someone could translate this code?

[BlackDaimond]

need help!!someone could translate this code please?
for(int ii=0;ii<(128*640);ii++)
{
b=((buffer[ii]>>16)& 0xff);
g=((buffer[ii]>>8)& 0xff);
r=(buffer[ii]& 0xff);
buffer[ii]=RGB(b,g,r);
}
thanks!!

 

[straiph]

buffer = 81920 double words probably but only 3 bytes used for r,g,b bytes!

ii loops from zero to 81920 in increments

b=third byte of buffer[ii]
g=second byte of buffer[ii]
r=first byte of buffer[ii]

buffer[ii]=RGB(b,g,r) ;converts the 3 bytes into a RGB code.

(order of b,g,r and not r,g,b - i think red and blue are swapped in this routine!)


&quot;People who have nothing to say, say it too loud and have little knowledge. It's the quiet ones you need to worry about!&quot;

 

[Leonardozwei]

I think that buffer is an array of 32-Bit integers, and you are working an a 80x86 mashine. The best way is to acess the array by its bytes, so you don't have to do any shifting.

mov  ecx, 128*640-1
lea  esi, buffer
@@LoopStart:
; read the colors 
mov  al, Byte Ptr [esi+ecx*4][0]; read red
;mov  ah, Byte Ptr [esi+ecx*4][1]; read green
mov  bl, Byte Ptr [esi+ecx*4][2]; read blue
; write them in the other order back
mov  Byte Ptr [esi+ecx*4][2], al; write red
;mov  Byte Ptr [esi+ecx*4][1], ah; write green
mov  Byte Ptr [esi+ecx*4][0], bl; write blue
sub  ecx,1
jae  @@LoopStart

Remark: the green-value is not changed, so we don't need to read and write it.

 

[JamesCC]

In most compilers you can convert it to Assembly in Borland Free compiler you can do bcc32 -S filename.cpp
I would of converted your code but your missing some type defs.