assembly/dino.asm

SYS_EXIT equ 1
SYS_READ equ 3
SYS_WRITE equ 4
STDIN equ 0
STDOUT equ 1
SYS_IOCTL equ 54
SYS_TIMER_FD_CREATE equ 0x142
SYS_TIMER_FD_SETTIME equ 0x145

section .bss
	sz RESB 4 ; 4 byte for window size
	num resb 4 ;4 byte for ascii numbers
	srow resb 1		;screen rows
	scol resb 1		;screen columns
	tof resb 1		; 1 byte store top offstet

	tmp resb 1

section .data
	;num to ascii variables
	ha db 0 ;hundreds
	ta db 0 ;tens
	
	;graphics layout
	rcount db 0;
	lb db 0xa; linebrak
	lof db 0;	; left offset
	gh db 42;	; game height
	gw db 102;	; game width
	scrst db 'Score: 000'	; score string
	scrstln equ $ - scrst	; sore string length
	scrlof equ 5		;score lfet offset
	scrfll equ 85		;score lfet offset
	pls db 0x2b		;plus for corner
	hl db 0x2d		;horizontal line |
	vl db 0x7c		;vertical line -

	;error
	txt_error_term_dim db 'Error terminal got wrong dimensions'
	txt_error_term_dim edu 35
	
	;timer
	tfd RESB 4		;file descriptro
	itimer RESQ 2		;timer init struct
	tval RESB 8		;variable to store triggercount when reading timmerfd
	
	;dino1
	;            __
	;           / _)
	;    .-^^^-/ /
	; __/       /
	;<__.|_|-|_|

	dino11 db '            __ '
	dino12 db '           / _)'
	dino13 db '    .-^^^-/ /  '
	dino14 db ' __/       /   '
	dino15 db '<__.|_|-|_|    '

	;dino2
	;           __
	;          | _)
	;    .-^^^-| |
	; __/       /
	;<__./_/-\_\

	dino21 db '           __  '
	dino22 db '          | _) '
	dino23 db '    .-^^^-| |  '
	dino24 db ' __/       /   '
	dino25 db '<__./_/-\_\    '
	
	dinolen equ 15

section .text
	global _start
		
_start:

	;create timer
	mov eax, SYS_TIMER_FD_CREATE
	mov ebx, 1
	mov ecx, 0
	int 0x80

	;store fd adress
	mov [tfd], eax	

	; get windwo size	
	mov eax, SYS_IOCTL	; syscall ioctl
	mov ebx, STDOUT		; stdout for something?
	mov ecx, 0x5413		; get windowsize command TIOCGWINSZ
	mov edx, sz		; target struct
	int 0x80		; call kernel

	;print fullscreen

	;save window size
	mov al, [sz]
	mov [srow], al
	mov al, [sz+2]
	mov [scol], al

	;calc offset
	;top	
	xor eax, eax
	xor bx, bx
	movzx ax, [srow]	;move one byte fill rest with zero
	;and ax, 0xFF		; bitmask so that only srow (1byte) is inside ax (2byte) else it is scol+srow
	;mov bx, [gh]
	;and bx, 0xFF
	sub ax, [gh]		;screenrows - geameheight
	mov bl, 2
	div bl
	mov al, 0x6
	mov [tof], al
	;jmp exit

	;left
	movxz ax, [scol]
	;and ax, 0xFF
	;mov bx, [gw]
	;and bx, 0xFF
	sub ax, [gw]
	mov bl, 0x2
	div bl
	mov [lof], al

	;print terminal
print:
	jmp topoffset
emptyterminal:
	mov eax, SYS_WRITE
	mov ebx, STDOUT
	mov ecx, lb
	mov edx, 1
	;int 0x80

	inc byte [rcount]
	mov al, [rcount]
	;cmp [srow], al
	cmp al, [srow]
	jl emptyterminal

topoffset:
	mov [rcount], byte 0x0	

	mov eax, SYS_WRITE
	mov ebx, STDOUT
	mov ecx, lb
	mov edx, 1
	;int 0x80

	inc byte [rcount]
	mov al, [rcount]
	cmp al, [tof]
	jle topoffset

toprow:	 
tlcorner:
	mov eax, SYS_WRITE
	mov ebx, STDOUT
	mov ecx, pls
	mov edx, 1
	int 0x80

tr_start:
	mov eax, SYS_WRITE
	mov ebx, STDOUT
	mov ecx, hl
	mov edx, 1
	int 0x80

	inc byte [rcount]
	mov al, [rcount]
	cmp al, scrlof
	jl tr_start
	mov al, 0
	mov [rcount], al
	
tr_score:
	mov eax, SYS_WRITE
	mov ebx, STDOUT
	mov ecx, scrst
	mov edx, scrstln
	int 0x80

tr_fill:
	mov eax, SYS_WRITE
	mov ebx, STDOUT
	mov ecx, hl
	mov edx, 1
	int 0x80

	inc byte [rcount]
	mov al, [rcount]
	cmp al, scrfll
	jl tr_fill

trcorner:
	mov eax, SYS_WRITE
	mov ebx, STDOUT
	mov ecx, pls 
	mov edx, 1
	int 0x80

linebreak:
	mov eax, SYS_WRITE
	mov ebx, STDOUT
	mov ecx, lb 
	mov edx, 1
	int 0x80

exit:
	;exit
	mov eax, 1
	mov ebx, 0
	int 0x80

	; print rows
	
	mov ecx, 0
	mov cl, [sz]		;rows in ecx

hundreds:
	mov ebx, 100
	cmp ecx, ebx		;check if above 100
	js bla
	jae inchundred		;jump to increment hundreds if needed
	

bla:
	mov eax,[ha]		;hundred count to eax
	add eax, '0'		;convert to ascii
	mov [num+0], eax	;move to first byte of num string

tens:
	cmp ecx, 0xa		;check if above 10
	jge inctens		;jump to increment tens if needed
	
	mov eax,[ta]
	add eax, '0'
	mov [num+1], eax

	mov eax, ecx
	add eax, '0'
	mov [num+2], eax	
	mov [num+3], byte 0xa 	;linebreak

	mov eax, SYS_WRITE
	mov ebx, STDOUT
	mov ecx, num
	mov edx, 4
	int 0x80


	;print hundreds
	;mov eax, [ha]
	;add eax, '0'
	;mov[ha], eax
	
	;mov eax, SYS_WRITE
	;mov ebx, STDOUT
	;mov ecx, ha
	;mov edx, 1
	;int 0x80	

	; print cols

	;mov eax, SYS_WRITE
	;mov ebx, STDOUT
	;mov ecx, sz+2
	;mov edx, 3
	;int 0x80

inchundred:
	inc byte [ha]		;increment hundreds
	sub ecx, 0x64
	jmp hundreds

inctens:
	inc byte [ta]		;increment tens
	sub ecx, 0xa
	jmp tens

;read from timerfd blocking system till timer triggers
fd_wait:
	mov eax, SYS_READ
	mov ebx, [tfd]
	mov ecx, tval
	mov edx, 0x20
	int 0x80
	ret


error_term_dim:
	mov eax, SYS_WRITE
	mov ebx, STDOUT
	mov ecx, txt_error_term_dim
	mov edx, txt_error_term_dim_size
	int 0x80

	jmp exit