vesa [pm] [rm] ref....

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dosin

Joined: 24 Aug 2007
Posts: 337

dosin 10 Sep 2007, 22:17

Great vga/vesa rm/pm .pdf-
just thought I would share this!!
has a lot of good info vga/vesa bios and pm modes

http://www.buissoft.com/vga.zip

10 Sep 2007, 22:17

Dex4u

Joined: 08 Feb 2005
Posts: 1601
Location: web

Dex4u 11 Sep 2007, 20:46

Thanks dosin

11 Sep 2007, 20:46

dosin

Joined: 24 Aug 2007
Posts: 337

dosin 12 Sep 2007, 01:29

I ran across this code of yours Dex4U:
I had a couple of questions about creating a pixel function...

Code:

mov  edi,[ModeInfo_PhysBasePtr]   ; This is = to mov   edi,0xA0000 in vga
add  edi, 640*6    ; This is = to x = 0, y = 6
mov  al,0x09   ; Color of pixel
stosb   ; Put whats in al at es:edi

**************************

Code:

example:
mov [x],10
mov [y],13
mov [color],0xFF

plot_pixel:

ck_24:
        cmp   [BitsPerPixel],24
        jne   try32
        call  go_pixel_24
        jmp   ck_24
try32:
        cmp   [BitsPerPixel],32
        jne   cont_
        call  go_pixel_32 
cont_:

ret
**************************

go_pixel_24:
mov  edi,[BasePtr]   
add  edi,x+640*y   
mov  al,color  

cli
stosb
sti 

ret

***************************
go_pixel_32 :

mov  edi,[BasePtr]   
add  edi,x+640*y   
mov  al,color  

cli
stosb
sti 


ret
****************************

Basically you said in the example I would need to check for 24/32bit color
and then plot the pixel... Well needless to say the code above needs some work, but when I write more than one pixel it writes only the last one...

Thanks for any help!

12 Sep 2007, 01:29

Dex4u

Joined: 08 Feb 2005
Posts: 1601
Location: web

Dex4u 12 Sep 2007, 02:13

Right you only need to test for 24 or 32 if the mode is for 32bits per pixel.
Now let say you are using that mode, the color need to be RRGGBB for 24bit or 00RRGGBB for 32bit.
Now heres a unoptimised put pixel, note this is direct to screen, you should really write to a buffer, than write it to screen

Code:

VesaPutPixel:   push  eax     push  ebx        mov   edi,[ModeInfo_PhysBasePtr]  ; vesa start address     xor   ebx,ebx       mov   ebx,[VesaX] ;pixel X    shl   ebx,2        cmp   [ModeInfo_BitsPerPixel],24        jne   @F        sub   ebx,[VesaX]@@:   add   edi, ebx        mov   ebx,[VesaY] ;pixel Y    mov   eax,[ModeInfo_XResolution]  ;vesa X size        shl   eax,2        cmp   [ModeInfo_BitsPerPixel],24        jne   @f        sub   eax,[ModeInfo_XResolution]@@:    mul   ebx     add   edi,eax mov   eax,dword[color] ;put you color eg 0x00bcbcbc   stosd         pop   ebx     pop   eax             ret

Also if you write to a buffer first, you will get no flicker and you can write to the buffer as if it a 32bpp and than test when writing buffer to screen, for 32 or 24 BPP.

Can you post what mode your setting vesa to.

12 Sep 2007, 02:13

dosin

Joined: 24 Aug 2007
Posts: 337

dosin 12 Sep 2007, 03:58

mode:4112h = 32/24bit

12 Sep 2007, 03:58

Dex4u

Joined: 08 Feb 2005
Posts: 1601
Location: web

Dex4u 12 Sep 2007, 04:23

dosin wrote:

mode:4112h = 32/24bit

So you will need to check for that mode, as its 640*480 32/24bits

12 Sep 2007, 04:23

dosin

Joined: 24 Aug 2007
Posts: 337

dosin 12 Sep 2007, 05:03

Ya! I did... Thanks....

12 Sep 2007, 05:03

DOS386

Joined: 08 Dec 2006
Posts: 1903

DOS386 14 Sep 2007, 21:34

Quote:

Great vga/vesa rm/pm .pdf-
just thought I would share this!!

Thanks

14 Sep 2007, 21:34

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