snake.asm

game snake in assembly lang.

TITLE GAME SNAKE           (2006510040-Assignment3.asm)

; Program Description : This program is for playing game called "snake"
; Author : Ceren 轆H軳                       Last update :02.02.09
; Creation Date : 30.01.09
; Date : 02.02.09                         

include irvine32.inc
.data
;variables
	sym_snake 	BYTE 219	; symbol of snake something like a square
	sym_spc	BYTE 32 	; sybol of space
	x byte 2		;starting x index of snake
	y byte 2		;starting y index of snake
	
	endX BYTE 24 	;ending x index of snake stansdart msdos screen
	endY BYTE 80	; ending y index of snake
	
	xEat BYTE ?	; index of the food's x coordinate
	yEat BYTE ?	;index of the food's y coordinate
	
	Eat BYTE 42	; this is a char like "*" for food
	scorecounter BYTE 0
	msg	BYTE " Total Score is: :",0
	score BYTE "SCORE :",0
	wall BYTE "##############################################################################",0; top wall
	;warning BYTE "Press CTRL+C to break",0
	
	
.code
main proc
	
	call screen		 	; tto write to "score " to the first line and draws the wall
	call printEat	; Eat is determinden where to put
	
	loop1:					
	
		mov al,[sym_snake];snakes value is put on the game area and in al register
		mov dh,[x] ;in dh register there is snake's starting x coordinate
		mov dl,[y] ;in dl register there is snake's starting y coordinate
		 
		call WallControl	; control of wall
		call EatControl ; Control of eat
		mov al,[sym_snake]
		mov dh,[x]
		mov dl,[y]
		
		call gotoxy ;the gotoxy proc locates the cursor at a given row and column on the screen.By default the console window's X-coordinate range is 0-79,and the Y-coordinate range is 0-24.
					;when you call Gotoxy,pass the Y-coordinate(row) in dh and thr X-coordinate (column)in dl.
		call WriteChar;the WriteChar proc. writes a single char. to standart output.Place the char(or its ASCII code) in al before calling the proc.
		
		mov eax,100
		call delay; the delay proc.pauses the program for a specified time interval.When calling this function set eax register to the desired interval,in miliseconds.
		
		mov al,[sym_spc]			;  the location where the snake was is erased.
		call gotoxy
		call writeChar
		
		inc y					;the snake is going to the East
		
		;controling the direction acoording to the arrow keys
			call readkey
		cmp ah,77				
		je East

		cmp ah,75
		je West

		cmp ah,80
		je South
		;mov ah,72
		cmp ah,72					
		je North
	
	jmp loop1
	

		;WHEN FINISHED (SAME MEANING WITH GAME OVER IT CALLS THIS)
		finished::;end of the program
	
	mov edx,OFFSET msg
	call clrscr
	call WriteString
	
	movzx eax,scorecounter
	call WriteDec
	call crlf
	call readKey
	


	
exit
main endp


	
	;IS THERE A WALL?
;this controls the walls in case the snake hit the wall!
	WallControl PROC
	
		mov al,1
		cmp al,x
		je gameover
		
		mov al,1
		cmp al,y
		je gameover
		
		mov al,endX
		cmp al,x
		je gameover
		
		mov al,endY
		cmp al,y
		je gameover
		
		ret
	
	WallControl ENDP

	
	;this is for writing the Score counter on the screen so that it increases after every eat is eaten by the snake
	screen PROC

		mov edx,0
		mov edx,OFFSET score
		call writeString
		
		call crlf
		mov edx,OFFSET wall
		call WriteString
		
		ret
		
	screen ENDP
	
	;these are the directions controls that the snake move according to the user's arrow keys.
	;TO SOUTH DIRECTION
	South PROC
		
		start:
			
			mov al,[sym_snake]
			mov dh,[x]
			mov dl,[y]
			call WallControl
			call EatControl
			mov al,[sym_snake]
			mov dh,[x]
			mov dl,[y]
			
			call gotoxy
			call WriteChar
			mov eax,100
			call Delay
			mov al,[sym_spc]
			call gotoxy
			call WriteChar
			
			inc x		
			;the same op. for contorling the directions with arrow keys,
			
	call readkey
		;mov ah,77
		cmp ah,77				
		je East
		;mov ah,75
		cmp ah,75	
		;mov ah,80
		cmp ah,80
		je South
		;mov ah,72
		cmp ah,72					
		je North
		
		jmp start
		ret
		
	South ENDP

	;THE NORTH DIRECTION
	North PROC
	
		start:
			
			mov al,[sym_snake]
			mov dh,[x]
			mov dl,[y]
 
			call WallControl
			call EatControl
			mov al,[sym_snake]
			mov dh,[x]
			mov dl,[y]
			call gotoxy
			call writeChar
			mov eax,100
			call delay	
			mov al,[sym_spc]
			call gotoxy
			call writeChar
			
			dec x			
		call readkey
		;mov ah,77
		cmp ah,77				
		je East
		;mov ah,75
		cmp ah,75
		je West
		;mov ah,80
		cmp ah,80
		je South	
		;mov ah,72
		cmp ah,72					
		je North

		
		jmp start
		ret
	
	North ENDP

	;TO EAST DIRECTION
	East PROC
	
		start:
			
			mov al,[sym_snake]
			mov dh,[x]
			mov dl,[y]	 
			call WallControl
			call EatControl
			mov al,[sym_snake]
			mov dh,[x]
			mov dl,[y]
			call gotoxy
			call writeChar
			mov eax,100
			call delay
			mov al,[sym_spc]
			call gotoxy
			call writeChar
			
			inc y			
			
		call readkey
		;mov ah,77
		cmp ah,77				
		je East
		;mov ah,75
		cmp ah,75
		je West	
		;mov ah,80
		cmp ah,80
		je South
		;mov ah,72
		cmp ah,72					;
		je North

		jmp start
		ret
		
	East ENDP
	
	
	;TO WEST DIRECTION
	West PROC
	
		start:
			
			mov al,[sym_snake]
			mov dh,[x]
			mov dl,[y] 
			call WallControl
			call EatControl
			mov al,[sym_snake]
			mov dh,[x]
			mov dl,[y]
			call gotoxy
			call writeChar
			mov eax,100
			call delay
			mov al,[sym_spc]
			call gotoxy
			call writechar
			
			dec y
			
		call readkey
		;mov ah,77
		cmp ah,77				
		je East
		;mov ah,75
		cmp ah,75
		je West
		;mov ah,80
		cmp ah,80
		je South
		;mov ah,72
		cmp ah,72				
		je North
		

		jmp start
		ret
	
	West ENDP
	
	
;EATING CONTROL
	EatControl PROC
	
		;  if the eat and snake in the same coordinat; x and y, erase the previous location
		
		mov al,x
		cmp xEat,al
		jne continue		
		
		mov al,y			
		cmp yEat,al
		jne continue
		
		mov dl,[yEat]	
		mov dh,[xEat]
		mov al,[sym_spc]
		
		
		call gotoxy
		call writeChar
		
		inc scorecounter		;increasing the score after each crash to the eat
		mov al,scorecounter
		mov dl,7
		mov dh,0
		
		call gotoxy
		call Writedec
		call printEat	; write the new location of eat eith its proc. printEat
		
		continue:
		ret
		
	EatControl ENDP
	

	;PRINTING THE EAT BY RANDOM
	printEat PROC
		
		coorX:	
				
			call Randomize		;this random value is restricted by endx value
					
			movzx eax,endX
			call randomRange
				
		cmp al,3
		jb coorX				; not to enter the score area
	
		cmp al,endX
		ja coorX				; not the crash the wall
		
		mov xEat,0
		add xEat,al
		
		coorY:				; for y coordinate
		
			call Randomize
			movzx eax,endY
			call randomRange
			
		cmp al,3
		jb coorY
		
		cmp al,endY
		ja coorY
		
		mov yEat,0
		add yEat,al
		
		
		mov al,[Eat]
		mov dh,[xEat]
		mov dl,[yEat]
		
		call gotoxy				
		call writeChar
		
		ret
		
	printEat ENDP

;WHEN THE GAME OVER:
	gameOver PROC

jmp  finished	
	ret
		
	gameOver ENDP
	
end main