[Xinhuan]

The rendering engine:

There are 7 stratas. Each strata is completely above the next strata. Frames need to belong to a strata, defaulting to MEDIUM.

Frames further have a frame level. Frame levels determine the rendering order of frames with respect to its parent frame.

Within each frame, there are several layers. Layers determine the rendering order of children textures and fontstrings.


Strata differences override frame levels. So frameA on MEDIUM parented to frameB on HIGH, will cause B to be drawn above A, regardless of framelevels. But visibility, alpha and scaling are controlled by frame parents, so whether A is visible depends entirely on B's visbility/alpha/scaling.

Anchoring of frames is on a totally different hierarchy from parent-child hierarchy. That is, frame positioning is independent of parent-child relationships.