G'MIC Quadrangle improvement idea

gmic
quadrangle

#1

Right now, the current implementation of it is kinda real slow. It’s not really interactive.A way to interact with point via mouse would be nice to have.

Also zooming seem to have undesirable result. Like if you zoom in, the result is altered. That’s not the expected behavior.The expected behavior is that the quadrangle scales with the picture being used.


(David Tschumperlé) #2

It is how it’s done in latest version. What version of G’MIC do you use ? Have you tried updating your filters ? This filter works quite fast for me.

That’s wrong. It is actually the expected behavior. Point parameters are supposed to stay constant when the user move the image in the preview window (zooming or panning).

I repeat it probably for a thousand times, but zooming an image preview is most of the time a bad idea, as the preview of a filter is only designed to be accurate at a certain zoom factor. Usually, filters use a 1:1 preview, or a full-size image, and if you deviate from that, you’ll get a warning icon displaying under the preview widget, telling you that the preview is not accurate anymore. I often wonder if we shouldn’t just disable preview zooming for these filters (instead of displaying a warning icon), but I guess that if we do that, some people will complain about the fact they can’t zoom anymore.

There are only a few filters that give accurate previews for any zoom factor, it’s those doing pixel by pixel transformations only (color mixers for instance).


#3

I have tested the latest version, it does work well for what it is.

As for the second part, yeah, I think that those should be disabled as it gives false expectation, and therefore can be perceived as buggy. Ideally, it would work on any zoom level and the quadrangle scales with it so that you can fix deviations with more control, but if that can’t be done, then I guess it’s a case of “well, ok”. It not like it matters so much for most program with G’MIC support can be used to get rid of those deviations.