Phase 4

apps/LoopThroughWithOpenGLCompositing/gl/OpenGLComposite.cpp

@@ -23,10 +23,8 @@
 #include <vector>
 
 OpenGLComposite::OpenGLComposite(HWND hWnd, HDC hDC, HGLRC hRC) :
-	hGLWnd(hWnd), hGLDC(hDC), hGLRC(hRC),
-	mScreenshotRequested(false)
+	hGLWnd(hWnd), hGLDC(hDC), hGLRC(hRC)
 {
-	InitializeCriticalSection(&pMutex);
 	mRuntimeStore = std::make_unique<RuntimeStore>();
 	mRuntimeEventDispatcher = std::make_unique<RuntimeEventDispatcher>();
 	mRuntimeSnapshotProvider = std::make_unique<RuntimeSnapshotProvider>(mRuntimeStore->GetRenderSnapshotBuilder(), *mRuntimeEventDispatcher);
@@ -34,11 +32,10 @@ OpenGLComposite::OpenGLComposite(HWND hWnd, HDC hDC, HGLRC hRC) :
 	mRenderEngine = std::make_unique<RenderEngine>(
 		*mRuntimeSnapshotProvider,
 		mRuntimeStore->GetHealthTelemetry(),
-		pMutex,
 		hGLDC,
 		hGLRC,
 		[this]() { renderEffect(); },
-		[this]() { ProcessScreenshotRequest(); },
+		[]() {},
 		[this]() { paintGL(false); });
 	mVideoBackend = std::make_unique<VideoBackend>(*mRenderEngine, mRuntimeStore->GetHealthTelemetry(), *mRuntimeEventDispatcher);
 	mShaderBuildQueue = std::make_unique<ShaderBuildQueue>(*mRuntimeSnapshotProvider, *mRuntimeEventDispatcher);
@@ -61,8 +58,6 @@ OpenGLComposite::~OpenGLComposite()
 		mShaderBuildQueue->Stop();
 	if (mVideoBackend)
 		mVideoBackend->ReleaseResources();
-
-	DeleteCriticalSection(&pMutex);
 }
 
 bool OpenGLComposite::InitDeckLink()
@@ -294,8 +289,50 @@ bool OpenGLComposite::ReloadShader(bool preserveFeedbackState)
 
 bool OpenGLComposite::RequestScreenshot(std::string& error)
 {
-	(void)error;
-	mScreenshotRequested.store(true);
+	if (!mRenderEngine || !mVideoBackend)
+	{
+		error = "The render engine is not ready.";
+		return false;
+	}
+
+	const unsigned width = mVideoBackend->OutputFrameWidth();
+	const unsigned height = mVideoBackend->OutputFrameHeight();
+	if (width == 0 || height == 0)
+	{
+		error = "The output frame size is not available.";
+		return false;
+	}
+
+	std::filesystem::path outputPath;
+	try
+	{
+		outputPath = BuildScreenshotPath();
+		std::filesystem::create_directories(outputPath.parent_path());
+	}
+	catch (const std::exception& exception)
+	{
+		error = exception.what();
+		return false;
+	}
+
+	if (!mRenderEngine->RequestScreenshotCapture(
+		width,
+		height,
+		[outputPath](unsigned captureWidth, unsigned captureHeight, std::vector<unsigned char> topDownPixels) {
+			try
+			{
+				WritePngFileAsync(outputPath, captureWidth, captureHeight, std::move(topDownPixels));
+			}
+			catch (const std::exception& exception)
+			{
+				OutputDebugStringA((std::string("Screenshot request failed: ") + exception.what() + "\n").c_str());
+			}
+		}))
+	{
+		error = "Screenshot capture request failed.";
+		return false;
+	}
+
 	return true;
 }
 
@@ -342,32 +379,6 @@ void OpenGLComposite::RenderFrame(const RenderFrameInput& frameInput)
 	mRenderEngine->RenderPreparedFrame(frameState);
 }
 
-void OpenGLComposite::ProcessScreenshotRequest()
-{
-	if (!mScreenshotRequested.exchange(false))
-		return;
-
-	const unsigned width = mVideoBackend ? mVideoBackend->OutputFrameWidth() : 0;
-	const unsigned height = mVideoBackend ? mVideoBackend->OutputFrameHeight() : 0;
-	if (width == 0 || height == 0)
-		return;
-
-	std::vector<unsigned char> topDownPixels;
-	if (!mRenderEngine->CaptureOutputFrameRgbaTopDown(width, height, topDownPixels))
-		return;
-
-	try
-	{
-		const std::filesystem::path outputPath = BuildScreenshotPath();
-		std::filesystem::create_directories(outputPath.parent_path());
-		WritePngFileAsync(outputPath, width, height, std::move(topDownPixels));
-	}
-	catch (const std::exception& exception)
-	{
-		OutputDebugStringA((std::string("Screenshot request failed: ") + exception.what() + "\n").c_str());
-	}
-}
-
 std::filesystem::path OpenGLComposite::BuildScreenshotPath() const
 {
 	const std::filesystem::path root = mRuntimeStore && !mRuntimeStore->GetRuntimeDataRoot().empty()