; Loading bmp files on a screen with background. Paints the background first ; with background and drawone procs, then loads the same bmp into 2 locations ; on the screen. All you need to change in order to load your own images, is ; the proc 'loadshape'. The rest you can treat as a 'black box'. IDEAL MODEL small STACK 100h MAX_BMP_WIDTH = 320 MAX_BMP_HEIGHT = 200 DATASEG x1 dw ? y1 dw ? xx equ [bp+4] yy equ [bp+6] ;BMP File data FileHandle dw ? Header db 54 dup(0) Palette db 400h dup (0) filename db 'sample.bmp',0 ;chng BmpFileErrorMsg db 'Error At Opening Bmp File .', 0dh, 0ah,'$' ErrorFile db 0 BmpLeft dw ? BmpTop dw ? BmpColSize dw ? BmpRowSize dw ? OneBmpLine db MAX_BMP_WIDTH dup (0) ; One Color line read buffer ScreenLineMax db MAX_BMP_WIDTH dup (0) ; One Color line read buffer bg equ 10 ;background color x dw 160 y dw 100 CODESEG ;-------------------------------------------------------------------------- proc background ; 1 parameter - color ; calls drawone 200 time to draw 200 horizontal lines and cover the screen push bp mov bp,sp ;Save registers state push ax push bx push cx push dx mov al,[bp+4] ; color mov bx,200 mov cx,0 mov dx,0 drlines: call drawone inc dx mov cx,0 dec bx cmp bx,0 jnz drlines ;loop on lines, creates the square ;Restore registers pop dx pop cx pop bx pop ax pop bp ret 2 endp background ;----------------------------------- proc drawone ; receives no parameters, draws one line, 320 pixels long (horizontal) push bx mov bx,320 oneline: mov ah,0ch int 10h inc cx dec bx cmp bx,0 jnz oneline pop bx ret endp drawone ;----------------------------------- proc loadshape ; General proc to load a bmp file (picture) on the screen. Receives 2 ; parameters: y coordinate (counted from the top), and x coordinate ; (counted from the left). The size of the bmp is hard-coded, here ; 48x48 (we could receive them also as parms). loadshape places the ; image x pixels to the right of the left screen boarder, and y pixels ; to down from the top of the screen. push bp mov bp ,sp push ax mov ax,xx mov [BmpLeft],ax mov ax,yy mov [BmpTop],ax mov [BmpColSize], 48 mov [BmpRowSize] ,48 mov dx,offset filename call OpenShowBmp cmp [ErrorFile],1 jne continue mov dx, offset BmpFileErrorMsg ;reading error mov ah,9 int 21h continue: pop ax pop bp ret 4 endp loadshape ; BMP processing procs (standard) ;----------------------------------------------------------------- ; input : ; 1.BmpLeft offset from left (where to start draw the picture) ; 2. BmpTop offset from top ; 3. BmpColSize picture width , ; 4. BmpRowSize bmp height ; 5. dx offset to file name with zero at the end ;------------------------------------- proc OpenShowBmp near push cx push bx call OpenBmpFile cmp [ErrorFile],1 je @@ExitProc call ReadBmpHeader ; from here assume bx is global param with file handle. call ReadBmpPalette call CopyBmpPalette call ShowBMP call CloseBmpFile @@ExitProc: pop bx pop cx ret endp OpenShowBmp ;-------------------------------------- ; input dx filename to open proc OpenBmpFile near mov ah, 3Dh xor al, al int 21h jc @@ErrorAtOpen mov [FileHandle], ax jmp @@ExitProc @@ErrorAtOpen: mov [ErrorFile],1 @@ExitProc: ret endp OpenBmpFile ;-------------------------------------- proc CloseBmpFile near mov ah,3Eh mov bx, [FileHandle] int 21h ret endp CloseBmpFile ;-------------------------------------- ; Read 54 bytes the Header proc ReadBmpHeader near push cx push dx mov ah,3fh mov bx, [FileHandle] mov cx,54 mov dx,offset Header int 21h pop dx pop cx ret endp ReadBmpHeader ;-------------------------------------- proc ReadBmpPalette near ; Read BMP file color palette, 256 colors * 4 bytes (400h) ; 4 bytes for each color BGR + null) push cx push dx mov ah,3fh mov cx,400h mov dx,offset Palette int 21h pop dx pop cx ret endp ReadBmpPalette ;-------------------------------------- ; Will move out to screen memory the colors ; video ports are 3C8h for number of first color ; and 3C9h for all rest proc CopyBmpPalette near push cx push dx mov si,offset Palette mov cx,256 mov dx,3C8h mov al,0 ; black first out dx,al ;3C8h inc dx ;3C9h CopyNextColor: mov al,[si+2] ; Red shr al,2 ; divide by 4 Max (cos max is 63 and we have here max 255 ) (loosing color resolution). out dx,al mov al,[si+1] ; Green. shr al,2 out dx,al mov al,[si] ; Blue. shr al,2 out dx,al add si,4 ; Point to next color. (4 bytes for each color BGR + null) loop CopyNextColor pop dx pop cx ret endp CopyBmpPalette ;-------------------------------------- proc ShowBMP ; BMP graphics are saved upside-down. ; Read the graphic line by line (BmpRowSize lines in VGA format), ; displaying the lines from bottom to top. push cx mov ax, 0A000h mov es, ax mov cx,[BmpRowSize] mov ax,[BmpColSize] ; row size must dived by 4 so if it less we must calculate the extra padding bytes xor dx,dx mov si,4 div si mov bp,dx mov dx,[BmpLeft] @@NextLine: push cx push dx mov di,cx ; Current Row at the small bmp (each time -1) add di,[BmpTop] ; add the Y on entire screen ; next 5 lines di will be = cx*320 + dx , point to the correct screen line mov cx,di shl cx,6 shl di,8 add di,cx add di,dx ; small Read one line mov ah,3fh mov cx,[BmpColSize] add cx,bp ; extra bytes to each row must be divided by 4 mov dx,offset ScreenLineMax int 21h ; Copy one line into video memory cld ; Clear direction flag, for movsb mov cx,[BmpColSize] mov si,offset ScreenLineMax rep movsb ; Copy line to the screen pop dx pop cx loop @@NextLine pop cx ret endp ShowBMP ;-------------------------------------- ;----- MAIN ------ start: mov ax, @data mov ds, ax ; Graphics mode mov ax, 13h int 10h push bg ;paint the background call background push 40 ;y ; load a .bmp with x,y as top left corner push 60 ;x call loadshape push 100 ;y ; load a .bmp with x,y as top left corner push 200 ;x call loadshape ;Init mouse mov ax,0h int 33h ;Show mouse ;graphics mouse, just for fun. mov ax,1h int 33h ; wait for key press ;Allows a key press to end the program. mov ah, 1 int 21h mov ah, 0 mov al, 2 int 10h exit: mov ax, 4c00h int 21h END start