[sane-devel] SANE2 proposal

Dave Close dclose@anim.dreamworks.com
Thu, 30 May 2002 14:27:14 -0700

I hope this comment is constructive criticism of the SANE2 document.

Section 4.3.14 of the document (version 0.06) describes the sane_
strstatus() function. Unlike the other functions in section 4.3, I
don't believe that it is intended that a backend should implement
this one. Instead, this is a description of a standard function
provided by SANE and which may be used by a backend. I find that
organization of the document confusing.

There are many more functions provided to a backend by SANE, most
of which are not documented anywhere, including in this document.
In fact, it is impossible to write a backend without using many of
those other functions. So, if this document is taken as a guide to
writers of backends, I think it should, at least, contain a list of
those other functions. The description of sane_strstatus() should
then be moved into the new section with the other descriptions.

I believe the document also needs additional exposition of the
migration path from SANE1 to SANE2. Although there is some mention
of issues involved, most questions are not answered. For example,
the document says that SANE_FRAME_RAW supercedes SANE_FRAME_RGB
(and others). However, all the frame types are then listed under
sane_get_parameters(). There is no mention of mixing usage nor of
how a frontend should handle such mixed usage.

To me, it would also help if there was some additional discussion
of the preview option. That option is permitted to override some
other options, particularly resolution, without changing them. The
document does not make clear the impact of such overriding on the
sane_get_parameters() function. I have found by experiment that it
works if the function returns the temporary values, but I think the
document should say so if that is correct. There should also be
some caution to a frontend to re-call sane_get_parameters() when
changing the preview option.

Dave Close                    Dreamworks SKG, Animation Technology
+1 818 695 6962               Glendale California 91201-3007
dclose@anim.dreamworks.com    http://www.dreamworks.com/