Graphics tutorials

[ChimpFace9000]

Are there any graphics tutorials in pure assembly? Ive done a few that were for assembly in pscal or c, but i just cant get those to work because they were meant to be used in an hll. Any thing would be appriciated.

[ChimpFace9000]

Ok, ive figured out how to do some simple graphics. Its just a pixel bouncing around the screen. My problem is that when the pixel gets to the bottom, it disapears. Heres the code...

	.model tiny
	.386
	.code
	org 100h
start:
	mov	ax, 0013h
	int	10h

	mov	ax, 0a000h
	mov	es, ax

main_loop:
	mov	di, 0a000h					; Clear screen, es = address
	mov	ax, 0000h					; color
	mov	cx, 64000					; size
	rep	stosw

	mov	dx, 03dah					; Wait for retrace
waitforretrace:
	in	al, dx
	and	al, 08h
	jz	waitforretrace

	mov	bx, [PointX]
	mov	dx, [PointY]
	xchg	dh, dl
	mov	al, [PointColor]
	mov	di, dx
	shr	di, 2
	add	di, dx
	add	di, bx
	stosb

	cmp	PointX, 0000h					; Update directin bytes
	je	directionx0
	cmp	PointX, 320
	je	directionx1
afterdirectionx:
	cmp	PointY, 0000h
	je	directiony0
	cmp	PointY, 200
	je	directiony1
afterdirectiony:

	cmp	DirectionX, 00h					; Update points
	je	incpointx
	dec	PointX
afterpointx:
	cmp	DirectionY, 00h
	je	incpointy
	dec	PointY
afterpointy:

	mov	ah, 86h						; Wait
	xor	cx, cx
	mov	dx, 2240h
	int	15h

	mov	ah, 01h						; Check for keypress
	int	16h
	jz	main_loop
	xor	ah, ah						; Get the keypress
	int	16h
	cmp	al, 1bh						; Check for escape
	jne	main_loop

	mov	ax, 0003h
	int	10h

	ret

directionx0:
	mov	DirectionX, 00h
	jmp	afterdirectionx
directionx1:
	mov	DirectionX, 01h
	jmp	afterdirectionx
directiony0:
	mov	DirectionY, 00h
	jmp	afterdirectiony
directiony1:
	mov	DirectionY, 01h
	jmp	afterdirectiony
incpointx:
	inc	PointX
	jmp	afterpointx
incpointy:
	inc	PointY
	jmp	afterpointy
;--------------------------------------------------------------------------------------------------------
PointX		word	0
PointY		word	0
PointColor	byte	10
DirectionX	byte	0					; 0 = plus, 1 = minus
DirectionY	byte	0
;--------------------------------------------------------------------------------------------------------

end start

Ive also attached the finished file. Any idea why its doing that?

[deoblo1]

i tried to compile your code, and it would not work i am useing tasm 5...what did you use to compile?

[deoblo1]

i tried to compile your code, and it would not work i am useing tasm 5...what did you use to compile?

[ChimpFace9000]

I use masm. Thats ok, ive figured it out. Now i use a buffer and then copy it to the screen. Much faster.