Re: MaskBlt implementation.

[Dan Kegel]

> BYTE SwapROP3_SrcDst(BYTE bRop3)
> {
>     /* swap 1,2 bit and 5,6 bit */
>     BYTE bit1 = (bRop3 & 0x04) ? 0x02 : 0;
>     BYTE bit2 = (bRop3 & 0x02) ? 0x04 : 0;
>     BYTE bit5 = (bRop3 & 0x40) ? 0x20 : 0;
>     BYTE bit6 = (bRop3 & 0x20) ? 0x40 : 0;
>     return (bRop3 & 0x99) | bit1 | bit2 | bit5 | bit6;
> }

How 'bout

BYTE SwapROP3_SrcDst(BYTE bRop3)
{
     /* swap 1,2 bit and 5,6 bit */
     BYTE bits44 = (bRop3 & 0x44) >> 1;
     BYTE bits22 = (bRop3 & 0x22) << 1;
     return (bRop3 & 0x99) | bits22 | bits44;
}

-- 
Dan Kegel
http://www.kegel.com
http://counter.li.org/cgi-bin/runscript/display-person.cgi?user=78045

MaskBlt implementation.

[Dimitrie O. Paun]

On April 9, 2003 01:22 am, Dan Kegel wrote:
> How 'bout
>
> BYTE SwapROP3_SrcDst(BYTE bRop3)
> {
>      /* swap 1,2 bit and 5,6 bit */
>      BYTE bits44 = (bRop3 & 0x44) >> 1;
>      BYTE bits22 = (bRop3 & 0x22) << 1;
>      return (bRop3 & 0x99) | bits22 | bits44;
> }

Nice! At which point we might as well inline it all:

inline BYTE SwapROP3_SrcDst(BYTE bRop3)
{
    return (bRop3 & 0x99) | ((bRop3 & 0x22) << 1) | ((bRop3 & 0x44) >> 1);
}

:)

-- 
Dimi.