[ros-dev] DecompressBitmap et alumni

Love Nystrom love.nystrom at gmail.com
Mon May 10 13:21:59 CEST 2010


Gregor Schneider <grschneider at gmail.com> wrote:
> Concerning using an internal format: let's assume we got three 8bpp 
> surfaces (source, destination, pattern), which are quite big pending 
> for a raster operation. You would convert these three to another 
> format like 32bpp, process them and convert back?

No, of course not, Gregor,

You're absolutely right about the 8bpp  S/D/P situation.
It would be a terrible idea to convert such a simple format to another 
for a tertiary rop.
I think I was thinking about an internal graphic structure for the 
display context .. ;-)
Accumulate all rops to an 32bit DIB internally, unless the physical 
device is low bpp.
Come to think of it, almost anything but RLE is suitable internally, 
depending
on the output color requirements. The graphics primitives for lines, 
ellipses, and
so on can be small enough to separate a few specialized implementations for
different bit depths. I guess that's what You do ? (I didn't look yet).
Branching for different bit formats in the primitives would be a bad 
idea though..
Wouldn't You agree ?

Best Regards
// Love

PS. I have a slice-line routine that's faster than an oiled lightning, 
and it's really
small enough that it'd be worth replicating the code for different bit 
depths.
Let me know if you're interested.




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