[openbeos] Re: openbeos Digest V8 #104
- From: Sergei Dolgov <dolgov@xxxxx>
- To: openbeos@xxxxxxxxxxxxx
- Date: Thu, 26 Jun 2008 19:35:47 +0300
the BFont level instead of on the individual view class level. As for
drawing thousands of 1x1 bitmaps, I would be surprised if the Firefox
implementation on other platforms indeed used API calls to draw those.
Doesn't Firefox draw into a bitmap anyways (ie client side drawing)? Only
stuff like font rendering would have to go through the app_server, unless
you use Freetype yourself, but even that is possible if it needs to be
done. All one would be left with is one DrawBitmap() call for the entire
resulting view bitmap that actually reaches app_server in the extreme case.
I am not saying this is necessarily how it should be done, but a good
ballance should be possible where Firefox uses partly it's own client side
drawing and partly app_server based drawing. I am guessing that Firefox or
any browser could depend implementing a drawing API that is more capable
and advanced than what app_server offers, so it needs to implement its own
drawing anyways.
Seems like initially all platforms (or almost all) used OS APIs to
implement method DrawTile().
Then lot of hacks and workarounds appeared in nsImage methods. But as
fallback case those still use "direct" slow way.
Now, about single DrawBitmap call. We finished with using that - to draw
filled offscreen bitmap to target bitmap. Which resulted in much
better results, as you can see. But problem was that even on off-screen
bbitmaps usage of DrawBitmap had too high price. So, lot of work was
done for tricky manual bitblitting of those "tiles" - but that way is
not always too convinient, if you meet need for:
1)drawing when destination and target have different colorspaces
2)when scaling is needed.
Both problems were solved that or this way in Mozilla BeOS port, but it
is actually shame, when and if we need lot of coding which is like yet
another bicycle invention, when we have nice API method which should
care about all of that. In theory.
Regards, SD
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