Re: [AD] question about opengl bitmaps

[Peter Wang <novalazy@xxxxxxxxxx>]

On 2008-03-24, Milan Mimica <milan.mimica@xxxxxxxxxx> wrote:
> Peter Wang wrote:
> > 
> > Ah, how could I miss that.  Can we somehow avoid that step in the usual case
> > when the copy in main memory is already up to date?
> 
> We can mark the memory dirty if drawing to the texture happened since the last 
> lock_region(), but i think it's error prone, and an optimization at the wrong 
> level in general.
> The font loader should just lock the bitmap once.

That would be good, but how to do that?  If I have locked a bitmap, can I use
it as the source of a blitting operation without unlocking first?  I assumed
yes, but it didn't really work in fontbmp.c.  And it would raise all sorts of
questions about locking, I think.

> Or use a memory bitmap (um, do they even exist?).

Ok, it fixes this particular problem.

> And try not to copy the whole bitmap if not necessary. Or an 
> bitmap function would would mark it read only?
> See, plenty of other things to consider. :)

I never suggested otherwise :)

Peter