Isolate XCNewEditor default build from ImGui headers

editor/src/Platform/D3D12WindowRendererImGuiInterop.h

@@ -0,0 +1,82 @@
+#pragma once
+
+#include "D3D12WindowRenderer.h"
+
+#ifdef min
+#undef min
+#endif
+
+#ifdef max
+#undef max
+#endif
+
+#include "../UI/ImGuiBackendBridge.h"
+
+namespace XCEngine {
+namespace Editor {
+namespace Platform {
+
+inline void RenderImGuiFrame(
+    D3D12WindowRenderer& windowRenderer,
+    UI::ImGuiBackendBridge& imguiBackend,
+    const float clearColor[4],
+    const D3D12WindowRenderer::RenderCallback& beforeUiRender = {},
+    const D3D12WindowRenderer::RenderCallback& afterUiRender = {}) {
+    const Rendering::RenderSurface* renderSurface = windowRenderer.GetCurrentRenderSurface();
+    Rendering::RenderContext renderContext = windowRenderer.GetRenderContext();
+    if (!renderContext.IsValid() ||
+        renderContext.commandList == nullptr ||
+        renderContext.commandQueue == nullptr ||
+        windowRenderer.GetSwapChain() == nullptr ||
+        renderSurface == nullptr ||
+        windowRenderer.GetSrvHeap() == nullptr) {
+        return;
+    }
+    auto* d3d12CommandList = static_cast<RHI::D3D12CommandList*>(renderContext.commandList);
+
+    const auto& colorAttachments = renderSurface->GetColorAttachments();
+    if (colorAttachments.empty() || colorAttachments[0] == nullptr) {
+        return;
+    }
+
+    RHI::RHIResourceView* renderTargetView = colorAttachments[0];
+    renderContext.commandList->TransitionBarrier(
+        renderTargetView,
+        RHI::ResourceStates::Present,
+        RHI::ResourceStates::RenderTarget);
+    renderContext.commandList->SetRenderTargets(1, &renderTargetView, nullptr);
+    renderContext.commandList->ClearRenderTarget(renderTargetView, clearColor);
+
+    // Host-owned swapchain surfaces are handed to the callback already bound and ready for rendering.
+    // The callback must leave the color attachment in RenderTarget state so ImGui can render after it.
+    if (beforeUiRender) {
+        beforeUiRender(renderContext, *renderSurface);
+
+        // Viewport rendering can bind offscreen render targets on the shared command list.
+        // Rebind the swapchain backbuffer so the subsequent ImGui draw data lands on the main window.
+        renderContext.commandList->SetRenderTargets(1, &renderTargetView, nullptr);
+    }
+
+    ID3D12DescriptorHeap* descriptorHeaps[] = { windowRenderer.GetSrvHeap() };
+    d3d12CommandList->SetDescriptorHeaps(1, descriptorHeaps);
+    imguiBackend.RenderDrawData(d3d12CommandList->GetCommandList());
+
+    if (afterUiRender) {
+        renderContext.commandList->SetRenderTargets(1, &renderTargetView, nullptr);
+        afterUiRender(renderContext, *renderSurface);
+    }
+
+    renderContext.commandList->TransitionBarrier(
+        renderTargetView,
+        RHI::ResourceStates::RenderTarget,
+        RHI::ResourceStates::Present);
+    renderContext.commandList->Close();
+
+    void* commandLists[] = { renderContext.commandList };
+    renderContext.commandQueue->ExecuteCommandLists(1, commandLists);
+    windowRenderer.GetSwapChain()->Present(1, 0);
+}
+
+} // namespace Platform
+} // namespace Editor
+} // namespace XCEngine