I'm working on an assembly project for class and I have some code. My problem is that I have errors because the code is not designed to print the same .bmp image multiple times.
What I need is some code that I can use so I can print my .bmp image multiple times. Any advice will be very helpful. Thanks!
I've tried some other code for printing .bmp files in assembly but wasn't successful.
If you have some sort of code for printing .bmp files, it will be very useful.
CODE:
IDEAL
MODEL small
STACK 100h
DATASEG
;================================
filename db 'test.bmp',0
filehandle dw ?
Header db 54 dup (0)
Palette db 256*4 dup (0)
ScrLine db 320 dup (0)
ErrorMsg db 'Error', 13, 10,'$'
;================================
CODESEG
;================================
proc OpenFile
; Open file
mov ah, 3Dh
xor al, al
mov dx, offset filename
int 21h
jc openerror
mov [filehandle], ax
ret
openerror:
mov dx, offset ErrorMsg
mov ah, 9h
int 21h
ret
endp OpenFile
proc ReadHeader
; Read BMP file header, 54 bytes
mov ah,3fh
mov bx, [filehandle]
mov cx,54
mov dx,offset Header
int 21h
ret
endp ReadHeader
proc ReadPalette
; Read BMP file color palette, 256 colors * 4 bytes (400h)
mov ah,3fh
mov cx,400h
mov dx,offset Palette
int 21h
ret
endp ReadPalette
proc CopyPal
; Copy the colors palette to the video memory
; The number of the first color should be sent to port 3C8h
; The palette is sent to port 3C9h
mov si,offset Palette
mov cx,256
mov dx,3C8h
mov al,0
; Copy starting color to port 3C8h
out dx,al
; Copy palette itself to port 3C9h
inc dx
PalLoop:
; Note: Colors in a BMP file are saved as BGR values rather than RGB.
mov al,[si+2] ; Get red value.
shr al,2 ; Max. is 255, but video palette maximal
; value is 63. Therefore dividing by 4.
out dx,al ; Send it.
mov al,[si+1] ; Get green value.
shr al,2
out dx,al ; Send it.
mov al,[si] ; Get blue value.
shr al,2
out dx,al ; Send it.
add si,4 ; Point to next color.
; (There is a null chr. after every color.)
loop PalLoop
ret
endp CopyPal
proc CopyBitmap
; BMP graphics are saved upside-down.
; Read the graphic line by line (200 lines in VGA format),
; displaying the lines from bottom to top.
mov ax, 0A000h
mov es, ax
mov cx,200
PrintBMPLoop:
push cx
; di = cx*320, point to the correct screen line
mov di,cx
shl cx,6
shl di,8
add di,cx
; Read one line
mov ah,3fh
mov cx,320
mov dx,offset ScrLine
int 21h
; Copy one line into video memory
cld
; Clear direction flag, for movsb
mov cx,320
mov si,offset ScrLine
rep movsb
; Copy line to the screen
;rep movsb is same as the following code:
;mov es:di, ds:si
;inc si
;inc di
;dec cx
;loop until cx=0
pop cx
loop PrintBMPLoop
ret
endp CopyBitmap
;================================
start:
mov ax, @data
mov ds, ax
;================================
; Graphic mode
mov ax, 13h
int 10h
; Process BMP file
call OpenFile
call ReadHeader
call ReadPalette
call CopyPal
call CopyBitmap
; Wait for key press
mov ah,1
int 21h
; Back to text mode
mov ah, 0
mov al, 2
int 10h
;================================
exit:
mov ax, 4c00h
int 21h
END start
It's my first time using this website, so I'm not sure how things work here, but I can upload my project if needed.
Repeating is simply a matter of closing the file and then looping back in the program. To close the file you use DOS function 3Eh
proc CloseFile
mov ah, 3Eh
mov bx, [filehandle]
int 21h
ret
endp CloseFile
mov ax, 0013h ;Graphic mode
int 10h
Again:
call OpenFile
call ReadHeader
call ReadPalette
call CopyPal
call CopyBitmap
call CloseFile
mov ah, 01h ;Key
int 21h
cmp al, 27
jne Again ;Loop until users presses <ESC>
mov ax, 0003h ;Text mode
int 10h
exit:
mov ax, 4C00h
int 21h