Of course, on that first line, I meant to write "those in imagebufalgo.h".
On Jul 13, 2012, at 11:39 PM, Larry Gritz wrote: > The public comments (i.e., those in imagebufalgo) don't need to explain the > algorithms, except as possibly a one-line formula involving only the > pre-multiplied images. E.g., for "over", you might say > > // The "over" operation is: R = A + (1-A[alpha]) * B > > and leave it at that. > > But the implementation (in imagebufalgo.cpp, or wherever you put it), can > have comments giving details about the derivation or internal operations, for > any that are not very straightforward to somebody reading that code. > > I consider the pre-multiplied formulas to be the canonical ones, I would not > bother discussing the un-premultipled ones at all, unless the premult version > is so complex and ugly that it's likely that somebody looking at the code > later will suspect it's wrong, if you don't fully explain how you came up > with it. > > > > On Jul 13, 2012, at 11:17 PM, Stefan Stavrev wrote: > >> I confirmed from other sources that it only makes >> sense to use over with blend modes, and other Porter-Duff >> operations should be separate from blend modes. >> That makes things so much easier now. >> >> Larry, should I write the derivations in the >> comments for the functions or is it enough to write just the >> formula as it is, non-reduced? It will clutter the comments a >> lot if I include the derivations. >> >> I think I should keep the comments light and give the >> basic formula, but of course use the reduced version >> in the function. > > -- > Larry Gritz > [email protected] > > > _______________________________________________ > Oiio-dev mailing list > [email protected] > http://lists.openimageio.org/listinfo.cgi/oiio-dev-openimageio.org -- Larry Gritz [email protected] _______________________________________________ Oiio-dev mailing list [email protected] http://lists.openimageio.org/listinfo.cgi/oiio-dev-openimageio.org
