apply changes requested in the code review

apps/openmw/mwlua/landbindings.cpp

@@ -17,13 +17,6 @@ namespace MWLua
         sol::state_view& lua = context.mLua->sol();
         sol::table landApi(lua, sol::create);
 
-        // Constants
-        landApi["RANGE"] = LuaUtil::makeStrictReadOnly(context.mLua->tableFromPairs<std::string_view, ESM::RangeType>({
-            { "Self", ESM::RT_Self },
-            { "Touch", ESM::RT_Touch },
-            { "Target", ESM::RT_Target },
-        }));
-
         landApi["getHeightAt"] = [](const osg::Vec3f& pos, sol::object cellOrName) {
             ESM::RefId worldspace;
             if (cellOrName.is<GCell>())
@@ -63,7 +56,7 @@ namespace MWLua
             return ESMTerrain::Storage::getHeightAt(landData->mHeights, landData->sLandSize, pos, cellSize);
         };
 
-        landApi["getLandTextureAt"] = [lua = context.mLua](const osg::Vec3f& pos, sol::object cellOrName) {
+        landApi["getTextureAt"] = [lua = context.mLua](const osg::Vec3f& pos, sol::object cellOrName) {
             sol::variadic_results values;
             ESM::RefId worldspace;
             if (cellOrName.is<GCell>())
@@ -85,6 +78,11 @@ namespace MWLua
             auto store = MWBase::Environment::get().getESMStore();
             // We need to read land twice. Once to get the amount of texture samples per cell edge, and the second time
             // to get the actual data
+            // This is because the visual land textures are offset with regards to quads that are rendered for terrain.
+            // To properly calculate that offset, we need to know how many texture samples exist per cell edge,
+            // as it differs between tes3 and tes4. It's equal -
+            // Once we know the value, we will calculate the offset and retrieve a sample again, this time
+            // with the offset taken into account.
             auto landStore = store->get<ESM::Land>();
             auto land = landStore.search(cellX, cellY);
             const ESM::Land::LandData* landData = nullptr;
@@ -105,6 +103,8 @@ namespace MWLua
                 return values;
             }
 
+            // Use landData to get amount of sampler per cell edge (sLandTextureSize)
+            // and then get the corrected position that will map to the rendered texture
             const osg::Vec3f correctedPos
                 = ESMTerrain::Storage::getTextureCorrectedWorldPos(pos, landData->sLandTextureSize, cellSize);
             int correctedCellX = static_cast<int>(std::floor(correctedPos.x() / cellSize));
@@ -128,7 +128,7 @@ namespace MWLua
 
             // We're passing in sLandTextureSize, NOT sLandSize like with getHeightAt
             const ESMTerrain::UniqueTextureId textureId
-                = ESMTerrain::Storage::getLandTextureAt(correctedLandData->mTextures, correctedLand->getPlugin(),
+                = ESMTerrain::Storage::getTextureAt(correctedLandData->mTextures, correctedLand->getPlugin(),
                     correctedLandData->sLandTextureSize, correctedPos, cellSize);
 
             // Need to check for 0, 0 so that we can safely subtract 1 later, as per documentation on UniqueTextureId

components/esmterrain/storage.cpp

@@ -2,11 +2,11 @@
 
 #include <algorithm>
 #include <optional>
-#include <osg/Vec3f>
 #include <stdexcept>
 
 #include <osg/Image>
 #include <osg/Plane>
+#include <osg/Vec3f>
 
 #include <components/debug/debuglog.hpp>
 #include <components/esm/esmterrain.hpp>
@@ -475,6 +475,7 @@ namespace ESMTerrain
             blendmaps.clear(); // If a single texture fills the whole terrain, there is no need to blend
     }
 
+    // Returns a position that can be used to look up a land texture, while taking their offset into account
     osg::Vec3f Storage::getTextureCorrectedWorldPos(
         const osg::Vec3f& uncorrectedWorldPos, const int textureSize, const float cellSize)
     {
@@ -485,7 +486,7 @@ namespace ESMTerrain
     }
 
     // Takes in a corrected world pos to match the visuals.
-    UniqueTextureId Storage::getLandTextureAt(const std::span<const std::uint16_t> landData, const int plugin,
+    UniqueTextureId Storage::getTextureAt(const std::span<const std::uint16_t> landData, const int plugin,
         const int textureSize, const osg::Vec3f& correctedWorldPos, const float cellSize)
     {
         int cellX = static_cast<int>(std::floor(correctedWorldPos.x() / cellSize));

components/esmterrain/storage.hpp

@@ -120,7 +120,7 @@ namespace ESMTerrain
         static osg::Vec3f getTextureCorrectedWorldPos(
             const osg::Vec3f& uncorrectedWorldPos, const int textureSize, const float cellSize);
 
-        static UniqueTextureId getLandTextureAt(const std::span<const std::uint16_t> landData, const int plugin,
+        static UniqueTextureId getTextureAt(const std::span<const std::uint16_t> landData, const int plugin,
             const int textureSize, const osg::Vec3f& worldPos, const float cellSize);
 
         /// Get the transformation factor for mapping cell units to world units.

files/lua_api/openmw/core.lua

@@ -467,10 +467,10 @@
 
 ---
 -- Get the terrain texture at a given location.
--- @function [parent=#Land] getLandTextureAt
+-- @function [parent=#Land] getTextureAt
 -- @param openmw.util#Vector3 position
 -- @param #any cellOrName (optional) cell or cell name in their exterior world space to query
--- @return #nil, #number Land texture index or nil if failed to retrieve the texture
+-- @return #nil, #number Land texture index or nil if failed to retrieve the texture. Landscape textures created through editors such as openmw-cs can be assigned an id to differentiate them, that is also used for terrain rendering. The value returned here corresponds to that value. See also LTEX records (https://en.uesp.net/wiki/Morrowind_Mod:Mod_File_Format/LTEX)
 -- @return #nil, #number Plugin id or nil if failed to retrieve the texture
 -- @return #nil, #string Texture path or nil if one isn't defined