The Offset Menu

Esper · **Joined:** Jul 17, 2012 **Posts:** 2769

when you use the Offset Menu in Gimp you have to put in values for the x-axis and the y-axis
Layer → Transform → Offset

i learned in school, that in a coordinate system, the x-axis is horizontical and the y-axis vertical
positive and negative values are like this

but in Gimp, the negative y-axis is on top - so the other way round

this is confusing me
is this a bug ??

K1TesseraEna · **Joined:** Sep 22, 2012 **Posts:** 2089 **Location:** US

It's not a bug. It was decided once by the dev's that the positive values move the layer to the right and downward.
Guess, western right to left style of writing had prevailed.
http://docs.gimp.org/2.8/en/gimp-layer-offset.html

Edit. *left to right, of course

Esper · **Joined:** Jul 17, 2012 **Posts:** 2769

how odd

thanks K1te

K1TesseraEna · **Joined:** Sep 22, 2012 **Posts:** 2089 **Location:** US

Esper wrote:

how odd

thanks K1te

No problem, Esper.
Maybe it has more to do with clockwise (more intuitive) movement rather than the writing style. Me guessing here, lol
BTW, did you know that you can offset layer masks as well, not just the layers?
I wrote a tutorial on that, but never published it here. Made an interesting animation based on layer masks offset.

Esper · **Joined:** Jul 17, 2012 **Posts:** 2769

it doesnt surprise me as you can offset saved channels too

what would be the use of offsetting a layermask ?

K1TesseraEna · **Joined:** Sep 22, 2012 **Posts:** 2089 **Location:** US

Esper wrote:

what would be the use off offsetting a layermask ?

hmm..... an animation...

Like this one

saulgoode · **Posted:** Sun Mar 03, 2013 1:39 am **(#7)**

The logic is based upon the coordinates of the upper left corner of the image being x=0,y=0.

Esper · **Joined:** Jul 17, 2012 **Posts:** 2769

saulgoode wrote:

The logic is based upon the coordinates of the upper left corner of the image being x=0,y=0.

i see !

well thats a good way to memorize it too

molly · **Joined:** Apr 07, 2010 **Posts:** 14182

K1TesseraEna wrote:

Esper wrote:

what would be the use off offsetting a layermask ?

hmm..... an animation...

Like this one

Wow! there is a big green worm going across my screen first thing I saw before I finished my first coffee.
That is cool Kit...as long as it stays inside the monitor. :jumpclap

ofnuts · **Joined:** Oct 25, 2010 **Posts:** 4812

saulgoode wrote:

The logic is based upon the coordinates of the upper left corner of the image being x=0,y=0.

Which itself stems from the coordinates system used in the various graphics APIs, which in turn use downward rows to be coherent with the top->down scan in CRT displays...

he4rty · **Joined:** Aug 30, 2012 **Posts:** 2174

Must be honest never found the offset that confusing as the minus movement is taking away from my pixel position so it just feels natural for the layer to then be moved up.

Erisian · **Posted:** Mon Mar 04, 2013 5:52 am **(#12)**

That's cleared it up for me too. Thanks for asking this Esper.

Lovely worm Kite. The animation is incredibly smooth. I'm always impressed with what you do.