On Friday 27 June 2008, Øyvind Kolås wrote:
On Thu, Jun 26, 2008 at 4:33 PM, yahvuu [EMAIL PROTECTED] wrote:
On Thu, Jun 26, 2008 at 2:31 PM, Øyvind Kolås [EMAIL PROTECTED]
wrote: Anyhow, implementing these filters as new operations
solves the problem for now. Having two kinds of gaussian blur
seems awkward at first, but it is a user choice which edges to
blur and not GEGL's.
The filter pairs can be merged later on by implementing
one as a meta operation of the other or simply by an
option property like preserve bounding box.
I'll derive the new filters from GeglOperationEdgedAreaFilter if
no better naming comes up. For the filters probably:
gaussian-blur-edged,
box-blur-edged
It is much better to extend GeglBuffer to have an abyss policy,
this means that requests for pixels outside
the define area gets read back as if they were smeared/mirrored (or
like now all 0). After this the gaussian blur could be changed to
not expand it's result rectangle beyond the original input, and
still use the current easily managable code paths for the actual
filtering.
This looks plainly as the right thing to do.
Just to formalize the behavior. The most natural way of doing it would
be if the filter should have a way to tell the buffer what it
wants from the abyss. Note that this is different than setting the
behavior as a property in the source buffer - it sounds more like
a temporary property defined by whoever is consuming the buffer.
If that is too weird, or would make the code too insane, plain object
properties to set the buffer behavior would be fine.
So, far I think the desired behaviors for the abyss could be:
- solid color (any, including transparent colors)
- stretch (smear)
- wrap (tile)
- mirror
and maybe:
- offset buffer
where offset buffer would be another buffer linked to the source one,
just like a larger background layer. This would allow one to
implement any desired behavior by creating the other buffer prior to
applying the filter - (gradients, scaled mirroring, relief effects,
etc... )
js
--
/Øyvind K.
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