refactor(new_editor): snapshot hosted editor restructuring

new_editor/app/Platform/Win32/EditorWindowRuntimeController.cpp

@@ -1,17 +1,25 @@
 #include "Platform/Win32/EditorWindowRuntimeController.h"
 
 #include "Bootstrap/EditorResources.h"
-#include "Internal/EmbeddedPngLoader.h"
-#include "Platform/Win32/EditorWindowRuntimeInternal.h"
 #include "Composition/EditorContext.h"
+#include "Platform/Win32/EditorWindowSupport.h"
+#include "Support/EmbeddedPngLoader.h"
 
 #include <algorithm>
+#include <chrono>
+#include <cstdio>
 #include <utility>
 
-namespace XCEngine::UI::Editor::App::Internal {
+namespace XCEngine::UI::Editor::App {
 
-using App::Internal::LoadEmbeddedPngTexture;
-using namespace EditorWindowInternal;
+using App::LoadEmbeddedPngTexture;
+using namespace EditorWindowSupport;
+
+namespace {
+
+constexpr float kFrameTimeSmoothingFactor = 0.12f;
+
+}
 
 EditorWindowRuntimeController::EditorWindowRuntimeController(
     UIEditorWorkspaceController workspaceController)
@@ -135,6 +143,7 @@ bool EditorWindowRuntimeController::Initialize(
             editorContext.DescribeWorkspaceState(
                 m_workspaceController,
                 m_shellRuntime.GetShellInteractionState()));
+    ResetFrameTiming();
     m_ready = true;
 
     m_autoScreenshot.Initialize(captureRoot);
@@ -148,6 +157,7 @@ bool EditorWindowRuntimeController::Initialize(
 
 void EditorWindowRuntimeController::Shutdown() {
     m_ready = false;
+    ResetFrameTiming();
     m_autoScreenshot.Shutdown();
     m_shellRuntime.Shutdown();
     m_renderer.ReleaseTexture(m_titleBarLogoIcon);
@@ -158,6 +168,7 @@ void EditorWindowRuntimeController::Shutdown() {
 
 void EditorWindowRuntimeController::ResetInteractionState() {
     m_shellRuntime.ResetInteractionState();
+    ResetFrameTiming();
 }
 
 bool EditorWindowRuntimeController::ApplyResize(UINT width, UINT height) {
@@ -181,7 +192,8 @@ bool EditorWindowRuntimeController::ApplyResize(UINT width, UINT height) {
     return resizeResult.hasViewportSurfacePresentation;
 }
 
-Host::D3D12WindowRenderLoopFrameContext EditorWindowRuntimeController::BeginFrame() const {
+Host::D3D12WindowRenderLoopFrameContext EditorWindowRuntimeController::BeginFrame() {
+    UpdateFrameTiming();
     return m_windowRenderLoop.BeginFrame();
 }
 
@@ -223,4 +235,55 @@ std::string EditorWindowRuntimeController::BuildCaptureStatusText() const {
     return {};
 }
 
-} // namespace XCEngine::UI::Editor::App::Internal
+std::string EditorWindowRuntimeController::BuildFrameRateText() const {
+    if (m_displayFps <= 0.0f || m_displayFrameTimeMs <= 0.0f) {
+        return {};
+    }
+
+    char buffer[48] = {};
+    std::snprintf(
+        buffer,
+        sizeof(buffer),
+        "FPS %.1f | %.2f ms",
+        m_displayFps,
+        m_displayFrameTimeMs);
+    return buffer;
+}
+
+void EditorWindowRuntimeController::ResetFrameTiming() {
+    m_lastFrameTime = {};
+    m_hasLastFrameTime = false;
+    m_smoothedDeltaTimeSeconds = 0.0f;
+    m_displayFps = 0.0f;
+    m_displayFrameTimeMs = 0.0f;
+}
+
+void EditorWindowRuntimeController::UpdateFrameTiming() {
+    const auto now = std::chrono::steady_clock::now();
+    if (!m_hasLastFrameTime) {
+        m_lastFrameTime = now;
+        m_hasLastFrameTime = true;
+        return;
+    }
+
+    const float deltaTime = std::chrono::duration<float>(now - m_lastFrameTime).count();
+    m_lastFrameTime = now;
+    if (deltaTime <= 0.0f) {
+        return;
+    }
+
+    if (m_smoothedDeltaTimeSeconds <= 0.0f) {
+        m_smoothedDeltaTimeSeconds = deltaTime;
+    } else {
+        m_smoothedDeltaTimeSeconds +=
+            (deltaTime - m_smoothedDeltaTimeSeconds) * kFrameTimeSmoothingFactor;
+    }
+
+    m_displayFrameTimeMs = m_smoothedDeltaTimeSeconds * 1000.0f;
+    m_displayFps = m_smoothedDeltaTimeSeconds > 0.0f
+        ? 1.0f / m_smoothedDeltaTimeSeconds
+        : 0.0f;
+}
+
+} // namespace XCEngine::UI::Editor::App
+