On 7/8/08, Olaf Meeuwissen <olaf.meeuwissen at avasys.jp> wrote: > Checking out why setting X/Y resolutions independently didn't quite > work as expected, I discovered that saneopts.h has this: > > #define SANE_NAME_SCAN_RESOLUTION "resolution" > #define SANE_NAME_SCAN_X_RESOLUTION "resolution" > #define SANE_NAME_SCAN_Y_RESOLUTION "y-resolution" > > That means that trying to set the X resolution always does the same > thing as setting the scan resolution. I think that is incorrect in > the general case and suggest the above gets changed to: > > #define SANE_NAME_SCAN_RESOLUTION "resolution" > #define SANE_NAME_SCAN_X_RESOLUTION "x-resolution" > #define SANE_NAME_SCAN_Y_RESOLUTION "y-resolution" > > So that backend implementations can distinguish these cases if they > want to. The corresponding descriptions for these option hint that > setting the image's scan resolution is not necessarily the same as > setting the horizontal scan resolution. > > In my particular situation, I have a use case where it makes sense to > use SANE_NAME_SCAN_RESOLUTION with one set of allowed resolutions and > different sets of allowed resolutions for the individual horizontal > and vertical resolution settings. > > On a more general note, there is no point in having different option > name macros that resolve to the same name. All of the SANE_NAME_* > macros should be unique. At the moment (sane-backends-1.0.19), only > SANE_NAME_SCAN_X_RESOLUTION is not unique. > > I don't think that the suggested change will break any of the current > backends and frontends, but would like to ask everyone to take a look > and comment on my suggestion before I file a bug report.
i agree with your assessment, but i am not sure i can envision a use case with all three controls active at the same time. or, are you going to have a locked/unlocked choice that switches between the two sets? allan -- "The truth is an offense, but not a sin"