fix: support seasons swaps in PBR and TerrainHelper

src/Features/TerrainHelper.cpp

@@ -71,10 +71,10 @@ bool TerrainHelper::TESObjectLAND_SetupMaterial(RE::TESObjectLAND* land)
 		std::array<RE::BGSTextureSet*, 6> textureSets;
 		auto defTexture = land->loadedData->defQuadTextures[quadI];
 		if (defTexture != nullptr && defTexture->formID != 0) {
-			textureSets[0] = defTexture->textureSet;
+			textureSets[0] = Util::GetSeasonalSwap(defTexture->textureSet);
 		} else {
 			// this is a default texture
-			textureSets[0] = defaultLandTexture;
+			textureSets[0] = Util::GetSeasonalSwap(defaultLandTexture);
 		}
 		for (uint32_t textureI = 0; textureI < 5; ++textureI) {
 			auto curTexture = land->loadedData->quadTextures[quadI][textureI];
@@ -85,9 +85,9 @@ bool TerrainHelper::TESObjectLAND_SetupMaterial(RE::TESObjectLAND* land)
 
 			if (curTexture->formID == 0) {
 				// this is a default texture
-				textureSets[textureI + 1] = defaultLandTexture;
+				textureSets[textureI + 1] = Util::GetSeasonalSwap(defaultLandTexture);
 			} else {
-				textureSets[textureI + 1] = land->loadedData->quadTextures[quadI][textureI]->textureSet;
+				textureSets[textureI + 1] = Util::GetSeasonalSwap(land->loadedData->quadTextures[quadI][textureI]->textureSet);
 			}
 		}
 

src/Hooks.cpp

@@ -806,15 +806,15 @@ namespace Hooks
 	{
 		static bool thunk(RE::TESObjectLAND* land)
 		{
+			bool vanillaResult = func(land);
+
 			// setup material for PBR
 			auto TruePBRSingleton = globals::truePBR;
 			if (TruePBRSingleton->TESObjectLAND_SetupMaterial(land)) {
 				// if PBR, we are done
 				return true;
 			}
 
-			bool vanillaResult = func(land);
-
 			// setup material for terrain helper
 			auto terrainHelper = globals::features::terrainHelper;
 			if (vanillaResult && terrainHelper->loaded) {

src/TruePBR.cpp

@@ -1059,13 +1059,13 @@ void SetupLandscapeTexture(BSLightingShaderMaterialPBRLandscape& material, RE::T
 		return;
 	}
 
-	auto textureSet = landTexture.textureSet;
+	auto textureSet = Util::GetSeasonalSwap(landTexture.textureSet);
 	if (textureSet == nullptr) {
 		return;
 	}
 
 	auto truePBR = globals::truePBR;
-	auto* textureSetData = truePBR->GetPBRTextureSetData(landTexture.textureSet);
+	auto* textureSetData = truePBR->GetPBRTextureSetData(textureSet);
 	const bool isPbr = textureSetData != nullptr;
 
 	textureSets[textureIndex] = textureSetData;
@@ -1099,7 +1099,7 @@ bool TruePBR::TESObjectLAND_SetupMaterial(RE::TESObjectLAND* land)
 	if (land->loadedData != nullptr) {
 		for (uint32_t quadIndex = 0; quadIndex < 4; ++quadIndex) {
 			if (land->loadedData->defQuadTextures[quadIndex] != nullptr) {
-				if (singleton->IsPBRTextureSet(land->loadedData->defQuadTextures[quadIndex]->textureSet)) {
+				if (singleton->IsPBRTextureSet(Util::GetSeasonalSwap(land->loadedData->defQuadTextures[quadIndex]->textureSet))) {
 					isPbr = true;
 					break;
 				}
@@ -1108,7 +1108,7 @@ bool TruePBR::TESObjectLAND_SetupMaterial(RE::TESObjectLAND* land)
 			}
 			for (uint32_t textureIndex = 0; textureIndex < 6; ++textureIndex) {
 				if (land->loadedData->quadTextures[quadIndex][textureIndex] != nullptr) {
-					if (singleton->IsPBRTextureSet(land->loadedData->quadTextures[quadIndex][textureIndex]->textureSet)) {
+					if (singleton->IsPBRTextureSet(Util::GetSeasonalSwap(land->loadedData->quadTextures[quadIndex][textureIndex]->textureSet))) {
 						isPbr = true;
 						break;
 					}

src/Utils/Game.cpp

@@ -182,4 +182,19 @@ namespace Util
 	{
 		return IsNewFrame(globals::state->frameCount);
 	}
+
+	RE::BGSTextureSet* GetSeasonalSwap(RE::BGSTextureSet* textureSet)
+	{
+		if (textureSet == nullptr) {
+			return nullptr;
+		}
+
+		if (textureSet->pad12C > 0) {
+			if (auto* form = RE::TESForm::LookupByID<RE::BGSTextureSet>(textureSet->pad12C)) {
+				return form;
+			}
+		}
+
+		return textureSet;
+	}
 }  // namespace Util

src/Utils/Game.h

@@ -77,4 +77,19 @@ namespace Util
 		}
 		bool IsNewFrame();
 	};
+
+	/**
+     * @brief Retrieves the seasonal texture swap for a given texture set, if available.
+     *
+     * This function checks if a given texture set has been swapped by Seasons of Skyrim.
+     * If swapped, pad12C will be > 0 and will be the formid of the swapped texture set.
+     *
+     * @param textureSet Pointer to the original BGSTextureSet to check for seasonal swaps.
+     *                   Can be nullptr.
+     *
+     * @return Pointer to the seasonal swap texture set if found and valid, otherwise
+     *         returns the original textureSet parameter. Returns nullptr if the input
+     *         textureSet is nullptr.
+     */
+	[[nodiscard]] RE::BGSTextureSet* GetSeasonalSwap(RE::BGSTextureSet* textureSet);
 }  // namespace Util