Another Draw Line rutine

I make a line draw with fixed point aproach, parameters in registers.

XRES is framebuffer width
SYSFRAME is framebuffer adress (32 bits color)
color is constant $ff00

Code:

;*******************************************
LINEA:  ; eax=x1 ebx=y1 ecx=x2 edx=y2
        cmp ebx,edx
        je horizontal
        jg .noswap
        xchg eax,ecx
        xchg ebx,edx
.noswap:
        shl eax,16
        shl ecx,16
        sub eax,ecx
        push ebx
        push edx
        sub ebx,edx
        add ebx,1
        cdq
        idiv ebx
        mov esi,eax
        add ecx,$7fff
        pop ebx
        pop edx
.lineas:
        mov eax,ecx
        add eax,esi
        push ebx
        push eax
        shr ecx,16
        shr eax,16
        call horizontal
        pop ecx
        pop ebx
        add ebx,1
        cmp ebx,edx
        jle .lineas
        ret

horizontal:  ; eax=x1 ebx=y1 ecx=x2
        cmp ecx,eax
        jg .m
        xchg ecx,eax
.m:
        sub ecx,eax
        jnz .n
        add ecx,1
.n:
        imul ebx,ebx,XRES
        add eax,ebx
        lea edi,[SYSFRAME+eax*4]
.l:
        mov dword [edi],$ff00
        add edi,4
        sub ecx,1
        jnz .l
        ret