Shader test past

CMakeLists.txt

@@ -287,6 +287,9 @@ set(RENDER_CADENCE_APP_SOURCES
 	"${APP_DIR}/videoio/decklink/DeckLinkVideoIOFormat.h"
 	"${APP_DIR}/gl/renderer/GLExtensions.cpp"
 	"${APP_DIR}/gl/renderer/GLExtensions.h"
+	"${APP_DIR}/shader/ShaderCompiler.cpp"
+	"${APP_DIR}/shader/ShaderCompiler.h"
+	"${APP_DIR}/shader/ShaderTypes.h"
 	"${APP_DIR}/videoio/VideoIOFormat.cpp"
 	"${APP_DIR}/videoio/VideoIOFormat.h"
 	"${APP_DIR}/videoio/VideoIOTypes.h"
@@ -310,8 +313,12 @@ set(RENDER_CADENCE_APP_SOURCES
 	"${RENDER_CADENCE_APP_DIR}/render/RenderCadenceClock.h"
 	"${RENDER_CADENCE_APP_DIR}/render/RenderThread.cpp"
 	"${RENDER_CADENCE_APP_DIR}/render/RenderThread.h"
+	"${RENDER_CADENCE_APP_DIR}/render/RuntimeShaderRenderer.cpp"
+	"${RENDER_CADENCE_APP_DIR}/render/RuntimeShaderRenderer.h"
 	"${RENDER_CADENCE_APP_DIR}/render/SimpleMotionRenderer.cpp"
 	"${RENDER_CADENCE_APP_DIR}/render/SimpleMotionRenderer.h"
+	"${RENDER_CADENCE_APP_DIR}/runtime/RuntimeSlangShaderCompiler.cpp"
+	"${RENDER_CADENCE_APP_DIR}/runtime/RuntimeSlangShaderCompiler.h"
 	"${RENDER_CADENCE_APP_DIR}/telemetry/CadenceTelemetry.h"
 	"${RENDER_CADENCE_APP_DIR}/telemetry/TelemetryPrinter.h"
 	"${RENDER_CADENCE_APP_DIR}/video/DeckLinkOutput.cpp"
@@ -324,6 +331,8 @@ add_executable(RenderCadenceCompositor ${RENDER_CADENCE_APP_SOURCES})
 target_include_directories(RenderCadenceCompositor PRIVATE
 	"${APP_DIR}"
 	"${APP_DIR}/gl/renderer"
+	"${APP_DIR}/platform"
+	"${APP_DIR}/shader"
 	"${APP_DIR}/videoio"
 	"${APP_DIR}/videoio/decklink"
 	"${RENDER_CADENCE_APP_DIR}"
@@ -331,6 +340,7 @@ target_include_directories(RenderCadenceCompositor PRIVATE
 	"${RENDER_CADENCE_APP_DIR}/frames"
 	"${RENDER_CADENCE_APP_DIR}/platform"
 	"${RENDER_CADENCE_APP_DIR}/render"
+	"${RENDER_CADENCE_APP_DIR}/runtime"
 	"${RENDER_CADENCE_APP_DIR}/telemetry"
 	"${RENDER_CADENCE_APP_DIR}/video"
 )

apps/RenderCadenceCompositor/README.md

@@ -37,6 +37,8 @@ Included now:
 - async PBO readback
 - latest-N system-memory frame exchange
 - rendered-frame warmup
+- background Slang compile of `shaders/happy-accident`
+- render-thread-only GL commit once compiled shader source is ready
 - compact telemetry
 - non-GL frame-exchange tests
 
@@ -85,7 +87,7 @@ Press Enter to stop.
 The app prints one line per second:
 
 ```text
-renderFps=59.9 scheduleFps=59.9 free=7 completed=1 scheduled=4 completedPollMisses=0 scheduleFailures=0 completions=119 late=0 dropped=0 decklinkBuffered=4 scheduleCallMs=0.0
+renderFps=59.9 scheduleFps=59.9 free=7 completed=1 scheduled=4 completedPollMisses=0 scheduleFailures=0 completions=119 late=0 dropped=0 shaderCommitted=1 shaderFailures=0 decklinkBuffered=4 scheduleCallMs=0.0
 ```
 
 Healthy first-run signs:
@@ -97,9 +99,25 @@ Healthy first-run signs:
 - `decklinkBuffered` stays near 4 when available
 - `late` and `dropped` do not increase continuously
 - `scheduleFailures` does not increase
+- `shaderCommitted` becomes `1` after the background Happy Accident compile completes
+- `shaderFailures` remains `0`
 
 `completedPollMisses` means the DeckLink scheduling thread woke up before a completed frame was available. It is not a DeckLink playout underrun by itself. Treat it as healthy polling noise when `scheduled`, `decklinkBuffered`, `late`, `dropped`, and `scheduleFailures` remain stable.
 
+## Runtime Slang Shader Test
+
+On startup the app begins compiling `shaders/happy-accident` on a background thread.
+
+The render thread keeps drawing the simple motion renderer while Slang compiles. It only attempts the OpenGL shader compile/link once a complete GLSL fragment shader is ready. If either the Slang build or GL commit fails, the app keeps rendering the simple motion fallback.
+
+Successful handoff signs:
+
+- console prints `Runtime shader committed: happy-accident`
+- telemetry shows `shaderCommitted=1`
+- output changes from the simple motion pattern to the Happy Accident shader
+- render/schedule cadence remains near 60 fps during and after the handoff
+- DeckLink buffer remains stable
+
 ## Baseline Result
 
 Date: 2026-05-12

apps/RenderCadenceCompositor/app/RenderCadenceApp.h

@@ -106,7 +106,7 @@ public:
 			return false;
 		}
 
-		mTelemetry.Start(mFrameExchange, mOutput, mOutputThread);
+		mTelemetry.Start(mFrameExchange, mOutput, mOutputThread, mRenderThread);
 		mStarted = true;
 		return true;
 	}

apps/RenderCadenceCompositor/render/RenderThread.cpp

@@ -5,10 +5,13 @@
 #include "../platform/HiddenGlWindow.h"
 #include "Bgra8ReadbackPipeline.h"
 #include "GLExtensions.h"
+#include "RuntimeShaderRenderer.h"
 #include "SimpleMotionRenderer.h"
 
 #include <algorithm>
+#include <iostream>
 #include <thread>
+#include <windows.h>
 
 RenderThread::RenderThread(SystemFrameExchange& frameExchange, Config config) :
 	mFrameExchange(frameExchange),
@@ -83,12 +86,14 @@ void RenderThread::ThreadMain()
 	}
 
 	SimpleMotionRenderer renderer;
+	RuntimeShaderRenderer runtimeShaderRenderer;
 	Bgra8ReadbackPipeline readback;
 	if (!renderer.InitializeGl(mConfig.width, mConfig.height) || !readback.Initialize(mConfig.width, mConfig.height, mConfig.pboDepth))
 	{
 		SignalStartupFailure("Render pipeline initialization failed.");
 		return;
 	}
+	mSlangCompiler.StartHappyAccidentBuild();
 
 	RenderCadenceClock clock(mConfig.frameDurationMilliseconds);
 	uint64_t frameIndex = 0;
@@ -114,7 +119,13 @@ void RenderThread::ThreadMain()
 			continue;
 		}
 
-		if (!readback.RenderAndQueue(frameIndex, [&renderer](uint64_t index) { renderer.RenderFrame(index); }))
+		TryCommitReadyRuntimeShader(runtimeShaderRenderer);
+		if (!readback.RenderAndQueue(frameIndex, [this, &renderer, &runtimeShaderRenderer](uint64_t index) {
+			if (runtimeShaderRenderer.HasProgram())
+				runtimeShaderRenderer.RenderFrame(index, mConfig.width, mConfig.height);
+			else
+				renderer.RenderFrame(index);
+		}))
 		{
 			std::lock_guard<std::mutex> lock(mMetricsMutex);
 			++mMetrics.pboQueueMisses;
@@ -143,7 +154,9 @@ void RenderThread::ThreadMain()
 	}
 
 	readback.Shutdown();
+	runtimeShaderRenderer.ShutdownGl();
 	renderer.ShutdownGl();
+	mSlangCompiler.Stop();
 	window.ClearCurrent();
 	mRunning.store(false, std::memory_order_release);
 }
@@ -179,3 +192,34 @@ void RenderThread::CountAcquireMiss()
 	std::lock_guard<std::mutex> lock(mMetricsMutex);
 	++mMetrics.acquireMisses;
 }
+
+void RenderThread::TryCommitReadyRuntimeShader(RuntimeShaderRenderer& runtimeShaderRenderer)
+{
+	RuntimeSlangShaderBuild build;
+	if (!mSlangCompiler.TryConsume(build))
+		return;
+
+	if (!build.succeeded)
+	{
+		std::cout << "Runtime Slang build failed: " << build.message << "\n";
+		OutputDebugStringA(("Runtime Slang build failed: " + build.message + "\n").c_str());
+		std::lock_guard<std::mutex> lock(mMetricsMutex);
+		++mMetrics.shaderBuildFailures;
+		return;
+	}
+
+	std::string commitError;
+	if (!runtimeShaderRenderer.CommitFragmentShader(build.fragmentShaderSource, commitError))
+	{
+		std::cout << "Runtime shader GL commit failed: " << commitError << "\n";
+		OutputDebugStringA(("Runtime shader GL commit failed: " + commitError + "\n").c_str());
+		std::lock_guard<std::mutex> lock(mMetricsMutex);
+		++mMetrics.shaderBuildFailures;
+		return;
+	}
+
+	std::cout << "Runtime shader committed: " << build.shaderId << ". " << build.message << "\n";
+	OutputDebugStringA(("Runtime shader committed: " + build.shaderId + ". " + build.message + "\n").c_str());
+	std::lock_guard<std::mutex> lock(mMetricsMutex);
+	++mMetrics.shaderBuildsCommitted;
+}

apps/RenderCadenceCompositor/render/RenderThread.h

@@ -1,6 +1,8 @@
 #pragma once
 
 #include "RenderCadenceClock.h"
+#include "../runtime/RuntimeSlangShaderCompiler.h"
+#include "RuntimeShaderRenderer.h"
 
 #include <atomic>
 #include <condition_variable>
@@ -31,6 +33,8 @@ public:
 		uint64_t pboQueueMisses = 0;
 		uint64_t clockOverruns = 0;
 		uint64_t skippedFrames = 0;
+		uint64_t shaderBuildsCommitted = 0;
+		uint64_t shaderBuildFailures = 0;
 	};
 
 	RenderThread(SystemFrameExchange& frameExchange, Config config);
@@ -51,9 +55,11 @@ private:
 	void CountRendered();
 	void CountCompleted();
 	void CountAcquireMiss();
+	void TryCommitReadyRuntimeShader(RuntimeShaderRenderer& runtimeShaderRenderer);
 
 	SystemFrameExchange& mFrameExchange;
 	Config mConfig;
+	RuntimeSlangShaderCompiler mSlangCompiler;
 	std::thread mThread;
 	std::atomic<bool> mStopping{ false };
 	std::atomic<bool> mRunning{ false };

apps/RenderCadenceCompositor/render/RuntimeShaderRenderer.cpp

@@ -0,0 +1,214 @@
+#include "RuntimeShaderRenderer.h"
+
+#include <array>
+#include <cstring>
+#include <string>
+
+namespace
+{
+constexpr GLuint kGlobalParamsBindingPoint = 0;
+
+const char* kVertexShaderSource = R"GLSL(
+#version 430 core
+out vec2 vTexCoord;
+void main()
+{
+	vec2 positions[3] = vec2[3](
+		vec2(-1.0, -1.0),
+		vec2( 3.0, -1.0),
+		vec2(-1.0,  3.0));
+	vec2 texCoords[3] = vec2[3](
+		vec2(0.0, 0.0),
+		vec2(2.0, 0.0),
+		vec2(0.0, 2.0));
+	gl_Position = vec4(positions[gl_VertexID], 0.0, 1.0);
+	vTexCoord = texCoords[gl_VertexID];
+}
+)GLSL";
+
+struct GlobalParamsStd140
+{
+	float time = 0.0f;
+	float pad0 = 0.0f;
+	float inputResolution[2] = {};
+	float outputResolution[2] = {};
+	float utcTimeSeconds = 0.0f;
+	float utcOffsetSeconds = 0.0f;
+	float startupRandom = 0.37f;
+	float frameCount = 0.0f;
+	float mixAmount = 1.0f;
+	float bypass = 0.0f;
+	int sourceHistoryLength = 0;
+	int temporalHistoryLength = 0;
+	int feedbackAvailable = 0;
+	float speed = 1.0f;
+	float scale = 1.0f;
+	float raySteps = 77.0f;
+	float intensity = 1.0f;
+	float sourceMix = 0.0f;
+	float pad1[3] = {};
+};
+}
+
+RuntimeShaderRenderer::~RuntimeShaderRenderer()
+{
+	ShutdownGl();
+}
+
+bool RuntimeShaderRenderer::CommitFragmentShader(const std::string& fragmentShaderSource, std::string& error)
+{
+	if (fragmentShaderSource.empty())
+	{
+		error = "Cannot commit an empty fragment shader.";
+		return false;
+	}
+
+	if (!EnsureStaticGlResources(error))
+		return false;
+
+	GLuint vertexShader = 0;
+	GLuint fragmentShader = 0;
+	GLuint program = 0;
+	if (!CompileShader(GL_VERTEX_SHADER, kVertexShaderSource, vertexShader, error))
+		return false;
+	if (!CompileShader(GL_FRAGMENT_SHADER, fragmentShaderSource.c_str(), fragmentShader, error))
+	{
+		glDeleteShader(vertexShader);
+		return false;
+	}
+
+	program = glCreateProgram();
+	glAttachShader(program, vertexShader);
+	glAttachShader(program, fragmentShader);
+	glLinkProgram(program);
+
+	GLint linkResult = GL_FALSE;
+	glGetProgramiv(program, GL_LINK_STATUS, &linkResult);
+	if (linkResult == GL_FALSE)
+	{
+		std::array<char, 4096> log = {};
+		GLsizei length = 0;
+		glGetProgramInfoLog(program, static_cast<GLsizei>(log.size()), &length, log.data());
+		error = std::string(log.data(), static_cast<std::size_t>(length));
+		glDeleteProgram(program);
+		glDeleteShader(vertexShader);
+		glDeleteShader(fragmentShader);
+		return false;
+	}
+
+	const GLuint globalParamsIndex = glGetUniformBlockIndex(program, "GlobalParams");
+	if (globalParamsIndex != GL_INVALID_INDEX)
+		glUniformBlockBinding(program, globalParamsIndex, kGlobalParamsBindingPoint);
+
+	glUseProgram(program);
+	const GLint videoInputLocation = glGetUniformLocation(program, "gVideoInput");
+	if (videoInputLocation >= 0)
+		glUniform1i(videoInputLocation, 0);
+	const GLint layerInputLocation = glGetUniformLocation(program, "gLayerInput");
+	if (layerInputLocation >= 0)
+		glUniform1i(layerInputLocation, 0);
+	glUseProgram(0);
+
+	DestroyProgram();
+	mProgram = program;
+	mVertexShader = vertexShader;
+	mFragmentShader = fragmentShader;
+	return true;
+}
+
+void RuntimeShaderRenderer::RenderFrame(uint64_t frameIndex, unsigned width, unsigned height)
+{
+	if (mProgram == 0)
+		return;
+
+	GlobalParamsStd140 params;
+	params.time = static_cast<float>(frameIndex) / 60.0f;
+	params.inputResolution[0] = static_cast<float>(width);
+	params.inputResolution[1] = static_cast<float>(height);
+	params.outputResolution[0] = static_cast<float>(width);
+	params.outputResolution[1] = static_cast<float>(height);
+	params.frameCount = static_cast<float>(frameIndex);
+
+	glViewport(0, 0, static_cast<GLsizei>(width), static_cast<GLsizei>(height));
+	glDisable(GL_SCISSOR_TEST);
+	glDisable(GL_DEPTH_TEST);
+	glDisable(GL_BLEND);
+	glBindBuffer(GL_UNIFORM_BUFFER, mGlobalParamsBuffer);
+	glBufferSubData(GL_UNIFORM_BUFFER, 0, sizeof(params), &params);
+	glBindBufferBase(GL_UNIFORM_BUFFER, kGlobalParamsBindingPoint, mGlobalParamsBuffer);
+	glBindBuffer(GL_UNIFORM_BUFFER, 0);
+	glBindVertexArray(mVertexArray);
+	glUseProgram(mProgram);
+	glDrawArrays(GL_TRIANGLES, 0, 3);
+	glUseProgram(0);
+	glBindVertexArray(0);
+}
+
+void RuntimeShaderRenderer::ShutdownGl()
+{
+	DestroyProgram();
+	DestroyStaticGlResources();
+}
+
+bool RuntimeShaderRenderer::EnsureStaticGlResources(std::string& error)
+{
+	if (mVertexArray == 0)
+		glGenVertexArrays(1, &mVertexArray);
+	if (mGlobalParamsBuffer == 0)
+	{
+		glGenBuffers(1, &mGlobalParamsBuffer);
+		glBindBuffer(GL_UNIFORM_BUFFER, mGlobalParamsBuffer);
+		glBufferData(GL_UNIFORM_BUFFER, static_cast<GLsizeiptr>(sizeof(GlobalParamsStd140)), nullptr, GL_DYNAMIC_DRAW);
+		glBindBuffer(GL_UNIFORM_BUFFER, 0);
+	}
+
+	if (mVertexArray == 0 || mGlobalParamsBuffer == 0)
+	{
+		error = "Failed to create runtime shader GL resources.";
+		return false;
+	}
+	return true;
+}
+
+bool RuntimeShaderRenderer::CompileShader(GLenum shaderType, const char* source, GLuint& shader, std::string& error) const
+{
+	shader = glCreateShader(shaderType);
+	glShaderSource(shader, 1, &source, nullptr);
+	glCompileShader(shader);
+
+	GLint compileResult = GL_FALSE;
+	glGetShaderiv(shader, GL_COMPILE_STATUS, &compileResult);
+	if (compileResult != GL_FALSE)
+		return true;
+
+	std::array<char, 4096> log = {};
+	GLsizei length = 0;
+	glGetShaderInfoLog(shader, static_cast<GLsizei>(log.size()), &length, log.data());
+	error = std::string(log.data(), static_cast<std::size_t>(length));
+	glDeleteShader(shader);
+	shader = 0;
+	return false;
+}
+
+void RuntimeShaderRenderer::DestroyProgram()
+{
+	if (mProgram != 0)
+		glDeleteProgram(mProgram);
+	if (mVertexShader != 0)
+		glDeleteShader(mVertexShader);
+	if (mFragmentShader != 0)
+		glDeleteShader(mFragmentShader);
+	mProgram = 0;
+	mVertexShader = 0;
+	mFragmentShader = 0;
+}
+
+void RuntimeShaderRenderer::DestroyStaticGlResources()
+{
+	if (mGlobalParamsBuffer != 0)
+		glDeleteBuffers(1, &mGlobalParamsBuffer);
+	if (mVertexArray != 0)
+		glDeleteVertexArrays(1, &mVertexArray);
+	mGlobalParamsBuffer = 0;
+	mVertexArray = 0;
+}

apps/RenderCadenceCompositor/render/RuntimeShaderRenderer.h

@@ -0,0 +1,32 @@
+#pragma once
+
+#include "GLExtensions.h"
+
+#include <cstdint>
+#include <string>
+
+class RuntimeShaderRenderer
+{
+public:
+	RuntimeShaderRenderer() = default;
+	RuntimeShaderRenderer(const RuntimeShaderRenderer&) = delete;
+	RuntimeShaderRenderer& operator=(const RuntimeShaderRenderer&) = delete;
+	~RuntimeShaderRenderer();
+
+	bool CommitFragmentShader(const std::string& fragmentShaderSource, std::string& error);
+	bool HasProgram() const { return mProgram != 0; }
+	void RenderFrame(uint64_t frameIndex, unsigned width, unsigned height);
+	void ShutdownGl();
+
+private:
+	bool EnsureStaticGlResources(std::string& error);
+	bool CompileShader(GLenum shaderType, const char* source, GLuint& shader, std::string& error) const;
+	void DestroyProgram();
+	void DestroyStaticGlResources();
+
+	GLuint mProgram = 0;
+	GLuint mVertexShader = 0;
+	GLuint mFragmentShader = 0;
+	GLuint mVertexArray = 0;
+	GLuint mGlobalParamsBuffer = 0;
+};

apps/RenderCadenceCompositor/runtime/RuntimeSlangShaderCompiler.cpp

@@ -0,0 +1,148 @@
+#include "RuntimeSlangShaderCompiler.h"
+
+#include "ShaderCompiler.h"
+#include "ShaderTypes.h"
+
+#include <chrono>
+#include <filesystem>
+#include <iostream>
+
+namespace
+{
+ShaderParameterDefinition FloatParam(const std::string& id, double defaultValue)
+{
+	ShaderParameterDefinition parameter;
+	parameter.id = id;
+	parameter.label = id;
+	parameter.type = ShaderParameterType::Float;
+	parameter.defaultNumbers.push_back(defaultValue);
+	return parameter;
+}
+
+std::filesystem::path FindRepoRoot()
+{
+	std::filesystem::path current = std::filesystem::current_path();
+	for (;;)
+	{
+		if (std::filesystem::exists(current / "shaders" / "happy-accident" / "shader.slang") &&
+			std::filesystem::exists(current / "runtime" / "templates" / "shader_wrapper.slang.in"))
+		{
+			return current;
+		}
+
+		const std::filesystem::path parent = current.parent_path();
+		if (parent.empty() || parent == current)
+			return std::filesystem::current_path();
+		current = parent;
+	}
+}
+}
+
+RuntimeSlangShaderCompiler::~RuntimeSlangShaderCompiler()
+{
+	Stop();
+}
+
+void RuntimeSlangShaderCompiler::StartHappyAccidentBuild()
+{
+	if (mRunning.load(std::memory_order_acquire))
+		return;
+
+	if (mThread.joinable())
+		mThread.join();
+
+	{
+		std::lock_guard<std::mutex> lock(mMutex);
+		mReadyBuild = RuntimeSlangShaderBuild();
+	}
+
+	mRunning.store(true, std::memory_order_release);
+	mThread = std::thread([this]() {
+		RuntimeSlangShaderBuild build = BuildHappyAccident();
+		{
+			std::lock_guard<std::mutex> lock(mMutex);
+			mReadyBuild = std::move(build);
+			mReadyBuild.available = true;
+		}
+		mRunning.store(false, std::memory_order_release);
+	});
+}
+
+void RuntimeSlangShaderCompiler::Stop()
+{
+	if (mThread.joinable())
+		mThread.join();
+	mRunning.store(false, std::memory_order_release);
+}
+
+bool RuntimeSlangShaderCompiler::TryConsume(RuntimeSlangShaderBuild& build)
+{
+	std::lock_guard<std::mutex> lock(mMutex);
+	if (!mReadyBuild.available)
+		return false;
+
+	build = std::move(mReadyBuild);
+	mReadyBuild = RuntimeSlangShaderBuild();
+	return true;
+}
+
+RuntimeSlangShaderBuild RuntimeSlangShaderCompiler::BuildHappyAccident() const
+{
+	RuntimeSlangShaderBuild build;
+	build.shaderId = "happy-accident";
+
+	try
+	{
+		const std::filesystem::path repoRoot = FindRepoRoot();
+		const std::filesystem::path shaderDir = repoRoot / "shaders" / "happy-accident";
+		const std::filesystem::path runtimeBuildDir = repoRoot / "runtime" / "generated" / "render-cadence-compositor";
+
+		ShaderPackage shaderPackage;
+		shaderPackage.id = "happy-accident";
+		shaderPackage.displayName = "Happy Accident";
+		shaderPackage.entryPoint = "shadeVideo";
+		shaderPackage.directoryPath = shaderDir;
+		shaderPackage.shaderPath = shaderDir / "shader.slang";
+		shaderPackage.manifestPath = shaderDir / "shader.json";
+		shaderPackage.parameters.push_back(FloatParam("speed", 1.0));
+		shaderPackage.parameters.push_back(FloatParam("scale", 1.0));
+		shaderPackage.parameters.push_back(FloatParam("raySteps", 77.0));
+		shaderPackage.parameters.push_back(FloatParam("intensity", 1.0));
+		shaderPackage.parameters.push_back(FloatParam("sourceMix", 0.0));
+
+		ShaderPassDefinition pass;
+		pass.id = "main";
+		pass.entryPoint = shaderPackage.entryPoint;
+		pass.sourcePath = shaderPackage.shaderPath;
+		pass.outputName = "output";
+		shaderPackage.passes.push_back(pass);
+
+		ShaderCompiler compiler(
+			repoRoot,
+			runtimeBuildDir / "happy_accident_wrapper.slang",
+			runtimeBuildDir / "happy_accident.generated.glsl",
+			runtimeBuildDir / "happy_accident.patched.glsl",
+			0);
+
+		std::string error;
+		const auto start = std::chrono::steady_clock::now();
+		if (!compiler.BuildPassFragmentShaderSource(shaderPackage, pass, build.fragmentShaderSource, error))
+		{
+			build.succeeded = false;
+			build.message = error.empty() ? "Happy Accident Slang compile failed." : error;
+			return build;
+		}
+
+		const auto end = std::chrono::steady_clock::now();
+		const double milliseconds = std::chrono::duration_cast<std::chrono::duration<double, std::milli>>(end - start).count();
+		build.succeeded = true;
+		build.message = "Happy Accident Slang compile completed in " + std::to_string(milliseconds) + " ms.";
+		return build;
+	}
+	catch (const std::exception& exception)
+	{
+		build.succeeded = false;
+		build.message = exception.what();
+		return build;
+	}
+}

apps/RenderCadenceCompositor/runtime/RuntimeSlangShaderCompiler.h

@@ -0,0 +1,37 @@
+#pragma once
+
+#include <atomic>
+#include <mutex>
+#include <string>
+#include <thread>
+
+struct RuntimeSlangShaderBuild
+{
+	bool available = false;
+	bool succeeded = false;
+	std::string shaderId;
+	std::string fragmentShaderSource;
+	std::string message;
+};
+
+class RuntimeSlangShaderCompiler
+{
+public:
+	RuntimeSlangShaderCompiler() = default;
+	RuntimeSlangShaderCompiler(const RuntimeSlangShaderCompiler&) = delete;
+	RuntimeSlangShaderCompiler& operator=(const RuntimeSlangShaderCompiler&) = delete;
+	~RuntimeSlangShaderCompiler();
+
+	void StartHappyAccidentBuild();
+	void Stop();
+	bool TryConsume(RuntimeSlangShaderBuild& build);
+	bool Running() const { return mRunning.load(std::memory_order_acquire); }
+
+private:
+	RuntimeSlangShaderBuild BuildHappyAccident() const;
+
+	std::thread mThread;
+	std::atomic<bool> mRunning{ false };
+	std::mutex mMutex;
+	RuntimeSlangShaderBuild mReadyBuild;
+};

apps/RenderCadenceCompositor/telemetry/CadenceTelemetry.h

@@ -24,6 +24,8 @@ struct CadenceTelemetrySnapshot
 	uint64_t completions = 0;
 	uint64_t displayedLate = 0;
 	uint64_t dropped = 0;
+	uint64_t shaderBuildsCommitted = 0;
+	uint64_t shaderBuildFailures = 0;
 	bool deckLinkBufferedAvailable = false;
 	uint64_t deckLinkBuffered = 0;
 	double deckLinkScheduleCallMilliseconds = 0.0;
@@ -78,6 +80,20 @@ public:
 		return snapshot;
 	}
 
+	template <typename SystemFrameExchange, typename OutputThread, typename RenderThread>
+	CadenceTelemetrySnapshot Sample(
+		const SystemFrameExchange& exchange,
+		const DeckLinkOutput& output,
+		const OutputThread& outputThread,
+		const RenderThread& renderThread)
+	{
+		CadenceTelemetrySnapshot snapshot = Sample(exchange, output, outputThread);
+		const auto renderMetrics = renderThread.GetMetrics();
+		snapshot.shaderBuildsCommitted = renderMetrics.shaderBuildsCommitted;
+		snapshot.shaderBuildFailures = renderMetrics.shaderBuildFailures;
+		return snapshot;
+	}
+
 private:
 	using Clock = std::chrono::steady_clock;
 

apps/RenderCadenceCompositor/telemetry/TelemetryPrinter.h

@@ -31,18 +31,18 @@ public:
 		Stop();
 	}
 
-	template <typename SystemFrameExchange, typename OutputThread>
-	void Start(const SystemFrameExchange& exchange, const DeckLinkOutput& output, const OutputThread& outputThread)
+	template <typename SystemFrameExchange, typename OutputThread, typename RenderThread>
+	void Start(const SystemFrameExchange& exchange, const DeckLinkOutput& output, const OutputThread& outputThread, const RenderThread& renderThread)
 	{
 		if (mRunning)
 			return;
 		mStopping = false;
-		mThread = std::thread([this, &exchange, &output, &outputThread]() {
+		mThread = std::thread([this, &exchange, &output, &outputThread, &renderThread]() {
 			CadenceTelemetry telemetry;
 			while (!mStopping)
 			{
 				std::this_thread::sleep_for(mConfig.interval);
-				Print(telemetry.Sample(exchange, output, outputThread));
+				Print(telemetry.Sample(exchange, output, outputThread, renderThread));
 			}
 		});
 		mRunning = true;
@@ -70,6 +70,8 @@ private:
 			<< " completions=" << snapshot.completions
 			<< " late=" << snapshot.displayedLate
 			<< " dropped=" << snapshot.dropped
+			<< " shaderCommitted=" << snapshot.shaderBuildsCommitted
+			<< " shaderFailures=" << snapshot.shaderBuildFailures
 			<< " decklinkBuffered=";
 		if (snapshot.deckLinkBufferedAvailable)
 			std::cout << snapshot.deckLinkBuffered;