The reason of setOrigin doesn't affect Actor's position

Issue details

Origin is the center of the object. If origin is outside and object having position (0, 0) it’s logical that origin point must be at (0, 0) and object must keep offset from origin and not only affect rotation/scale but position too.

Reproduction steps/code

Actor actor = new Image("something.png");
actor.setPosition(0, 0);
actor.setOrigin(1000, 1000); // Nothing happened
actor.setOrigin(-1000, -1000); // Nothing happened

Version of LibGDX and/or relevant dependencies

1.9.8

Please select the affected platforms

• Android
• iOS (robovm)
• iOS (MOE)
• HTML/GWT
• Windows
• Linux
• MacOS

Another design issue

[Darkyenus]

scene2d implements a 2D scenegraph and such has different needs than 3D scenegraph that you are probably familiar with. In this context, it makes more sense that Actors origin comes into consideration only for scaling and rotation, as it simplifies most operations that deal with position.

Most applications of scene2d use rectangular actors (UI, platformers, top-down games…) where the point in the center of the rectangle (your suggested origin) is really used only for scaling and rotation, all position/size related logic deals with the rectangle’s corners.

This is not a design issue, the design here is sound. One could argue that it shouldn’t be called origin but something like “transformCenter”, as “origin” really does suggest something related to position, but changing that now would break too much code. The documentation on this could be improved though.

[Darkyenus]

You keep assuming that scene2ds purpose is to be used like a 3D scene-graph. If that were the case, you would be 100% right. But this is not the case, as I have explained before. Changing this now would break virtually every class in the scene2d.[ui] packages.

How often people override setPosition […]

I don’t remember ever encountering that. I imagine that doing so will break a lot of existing code, so it can’t be used, in which case why bother with scene2d at all?

Major version increment is soon […]

Just because the next version is 1.9.9, it does not mean that next version must be 2.0.0. These dots are just version separators, not decimal points.