Applies review comments
getWorldspaceTerrain => returns a reference because never null
crashfix in navigator
updateLandPositions fixes naming of it
const ESM4::Land* MWWorld::Store<ESM4::Land>::search(ESM::ExteriorCellLocation cellLocation) const removes useless else
ExteriorCellLocation uses default initializers
get terrain height returns -MAX_FLOAT when there is no esm4 terrain.
applied review comments
use default initlializer when possible
factorise code
uses pattern matching in for loop.
Rendering manager can have multiple terrain, one for each queried worldspace
Terrain::World has a worldspace member
storage functions require a worldspace parameter.
This PR aims to solve all issues with `Groundcover` view distance handling in a satisfying way while preserving other optimisations that benefit other features. The main idea here is not to rely on `ViewData` updates for distance culling calculations because we can not accurately determine distance against lazily updated views. Instead, we perform an accurate measurement in a cull callback we can run every frame in `Groundcover` itself. While we do have to add some code to handle this feature, it is quite loosely coupled code that could be useful elsewhere in the future. These changes should address a performance regression @akortunov experienced.
I have been informed by @akortunov that my addition of `Groundcover::getViewDistance` is not working in some cases. Investigations revealed that some `ViewData` code interacting with my additions had been quite thoroughly optimised in a way that was not sufficiently documented and interfered with the new feature. With this PR we repair `getViewDistance` while preserving such optimisations and add a necessary comment to avoid issues in the future. In addition, we now rebuild views when the global `mViewDistance` changes.
This reduces average time spent on in. 5 milliseconds as a base precision is
quite a lot considering that for 60 FPS frame time is 1000/16 = ~16.67 ms
when it's a cell loading frame and there is more important work to do rather
than sleeping.