Erik Thiele wrote:

> "I render into a buffer allocated with malloc. at the end i write
> its content with a ggiPutBox to the graphics card (video-ram).
> in my new design i use an a memory-visual instead of the own
> buffer and do a ggiCrossBlit to a default-visual
> => Speed up by factor 10."
> i cannot believe this.
> i really do not understand why this should be true.
> i thought if i cannot get directbuffer the fastest way
> is use malloced buffer and do ggiPutBox.
> why should the CrossBlit be faster, even though it should
> do EXACTLY the same ?

what about a memory visual using video memory ? It's still
offscreen but bitblit operations should be *much* faster.

Which reminds me of a question I wanted to ask on the list here:
Are there any plans to create a visual like structure which's
only use is for caching a la double buffering or backing graphics ?

We'd like to make use of such a data type in the berlin project
quite extensively but as I heared, the visual structure itself
is too complex to be used for that. We really don't want event
support or anything in this structure, it's just a chunk of (hopefully
video) memory. Then it's GGI's responsability to allocate the memory
either from video (if available) or fall back to malloc. There are a lot
of situations where such offscreen 'drawables' would come very handy,
starting from little animated cursors over backing drawables for
the scene behind transient graphics, ...

Stefan Seefeld
Departement de Physique
Universite de Montreal


      ...ich hab' noch einen Koffer in Berlin...

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