> > To catch all cases you need a loop,
> A loop over what? Over the rgb-compontents? Or over different colordepth?
Over the width of the expanded version, with a stepsize determined by the
significant bits of the to-be-expanded one.
> > which is why I am worrying about performance.
> What about unrolling the loop?
You can't do that generically. You'd have to introduce lots of special cases
for the different color schemes, then.
The algorithm for expanding a right-aligned "value" of length "nowlegth"
to "exlength" is:
res=0;
for(a=exlength-nowlength;a>-nowlength;a-=nowlength)
if (a>=0)
res|=(value<<a);
else
res|=(value>>(-a));
CU, ANdy
--
= Andreas Beck | Email : <[EMAIL PROTECTED]> =
