Attempt to implement barrier for fonts

Author: WSSDude

src/d3d12/D3D12.h

@@ -100,4 +100,5 @@ struct D3D12
     std::array<ImDrawData, 3> m_imguiDrawDataBuffers;
     std::atomic_bool m_delayedTrapInput{false};
     std::atomic_bool m_delayedTrapInputState{false};
+    bool m_imGuiInitialized{false};
 };

src/d3d12/D3D12_Functions.cpp

@@ -22,11 +22,16 @@ bool D3D12::ResetState(const bool acClearDownlevelBackbuffers, const bool acDest
             drawData.Clear();
         }
 
-        ImGui_ImplDX12_Shutdown();
-        ImGui_ImplWin32_Shutdown();
+        ImGui::GetIO().Fonts->Clear();
 
         if (acDestroyContext)
+        {
+            ImGui_ImplDX12_Shutdown();
+            ImGui_ImplWin32_Shutdown();
             ImGui::DestroyContext();
+
+            m_imGuiInitialized = false;
+        }
     }
 
     m_frameContexts.clear();
@@ -278,14 +283,15 @@ bool D3D12::InitializeDownlevel(ID3D12CommandQueue* apCommandQueue, ID3D12Resour
 void D3D12::ReloadFonts()
 {
     std::lock_guard _(m_imguiLock);
+    
+    auto& io = ImGui::GetIO();
+    if (io.Fonts->IsBuilt())
+        return;
 
     // TODO - scale also by DPI
     const auto [resx, resy] = m_outSize;
     const auto scaleFromReference = std::min(static_cast<float>(resx) / 1920.0f, static_cast<float>(resy) / 1080.0f);
 
-    auto& io = ImGui::GetIO();
-    io.Fonts->Clear();
-
     ImFontConfig config;
     const auto& fontSettings = m_options.Font;
     config.SizePixels = std::floorf(fontSettings.BaseSize * scaleFromReference);
@@ -415,12 +421,16 @@ void D3D12::ReloadFonts()
     static const ImWchar icon_ranges[] = {ICON_MIN_MD, ICON_MAX_MD, 0};
     auto cetIconPath = GetAbsolutePath(L"materialdesignicons.ttf", m_paths.Fonts(), false);
     io.Fonts->AddFontFromFileTTF(UTF16ToUTF8(cetIconPath.native()).c_str(), config.SizePixels, &config, icon_ranges);
+    io.Fonts->Build();
 }
 
 bool D3D12::InitializeImGui(size_t aBuffersCounts)
 {
     std::lock_guard _(m_imguiLock);
 
+    if (m_imGuiInitialized)
+        return true;
+
     // TODO - scale also by DPI
     const auto [resx, resy] = m_outSize;
     const auto scaleFromReference = std::min(static_cast<float>(resx) / 1920.0f, static_cast<float>(resy) / 1080.0f);
@@ -469,9 +479,13 @@ bool D3D12::InitializeImGui(size_t aBuffersCounts)
         Log::Error("D3D12::InitializeImGui() - ImGui_ImplDX12_CreateDeviceObjects call failed!");
         ImGui_ImplDX12_Shutdown();
         ImGui_ImplWin32_Shutdown();
+
+        ImGui::GetIO().Fonts->Clear();
+
         return false;
     }
 
+    m_imGuiInitialized = true;
     return true;
 }
 
@@ -482,6 +496,13 @@ void D3D12::PrepareUpdate()
 
     std::lock_guard _(m_imguiLock);
 
+    if (!ImGui::GetIO().Fonts->IsBuilt())
+    {
+        ReloadFonts();
+
+        ImGui_ImplDX12_CreateDeviceObjects(m_pCommandQueue.Get());
+    }
+
     ImGui_ImplWin32_NewFrame(m_outSize);
     ImGui::NewFrame();