`gfx` explicit transient resource management. (#1774)

6 files changed, 250 insertions, 325 deletions

diff --git a/examples/example-base/example-base.cpp b/examples/example-base/example-base.cpp
new file mode 100644
index 000000000..b06bbdf7e
--- /dev/null
+++ b/examples/example-base/example-base.cpp
@@ -0,0 +1,160 @@
+#include "example-base.h"
+
+using namespace Slang;
+using namespace gfx;
+
+Slang::Result WindowedAppBase::initializeBase(const char* title, int width, int height)
+{
+    // Create a window for our application to render into.
+    //
+    platform::WindowDesc windowDesc;
+    windowDesc.title = title;
+    windowDesc.width = width;
+    windowDesc.height = height;
+    windowWidth = width;
+    windowHeight = height;
+    windowDesc.style = platform::WindowStyle::Default;
+    gWindow = platform::Application::createWindow(windowDesc);
+    gWindow->events.mainLoop = [this]() { mainLoop(); };
+    gWindow->events.sizeChanged = Slang::Action<>(this, &WindowedAppBase::windowSizeChanged);
+
+    // Initialize the rendering layer.
+    IDevice::Desc deviceDesc = {};
+    gfx::Result res = gfxCreateDevice(&deviceDesc, gDevice.writeRef());
+    if (SLANG_FAILED(res))
+        return res;
+
+    auto deviceInfo = gDevice->getDeviceInfo();
+    Slang::StringBuilder titleSb;
+    titleSb << title << " (" << deviceInfo.apiName << ": " << deviceInfo.adapterName << ")";
+    gWindow->setText(titleSb.getBuffer());
+
+    ICommandQueue::Desc queueDesc = {};
+    queueDesc.type = ICommandQueue::QueueType::Graphics;
+    gQueue = gDevice->createCommandQueue(queueDesc);
+
+    // Create swapchain and framebuffers.
+    gfx::ISwapchain::Desc swapchainDesc = {};
+    swapchainDesc.format = gfx::Format::RGBA_Unorm_UInt8;
+    swapchainDesc.width = width;
+    swapchainDesc.height = height;
+    swapchainDesc.imageCount = kSwapchainImageCount;
+    swapchainDesc.queue = gQueue;
+    gfx::WindowHandle windowHandle = gWindow->getNativeHandle().convert<gfx::WindowHandle>();
+    gSwapchain = gDevice->createSwapchain(swapchainDesc, windowHandle);
+
+    IFramebufferLayout::AttachmentLayout renderTargetLayout = {gSwapchain->getDesc().format, 1};
+    IFramebufferLayout::AttachmentLayout depthLayout = {gfx::Format::D_Float32, 1};
+    IFramebufferLayout::Desc framebufferLayoutDesc;
+    framebufferLayoutDesc.renderTargetCount = 1;
+    framebufferLayoutDesc.renderTargets = &renderTargetLayout;
+    framebufferLayoutDesc.depthStencil = &depthLayout;
+    SLANG_RETURN_ON_FAIL(
+        gDevice->createFramebufferLayout(framebufferLayoutDesc, gFramebufferLayout.writeRef()));
+
+    createSwapchainFramebuffers();
+
+    for (uint32_t i = 0; i < kSwapchainImageCount; i++)
+    {
+        gfx::ITransientResourceHeap::Desc transientHeapDesc;
+        transientHeapDesc.constantBufferSize = 4096 * 1024;
+        auto transientHeap = gDevice->createTransientResourceHeap(transientHeapDesc);
+        gTransientHeaps.add(transientHeap);
+    }
+
+    gfx::IRenderPassLayout::Desc renderPassDesc = {};
+    renderPassDesc.framebufferLayout = gFramebufferLayout;
+    renderPassDesc.renderTargetCount = 1;
+    IRenderPassLayout::AttachmentAccessDesc renderTargetAccess = {};
+    IRenderPassLayout::AttachmentAccessDesc depthStencilAccess = {};
+    renderTargetAccess.loadOp = IRenderPassLayout::AttachmentLoadOp::Clear;
+    renderTargetAccess.storeOp = IRenderPassLayout::AttachmentStoreOp::Store;
+    renderTargetAccess.initialState = ResourceState::Undefined;
+    renderTargetAccess.finalState = ResourceState::Present;
+    depthStencilAccess.loadOp = IRenderPassLayout::AttachmentLoadOp::Clear;
+    depthStencilAccess.storeOp = IRenderPassLayout::AttachmentStoreOp::Store;
+    depthStencilAccess.initialState = ResourceState::Undefined;
+    depthStencilAccess.finalState = ResourceState::DepthWrite;
+    renderPassDesc.renderTargetAccess = &renderTargetAccess;
+    renderPassDesc.depthStencilAccess = &depthStencilAccess;
+    gRenderPass = gDevice->createRenderPassLayout(renderPassDesc);
+
+    return SLANG_OK;
+}
+
+void WindowedAppBase::mainLoop()
+{
+    int frameBufferIndex = gSwapchain->acquireNextImage();
+    if (frameBufferIndex == -1)
+        return;
+
+    gTransientHeaps[frameBufferIndex]->synchronizeAndReset();
+    renderFrame(frameBufferIndex);
+}
+
+void WindowedAppBase::createSwapchainFramebuffers()
+{
+    gFramebuffers.clear();
+    for (uint32_t i = 0; i < kSwapchainImageCount; i++)
+    {
+        gfx::ITextureResource::Desc depthBufferDesc;
+        depthBufferDesc.setDefaults(gfx::IResource::Usage::DepthWrite);
+        depthBufferDesc.init2D(
+            gfx::IResource::Type::Texture2D,
+            gfx::Format::D_Float32,
+            gSwapchain->getDesc().width,
+            gSwapchain->getDesc().height,
+            0);
+
+        ComPtr<gfx::ITextureResource> depthBufferResource = gDevice->createTextureResource(
+            gfx::IResource::Usage::DepthWrite, depthBufferDesc, nullptr);
+        ComPtr<gfx::ITextureResource> colorBuffer;
+        gSwapchain->getImage(i, colorBuffer.writeRef());
+
+        gfx::IResourceView::Desc colorBufferViewDesc;
+        memset(&colorBufferViewDesc, 0, sizeof(colorBufferViewDesc));
+        colorBufferViewDesc.format = gSwapchain->getDesc().format;
+        colorBufferViewDesc.renderTarget.shape = gfx::IResource::Type::Texture2D;
+        colorBufferViewDesc.type = gfx::IResourceView::Type::RenderTarget;
+        ComPtr<gfx::IResourceView> rtv =
+            gDevice->createTextureView(colorBuffer.get(), colorBufferViewDesc);
+
+        gfx::IResourceView::Desc depthBufferViewDesc;
+        memset(&depthBufferViewDesc, 0, sizeof(depthBufferViewDesc));
+        depthBufferViewDesc.format = gfx::Format::D_Float32;
+        depthBufferViewDesc.renderTarget.shape = gfx::IResource::Type::Texture2D;
+        depthBufferViewDesc.type = gfx::IResourceView::Type::DepthStencil;
+        ComPtr<gfx::IResourceView> dsv =
+            gDevice->createTextureView(depthBufferResource.get(), depthBufferViewDesc);
+
+        gfx::IFramebuffer::Desc framebufferDesc;
+        framebufferDesc.renderTargetCount = 1;
+        framebufferDesc.depthStencilView = dsv.get();
+        framebufferDesc.renderTargetViews = rtv.readRef();
+        framebufferDesc.layout = gFramebufferLayout;
+        ComPtr<gfx::IFramebuffer> frameBuffer = gDevice->createFramebuffer(framebufferDesc);
+        gFramebuffers.add(frameBuffer);
+    }
+}
+
+void WindowedAppBase::windowSizeChanged()
+{
+    // Wait for the GPU to finish.
+    gQueue->wait();
+
+    auto clientRect = gWindow->getClientRect();
+    if (clientRect.width > 0 && clientRect.height > 0)
+    {
+        // Free all framebuffers before resizing swapchain.
+        gFramebuffers = decltype(gFramebuffers)();
+
+        // Resize swapchain.
+        if (gSwapchain->resize(clientRect.width, clientRect.height) == SLANG_OK)
+        {
+            // Recreate framebuffers for each swapchain back buffer image.
+            createSwapchainFramebuffers();
+            windowWidth = clientRect.width;
+            windowHeight = clientRect.height;
+        }
+    }
+}
diff --git a/examples/example-base/example-base.h b/examples/example-base/example-base.h
new file mode 100644
index 000000000..ab7522f06
--- /dev/null
+++ b/examples/example-base/example-base.h
@@ -0,0 +1,52 @@
+#pragma once
+
+#include "slang-gfx.h"
+#include "tools/platform/window.h"
+#include "source/core/slang-basic.h"
+
+struct WindowedAppBase
+{
+protected:
+    static const int kSwapchainImageCount = 2;
+
+    Slang::RefPtr<platform::Window> gWindow;
+    uint32_t windowWidth;
+    uint32_t windowHeight;
+
+    Slang::ComPtr<gfx::IDevice> gDevice;
+
+    Slang::ComPtr<gfx::ISwapchain> gSwapchain;
+    Slang::ComPtr<gfx::IFramebufferLayout> gFramebufferLayout;
+    Slang::List<Slang::ComPtr<gfx::IFramebuffer>> gFramebuffers;
+    Slang::List<Slang::ComPtr<gfx::ITransientResourceHeap>> gTransientHeaps;
+    Slang::ComPtr<gfx::IRenderPassLayout> gRenderPass;
+    Slang::ComPtr<gfx::ICommandQueue> gQueue;
+
+    Slang::Result initializeBase(const char* titile, int width, int height);
+    void createSwapchainFramebuffers();
+    void mainLoop();
+
+    virtual void windowSizeChanged();
+
+protected:
+    virtual void renderFrame(int framebufferIndex) = 0;
+public:
+    platform::Window* getWindow() { return gWindow.Ptr(); }
+    virtual void finalize() { gQueue->wait(); }
+};
+
+template<typename TApp>
+int innerMain()
+{
+    TApp app;
+
+    if (SLANG_FAILED(app.initialize()))
+    {
+        return -1;
+    }
+
+    platform::Application::run(app.getWindow());
+
+    app.finalize();
+    return 0;
+}
diff --git a/examples/gpu-printing/main.cpp b/examples/gpu-printing/main.cpp
index 0315d4827..a0acb8159 100644
--- a/examples/gpu-printing/main.cpp
+++ b/examples/gpu-printing/main.cpp
@@ -113,9 +113,13 @@ Result execute()
     printBufferViewDesc.type = IResourceView::Type::UnorderedAccess;
     auto printBufferView = gDevice->createBufferView(printBuffer, printBufferViewDesc);
 
+    ITransientResourceHeap::Desc transientResourceHeapDesc = {};
+    transientResourceHeapDesc.constantBufferSize = 256;
+    auto transientHeap = gDevice->createTransientResourceHeap(transientResourceHeapDesc);
+
     ICommandQueue::Desc queueDesc = {ICommandQueue::QueueType::Graphics};
     auto queue = gDevice->createCommandQueue(queueDesc);
-    auto commandBuffer = queue->createCommandBuffer();
+    auto commandBuffer = transientHeap->createCommandBuffer();
     auto encoder = commandBuffer->encodeComputeCommands();
     auto rootShaderObject = gDevice->createRootShaderObject(gProgram);
     encoder->setPipelineState(gPipelineState);
diff --git a/examples/hello-world/main.cpp b/examples/hello-world/main.cpp
index b3bee9c07..19413948a 100644
--- a/examples/hello-world/main.cpp
+++ b/examples/hello-world/main.cpp
@@ -37,6 +37,7 @@
 #include "tools/platform/window.h"
 #include "slang-com-ptr.h"
 #include "source/core/slang-basic.h"
+#include "examples/example-base/example-base.h"
 
 using namespace gfx;
 using namespace Slang;
@@ -62,7 +63,7 @@ static const Vertex kVertexData[kVertexCount] =
 // The example application will be implemented as a `struct`, so that
 // we can scope the resources it allocates without using global variables.
 //
-struct HelloWorld
+struct HelloWorld : public WindowedAppBase
 {
 
 // Many Slang API functions return detailed diagnostic information
@@ -197,12 +198,6 @@ gfx::Result loadShaderProgram(
 // we have just defined.
 //
 
-// We will hard-code the size of our rendering window.
-//
-int gWindowWidth = 1024;
-int gWindowHeight = 768;
-const uint32_t kSwapchainImageCount = 2;
-
 // We will define global variables for the various platform and
 // graphics API objects that our application needs:
 //
@@ -210,16 +205,9 @@ const uint32_t kSwapchainImageCount = 2;
 // of them come from the utility library we are using to simplify
 // building an example program.
 //
-RefPtr<platform::Window> gWindow;
-Slang::ComPtr<gfx::IDevice>       gDevice;
-
 ComPtr<gfx::IPipelineState> gPipelineState;
 ComPtr<gfx::IShaderObject> gRootObject;
-ComPtr<gfx::ISwapchain> gSwapchain;
-List<ComPtr<gfx::IFramebuffer>> gFramebuffers;
 ComPtr<gfx::IBufferResource> gVertexBuffer;
-ComPtr<gfx::IRenderPassLayout> gRenderPass;
-ComPtr<gfx::ICommandQueue> gQueue;
 
 // Now that we've covered the function that actually loads and
 // compiles our Slang shade code, we can go through the rest
@@ -229,29 +217,9 @@ Slang::Result initialize()
 {
     // Create a window for our application to render into.
     //
-    platform::WindowDesc windowDesc;
-    windowDesc.title = "Hello, World!";
-    windowDesc.width = gWindowWidth;
-    windowDesc.height = gWindowHeight;
-    windowDesc.style = platform::WindowStyle::FixedSize;
-    gWindow = platform::Application::createWindow(windowDesc);
-    gWindow->events.mainLoop = [this]() { renderFrame(); };
-    // Initialize the rendering layer.
-    //
-    // Note: for now we are hard-coding logic to use the
-    // Direct3D11 back-end for the graphics API abstraction.
-    // A future version of this example may support multiple
-    // platforms/APIs.
-    //
-    IDevice::Desc deviceDesc = {};
-    gfx::Result res = gfxCreateDevice(&deviceDesc, gDevice.writeRef());
-    if(SLANG_FAILED(res)) return res;
-
-    ICommandQueue::Desc queueDesc = {};
-    queueDesc.type = ICommandQueue::QueueType::Graphics;
-    gQueue = gDevice->createCommandQueue(queueDesc);
-
-    // Now we will create objects needed to configur the "input assembler"
+    initializeBase("hello-world", 1024, 768);
+
+    // We will create objects needed to configur the "input assembler"
     // (IA) stage of the D3D pipeline.
     //
     // First, we create an input layout:
@@ -315,95 +283,19 @@ Slang::Result initialize()
     SLANG_RETURN_ON_FAIL(gDevice->createRootShaderObject(shaderProgram, rootObject.writeRef()));
     gRootObject = rootObject;
 
-    // Create swapchain and framebuffers.
-    gfx::ISwapchain::Desc swapchainDesc = {};
-    swapchainDesc.format = gfx::Format::RGBA_Unorm_UInt8;
-    swapchainDesc.width = gWindowWidth;
-    swapchainDesc.height = gWindowHeight;
-    swapchainDesc.imageCount = kSwapchainImageCount;
-    swapchainDesc.queue = gQueue;
-    gfx::WindowHandle windowHandle = gWindow->getNativeHandle().convert<gfx::WindowHandle>();
-    gSwapchain = gDevice->createSwapchain(swapchainDesc, windowHandle);
-
-    IFramebufferLayout::AttachmentLayout renderTargetLayout = {gSwapchain->getDesc().format, 1};
-    IFramebufferLayout::AttachmentLayout depthLayout = {gfx::Format::D_Float32, 1};
-    IFramebufferLayout::Desc framebufferLayoutDesc;
-    framebufferLayoutDesc.renderTargetCount = 1;
-    framebufferLayoutDesc.renderTargets = &renderTargetLayout;
-    framebufferLayoutDesc.depthStencil = &depthLayout;
-    ComPtr<IFramebufferLayout> framebufferLayout;
-    SLANG_RETURN_ON_FAIL(
-        gDevice->createFramebufferLayout(framebufferLayoutDesc, framebufferLayout.writeRef()));
-
-    for (uint32_t i = 0; i < kSwapchainImageCount; i++)
-    {
-        gfx::ITextureResource::Desc depthBufferDesc = {};
-        depthBufferDesc.setDefaults(gfx::IResource::Usage::DepthWrite);
-        depthBufferDesc.init2D(
-            gfx::IResource::Type::Texture2D,
-            gfx::Format::D_Float32,
-            gSwapchain->getDesc().width,
-            gSwapchain->getDesc().height,
-            0);
-        
-        ComPtr<gfx::ITextureResource> depthBufferResource = gDevice->createTextureResource(
-            gfx::IResource::Usage::DepthWrite, depthBufferDesc, nullptr);
-        ComPtr<gfx::ITextureResource> colorBuffer;
-        gSwapchain->getImage(i, colorBuffer.writeRef());
-
-        gfx::IResourceView::Desc colorBufferViewDesc = {};
-        colorBufferViewDesc.format = gSwapchain->getDesc().format;
-        colorBufferViewDesc.renderTarget.shape = gfx::IResource::Type::Texture2D;
-        colorBufferViewDesc.type = gfx::IResourceView::Type::RenderTarget;
-        ComPtr<gfx::IResourceView> rtv =
-            gDevice->createTextureView(colorBuffer.get(), colorBufferViewDesc);
-
-        gfx::IResourceView::Desc depthBufferViewDesc = {};
-        depthBufferViewDesc.format = gfx::Format::D_Float32;
-        depthBufferViewDesc.renderTarget.shape = gfx::IResource::Type::Texture2D;
-        depthBufferViewDesc.type = gfx::IResourceView::Type::DepthStencil;
-        ComPtr<gfx::IResourceView> dsv =
-            gDevice->createTextureView(depthBufferResource.get(), depthBufferViewDesc);
-
-        gfx::IFramebuffer::Desc framebufferDesc = {};
-        framebufferDesc.renderTargetCount = 1;
-        framebufferDesc.depthStencilView = dsv.get();
-        framebufferDesc.renderTargetViews = rtv.readRef();
-        framebufferDesc.layout = framebufferLayout;
-        ComPtr<gfx::IFramebuffer> frameBuffer = gDevice->createFramebuffer(framebufferDesc);
-        gFramebuffers.add(frameBuffer);
-    }
-
     // Following the D3D12/Vulkan style of API, we need a pipeline state object
     // (PSO) to encapsulate the configuration of the overall graphics pipeline.
     //
     GraphicsPipelineStateDesc desc;
     desc.inputLayout = inputLayout;
     desc.program = shaderProgram;
-    desc.framebufferLayout = framebufferLayout;
+    desc.framebufferLayout = gFramebufferLayout;
     auto pipelineState = gDevice->createGraphicsPipelineState(desc);
     if (!pipelineState)
         return SLANG_FAIL;
 
     gPipelineState = pipelineState;
 
-    gfx::IRenderPassLayout::Desc renderPassDesc = {};
-    renderPassDesc.framebufferLayout = framebufferLayout;
-    renderPassDesc.renderTargetCount = 1;
-    IRenderPassLayout::AttachmentAccessDesc renderTargetAccess = {};
-    IRenderPassLayout::AttachmentAccessDesc depthStencilAccess = {};
-    renderTargetAccess.loadOp = IRenderPassLayout::AttachmentLoadOp::Clear;
-    renderTargetAccess.storeOp = IRenderPassLayout::AttachmentStoreOp::Store;
-    renderTargetAccess.initialState = ResourceState::Undefined;
-    renderTargetAccess.finalState = ResourceState::Present;
-    depthStencilAccess.loadOp = IRenderPassLayout::AttachmentLoadOp::Clear;
-    depthStencilAccess.storeOp = IRenderPassLayout::AttachmentStoreOp::Store;
-    depthStencilAccess.initialState = ResourceState::Undefined;
-    depthStencilAccess.finalState = ResourceState::DepthWrite;
-    renderPassDesc.renderTargetAccess = &renderTargetAccess;
-    renderPassDesc.depthStencilAccess = &depthStencilAccess;
-    gRenderPass = gDevice->createRenderPassLayout(renderPassDesc);
-
     return SLANG_OK;
 }
 
@@ -412,17 +304,15 @@ Slang::Result initialize()
 // nothing really Slang-specific here, so the commentary doesn't need
 // to be very detailed.
 //
-void renderFrame()
+virtual void renderFrame(int frameBufferIndex) override
 {
-    uint32_t frameBufferIndex = gSwapchain->acquireNextImage();
-
-    ComPtr<ICommandBuffer> commandBuffer = gQueue->createCommandBuffer();
+    ComPtr<ICommandBuffer> commandBuffer = gTransientHeaps[frameBufferIndex]->createCommandBuffer();
     auto renderEncoder = commandBuffer->encodeRenderCommands(gRenderPass, gFramebuffers[frameBufferIndex]);
 
     gfx::Viewport viewport = {};
     viewport.maxZ = 1.0f;
-    viewport.extentX = (float)gWindowWidth;
-    viewport.extentY = (float)gWindowHeight;
+    viewport.extentX = (float)windowWidth;
+    viewport.extentY = (float)windowHeight;
     renderEncoder->setViewportAndScissor(viewport);
 
     // We will update the model-view-projection matrix that is passed
@@ -510,39 +400,8 @@ void renderFrame()
     gSwapchain->present();
 }
 
-void finalize()
-{
-    gQueue->wait();
-    gSwapchain = nullptr;
-}
-
 };
 
-// This "inner" main function is used by the platform abstraction
-// layer to deal with differences in how an entry point needs
-// to be defined for different platforms.
-//
-int innerMain()
-{
-    // We construct an instance of our example application
-    // `struct` type, and then walk through the lifecyle
-    // of the application.
-
-    HelloWorld app;
-
-    if (SLANG_FAILED(app.initialize()))
-    {
-        return -1;
-    }
-
-    platform::Application::run(app.gWindow);
-
-    app.finalize();
-
-    return 0;
-}
-
 // This macro instantiates an appropriate main function to
-// invoke the `innerMain` above.
-//
-PLATFORM_UI_MAIN(innerMain)
+// run the application defined above.
+PLATFORM_UI_MAIN(innerMain<HelloWorld>)
diff --git a/examples/shader-object/main.cpp b/examples/shader-object/main.cpp
index aaafc010a..9329a5418 100644
--- a/examples/shader-object/main.cpp
+++ b/examples/shader-object/main.cpp
@@ -136,8 +136,15 @@ int main()
     // interacting with the graphics API.
     Slang::ComPtr<gfx::IDevice> device;
     IDevice::Desc deviceDesc = {};
+    deviceDesc.deviceType = DeviceType::Vulkan;
     SLANG_RETURN_ON_FAIL(gfxCreateDevice(&deviceDesc, device.writeRef()));
 
+    Slang::ComPtr<gfx::ITransientResourceHeap> transientHeap;
+    ITransientResourceHeap::Desc transientHeapDesc = {};
+    transientHeapDesc.constantBufferSize = 4096;
+    SLANG_RETURN_ON_FAIL(
+        device->createTransientResourceHeap(transientHeapDesc, transientHeap.writeRef()));
+
     // Now we can load the shader code.
     // A `gfx::IShaderProgram` object for use in the `gfx` layer.
     ComPtr<gfx::IShaderProgram> shaderProgram;
@@ -212,7 +219,8 @@ int main()
     {
         ICommandQueue::Desc queueDesc = {ICommandQueue::QueueType::Graphics};
         auto queue = device->createCommandQueue(queueDesc);
-        auto commandBuffer = queue->createCommandBuffer();
+
+        auto commandBuffer = transientHeap->createCommandBuffer();
         auto encoder = commandBuffer->encodeComputeCommands();
         encoder->setPipelineState(pipelineState);
         encoder->bindRootShaderObject(rootObject);
diff --git a/examples/shader-toy/main.cpp b/examples/shader-toy/main.cpp
index c4424b294..a142c3c15 100644
--- a/examples/shader-toy/main.cpp
+++ b/examples/shader-toy/main.cpp
@@ -23,6 +23,7 @@ using Slang::ComPtr;
 #include "tools/gfx-util/shader-cursor.h"
 #include "tools/platform/window.h"
 #include "tools/platform/performance-counter.h"
+#include "examples/example-base/example-base.h"
 #include "source/core/slang-basic.h"
 
 #include <chrono>
@@ -54,7 +55,7 @@ const FullScreenTriangle::Vertex FullScreenTriangle::kVertices[FullScreenTriangl
 // The application itself will be encapsulated in a C++ `struct` type
 // so that it can easily scope its state without use of global variables.
 //
-struct ShaderToyApp
+struct ShaderToyApp : public WindowedAppBase
 {
 
 // The uniform data used by the shader is defined here as a simple
@@ -284,48 +285,17 @@ Result loadShaderProgram(gfx::IDevice* device, ComPtr<gfx::IShaderProgram>& outS
     return SLANG_OK;
 }
 
-int gWindowWidth = 1024;
-int gWindowHeight = 768;
-static const uint32_t kSwapchainImageCount = 2;
-
-Slang::RefPtr<platform::Window> gWindow;
-Slang::ComPtr<gfx::IDevice> gDevice;
 ComPtr<IShaderProgram> gShaderProgram;
 ComPtr<gfx::IShaderObject> gRootObject[kSwapchainImageCount];
-ComPtr<gfx::IFramebufferLayout> gFramebufferLayout;
 ComPtr<gfx::IPipelineState> gPipelineState;
 ComPtr<gfx::IBufferResource> gVertexBuffer;
-ComPtr<gfx::ISwapchain> gSwapchain;
-Slang::List<ComPtr<gfx::IFramebuffer>> gFramebuffers;
-ComPtr<gfx::IRenderPassLayout> gRenderPass;
-ComPtr<gfx::ICommandQueue> gQueue;
 
 Result initialize()
 {
-    platform::WindowDesc windowDesc;
-    const char* title = "Slang Shader Toy";
-    windowDesc.title = title;
-    windowDesc.width = gWindowWidth;
-    windowDesc.height = gWindowHeight;
-    gWindow = platform::Application::createWindow(windowDesc);
-    gWindow->events.mainLoop = [this]() { renderFrame(); };
+    initializeBase("Shader Toy", 1024, 768);
     gWindow->events.mouseMove = [this](const platform::MouseEventArgs& e) { handleEvent(e); };
     gWindow->events.mouseUp = [this](const platform::MouseEventArgs& e) { handleEvent(e); };
     gWindow->events.mouseDown = [this](const platform::MouseEventArgs& e) { handleEvent(e); };
-    gWindow->events.sizeChanged = Slang::Action<>(this, &ShaderToyApp::windowSizeChanged);
-
-    IDevice::Desc deviceDesc;
-    Result res = gfxCreateDevice(&deviceDesc, gDevice.writeRef());
-    if(SLANG_FAILED(res)) return res;
-
-    auto deviceInfo = gDevice->getDeviceInfo();
-    Slang::StringBuilder titleSb;
-    titleSb << title << " (" << deviceInfo.apiName << ": " << deviceInfo.adapterName << ")";
-    gWindow->setText(titleSb.getBuffer());
-
-    ICommandQueue::Desc queueDesc = {};
-    queueDesc.type = ICommandQueue::QueueType::Graphics;
-    gQueue = gDevice->createCommandQueue(queueDesc);
 
     InputElementDesc inputElements[] = {
         { "POSITION", 0, Format::RG_Float32, offsetof(FullScreenTriangle::Vertex, position) },
@@ -346,26 +316,6 @@ Result initialize()
 
     SLANG_RETURN_ON_FAIL(loadShaderProgram(gDevice, gShaderProgram));
 
-    // Create swapchain and framebuffers.
-    gfx::ISwapchain::Desc swapchainDesc = {};
-    swapchainDesc.format = gfx::Format::RGBA_Unorm_UInt8;
-    swapchainDesc.width = gWindowWidth;
-    swapchainDesc.height = gWindowHeight;
-    swapchainDesc.imageCount = kSwapchainImageCount;
-    swapchainDesc.queue = gQueue;
-    gSwapchain = gDevice->createSwapchain(swapchainDesc, gWindow->getNativeHandle().convert<gfx::WindowHandle>());
-
-    IFramebufferLayout::AttachmentLayout renderTargetLayout = {gSwapchain->getDesc().format, 1};
-    IFramebufferLayout::AttachmentLayout depthLayout = {gfx::Format::D_Float32, 1};
-    IFramebufferLayout::Desc framebufferLayoutDesc;
-    framebufferLayoutDesc.renderTargetCount = 1;
-    framebufferLayoutDesc.renderTargets = &renderTargetLayout;
-    framebufferLayoutDesc.depthStencil = &depthLayout;
-    SLANG_RETURN_ON_FAIL(
-        gDevice->createFramebufferLayout(framebufferLayoutDesc, gFramebufferLayout.writeRef()));
-
-    createSwapchainFramebuffers();
-
     // Create pipeline.
     GraphicsPipelineStateDesc desc;
     desc.inputLayout = inputLayout;
@@ -377,23 +327,6 @@ Result initialize()
 
     gPipelineState = pipelineState;
 
-    // Create render pass.
-    gfx::IRenderPassLayout::Desc renderPassDesc = {};
-    renderPassDesc.framebufferLayout = gFramebufferLayout;
-    renderPassDesc.renderTargetCount = 1;
-    IRenderPassLayout::AttachmentAccessDesc renderTargetAccess = {};
-    IRenderPassLayout::AttachmentAccessDesc depthStencilAccess = {};
-    renderTargetAccess.loadOp = IRenderPassLayout::AttachmentLoadOp::Clear;
-    renderTargetAccess.storeOp = IRenderPassLayout::AttachmentStoreOp::Store;
-    renderTargetAccess.initialState = ResourceState::Undefined;
-    renderTargetAccess.finalState = ResourceState::Present;
-    depthStencilAccess.loadOp = IRenderPassLayout::AttachmentLoadOp::Clear;
-    depthStencilAccess.storeOp = IRenderPassLayout::AttachmentStoreOp::Store;
-    depthStencilAccess.initialState = ResourceState::Undefined;
-    depthStencilAccess.finalState = ResourceState::DepthWrite;
-    renderPassDesc.renderTargetAccess = &renderTargetAccess;
-    renderPassDesc.depthStencilAccess = &depthStencilAccess;
-    gRenderPass = gDevice->createRenderPassLayout(renderPassDesc);
     return SLANG_OK;
 }
 
@@ -407,13 +340,9 @@ float clickMouseY = 0.0f;
 bool firstTime = true;
 platform::TimePoint startTime;
 
-void renderFrame()
+virtual void renderFrame(int frameIndex) override
 {
-    auto frameIndex = gSwapchain->acquireNextImage();
-    if (frameIndex == -1)
-        return;
-
-    auto commandBuffer = gQueue->createCommandBuffer();
+    auto commandBuffer = gTransientHeaps[frameIndex]->createCommandBuffer();
     if( firstTime )
     {
         startTime = platform::PerformanceCounter::now();
@@ -438,8 +367,8 @@ void renderFrame()
         uniforms.iMouse[2] = isMouseDown ? clickMouseX : -clickMouseX;
         uniforms.iMouse[3] = isMouseClick ? clickMouseY : -clickMouseY;
         uniforms.iTime = platform::PerformanceCounter::getElapsedTimeInSeconds(startTime);
-        uniforms.iResolution[0] = float(gWindowWidth);
-        uniforms.iResolution[1] = float(gWindowHeight);
+        uniforms.iResolution[0] = float(windowWidth);
+        uniforms.iResolution[1] = float(windowHeight);
 
     }
     gRootObject[frameIndex] = gDevice->createRootShaderObject(gShaderProgram);
@@ -451,8 +380,8 @@ void renderFrame()
 
     gfx::Viewport viewport = {};
     viewport.maxZ = 1.0f;
-    viewport.extentX = (float)gWindowWidth;
-    viewport.extentY = (float)gWindowHeight;
+    viewport.extentX = (float)windowWidth;
+    viewport.extentY = (float)windowHeight;
     encoder->setViewportAndScissor(viewport);
     encoder->setPipelineState(gPipelineState);
     encoder->bindRootShaderObject(gRootObject[frameIndex]);
@@ -466,101 +395,14 @@ void renderFrame()
     gSwapchain->present();
 }
 
-void finalize()
-{
-    gQueue->wait();
-}
-
 void handleEvent(const platform::MouseEventArgs& event)
 {
     isMouseDown = ((int)event.buttons & (int)platform::ButtonState::Enum::LeftButton) != 0;
     lastMouseX = (float)event.x;
     lastMouseY = (float)event.y;
 }
-
-void createSwapchainFramebuffers()
-{
-    gFramebuffers.clear();
-    for (uint32_t i = 0; i < kSwapchainImageCount; i++)
-    {
-        gfx::ITextureResource::Desc depthBufferDesc;
-        depthBufferDesc.setDefaults(gfx::IResource::Usage::DepthWrite);
-        depthBufferDesc.init2D(
-            gfx::IResource::Type::Texture2D,
-            gfx::Format::D_Float32,
-            gSwapchain->getDesc().width,
-            gSwapchain->getDesc().height,
-            0);
-
-        ComPtr<gfx::ITextureResource> depthBufferResource = gDevice->createTextureResource(
-            gfx::IResource::Usage::DepthWrite, depthBufferDesc, nullptr);
-        ComPtr<gfx::ITextureResource> colorBuffer;
-        gSwapchain->getImage(i, colorBuffer.writeRef());
-
-        gfx::IResourceView::Desc colorBufferViewDesc;
-        memset(&colorBufferViewDesc, 0, sizeof(colorBufferViewDesc));
-        colorBufferViewDesc.format = gSwapchain->getDesc().format;
-        colorBufferViewDesc.renderTarget.shape = gfx::IResource::Type::Texture2D;
-        colorBufferViewDesc.type = gfx::IResourceView::Type::RenderTarget;
-        ComPtr<gfx::IResourceView> rtv =
-            gDevice->createTextureView(colorBuffer.get(), colorBufferViewDesc);
-
-        gfx::IResourceView::Desc depthBufferViewDesc;
-        memset(&depthBufferViewDesc, 0, sizeof(depthBufferViewDesc));
-        depthBufferViewDesc.format = gfx::Format::D_Float32;
-        depthBufferViewDesc.renderTarget.shape = gfx::IResource::Type::Texture2D;
-        depthBufferViewDesc.type = gfx::IResourceView::Type::DepthStencil;
-        ComPtr<gfx::IResourceView> dsv =
-            gDevice->createTextureView(depthBufferResource.get(), depthBufferViewDesc);
-
-        gfx::IFramebuffer::Desc framebufferDesc;
-        framebufferDesc.renderTargetCount = 1;
-        framebufferDesc.depthStencilView = dsv.get();
-        framebufferDesc.renderTargetViews = rtv.readRef();
-        framebufferDesc.layout = gFramebufferLayout;
-        ComPtr<gfx::IFramebuffer> frameBuffer = gDevice->createFramebuffer(framebufferDesc);
-        gFramebuffers.add(frameBuffer);
-    }
-}
-
-void windowSizeChanged()
-{
-    // Wait for the GPU to finish.
-    gQueue->wait();
-
-    auto clientRect = gWindow->getClientRect();
-    if (clientRect.width > 0 && clientRect.height > 0)
-    {
-        // Free all framebuffers before resizing swapchain.
-        gFramebuffers = decltype(gFramebuffers)();
-
-        // Resize swapchain.
-        if (gSwapchain->resize(clientRect.width, clientRect.height) == SLANG_OK)
-        {
-            // Recreate framebuffers for each swapchain back buffer image.
-            createSwapchainFramebuffers();
-            gWindowWidth = clientRect.width;
-            gWindowHeight = clientRect.height;
-        }
-    }
-}
-
 };
 
-int innerMain()
-{
-    ShaderToyApp app;
-
-    if (SLANG_FAILED(app.initialize()))
-    {
-        return -1;
-    }
-
-    platform::Application::run(app.gWindow);
-
-    app.finalize();
-
-    return 0;
-}
-
-PLATFORM_UI_MAIN(innerMain)
+// This macro instantiates an appropriate main function to
+// run the application defined above.
+PLATFORM_UI_MAIN(innerMain<ShaderToyApp>)