INput

CMakeLists.txt

@@ -318,6 +318,8 @@ set(RENDER_CADENCE_APP_SOURCES
 	"${RENDER_CADENCE_APP_DIR}/control/http/HttpControlServer.h"
 	"${RENDER_CADENCE_APP_DIR}/control/http/HttpControlServerWebSocket.cpp"
 	"${RENDER_CADENCE_APP_DIR}/control/RuntimeStateJson.h"
+	"${RENDER_CADENCE_APP_DIR}/frames/InputFrameMailbox.cpp"
+	"${RENDER_CADENCE_APP_DIR}/frames/InputFrameMailbox.h"
 	"${RENDER_CADENCE_APP_DIR}/frames/SystemFrameExchange.cpp"
 	"${RENDER_CADENCE_APP_DIR}/frames/SystemFrameExchange.h"
 	"${RENDER_CADENCE_APP_DIR}/frames/SystemFrameTypes.h"
@@ -327,6 +329,8 @@ set(RENDER_CADENCE_APP_SOURCES
 	"${RENDER_CADENCE_APP_DIR}/logging/Logger.h"
 	"${RENDER_CADENCE_APP_DIR}/platform/HiddenGlWindow.cpp"
 	"${RENDER_CADENCE_APP_DIR}/platform/HiddenGlWindow.h"
+	"${RENDER_CADENCE_APP_DIR}/render/InputFrameTexture.cpp"
+	"${RENDER_CADENCE_APP_DIR}/render/InputFrameTexture.h"
 	"${RENDER_CADENCE_APP_DIR}/render/readback/Bgra8ReadbackPipeline.cpp"
 	"${RENDER_CADENCE_APP_DIR}/render/readback/Bgra8ReadbackPipeline.h"
 	"${RENDER_CADENCE_APP_DIR}/render/readback/PboReadbackRing.cpp"
@@ -360,6 +364,8 @@ set(RENDER_CADENCE_APP_SOURCES
 	"${RENDER_CADENCE_APP_DIR}/video/DeckLinkOutput.cpp"
 	"${RENDER_CADENCE_APP_DIR}/video/DeckLinkOutput.h"
 	"${RENDER_CADENCE_APP_DIR}/video/DeckLinkOutputThread.h"
+	"${RENDER_CADENCE_APP_DIR}/video/SyntheticInputProducer.cpp"
+	"${RENDER_CADENCE_APP_DIR}/video/SyntheticInputProducer.h"
 )
 
 add_executable(RenderCadenceCompositor ${RENDER_CADENCE_APP_SOURCES})
@@ -790,6 +796,23 @@ endif()
 
 add_test(NAME RenderCadenceCompositorFrameExchangeTests COMMAND RenderCadenceCompositorFrameExchangeTests)
 
+add_executable(RenderCadenceCompositorInputFrameMailboxTests
+	"${APP_DIR}/videoio/VideoIOFormat.cpp"
+	"${RENDER_CADENCE_APP_DIR}/frames/InputFrameMailbox.cpp"
+	"${CMAKE_CURRENT_SOURCE_DIR}/tests/RenderCadenceCompositorInputFrameMailboxTests.cpp"
+)
+
+target_include_directories(RenderCadenceCompositorInputFrameMailboxTests PRIVATE
+	"${APP_DIR}/videoio"
+	"${RENDER_CADENCE_APP_DIR}/frames"
+)
+
+if(MSVC)
+	target_compile_options(RenderCadenceCompositorInputFrameMailboxTests PRIVATE /W3)
+endif()
+
+add_test(NAME RenderCadenceCompositorInputFrameMailboxTests COMMAND RenderCadenceCompositorInputFrameMailboxTests)
+
 add_executable(RenderCadenceCompositorClockTests
 	"${RENDER_CADENCE_APP_DIR}/render/RenderCadenceClock.cpp"
 	"${CMAKE_CURRENT_SOURCE_DIR}/tests/RenderCadenceCompositorClockTests.cpp"

apps/RenderCadenceCompositor/README.md

@@ -11,10 +11,17 @@ Before adding features here, read the guardrails in [Render Cadence Golden Rules
 ```text
 RenderThread
   owns a hidden OpenGL context
+  polls latest input frames without waiting
+  uploads input frames into a render-owned GL texture
   renders simple BGRA8 motion at selected cadence
   queues async PBO readback
   publishes completed frames into SystemFrameExchange
 
+InputFrameMailbox
+  owns latest disposable CPU input slots
+  drops older unsampled input frames when newer frames arrive
+  protects the one frame currently being uploaded by render
+
 SystemFrameExchange
   owns Free / Rendering / Completed / Scheduled slots
   drops old completed unscheduled frames when render needs space
@@ -37,6 +44,9 @@ Included now:
 - hidden render-thread-owned OpenGL context
 - simple smooth-motion renderer
 - BGRA8-only output
+- synthetic BGRA8 input producer
+- non-blocking latest-frame input mailbox
+- render-thread-owned input texture upload
 - async PBO readback
 - latest-N system-memory frame exchange
 - rendered-frame warmup
@@ -55,18 +65,24 @@ Included now:
 - JSON serialization for cadence telemetry snapshots
 - background logging with `log`, `warning`, and `error` levels
 - local HTTP control server matching the OpenAPI route surface
+- HTTP layer controls for add, remove, reorder, bypass, shader change, parameter update, and parameter reset
+- trigger parameters as latest-pulse controls with shader-visible count/time
 - startup config provider for `config/runtime-host.json`
 - quiet telemetry health monitor
 - non-GL frame-exchange tests
+- non-GL input-mailbox tests
 
 Intentionally not included yet:
 
-- DeckLink input
+- real DeckLink input capture
+- input format conversion
 - temporal/history/feedback shader storage
 - texture/LUT asset upload
 - text-parameter rasterization
 - runtime state
-- OSC/API control
+- OSC control
+- persistent control/state writes
+- trigger event history for stacked repeated pulses
 - preview
 - screenshots
 - persistence
@@ -99,16 +115,22 @@ This tracks parity with `apps/LoopThroughWithOpenGLCompositing`.
 - [x] Startup config loading from `config/runtime-host.json`
 - [x] Cadence telemetry JSON
 - [x] Health logging for schedule/drop/starvation events
+- [x] Runtime parameter updates from HTTP controls
+- [x] Layer reorder/bypass/set-shader/update-parameter/reset-parameter HTTP controls
+- [x] Trigger parameter pulse count/time for latest trigger events
+- [x] Synthetic BGRA8 frame input producer
+- [x] Latest-frame CPU input mailbox
+- [x] Render-owned input texture upload
+- [x] Runtime shaders receive input through `gVideoInput`
 - [ ] DeckLink input capture
-- [ ] Input frame upload into the render scene
+- [ ] Live DeckLink input bound to `gVideoInput`
-- [ ] Live video input bound to `gVideoInput`
+- [ ] Input format conversion/scaling
 - [ ] Temporal history buffers
 - [ ] Feedback buffers
 - [ ] Texture asset loading and upload
 - [ ] LUT asset loading and upload
 - [ ] Text parameter rasterization
-- [ ] Runtime parameter updates from controls
+- [ ] Trigger history/event buffers for overlapping repeated trigger effects
-- [ ] Layer reorder/bypass/set-shader/update-parameter/reset-parameter controls
 - [ ] Full runtime state store/read model
 - [ ] Persistent layer stack/config writes
 - [ ] OSC ingress
@@ -256,13 +278,17 @@ Current runtime shader support is deliberately limited to stateless full-frame p
 - no feedback storage
 - no texture/LUT assets yet
 - no text parameters yet
-- manifest defaults are used for parameters
+- manifest defaults initialize parameters
+- HTTP controls can update runtime parameter values without rebuilding GL programs when the shader program is unchanged
+- trigger parameters are treated as latest-pulse controls: each press increments the trigger count and records the current runtime time
+- repeated trigger history is not stored yet, so effects such as `trigger-ripple` restart from the latest trigger rather than accumulating overlapping ripples
 - the first layer receives a small fallback source texture until DeckLink input is added
-- stacked layers receive the previous ready layer output through both `gVideoInput` and `gLayerInput`
+- the first layer receives the latest synthetic input texture through both `gVideoInput` and `gLayerInput` when input frames are available
+- stacked layers receive the original input through `gVideoInput` and the previous ready layer output through `gLayerInput`
 
 The `/api/state` shader list uses the same support rules as runtime shader compilation and reports only packages this app can run today. Unsupported manifest feature sets such as temporal, feedback, texture-backed, font-backed, or text-parameter shaders are hidden from the control UI for now.
 
-Runtime shaders are exposed through `RuntimeLayerModel` as display layers with manifest parameter defaults. The model also records whether each layer has a render-ready artifact. Add/remove POST controls mutate this app-owned model and may start background shader builds.
+Runtime shaders are exposed through `RuntimeLayerModel` as display layers with manifest parameter definitions, current parameter values, build status, and render-ready artifacts. POST controls mutate this app-owned model and may start background shader builds when the selected shader changes.
 
 When a layer becomes render-ready, the app publishes the ready render-layer snapshot to the render thread. The render thread owns the GL-side `RuntimeRenderScene`, diffs that snapshot at a frame boundary, queues new or changed pass programs to the shared-context prepare worker, swaps in a full prepared render plan only after every pass is ready, removes obsolete GL programs, and renders ready layers in order. Stacked stateless full-frame shaders render through internal ping-pong targets so each layer can sample the previous layer through `gLayerInput`; multipass shaders route named intermediate outputs through their manifest-declared pass inputs, and the final ready layer renders to the output target.
 
@@ -314,6 +340,9 @@ This app keeps the same core behavior but splits it into modules that can grow:
 - `frames/`: system-memory handoff
 - `platform/`: COM/Win32/hidden GL context support
 - `render/`: cadence thread, clock, and simple renderer
+- `frames/InputFrameMailbox`: non-blocking latest-frame CPU input handoff
+- `video/SyntheticInputProducer`: temporary BGRA8 test-pattern producer for proving the frame-input path
+- `render/InputFrameTexture`: render-thread-owned upload of the latest CPU input frame into GL
 - `render/readback/`: PBO-backed BGRA8 readback and completed-frame publication
 - `render/runtime/RuntimeRenderScene`: render-thread-owned GL scene for ready runtime shader layers
 - `render/runtime/RuntimeShaderPrepareWorker`: shared-context runtime shader program compile/link worker
@@ -336,4 +365,4 @@ Only after this app matches the probe's smooth output:
 3. port runtime snapshots/live state
 4. add control services
 5. add preview/screenshot from system-memory frames
-6. add DeckLink input as a CPU latest-frame mailbox
+6. replace synthetic input with DeckLink input capture into the existing CPU latest-frame mailbox

apps/RenderCadenceCompositor/RenderCadenceCompositor.cpp

@@ -1,9 +1,11 @@
 #include "app/AppConfig.h"
 #include "app/AppConfigProvider.h"
 #include "app/RenderCadenceApp.h"
+#include "frames/InputFrameMailbox.h"
 #include "frames/SystemFrameExchange.h"
 #include "logging/Logger.h"
 #include "render/RenderThread.h"
+#include "video/SyntheticInputProducer.h"
 #include "VideoIOFormat.h"
 
 #include <windows.h>
@@ -80,13 +82,33 @@ int main(int argc, char** argv)
 
 	SystemFrameExchange frameExchange(frameExchangeConfig);
 
+	InputFrameMailboxConfig inputMailboxConfig;
+	RenderCadenceCompositor::VideoFormatDimensions(
+		appConfig.inputVideoFormat,
+		inputMailboxConfig.width,
+		inputMailboxConfig.height);
+	inputMailboxConfig.pixelFormat = VideoIOPixelFormat::Bgra8;
+	inputMailboxConfig.rowBytes = VideoIORowBytes(inputMailboxConfig.pixelFormat, inputMailboxConfig.width);
+	inputMailboxConfig.capacity = 4;
+	InputFrameMailbox inputMailbox(inputMailboxConfig);
+
+	RenderCadenceCompositor::SyntheticInputProducerConfig inputProducerConfig;
+	inputProducerConfig.width = inputMailboxConfig.width;
+	inputProducerConfig.height = inputMailboxConfig.height;
+	inputProducerConfig.frameDurationMilliseconds = RenderCadenceCompositor::FrameDurationMillisecondsFromRateString(appConfig.inputFrameRate);
+	RenderCadenceCompositor::SyntheticInputProducer syntheticInput(inputMailbox, inputProducerConfig);
+	if (syntheticInput.Start())
+		RenderCadenceCompositor::Log("app", "Synthetic BGRA8 input producer started.");
+	else
+		RenderCadenceCompositor::LogWarning("app", "Synthetic input producer did not start; shaders will use fallback input.");
+
 	RenderThread::Config renderConfig;
 	renderConfig.width = frameExchangeConfig.width;
 	renderConfig.height = frameExchangeConfig.height;
 	renderConfig.frameDurationMilliseconds = RenderCadenceCompositor::FrameDurationMillisecondsFromRateString(appConfig.outputFrameRate);
 	renderConfig.pboDepth = 6;
 
-	RenderThread renderThread(frameExchange, renderConfig);
+	RenderThread renderThread(frameExchange, &inputMailbox, renderConfig);
 
 	RenderCadenceCompositor::RenderCadenceApp<RenderThread, SystemFrameExchange> app(renderThread, frameExchange, appConfig);
 
@@ -94,6 +116,7 @@ int main(int argc, char** argv)
 	if (!app.Start(error))
 	{
 		RenderCadenceCompositor::LogError("app", "RenderCadenceCompositor start failed: " + error);
+		syntheticInput.Stop();
 		RenderCadenceCompositor::Logger::Instance().Stop();
 		return 1;
 	}
@@ -101,6 +124,7 @@ int main(int argc, char** argv)
 	std::string line;
 	std::getline(std::cin, line);
 	app.Stop();
+	syntheticInput.Stop();
 	RenderCadenceCompositor::Log("app", "RenderCadenceCompositor stopped.");
 	RenderCadenceCompositor::Logger::Instance().Stop();
 	return 0;

apps/RenderCadenceCompositor/frames/InputFrameMailbox.cpp

@@ -0,0 +1,233 @@
+#include "InputFrameMailbox.h"
+
+#include <algorithm>
+#include <cstring>
+
+namespace
+{
+InputFrameMailboxConfig NormalizeConfig(InputFrameMailboxConfig config)
+{
+	if (config.rowBytes == 0)
+		config.rowBytes = VideoIORowBytes(config.pixelFormat, config.width);
+	return config;
+}
+}
+
+InputFrameMailbox::InputFrameMailbox(const InputFrameMailboxConfig& config)
+{
+	Configure(config);
+}
+
+void InputFrameMailbox::Configure(const InputFrameMailboxConfig& config)
+{
+	std::lock_guard<std::mutex> lock(mMutex);
+	mConfig = NormalizeConfig(config);
+	mReadyIndices.clear();
+	mSlots.clear();
+	mSlots.resize(mConfig.capacity);
+
+	const std::size_t byteCount = FrameByteCount();
+	for (Slot& slot : mSlots)
+	{
+		slot.bytes.resize(byteCount);
+		slot.state = InputFrameSlotState::Free;
+		slot.frameIndex = 0;
+		++slot.generation;
+	}
+
+	mCounters = InputFrameMailboxMetrics();
+}
+
+InputFrameMailboxConfig InputFrameMailbox::Config() const
+{
+	std::lock_guard<std::mutex> lock(mMutex);
+	return mConfig;
+}
+
+bool InputFrameMailbox::SubmitFrame(const void* bytes, unsigned rowBytes, uint64_t frameIndex)
+{
+	if (bytes == nullptr || rowBytes == 0)
+		return false;
+
+	std::lock_guard<std::mutex> lock(mMutex);
+	if (mSlots.empty() || mConfig.width == 0 || mConfig.height == 0)
+		return false;
+
+	std::size_t slotIndex = mSlots.size();
+	for (std::size_t index = 0; index < mSlots.size(); ++index)
+	{
+		if (mSlots[index].state == InputFrameSlotState::Free)
+		{
+			slotIndex = index;
+			break;
+		}
+	}
+
+	if (slotIndex == mSlots.size())
+	{
+		if (!DropOldestReadyLocked())
+		{
+			++mCounters.submitMisses;
+			return false;
+		}
+
+		for (std::size_t index = 0; index < mSlots.size(); ++index)
+		{
+			if (mSlots[index].state == InputFrameSlotState::Free)
+			{
+				slotIndex = index;
+				break;
+			}
+		}
+	}
+
+	if (slotIndex == mSlots.size())
+	{
+		++mCounters.submitMisses;
+		return false;
+	}
+
+	Slot& slot = mSlots[slotIndex];
+	const std::size_t destinationRowBytes = mConfig.rowBytes;
+	const std::size_t copyRowBytes = (std::min)(static_cast<std::size_t>(rowBytes), destinationRowBytes);
+	const unsigned char* source = static_cast<const unsigned char*>(bytes);
+	for (unsigned y = 0; y < mConfig.height; ++y)
+	{
+		std::memcpy(slot.bytes.data() + static_cast<std::size_t>(y) * destinationRowBytes, source + static_cast<std::size_t>(y) * rowBytes, copyRowBytes);
+	}
+
+	slot.state = InputFrameSlotState::Ready;
+	slot.frameIndex = frameIndex;
+	++slot.generation;
+	mReadyIndices.push_back(slotIndex);
+	++mCounters.submittedFrames;
+	mCounters.latestFrameIndex = frameIndex;
+	return true;
+}
+
+bool InputFrameMailbox::TryAcquireLatest(InputFrame& frame)
+{
+	std::lock_guard<std::mutex> lock(mMutex);
+	while (!mReadyIndices.empty())
+	{
+		const std::size_t index = mReadyIndices.back();
+		mReadyIndices.pop_back();
+		if (index >= mSlots.size() || mSlots[index].state != InputFrameSlotState::Ready)
+			continue;
+
+		while (!mReadyIndices.empty())
+		{
+			const std::size_t olderIndex = mReadyIndices.front();
+			mReadyIndices.pop_front();
+			if (olderIndex >= mSlots.size() || mSlots[olderIndex].state != InputFrameSlotState::Ready)
+				continue;
+			mSlots[olderIndex].state = InputFrameSlotState::Free;
+			++mSlots[olderIndex].generation;
+			++mCounters.droppedReadyFrames;
+		}
+
+		mSlots[index].state = InputFrameSlotState::Reading;
+		FillFrameLocked(index, frame);
+		++mCounters.consumedFrames;
+		return true;
+	}
+
+	frame = InputFrame();
+	++mCounters.consumeMisses;
+	return false;
+}
+
+bool InputFrameMailbox::Release(const InputFrame& frame)
+{
+	std::lock_guard<std::mutex> lock(mMutex);
+	if (!IsValidLocked(frame))
+		return false;
+
+	Slot& slot = mSlots[frame.index];
+	if (slot.state != InputFrameSlotState::Reading)
+		return false;
+
+	slot.state = InputFrameSlotState::Free;
+	slot.frameIndex = 0;
+	++slot.generation;
+	return true;
+}
+
+void InputFrameMailbox::Clear()
+{
+	std::lock_guard<std::mutex> lock(mMutex);
+	mReadyIndices.clear();
+	for (Slot& slot : mSlots)
+	{
+		slot.state = InputFrameSlotState::Free;
+		slot.frameIndex = 0;
+		++slot.generation;
+	}
+}
+
+InputFrameMailboxMetrics InputFrameMailbox::Metrics() const
+{
+	std::lock_guard<std::mutex> lock(mMutex);
+	InputFrameMailboxMetrics metrics = mCounters;
+	metrics.capacity = mSlots.size();
+
+	for (const Slot& slot : mSlots)
+	{
+		switch (slot.state)
+		{
+		case InputFrameSlotState::Free:
+			++metrics.freeCount;
+			break;
+		case InputFrameSlotState::Ready:
+			++metrics.readyCount;
+			break;
+		case InputFrameSlotState::Reading:
+			++metrics.readingCount;
+			break;
+		}
+	}
+
+	return metrics;
+}
+
+bool InputFrameMailbox::IsValidLocked(const InputFrame& frame) const
+{
+	return frame.index < mSlots.size() && mSlots[frame.index].generation == frame.generation;
+}
+
+void InputFrameMailbox::FillFrameLocked(std::size_t index, InputFrame& frame) const
+{
+	const Slot& slot = mSlots[index];
+	frame.bytes = slot.bytes.empty() ? nullptr : slot.bytes.data();
+	frame.rowBytes = static_cast<long>(mConfig.rowBytes);
+	frame.width = mConfig.width;
+	frame.height = mConfig.height;
+	frame.pixelFormat = mConfig.pixelFormat;
+	frame.index = index;
+	frame.generation = slot.generation;
+	frame.frameIndex = slot.frameIndex;
+}
+
+bool InputFrameMailbox::DropOldestReadyLocked()
+{
+	while (!mReadyIndices.empty())
+	{
+		const std::size_t index = mReadyIndices.front();
+		mReadyIndices.pop_front();
+		if (index >= mSlots.size() || mSlots[index].state != InputFrameSlotState::Ready)
+			continue;
+
+		mSlots[index].state = InputFrameSlotState::Free;
+		mSlots[index].frameIndex = 0;
+		++mSlots[index].generation;
+		++mCounters.droppedReadyFrames;
+		return true;
+	}
+
+	return false;
+}
+
+std::size_t InputFrameMailbox::FrameByteCount() const
+{
+	return static_cast<std::size_t>(mConfig.rowBytes) * static_cast<std::size_t>(mConfig.height);
+}

apps/RenderCadenceCompositor/frames/InputFrameMailbox.h

@@ -0,0 +1,87 @@
+#pragma once
+
+#include "VideoIOFormat.h"
+
+#include <cstddef>
+#include <cstdint>
+#include <deque>
+#include <mutex>
+#include <vector>
+
+enum class InputFrameSlotState
+{
+	Free,
+	Ready,
+	Reading
+};
+
+struct InputFrameMailboxConfig
+{
+	unsigned width = 0;
+	unsigned height = 0;
+	VideoIOPixelFormat pixelFormat = VideoIOPixelFormat::Bgra8;
+	unsigned rowBytes = 0;
+	std::size_t capacity = 0;
+};
+
+struct InputFrame
+{
+	const void* bytes = nullptr;
+	long rowBytes = 0;
+	unsigned width = 0;
+	unsigned height = 0;
+	VideoIOPixelFormat pixelFormat = VideoIOPixelFormat::Bgra8;
+	std::size_t index = 0;
+	uint64_t generation = 0;
+	uint64_t frameIndex = 0;
+};
+
+struct InputFrameMailboxMetrics
+{
+	std::size_t capacity = 0;
+	std::size_t freeCount = 0;
+	std::size_t readyCount = 0;
+	std::size_t readingCount = 0;
+	uint64_t submittedFrames = 0;
+	uint64_t consumedFrames = 0;
+	uint64_t droppedReadyFrames = 0;
+	uint64_t submitMisses = 0;
+	uint64_t consumeMisses = 0;
+	uint64_t latestFrameIndex = 0;
+};
+
+class InputFrameMailbox
+{
+public:
+	InputFrameMailbox() = default;
+	explicit InputFrameMailbox(const InputFrameMailboxConfig& config);
+
+	void Configure(const InputFrameMailboxConfig& config);
+	InputFrameMailboxConfig Config() const;
+
+	bool SubmitFrame(const void* bytes, unsigned rowBytes, uint64_t frameIndex);
+	bool TryAcquireLatest(InputFrame& frame);
+	bool Release(const InputFrame& frame);
+	void Clear();
+	InputFrameMailboxMetrics Metrics() const;
+
+private:
+	struct Slot
+	{
+		std::vector<unsigned char> bytes;
+		InputFrameSlotState state = InputFrameSlotState::Free;
+		uint64_t frameIndex = 0;
+		uint64_t generation = 0;
+	};
+
+	bool IsValidLocked(const InputFrame& frame) const;
+	void FillFrameLocked(std::size_t index, InputFrame& frame) const;
+	bool DropOldestReadyLocked();
+	std::size_t FrameByteCount() const;
+
+	mutable std::mutex mMutex;
+	InputFrameMailboxConfig mConfig;
+	std::vector<Slot> mSlots;
+	std::deque<std::size_t> mReadyIndices;
+	InputFrameMailboxMetrics mCounters;
+};

apps/RenderCadenceCompositor/render/InputFrameTexture.cpp

@@ -0,0 +1,83 @@
+#include "InputFrameTexture.h"
+
+InputFrameTexture::~InputFrameTexture()
+{
+	ShutdownGl();
+}
+
+GLuint InputFrameTexture::PollAndUpload(InputFrameMailbox* mailbox)
+{
+	if (mailbox == nullptr)
+		return mTexture;
+
+	InputFrame frame;
+	if (!mailbox->TryAcquireLatest(frame))
+	{
+		++mUploadMisses;
+		return mTexture;
+	}
+
+	if (frame.bytes != nullptr && frame.pixelFormat == VideoIOPixelFormat::Bgra8 && EnsureTexture(frame))
+	{
+		glBindTexture(GL_TEXTURE_2D, mTexture);
+		glPixelStorei(GL_UNPACK_ALIGNMENT, 4);
+		glPixelStorei(GL_UNPACK_ROW_LENGTH, frame.rowBytes > 0 ? static_cast<GLint>(frame.rowBytes / 4) : 0);
+		glTexSubImage2D(
+			GL_TEXTURE_2D,
+			0,
+			0,
+			0,
+			static_cast<GLsizei>(frame.width),
+			static_cast<GLsizei>(frame.height),
+			GL_BGRA,
+			GL_UNSIGNED_INT_8_8_8_8_REV,
+			frame.bytes);
+		glPixelStorei(GL_UNPACK_ROW_LENGTH, 0);
+		glBindTexture(GL_TEXTURE_2D, 0);
+		++mUploadedFrames;
+	}
+
+	mailbox->Release(frame);
+	return mTexture;
+}
+
+void InputFrameTexture::ShutdownGl()
+{
+	if (mTexture != 0)
+		glDeleteTextures(1, &mTexture);
+	mTexture = 0;
+	mWidth = 0;
+	mHeight = 0;
+}
+
+bool InputFrameTexture::EnsureTexture(const InputFrame& frame)
+{
+	if (frame.width == 0 || frame.height == 0)
+		return false;
+
+	if (mTexture != 0 && mWidth == frame.width && mHeight == frame.height)
+		return true;
+
+	ShutdownGl();
+	glGenTextures(1, &mTexture);
+	glBindTexture(GL_TEXTURE_2D, mTexture);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+	glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+	glTexImage2D(
+		GL_TEXTURE_2D,
+		0,
+		GL_RGBA8,
+		static_cast<GLsizei>(frame.width),
+		static_cast<GLsizei>(frame.height),
+		0,
+		GL_BGRA,
+		GL_UNSIGNED_INT_8_8_8_8_REV,
+		nullptr);
+	glBindTexture(GL_TEXTURE_2D, 0);
+
+	mWidth = frame.width;
+	mHeight = frame.height;
+	return mTexture != 0;
+}

apps/RenderCadenceCompositor/render/InputFrameTexture.h

@@ -0,0 +1,30 @@
+#pragma once
+
+#include "../frames/InputFrameMailbox.h"
+#include "GLExtensions.h"
+
+#include <cstdint>
+
+class InputFrameTexture
+{
+public:
+	InputFrameTexture() = default;
+	InputFrameTexture(const InputFrameTexture&) = delete;
+	InputFrameTexture& operator=(const InputFrameTexture&) = delete;
+	~InputFrameTexture();
+
+	GLuint PollAndUpload(InputFrameMailbox* mailbox);
+	GLuint Texture() const { return mTexture; }
+	uint64_t UploadedFrames() const { return mUploadedFrames; }
+	uint64_t UploadMisses() const { return mUploadMisses; }
+	void ShutdownGl();
+
+private:
+	bool EnsureTexture(const InputFrame& frame);
+
+	GLuint mTexture = 0;
+	unsigned mWidth = 0;
+	unsigned mHeight = 0;
+	uint64_t mUploadedFrames = 0;
+	uint64_t mUploadMisses = 0;
+};

apps/RenderCadenceCompositor/render/RenderThread.cpp

@@ -1,9 +1,11 @@
 #include "RenderThread.h"
 
+#include "../frames/InputFrameMailbox.h"
 #include "../frames/SystemFrameExchange.h"
 #include "../frames/SystemFrameTypes.h"
 #include "../logging/Logger.h"
 #include "../platform/HiddenGlWindow.h"
+#include "InputFrameTexture.h"
 #include "readback/Bgra8ReadbackPipeline.h"
 #include "GLExtensions.h"
 #include "runtime/RuntimeRenderScene.h"
@@ -20,6 +22,13 @@ RenderThread::RenderThread(SystemFrameExchange& frameExchange, Config config) :
 {
 }
 
+RenderThread::RenderThread(SystemFrameExchange& frameExchange, InputFrameMailbox* inputMailbox, Config config) :
+	mFrameExchange(frameExchange),
+	mInputMailbox(inputMailbox),
+	mConfig(config)
+{
+}
+
 RenderThread::~RenderThread()
 {
 	Stop();
@@ -109,6 +118,7 @@ void RenderThread::ThreadMain()
 	SimpleMotionRenderer renderer;
 	RuntimeRenderScene runtimeRenderScene;
 	Bgra8ReadbackPipeline readback;
+	InputFrameTexture inputTexture;
 	if (!runtimeRenderScene.StartPrepareWorker(std::move(prepareWindow), error))
 	{
 		SignalStartupFailure(error.empty() ? "Runtime shader prepare worker initialization failed." : error);
@@ -145,9 +155,10 @@ void RenderThread::ThreadMain()
 		}
 
 		TryCommitReadyRuntimeShader(runtimeRenderScene);
-		if (!readback.RenderAndQueue(frameIndex, [this, &renderer, &runtimeRenderScene](uint64_t index) {
+		const GLuint videoInputTexture = inputTexture.PollAndUpload(mInputMailbox);
+		if (!readback.RenderAndQueue(frameIndex, [this, &renderer, &runtimeRenderScene, videoInputTexture](uint64_t index) {
 			if (runtimeRenderScene.HasLayers())
-				runtimeRenderScene.RenderFrame(index, mConfig.width, mConfig.height);
+				runtimeRenderScene.RenderFrame(index, mConfig.width, mConfig.height, videoInputTexture);
 			else
 				renderer.RenderFrame(index);
 		}))
@@ -175,6 +186,7 @@ void RenderThread::ThreadMain()
 	}
 
 	readback.Shutdown();
+	inputTexture.ShutdownGl();
 	runtimeRenderScene.ShutdownGl();
 	renderer.ShutdownGl();
 	window.ClearCurrent();

apps/RenderCadenceCompositor/render/RenderThread.h

@@ -14,6 +14,7 @@
 #include <thread>
 
 class SystemFrameExchange;
+class InputFrameMailbox;
 
 class RenderThread
 {
@@ -39,6 +40,7 @@ public:
 	};
 
 	RenderThread(SystemFrameExchange& frameExchange, Config config);
+	RenderThread(SystemFrameExchange& frameExchange, InputFrameMailbox* inputMailbox, Config config);
 	RenderThread(const RenderThread&) = delete;
 	RenderThread& operator=(const RenderThread&) = delete;
 	~RenderThread();
@@ -63,6 +65,7 @@ private:
 	bool TryTakePendingRenderLayers(std::vector<RenderCadenceCompositor::RuntimeRenderLayerModel>& layers);
 
 	SystemFrameExchange& mFrameExchange;
+	InputFrameMailbox* mInputMailbox = nullptr;
 	Config mConfig;
 	std::thread mThread;
 	std::atomic<bool> mStopping{ false };

apps/RenderCadenceCompositor/render/runtime/RuntimeRenderScene.cpp

@@ -120,7 +120,7 @@ bool RuntimeRenderScene::HasLayers()
 	return false;
 }
 
-void RuntimeRenderScene::RenderFrame(uint64_t frameIndex, unsigned width, unsigned height)
+void RuntimeRenderScene::RenderFrame(uint64_t frameIndex, unsigned width, unsigned height, GLuint videoInputTexture)
 {
 	ConsumePreparedPrograms();
 
@@ -148,18 +148,18 @@ void RuntimeRenderScene::RenderFrame(uint64_t frameIndex, unsigned width, unsign
 
 	if (readyLayers.size() == 1)
 	{
-		RenderLayer(*readyLayers.front(), frameIndex, width, height, 0, static_cast<GLuint>(outputFramebuffer), true);
+		RenderLayer(*readyLayers.front(), frameIndex, width, height, videoInputTexture, videoInputTexture, static_cast<GLuint>(outputFramebuffer), true);
 		return;
 	}
 
 	if (!EnsureLayerTargets(width, height))
 	{
 		glBindFramebuffer(GL_FRAMEBUFFER, static_cast<GLuint>(outputFramebuffer));
-		RenderLayer(*readyLayers.back(), frameIndex, width, height, 0, static_cast<GLuint>(outputFramebuffer), true);
+		RenderLayer(*readyLayers.back(), frameIndex, width, height, videoInputTexture, videoInputTexture, static_cast<GLuint>(outputFramebuffer), true);
 		return;
 	}
 
-	GLuint layerInputTexture = 0;
+	GLuint layerInputTexture = videoInputTexture;
 	std::size_t nextTargetIndex = 0;
 	for (std::size_t layerIndex = 0; layerIndex < readyLayers.size(); ++layerIndex)
 	{
@@ -167,11 +167,11 @@ void RuntimeRenderScene::RenderFrame(uint64_t frameIndex, unsigned width, unsign
 		if (isFinalLayer)
 		{
 			glBindFramebuffer(GL_FRAMEBUFFER, static_cast<GLuint>(outputFramebuffer));
-			RenderLayer(*readyLayers[layerIndex], frameIndex, width, height, layerInputTexture, static_cast<GLuint>(outputFramebuffer), true);
+			RenderLayer(*readyLayers[layerIndex], frameIndex, width, height, videoInputTexture, layerInputTexture, static_cast<GLuint>(outputFramebuffer), true);
 			continue;
 		}
 
-		RenderLayer(*readyLayers[layerIndex], frameIndex, width, height, layerInputTexture, mLayerFramebuffers[nextTargetIndex], true);
+		RenderLayer(*readyLayers[layerIndex], frameIndex, width, height, videoInputTexture, layerInputTexture, mLayerFramebuffers[nextTargetIndex], true);
 		layerInputTexture = mLayerTextures[nextTargetIndex];
 		nextTargetIndex = 1 - nextTargetIndex;
 	}
@@ -309,6 +309,7 @@ GLuint RuntimeRenderScene::RenderLayer(
 	uint64_t frameIndex,
 	unsigned width,
 	unsigned height,
+	GLuint videoInputTexture,
 	GLuint layerInputTexture,
 	GLuint outputFramebuffer,
 	bool renderToOutput)
@@ -327,7 +328,11 @@ GLuint RuntimeRenderScene::RenderLayer(
 		if (!pass.inputNames.empty())
 		{
 			const std::string& inputName = pass.inputNames.front();
-			if (inputName != "layerInput" && inputName != "videoInput")
+			if (inputName == "videoInput")
+			{
+				sourceTexture = videoInputTexture;
+			}
+			else if (inputName != "layerInput")
 			{
 				for (std::size_t index = 0; index < 2; ++index)
 				{
@@ -344,7 +349,7 @@ GLuint RuntimeRenderScene::RenderLayer(
 		if (writesLayerOutput && renderToOutput)
 		{
 			glBindFramebuffer(GL_FRAMEBUFFER, outputFramebuffer);
-			pass.renderer->RenderFrame(frameIndex, width, height, sourceTexture, sourceTexture);
+			pass.renderer->RenderFrame(frameIndex, width, height, sourceTexture, layerInputTexture);
 			lastOutputTexture = 0;
 			continue;
 		}
@@ -355,7 +360,7 @@ GLuint RuntimeRenderScene::RenderLayer(
 		const std::size_t targetIndex = nextTargetIndex;
 		nextTargetIndex = nextTargetIndex == 2 ? 3 : 2;
 		glBindFramebuffer(GL_FRAMEBUFFER, mLayerFramebuffers[targetIndex]);
-		pass.renderer->RenderFrame(frameIndex, width, height, sourceTexture, sourceTexture);
+		pass.renderer->RenderFrame(frameIndex, width, height, sourceTexture, layerInputTexture);
 		const std::size_t namedIndex = targetIndex - 2;
 		namedOutputs[namedIndex] = mLayerTextures[targetIndex];
 		namedOutputNames[namedIndex] = pass.outputName;

apps/RenderCadenceCompositor/render/runtime/RuntimeRenderScene.h

@@ -22,7 +22,7 @@ public:
 	bool StartPrepareWorker(std::unique_ptr<HiddenGlWindow> sharedWindow, std::string& error);
 	bool CommitRenderLayers(const std::vector<RenderCadenceCompositor::RuntimeRenderLayerModel>& layers, std::string& error);
 	bool HasLayers();
-	void RenderFrame(uint64_t frameIndex, unsigned width, unsigned height);
+	void RenderFrame(uint64_t frameIndex, unsigned width, unsigned height, GLuint videoInputTexture = 0);
 	void ShutdownGl();
 
 private:
@@ -48,7 +48,7 @@ private:
 	void TryCommitPendingPrograms(LayerProgram& layer);
 	bool EnsureLayerTargets(unsigned width, unsigned height);
 	void DestroyLayerTargets();
-	GLuint RenderLayer(LayerProgram& layer, uint64_t frameIndex, unsigned width, unsigned height, GLuint layerInputTexture, GLuint outputFramebuffer, bool renderToOutput);
+	GLuint RenderLayer(LayerProgram& layer, uint64_t frameIndex, unsigned width, unsigned height, GLuint videoInputTexture, GLuint layerInputTexture, GLuint outputFramebuffer, bool renderToOutput);
 	LayerProgram* FindLayer(const std::string& layerId);
 	const LayerProgram* FindLayer(const std::string& layerId) const;
 	LayerProgram::PassProgram* FindPass(LayerProgram& layer, const std::string& passId);

apps/RenderCadenceCompositor/video/SyntheticInputProducer.cpp

@@ -0,0 +1,111 @@
+#include "SyntheticInputProducer.h"
+
+#include "VideoIOFormat.h"
+
+#include <algorithm>
+#include <cmath>
+
+namespace RenderCadenceCompositor
+{
+SyntheticInputProducer::SyntheticInputProducer(InputFrameMailbox& mailbox, SyntheticInputProducerConfig config) :
+	mMailbox(mailbox),
+	mConfig(config)
+{
+}
+
+SyntheticInputProducer::~SyntheticInputProducer()
+{
+	Stop();
+}
+
+bool SyntheticInputProducer::Start()
+{
+	if (mThread.joinable())
+		return true;
+	if (mConfig.width == 0 || mConfig.height == 0)
+		return false;
+
+	mStopping.store(false, std::memory_order_release);
+	mThread = std::thread([this]() { ThreadMain(); });
+	return true;
+}
+
+void SyntheticInputProducer::Stop()
+{
+	mStopping.store(true, std::memory_order_release);
+	if (mThread.joinable())
+		mThread.join();
+}
+
+SyntheticInputProducerMetrics SyntheticInputProducer::Metrics() const
+{
+	SyntheticInputProducerMetrics metrics;
+	metrics.generatedFrames = mGeneratedFrames.load(std::memory_order_relaxed);
+	metrics.submitMisses = mSubmitMisses.load(std::memory_order_relaxed);
+	return metrics;
+}
+
+void SyntheticInputProducer::ThreadMain()
+{
+	const unsigned rowBytes = VideoIORowBytes(VideoIOPixelFormat::Bgra8, mConfig.width);
+	std::vector<unsigned char> buffer(static_cast<std::size_t>(rowBytes) * static_cast<std::size_t>(mConfig.height));
+	const auto frameDuration = std::chrono::duration_cast<std::chrono::steady_clock::duration>(
+		std::chrono::duration<double, std::milli>(mConfig.frameDurationMilliseconds));
+
+	uint64_t frameIndex = 0;
+	auto nextFrameTime = std::chrono::steady_clock::now();
+	while (!mStopping.load(std::memory_order_acquire))
+	{
+		const auto now = std::chrono::steady_clock::now();
+		if (now < nextFrameTime)
+		{
+			std::this_thread::sleep_for((std::min)(std::chrono::milliseconds(1), std::chrono::duration_cast<std::chrono::milliseconds>(nextFrameTime - now)));
+			continue;
+		}
+
+		GenerateFrame(frameIndex, buffer);
+		if (!mMailbox.SubmitFrame(buffer.data(), rowBytes, frameIndex))
+			mSubmitMisses.fetch_add(1, std::memory_order_relaxed);
+		mGeneratedFrames.fetch_add(1, std::memory_order_relaxed);
+		++frameIndex;
+		nextFrameTime += frameDuration;
+		if (std::chrono::steady_clock::now() - nextFrameTime > frameDuration * 4)
+			nextFrameTime = std::chrono::steady_clock::now() + frameDuration;
+	}
+}
+
+void SyntheticInputProducer::GenerateFrame(uint64_t frameIndex, std::vector<unsigned char>& buffer) const
+{
+	const float t = static_cast<float>(frameIndex) / 60.0f;
+	const unsigned boxWidth = (std::max)(1u, mConfig.width / 5u);
+	const unsigned boxHeight = (std::max)(1u, mConfig.height / 6u);
+	const unsigned maxX = mConfig.width > boxWidth ? mConfig.width - boxWidth : 0u;
+	const unsigned maxY = mConfig.height > boxHeight ? mConfig.height - boxHeight : 0u;
+	const unsigned boxX = static_cast<unsigned>((0.5f + 0.5f * std::sin(t * 1.4f)) * static_cast<float>(maxX));
+	const unsigned boxY = static_cast<unsigned>((0.5f + 0.5f * std::sin(t * 0.9f + 1.2f)) * static_cast<float>(maxY));
+	const unsigned rowBytes = VideoIORowBytes(VideoIOPixelFormat::Bgra8, mConfig.width);
+
+	for (unsigned y = 0; y < mConfig.height; ++y)
+	{
+		for (unsigned x = 0; x < mConfig.width; ++x)
+		{
+			const std::size_t offset = static_cast<std::size_t>(y) * rowBytes + static_cast<std::size_t>(x) * 4;
+			const unsigned checker = ((x / 80u) + (y / 80u) + static_cast<unsigned>(frameIndex / 15u)) & 1u;
+			unsigned char red = checker ? 42 : 16;
+			unsigned char green = checker ? 70 : 28;
+			unsigned char blue = checker ? 110 : 55;
+			if (x >= boxX && x < boxX + boxWidth && y >= boxY && y < boxY + boxHeight)
+			{
+				red = 245;
+				green = static_cast<unsigned char>(160 + 60 * (0.5f + 0.5f * std::sin(t * 2.1f)));
+				blue = 35;
+			}
+
+			buffer[offset + 0] = blue;
+			buffer[offset + 1] = green;
+			buffer[offset + 2] = red;
+			buffer[offset + 3] = 255;
+		}
+	}
+}
+}

apps/RenderCadenceCompositor/video/SyntheticInputProducer.h

@@ -0,0 +1,49 @@
+#pragma once
+
+#include "../frames/InputFrameMailbox.h"
+
+#include <atomic>
+#include <chrono>
+#include <cstdint>
+#include <thread>
+#include <vector>
+
+namespace RenderCadenceCompositor
+{
+struct SyntheticInputProducerConfig
+{
+	unsigned width = 1920;
+	unsigned height = 1080;
+	double frameDurationMilliseconds = 1000.0 / 59.94;
+};
+
+struct SyntheticInputProducerMetrics
+{
+	uint64_t generatedFrames = 0;
+	uint64_t submitMisses = 0;
+};
+
+class SyntheticInputProducer
+{
+public:
+	SyntheticInputProducer(InputFrameMailbox& mailbox, SyntheticInputProducerConfig config);
+	SyntheticInputProducer(const SyntheticInputProducer&) = delete;
+	SyntheticInputProducer& operator=(const SyntheticInputProducer&) = delete;
+	~SyntheticInputProducer();
+
+	bool Start();
+	void Stop();
+	SyntheticInputProducerMetrics Metrics() const;
+
+private:
+	void ThreadMain();
+	void GenerateFrame(uint64_t frameIndex, std::vector<unsigned char>& buffer) const;
+
+	InputFrameMailbox& mMailbox;
+	SyntheticInputProducerConfig mConfig;
+	std::thread mThread;
+	std::atomic<bool> mStopping{ false };
+	std::atomic<uint64_t> mGeneratedFrames{ 0 };
+	std::atomic<uint64_t> mSubmitMisses{ 0 };
+};
+}

tests/RenderCadenceCompositorInputFrameMailboxTests.cpp

@@ -0,0 +1,109 @@
+#include "InputFrameMailbox.h"
+
+#include <cstdint>
+#include <cstring>
+#include <iostream>
+#include <vector>
+
+namespace
+{
+int gFailures = 0;
+
+void Expect(bool condition, const char* message)
+{
+	if (condition)
+		return;
+
+	++gFailures;
+	std::cerr << "FAIL: " << message << "\n";
+}
+
+InputFrameMailboxConfig MakeConfig(std::size_t capacity = 2)
+{
+	InputFrameMailboxConfig config;
+	config.width = 2;
+	config.height = 2;
+	config.pixelFormat = VideoIOPixelFormat::Bgra8;
+	config.rowBytes = VideoIORowBytes(config.pixelFormat, config.width);
+	config.capacity = capacity;
+	return config;
+}
+
+std::vector<unsigned char> MakeFrame(unsigned char value)
+{
+	return std::vector<unsigned char>(16, value);
+}
+
+void TestAcquireLatestDropsOlderReadyFrames()
+{
+	InputFrameMailbox mailbox(MakeConfig(3));
+	const std::vector<unsigned char> frame1 = MakeFrame(1);
+	const std::vector<unsigned char> frame2 = MakeFrame(2);
+	const std::vector<unsigned char> frame3 = MakeFrame(3);
+
+	Expect(mailbox.SubmitFrame(frame1.data(), 8, 1), "first input frame submits");
+	Expect(mailbox.SubmitFrame(frame2.data(), 8, 2), "second input frame submits");
+	Expect(mailbox.SubmitFrame(frame3.data(), 8, 3), "third input frame submits");
+
+	InputFrame latest;
+	Expect(mailbox.TryAcquireLatest(latest), "latest input frame can be acquired");
+	Expect(latest.frameIndex == 3, "mailbox returns newest frame");
+	Expect(latest.bytes != nullptr && static_cast<const unsigned char*>(latest.bytes)[0] == 3, "latest frame bytes match newest frame");
+	Expect(mailbox.Release(latest), "latest input frame can be released");
+
+	const InputFrameMailboxMetrics metrics = mailbox.Metrics();
+	Expect(metrics.droppedReadyFrames == 2, "older ready input frames are dropped after latest acquire");
+	Expect(metrics.freeCount == 3, "all slots are free after release");
+}
+
+void TestSubmitDropsOldestWhenFull()
+{
+	InputFrameMailbox mailbox(MakeConfig(2));
+	const std::vector<unsigned char> frame1 = MakeFrame(1);
+	const std::vector<unsigned char> frame2 = MakeFrame(2);
+	const std::vector<unsigned char> frame3 = MakeFrame(3);
+
+	Expect(mailbox.SubmitFrame(frame1.data(), 8, 1), "first frame submits into full test");
+	Expect(mailbox.SubmitFrame(frame2.data(), 8, 2), "second frame submits into full test");
+	Expect(mailbox.SubmitFrame(frame3.data(), 8, 3), "third frame submits by dropping oldest ready frame");
+
+	InputFrame latest;
+	Expect(mailbox.TryAcquireLatest(latest), "latest frame available after drop");
+	Expect(latest.frameIndex == 3, "newest frame survived full mailbox");
+	Expect(mailbox.Release(latest), "newest frame releases");
+
+	const InputFrameMailboxMetrics metrics = mailbox.Metrics();
+	Expect(metrics.droppedReadyFrames >= 1, "full mailbox records ready drop");
+	Expect(metrics.submitMisses == 0, "full mailbox did not block producer when ready slots were disposable");
+}
+
+void TestReadingFrameIsProtected()
+{
+	InputFrameMailbox mailbox(MakeConfig(1));
+	const std::vector<unsigned char> frame1 = MakeFrame(1);
+	const std::vector<unsigned char> frame2 = MakeFrame(2);
+
+	Expect(mailbox.SubmitFrame(frame1.data(), 8, 1), "protected frame submits");
+	InputFrame acquired;
+	Expect(mailbox.TryAcquireLatest(acquired), "protected frame acquired");
+	Expect(!mailbox.SubmitFrame(frame2.data(), 8, 2), "producer cannot overwrite frame currently being read");
+	Expect(mailbox.Release(acquired), "protected frame releases");
+	Expect(mailbox.SubmitFrame(frame2.data(), 8, 2), "producer can submit after release");
+}
+}
+
+int main()
+{
+	TestAcquireLatestDropsOlderReadyFrames();
+	TestSubmitDropsOldestWhenFull();
+	TestReadingFrameIsProtected();
+
+	if (gFailures != 0)
+	{
+		std::cerr << gFailures << " RenderCadenceCompositorInputFrameMailbox test failure(s).\n";
+		return 1;
+	}
+
+	std::cout << "RenderCadenceCompositorInputFrameMailbox tests passed.\n";
+	return 0;
+}