What exactly does this report?
The X center of a sprite. Like the rotation X of the middle of a sprite is 0.
The center of rotation’s x. Ie in the vector editor you know how you can change the 0,0 with one of the tools? The X of that tool is the rotation point. If you set the rotation to the edge of the sprite instead of center it would turn differently and 0,0 would be a different position.
- rotation x, rotation y: when reading with my, the same as x position, y position. When set, changes the sprite’s rotation center without moving the sprite, like dragging the rotation center in the paint editor. (manual p. 74)