Enhancement: Unlimit overlay render priorities and remove max overlay count per-face

[pivotman319-owo]

What would this enhancement be for?

Rendering

Describe your enhancement suggestion in more detail

This enhancement will require a BSP v25 struct version change.

Currently, info_overlay render orders for both wall/ground and water surfaces only support up to 4 maximum rendering orders due to the imposition of two separate 2-bit masks in the BSP structure. Setting a render order past these bits causes VBSP to exit immediately during compile.

Ideally, these bitmasks (OVERLAY_RENDER_ORDER_NUM_BITS and WATEROVERLAY_RENDER_ORDER_NUM_BITS) should both be eliminated from the engine to allow for virtually unlimited overlay render priorities. Variables OVERLAY_BSP_FACE_COUNT (the maximum per-face overlay count) and WATEROVERLAY_BSP_FACE_COUNT (the maximum per-face overlay count for water surfaces) should also probably be removed from the engine to allow for an unlimited number of overlays.

[TeamSpen210]

This is a bit trickier than it sounds. Each overlay structure has a fixed array for the face count, so it can’t actually be infinite. We’d need to redesign it so it’s variable in length. The bit masks exist because the two numbers are packed into the same value, so changing the amount of one affects the limit for the other, though we’ve got quite a few bits to use.