On Sun, Oct 04, 2009 at 08:50:18AM +0100, Martin Ling wrote: > On Sun, Oct 04, 2009 at 09:03:57AM +0200, Frank van Maarseveen wrote: > > > > On Sat, Oct 03, 2009 at 03:26:57PM -0500, Udi Fuchs wrote: > > > > - horizontal flip + reset doesn't work (no reset) > > > > > > Fixed. The problem was that value-changed signal was not emitted. > > > > > > > - vertical flip is translated into a 180 degree rotation which > > > > isn't. > > > > > > I define 0 angle as an arrow pointing upward (12 o'clock). With this > > > definition a vertical flip does translate into a 180 degree rotation. > > > > Rotation and mirroring are different transformations, visually and in math. > > Not entirely.
They are fundamentally different. > To go between an unmirrored image and a mirrored one, you > need to choose arbitrarily which axis to flip around. If we've chosen > the y axis, then the "flip horizontal" operation is just a flip around > that axis, but "flip vertical" is a combination of that flip and a 180 > degree rotation. Flip axis itself can effectively be rotated, yes. So we actually don't need two flip buttons ;-) > > The y axis is the right choice for our purposes, because for many > subjects without text or suchlike, a photo can be flipped on that axis > for pure compositional preference. However for almost any subject aside > from closeups of textures, a vertical flip would be considered "upside > down" as well as "mirrored" by the viewer. You mean that we actually need an "upside-down" button, i.e. rotate 180 degree button instead of a vertical flip button? If we extend that idea then we could even have four arrow buttons and the user just needs to press the one which reflects the current image orientation. I'm not arguing against the image transformation behind the vertical flip button: that's ok but the angle shown in the rotation control is not. > > If you allow flips around either axis without considering one of them to > involve a rotation, you have a state tracking and normalisation problem > because there are multiple ways to get the same result. There is always more than one way to get the same result with rotation and flipping (actually, one flip button and a rotation control can do it all). Currently, the vertical flip button does not vertically flip at all. Instead, it rotates and flips horizontally which happens to have visually the same effect but with a different rotation control afterwards. This is a choice but what the vertical flip button now does is not reflected by its icon image. And I still don't see why it is useful to present the user with a rotation control at 180 degrees after a vertical flip. -- Frank ------------------------------------------------------------------------------ Come build with us! The BlackBerry® Developer Conference in SF, CA is the only developer event you need to attend this year. Jumpstart your developing skills, take BlackBerry mobile applications to market and stay ahead of the curve. Join us from November 9-12, 2009. Register now! http://p.sf.net/sfu/devconf _______________________________________________ ufraw-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/ufraw-devel
