Wire viewport shell host chain and move host under app

new_editor/app/Host/D3D12WindowRenderLoop.cpp

@@ -0,0 +1,63 @@
+#include "D3D12WindowRenderLoop.h"
+
+namespace XCEngine::UI::Editor::Host {
+
+bool RenderD3D12WindowFrame(
+    D3D12WindowRenderer& windowRenderer,
+    const float clearColor[4],
+    const D3D12WindowRenderCallback& beforePresent,
+    const D3D12WindowRenderCallback& afterPresent) {
+    const ::XCEngine::Rendering::RenderSurface* renderSurface =
+        windowRenderer.GetCurrentRenderSurface();
+    ::XCEngine::Rendering::RenderContext renderContext =
+        windowRenderer.GetRenderContext();
+    if (!renderContext.IsValid() ||
+        renderContext.commandList == nullptr ||
+        renderContext.commandQueue == nullptr ||
+        windowRenderer.GetSwapChain() == nullptr ||
+        renderSurface == nullptr) {
+        return false;
+    }
+
+    auto* d3d12CommandList =
+        static_cast<::XCEngine::RHI::D3D12CommandList*>(renderContext.commandList);
+    if (d3d12CommandList == nullptr) {
+        return false;
+    }
+
+    const auto& colorAttachments = renderSurface->GetColorAttachments();
+    if (colorAttachments.empty() || colorAttachments[0] == nullptr) {
+        return false;
+    }
+
+    ::XCEngine::RHI::RHIResourceView* renderTargetView = colorAttachments[0];
+    renderContext.commandList->TransitionBarrier(
+        renderTargetView,
+        ::XCEngine::RHI::ResourceStates::Present,
+        ::XCEngine::RHI::ResourceStates::RenderTarget);
+    renderContext.commandList->SetRenderTargets(1, &renderTargetView, nullptr);
+    renderContext.commandList->ClearRenderTarget(renderTargetView, clearColor);
+
+    if (beforePresent) {
+        beforePresent(renderContext, *renderSurface);
+        renderContext.commandList->SetRenderTargets(1, &renderTargetView, nullptr);
+    }
+
+    if (afterPresent) {
+        afterPresent(renderContext, *renderSurface);
+        renderContext.commandList->SetRenderTargets(1, &renderTargetView, nullptr);
+    }
+
+    renderContext.commandList->TransitionBarrier(
+        renderTargetView,
+        ::XCEngine::RHI::ResourceStates::RenderTarget,
+        ::XCEngine::RHI::ResourceStates::Present);
+    renderContext.commandList->Close();
+
+    void* commandLists[] = { renderContext.commandList };
+    renderContext.commandQueue->ExecuteCommandLists(1, commandLists);
+    windowRenderer.GetSwapChain()->Present(1, 0);
+    return true;
+}
+
+} // namespace XCEngine::UI::Editor::Host