Hi,
Stefan Nobis <[EMAIL PROTECTED]> writes:
> > Lock the surface, write the data to it, then unlock it.
>
> How do i write data to a surface (with the public API)? Maybe i'm
> quite blind, but i don't see it. The only way i found to write
> data to an existing surface is either with private API or via
> ImageProvider. What am i missing?
I'll repeat it once more then...
Lock the surface, then write your data to the memory address the
IDirectFBSurface::Lock() call gives you. Do this line-by-line, taking
into account the pitch that you obtained with the Lock call. Then
unlock the surface again.
Here's a short code example. It assumes you have a data buffer of
width x height pixels of the same pixelformat as the DirectFB surface.
For simplicity we also assume that your data buffer's pitch is equal
to width * bpp.
{
char *src = buffer; /* buffer points to your data buffer */
char *dst;
int pitch;
surface->Lock (surface, (void **) &dst, &pitch);
for (y = 0; y < height; y++)
{
memcpy (dst, src, width * bpp);
src += width * bpp;
dst += pitch;
}
surface->UnLock (surface);
}
I've written this from the top of my head and didn't compile it. So if
there's a typo or something, please bear with me.
> If i have RGB24 or RGB32 surface then is the pitch cols*bpp? Or am
> i missing something here, too?
Yes, you are missing something. As I said, you cannot be sure that
this is the case. Not only might there be padding to assure that every
row starts on a word boundary, the surface might be laid out in memory
interleaved with rows of other surfaces. Simple rule: use pitch to
advance from one row to the next.
> BTW: DirectFB is a nice project and i really like it (for my
> project i looked to quite some libraries) -- but mixing one
> library with sparse documentation with another library with even
> less documentation sometimes become really frustrating (even more
> because it's not to easy to debug my application).
Help with the docs is always appreciated. Perhaps you want to
contribute to the tutorials? Perhaps a short example of how to write
data to a surface?
Sven
--
Info: To unsubscribe send a mail to [EMAIL PROTECTED] with
"unsubscribe directfb-users" as subject.
