Every display object has properties that affect where and how it is rendered on screen.
Corona calculates a transform matrix for a display object by applying the properties in a specific order.
Transforms are always relative to the parent, so the final transform includes the transforms of the object's parents (and ancestors). See Transforms in the Group Programming guide.
Anchors range from
1.0. When you change an anchor value, the object's origin does not change. Instead the geometry moves relative to the origin.
By default, the anchor is set to
(0.5, 0.5) which centers the geometry about the origin. An anchor pair of
(0,0) makes the top-left of the geometry's bounds the origin, while an anchor pair of
(1,1) makes it the bottom-right of the geometry's bounds.
You can change the default via display.setDefault().
The following diagram illustrates how changing the anchor affects objects. The dotted square is rotated to illustrate how geometry is rotated about the origin depending on the anchor.