[bits 32]
VIDEO_MEMORY equ 0xb8000
WHITE_ON_BLACK equ 0x0f
COLS equ 80
LINES equ 25

; screen coordinate offsets
POS_X : db 0
POS_Y : db 0

%include "screen/cursor.asm"

print_string_pm:
    pusha
    mov edx, VIDEO_MEMORY
   call get_current_position

print_string_pm_loop:
    mov al, [ebx]
    mov ah, WHITE_ON_BLACK

    cmp al, 0
    je print_string_pm_done

    mov [edx], ax

    inc ebx ; next char
   ;add edx, 2
   call next_char
   call get_current_position

    jmp print_string_pm_loop

print_string_pm_done:
   mov bh, byte [POS_Y]
   mov bl, byte [POS_X]
   call move_cursor

    popa
    ret

next_char:
   inc byte [POS_X]
   cmp byte [POS_X], COLS
   je next_line
   ret

next_line:
   mov byte [POS_X], 0
   inc byte [POS_Y]
   ret

get_current_position:
   ; compute the column byte
   xor eax, eax
   mov ecx, COLS * 2 ; number of bytes for columns
   mov al, byte [POS_Y] ; POS_Y in eax
   mul ecx ; multiply eax * ecx
   push eax ; save byte in eax

   ;compute the lign byte
   mov al, byte [POS_X] ; put POS_X in eax
   mov cl, 2 ; multiply eax by 2(char is 2 bytes)
   mul cl

   pop ecx ; get back result from eax put it in ecx
   add eax, ecx ; add the computed X pos and computed Y pos(stor in eax)

   xor ecx, ecx ; clear ecx
   add edx, eax ; add final byte offsets to video address

   ret