HnTextureRegistry: recycle texture IDs

DiligentGraphics · Oct 19, 2024 · ddb0c7c · ddb0c7c
1 parent c872a2c
commit ddb0c7c
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Showing 2 changed files with 28 additions and 4 deletions.
diff --git a/Hydrogent/include/HnTextureRegistry.hpp b/Hydrogent/include/HnTextureRegistry.hpp
@@ -193,7 +193,7 @@ class HnTextureRegistry final : public std::enable_shared_from_this<HnTextureReg
                      std::function<RefCntAutoPtr<ITextureLoader>()> CreateLoader,
                      std::shared_ptr<TextureHandle>                 TexHandle);
 
-    void OnHandleDestroyed(const TextureHandle& Handle);
+    void OnDestroyHandle(const TextureHandle& Handle);
 
 private:
     RefCntAutoPtr<IRenderDevice>     m_pDevice;
@@ -221,6 +221,9 @@ class HnTextureRegistry final : public std::enable_shared_from_this<HnTextureReg
     std::mutex                             m_AsyncTasksMtx;
     std::vector<RefCntAutoPtr<IAsyncTask>> m_AsyncTasks;
 
+    std::mutex          m_RecycledTextureIdsMtx;
+    std::vector<Uint32> m_RecycledTextureIds;
+
     std::atomic<Uint32> m_NextTextureId{0};
     std::atomic<Int32>  m_NumTexturesLoading{0};
     std::atomic<Int64>  m_LoadingTexDataSize{0};

diff --git a/Hydrogent/src/HnTextureRegistry.cpp b/Hydrogent/src/HnTextureRegistry.cpp
@@ -48,7 +48,7 @@ HnTextureRegistry::TextureHandle::~TextureHandle()
 {
     if (auto Registry = m_Registry.lock())
     {
-        Registry->OnHandleDestroyed(*this);
+        Registry->OnDestroyHandle(*this);
     }
     else
     {
@@ -339,7 +339,21 @@ HnTextureRegistry::TextureHandleSharedPtr HnTextureRegistry::Allocate(const pxr:
         [&]() {
             m_NumTexturesLoading.fetch_add(+1);
 
-            std::shared_ptr<TextureHandle> TexHandle = std::make_shared<TextureHandle>(*this, m_NextTextureId.fetch_add(1));
+            Uint32 TextureId = 0;
+            {
+                std::lock_guard<std::mutex> Lock{m_RecycledTextureIdsMtx};
+                if (!m_RecycledTextureIds.empty())
+                {
+                    TextureId = m_RecycledTextureIds.back();
+                    m_RecycledTextureIds.pop_back();
+                }
+                else
+                {
+                    TextureId = m_NextTextureId.fetch_add(1);
+                }
+            }
+
+            std::shared_ptr<TextureHandle> TexHandle = std::make_shared<TextureHandle>(*this, TextureId);
 
             if (IsAsync && m_pThreadPool)
             {
@@ -414,8 +428,15 @@ Uint32 HnTextureRegistry::GetDataVersion() const
     return m_DataVersion.load();
 }
 
-void HnTextureRegistry::OnHandleDestroyed(const TextureHandle& Handle)
+void HnTextureRegistry::OnDestroyHandle(const TextureHandle& Handle)
 {
+    {
+        std::lock_guard<std::mutex> Guard{m_RecycledTextureIdsMtx};
+        // Use m_TextureId since the handle may be uninitialized, which is totally
+        // OK here, but GetId() would assert in this case.
+        m_RecycledTextureIds.push_back(Handle.m_TextureId);
+    }
+
     if (Handle.m_pAtlasSuballocation)
     {
         m_AtlasDataSize.fetch_add(-static_cast<Int64>(Handle.DataSize));