,OFFSET snake

;////////////////////// Is snake out ?
mov al,(snake[esi]).x
mov ah,(snake[esi]).y

cmp al,79
je cik
cmp al,0
je cik
cmp ah,0
je cik
cmp ah,24
je cik

;////////////////////// Get the character using int21h fcn 6
;////////////////////// Keep the character in 'char' variable

mov al,0
mov ah,6
mov dl,0FFh
int 21h
jz skip
mov char,al
skip:
;////////////////////// Compare the 'char' value with arrow keys (a,s,d,f)
;////////////////////// If any keys pressed, use the last 'char' value
cmp char,'w'
je UP
cmp char,'s'
je DOWN
cmp char,'a'
je LEFT
cmp char,'d'
je RIGHT
cmp char,1Bh ;/////////////Press ESC to terminate the game//////
je cik

jmp kalan ;////////////////////// Use the last 'char' value

call PrintConsole ; Print the snake to screen
cmp isLevel,1
jne git
call DuvarBas ;If level is 2, print also the wall
git:

;////////////////////// if the key is UP, w
UP:
mov al,(snake[esi]).x
mov ah,(snake[esi]).y
mov Xcu,al
mov Ycu,ah

mov al,(snake[esi]).y
dec al
mov (snake[esi]).y,al
mov char,up_

INVOKE Elemanlar,Xcu,Ycu

call PrintConsole
cmp isLevel,1
jne git2
call DuvarBas
git2:
jmp devam

;////////////////////// if the key is DOWN, s
DOWN:
mov al,(snake[esi]).x
mov ah,(snake[esi]).y
mov Xcu,al
mov Ycu,ah

mov al,(snake[esi]).y
inc al
mov (snake[esi]).y,al
mov char,down_

INVOKE Elemanlar,Xcu,Ycu

call PrintConsole
cmp isLevel,1
jne git3
call DuvarBas
git3:


jmp devam
;////////////////////// if the key is LEFT, a
LEFT:
mov al,(snake[esi]).x
mov ah,(snake[esi]).y
mov Xcu,al
mov Ycu,ah

mov al,(snake[esi]).x
dec al
mov (snake[esi]).x,al
mov char,left_

INVOKE Elemanlar,Xcu,Ycu

call PrintConsole
cmp isLevel,1
jne git4
call DuvarBas
git4:
jmp devam

;////////////////////// if the key is RIGHT, d
RIGHT:
mov al,(snake[esi]).x
mov ah,(snake[esi]).y
mov Xcu,al
mov Ycu,ah

mov al,(snake[esi]).x
inc al
mov (snake[esi]).x,al
mov char,right_

INVOKE Elemanlar,Xcu,Ycu

call PrintConsole
cmp isLevel,1
jne git5
call DuvarBas
git5:
jmp devam

;///////////////// If user doesn't press any key \\\\\\\\\\\\\
;///////////////// Compare the last value of 'char' variable
;///////////////// Keep going with it
kalan:
cmp char,up_
jne bir
mov al,(snake[esi]).x
mov ah,(snake[esi]).y
mov Xcu,al
mov Ycu,ah

mov al,(snake[esi]).y
dec al
mov (snake[esi]).y,al
mov char,up_

INVOKE Elemanlar,Xcu,Ycu

call PrintConsole
cmp isLevel,1
jne git6
call DuvarBas
git6:

bir:
cmp char,left_
jne iki
mov al,(snake[esi]).x
mov ah,(snake[esi]).y
mov Xcu,al
mov Ycu,ah

mov al,(snake[esi]).x
dec al
mov (snake[esi]).x,al
mov char,left_

INVOKE Elemanlar,Xcu,Ycu

call PrintConsole
cmp isLevel,1
jne git7
call DuvarBas
git7:

iki:
cmp char,down_
jne uc
mov al,(snake[esi]).x
mov ah,(snake[esi]).y
mov Xcu,al
mov Ycu,ah

mov al,(snake[esi]).y
inc al
mov (snake[esi]).y,al
mov char,down_

INVOKE Elemanlar,Xcu,Ycu

call PrintConsole
cmp isLevel,1
jne git8
call DuvarBas
git8:

uc:
cmp char,right_
jne devam
mov al,(snake[esi]).x
mov ah,(snake[esi]).y
mov Xcu,al
mov Ycu,ah

mov al,(snake[esi]).x
inc al
mov (snake[esi]).x,al
mov char,right_

INVOKE Elemanlar,Xcu,Ycu
call PrintConsole
cmp isLevel,1
jne git9
call DuvarBas
git9:

devam:

mov eax,speed ;///////////////// Snake speed
call Delay

jmp Game_Start

;///////////////// Level is over \\\\\\\\\\\\\\\
;///////////////// If the level is 1, pass to the level 2
;///////////////// If it is 2, game is over
cik:
cmp isLevel,1
je cik3
mov dl,35
mov dh,12
call GotoXy

call ClrScr
;///////////////// Level 1 is over message
mov edx,OFFSET message
call WriteString
call Crlf

;///////////////// First level score
mov edx, OFFSET yourScore
call WriteString
mov eax,bonus
call WriteInt
call Crlf

call WaitMsg
jmp over

;///////////////// If the level is 2
cik3:
mov dl,35
mov dh,12
call GotoXy
call ClrScr

;///////////////// Game Over message
mov edx,OFFSET messe
call WriteString
call Crlf

;///////////////// Total game score
mov edx, OFFSET yourScore
call WriteString
mov eax,bonus
call WriteInt
call Crlf

call WaitMsg
jmp over

;///////////////// Congratulations! \\\\\\\\\\\\\\\\\
;///////////////// Show the level 1 is over message and the score
;///////////////// Pass to the level 2
cik2:
cmp isLevel,1
je yuce

mov dl,35
mov dh,12
call GotoXy

call ClrScr
mov edx,OFFSET mes
call WriteString
call Crlf
mov edx, OFFSET yourScore
call WriteString
mov eax,bonus
call WriteInt
call Crlf


mov edx,OFFSET level2Message
call WriteString
call Crlf

call WaitMsg

inc isLevel
mov s,12
mov speed,1300
jmp begin_level

;///////////////// Congratulations! \\\\\\\\\\\\\\\\\
;///////////////// Show the level 2 is over message and the total score
;///////////////// Game over
yuce:
mov dl,35
mov dh,12
call GotoXy

call ClrScr
mov edx,OFFSET mes2
call WriteString
call Crlf
mov edx, OFFSET yourScore
call WriteString
mov eax,bonus
call WriteInt
call Crlf

call WaitMsg
jmp over
over:

exit
main ENDP
;________________________________________________________________________

;-----------------------------------------------
PrintConsole PROC
;
; Print snake to console relative to it's x any y coordinate
; Use the second function of interrupt 21 to print the characters
; Receives: nothing
; Returns: nothing
;-----------------------------------------------
pushad

mov ecx,s
mov esi,OFFSET snake

L1:
mov dl,(snake[esi]).x
mov dh,(snake[esi]).y
call Gotoxy

mov ah,2
mov dl,'o'
int 21h

add esi,TYPE snake
LOOP L1

popad
ret
PrintConsole ENDP
;-----------------------------------------------

;-----------------------------------------------
Elemanlar PROC, currX:BYTE,currY:BYTE
;
; Print four character on the screen as the wall
; Check the current direction and print the character in terms of it
; Receives: currX, currY
; currX = The x coordinate of the head of the snake
; currY = The y coordinate of the head of the snake

; Returns: nothing
;-----------------------------------------------
pushad

mov ecx,s
mov esi,OFFSET snake

;///////////////// If the key is up
cmp char,up_
jne emin1

L4:
add esi,TYPE snake
mov al,currX
mov ah,currY
mov bl,(snake[esi]).x
mov bh,(snake[esi]).y
mov (snake[esi]).x,al
mov (snake[esi]).y,ah
mov currX,bl
mov currY,bh
Loop L4

jmp emin_cik

emin1:

;///////////////// If the key is left
cmp char,left_
jne emin2
L5:
add esi,TYPE snake
mov al,currX
mov ah,currY
mov bl,(snake[esi]).x
mov bh,(snake[esi]).y
mov (snake[esi]).x,al
mov (snake[esi]).y,ah
mov currX,bl
mov currY,bh
Loop L5
jmp emin_cik

emin2:

;///////////////// If the key is down
cmp char,down_
jne emin3

L6:
add esi,TYPE snake
mov al,currX
mov ah,currY
mov bl,(snake[esi]).x
mov bh,(snake[esi]).y
mov (snake[esi]).x,al
mov (snake[esi]).y,ah
mov currX,bl
mov currY,bh
Loop L6
jmp emin_cik

emin3:

;///////////////// If the key is right
cmp char,right_
jne emin_cik
L7:
add esi,TYPE snake
mov al,currX
mov ah,currY
mov bl,(snake[esi]).x
mov bh,(snake[esi]).y
mov (snake[esi]).x,al
mov (snake[esi]).y,ah
mov currX,bl
mov currY,bh
Loop L7

jmp emin_cik

emin_cik:

popad
ret
Elemanlar ENDP
;-----------------------------------------------

;-----------------------------------------------
DuvarBas PROC
;
; Print four character on the screen as the wall
; Receives: nothing
; Returns: nothing
;-----------------------------------------------
pushad

mov esi,OFFSET wall
mov ecx,stones

Ismail:
mov dl,(wall[esi]).xPos
mov dh,(wall[esi]).yPos
call GotoXy

mov ah,2
mov dl,189
int 21h

mov dl,(wall2[esi]).xPos
mov dh,(wall2[esi]).yPos
call GotoXy

mov ah,2
mov dl,189
int 21h


add esi,TYPE wall
Loop Ismail

popad

ret
DuvarBas ENDP
;-----------------------------------------------


END main