CODEWITHSUNDEEP
assemblyx86x86-16dosbox
Idan Gabrielov
Idan Gabrielov

Reputation: 17

int 33 always shows me the same data

On my code I have to check if the mouse press is on my image. When I am debugging the code I see the the interrupt returns the same information over and over again mikoon is the starting point of the printing of the picture (16*16)

proc checker
    xor bx, bx
    mov ax,05h  ; Return button press data
    int 33h 
    shr cx, 1
    mov ax, 0A000h
    sub [mikoom], ax
    shr [mikoom], 2
    jmp cont
check:
    mov ax,05h  ; Return button press data
    int 33h
    shr cx, 1
cont:
    cmp cx, [mikoom]
    jae odchaecker
    jmp check
odchaecker:
    mov ax, 16h
    add [mikoom], ax
    cmp cx, [mikoom]
    jbe caller
    mov ax, 16h
    sub [mikoom], ax
    jmp check
caller:
    call CleanScreen
    ret
endp
proc CleanScreen
    mov ah, 0
    int 10h
    ret
endp

Upvotes: 1

Views: 189

Answers (1)

Fifoernik
Fifoernik

Reputation: 9899

Whenever your CleanScreen procedure sets the video mode AL contains the (leftover) value 16h which is 22 in decimal. There's no such video mode available!

You don't mention it but I'm kind of assuming that you're using video mode 13h (320x200).

xor bx, bx
mov ax,05h  ; Return button press data
int 33h 
shr cx, 1

This mouse function returns x,y-coordinates in CX and DX.
Your program does not even use the y-coordinate!
Also what's with this subtraction of 0A000h? The video memory is at segment address 0A000h but that is of no concern in this program.

What you need to do is compare CX with the left side and right side coordinates of your picture and compare DX with the top side and bottom side coordinates of your picture.

  cmp cx, [LeftX]
  jb  outside
  cmp cx, [RightX]   ; RightX == LeftX + Width - 1
  ja  outside
  cmp dx, [TopY]
  jb  outside
  cmp dx, [BottomY]  ; BottomY == TopY + Height - 1
  ja  outside
  ;
  ; Here you're inside the picture
  ;
outside:
  ;
  ; Here you're outside the picture
  ;

Upvotes: 1

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