Fix crash when switching from a level with lightmaps to one without

src/common/rendering/vulkan/textures/vk_texture.cpp

@@ -397,6 +397,13 @@ void VkTextureManager::CreatePrefiltermap(int size, int count, TArray<uint16_t>&
 
 void VkTextureManager::CreateLightmap(int newLMTextureSize, int newLMTextureCount, TArray<uint16_t>&& newPixelData)
 {
+	if (newLMTextureCount == 0) // If there is no lightmap we create a dummy texture to simplify code elsewhere
+	{
+		newLMTextureSize = 1;
+		newLMTextureCount = 1;
+		newPixelData = {};
+	}
+
 	if (Lightmap.Size == newLMTextureSize && Lightmap.Count == newLMTextureCount + 1 && newPixelData.Size() == 0)
 		return;
 

src/common/rendering/vulkan/vk_lightmapper.cpp

@@ -73,7 +73,8 @@ void VkLightmapper::ReleaseResources()
 void VkLightmapper::SetLevelMesh(LevelMesh* level)
 {
 	mesh = level;
-	UpdateAccelStructDescriptors();
+	if (mesh)
+		UpdateAccelStructDescriptors();
 
 	lightmapRaytraceLast.Reset();
 	lastPixelCount = 0;

src/common/rendering/vulkan/vk_renderdevice.cpp

@@ -521,12 +521,9 @@ void VulkanRenderDevice::BeginFrame()
 	{
 		levelMeshChanged = false;
 		mLevelMesh->SetLevelMesh(levelMesh);
-
-		if (levelMesh && levelMesh->Lightmap.TextureCount > 0)
-		{
+		if (levelMesh)
 			GetTextureManager()->CreateLightmap(levelMesh->Lightmap.TextureSize, levelMesh->Lightmap.TextureCount, std::move(levelMesh->Lightmap.TextureData));
-			GetLightmapper()->SetLevelMesh(levelMesh);
-		}
+		GetLightmapper()->SetLevelMesh(levelMesh);
 	}
 
 	SetViewportRects(nullptr);

src/p_setup.cpp

@@ -379,6 +379,8 @@ void FLevelLocals::ClearLevelData(bool fullgc)
 	if (levelMesh) delete levelMesh;
 	aabbTree = nullptr;
 	levelMesh = nullptr;
+	if (screen)
+		screen->SetLevelMesh(nullptr);
 	if (screen && screen->mShadowMap)
 		screen->mShadowMap->SetAABBTree(nullptr);
 }

src/rendering/hwrenderer/doom_levelmesh.cpp

@@ -238,6 +238,10 @@ DoomLevelMesh::DoomLevelMesh(FLevelLocals& doomMap)
 	r_viewpoint.camera = oldcamera;
 }
 
+DoomLevelMesh::~DoomLevelMesh()
+{
+}
+
 void DoomLevelMesh::SetLimits(FLevelLocals& doomMap)
 {
 	// Try to estimate what the worst case memory needs are for the level

src/rendering/hwrenderer/doom_levelmesh.h

@@ -90,6 +90,7 @@ class DoomLevelMesh : public LevelMesh, public UpdateLevelMesh
 {
 public:
 	DoomLevelMesh(FLevelLocals &doomMap);
+	~DoomLevelMesh();
 
 	void PrintSurfaceInfo(const LevelMeshSurface* surface);