Integrate virutal texture allocator improvements from main.
[FYI] ben.ingram
#lockdown kevin.ortegren
#ROBOMERGE-SOURCE: CL 15922154 in //UE5/Release-5.0-EarlyAccess/...
#ROBOMERGE-BOT: STARSHIP (Release-5.0-EarlyAccess -> Main) (v786-15839533)
[CL 15922638 by jeremy moore in ue5-main branch]
- Check partially allocated block for fit, don't need to start with a completely free block for allocations
- Try to use the lowest possible vAddress for new allocations, this reduces the texture area covered by allocations
- Page table is no longer required to be square power-2 texture, instead allow it to grow organically as allocated area increases
- Allocator starts with maximum-sized block and tracks allocated area, no longer needs special logic to 'grow'
- Rectangular allocated VTs now mip based on min-size rather than max-size, relaxes alignment requirements and allows better packing
#rb jeremy.moore
#jira none
[CL 15825578 by Ben Ingram in ue5-main branch]
Disabled by default, set r.Mobile.VirtualTextures=1 to enable
known issues: RVT compression is not implementted, Android OpenGL will have R and G channels swapped for uncompressed streaming VT, no sRGB support
#jira UE-79955
#rb jeremy.moore
#ROBOMERGE-SOURCE: CL 11070636 via CL 11070637
#ROBOMERGE-BOT: (v637-11041722)
[CL 11070638 by dmitriy dyomin in Main branch]
#rnx
#rb none
#ROBOMERGE-OWNER: ryan.durand
#ROBOMERGE-AUTHOR: ryan.durand
#ROBOMERGE-SOURCE: CL 10869210 via CL 10869511 via CL 10869900
#ROBOMERGE-BOT: (v613-10869866)
[CL 10870549 by ryan durand in Main branch]
Replicated from CL# 7924370.
#rb none
#ROBOMERGE-OWNER: steve.robb
#ROBOMERGE-AUTHOR: steve.robb
#ROBOMERGE-SOURCE: CL 9279060 via CL 9279063
#ROBOMERGE-BOT: (v443-9013191)
[CL 9279836 by steve robb in Main branch]
This allows us to put texture layers into physical groups that will be accessed through the same page table layer (and so must share the same UV in different physical textures).
Physical spaces can now contain multiple texture layers (one for each member of a physical group).
Changed the logic for the physical space pool descriptions so that we can support multiple texture layers. And also made the description work for Min and Max tile size values so that we don't need to specify pool sizes multiple times for each possible tile size.
Runtime virtual texture can select if it wants to use a single physical group. By default this is on so that RVT uses a single page table channel.
#rb none
[FYI] Ben.Ingram
#ROBOMERGE-OWNER: jeremy.moore
#ROBOMERGE-AUTHOR: jeremy.moore
#ROBOMERGE-SOURCE: CL 8747955 via CL 8748343 via CL 8782324
#ROBOMERGE-BOT: (v422-8689730)
[CL 8790675 by jeremy moore in Main branch]
