GUI - Entity-Aligned Controls

[Stuart Walpole]

[We can probably get by without this feature, though since we're stacking up a fair number of C++-only controls, it may be worth investigating.]

• Solution: "Magic box" controls that can be relative to an entity (eg health bars, rank icon, a circle of BfME train buttons); set the control properties and who gets it, and the rest is hidden in C++).
  • Support for positioning controls relative to entities (ie the context-sensitive train buttons that surround a building).
  • GUI controls that remain relative to a world object, like hitpoint bars and "level-up" icons (perhaps an extension of billboard sprites?). Engine function to return object position relative to x/y screen coordinates.

[(none)]

Milestone Advanced Playability Demo deleted

[Freagarach]

Hitpoints bars (r8241) and level-icons (r21076) are in.