Refactor `gfx` to surface `CommandBuffer` interface. (#1735)

* Refactor `gfx` to surface `CommandBuffer` interface.

* Fixes.

* Fix code review issues, and make vulkan runnable on devices without VK_EXT_extended_dynamic_states.

* Update solution files

* Move out-of-date examples to examples/experimental

Co-authored-by: Yong He <yhe@nvidia.com>

13 files changed, 163 insertions, 135 deletions

diff --git a/examples/heterogeneous-hello-world/README.md b/examples/experimental/heterogeneous-hello-world/README.md
index 709652922..709652922 100644
--- a/examples/heterogeneous-hello-world/README.md
+++ b/examples/experimental/heterogeneous-hello-world/README.md
diff --git a/examples/heterogeneous-hello-world/main.cpp b/examples/experimental/heterogeneous-hello-world/main.cpp
index 010434bfa..372fcd615 100644
--- a/examples/heterogeneous-hello-world/main.cpp
+++ b/examples/experimental/heterogeneous-hello-world/main.cpp
@@ -1,3 +1,9 @@
+// This example is out of date and currently disabled from build.
+// The `gfx` layer has been refactored with a new command list based
+// model. The example must be updated to use the new `gfx` interface
+// before it can be included in build.
+
+#if 0
 // main.cpp
 
 // This file implements an extremely simple example of loading and
@@ -236,7 +242,7 @@ void printInitialValues(float* initialArray, int length)
 }
 
 void dispatchComputation(
-    gfx::IRenderer* gRenderer,
+    gfx::ICommandQueue* gQueue,
     gfx::IPipelineState* gPipelineState,
     gfx::IPipelineLayout* gPipelineLayout,
     gfx::IDescriptorSet* gDescriptorSet,
@@ -244,11 +250,13 @@ void dispatchComputation(
     unsigned int gridDimsY,
     unsigned int gridDimsZ)
 {
-
-    gRenderer->setPipelineState(gPipelineState);
-    gRenderer->setDescriptorSet(PipelineType::Compute, gPipelineLayout, 0, gDescriptorSet);
-
-    gRenderer->dispatchCompute(gridDimsX, gridDimsY, gridDimsZ);
+    auto cmdBuf = gQueue->createCommandBuffer();
+    auto encoder = cmdBuf->encodeComputeCommands();
+    encoder->setPipelineState(gPipelineState);
+    encoder->setDescriptorSet(PipelineType::Compute, gPipelineLayout, 0, gDescriptorSet);
+    encoder->dispatchCompute(gridDimsX, gridDimsY, gridDimsZ);
+    encoder->endEncoding();
+    gQueue->executeCommandBuffer(cmdBuf);
 }
 
 void print_output(
@@ -256,7 +264,9 @@ void print_output(
     gfx::IBufferResource* structuredBuffer,
     int length)
 {
-    if (float* outputData = (float*)renderer->map(structuredBuffer, MapFlavor::HostRead))
+    ComPtr<ISlangBlob> blob;
+    renderer->readBufferResource(structuredBuffer, 0, length * sizeof(float), blob.writeRef());
+    if (float* outputData = (float*)blob->getBufferPointer())
     {
         // Print out the values the the kernel produced
         printf("After: \n");
@@ -265,8 +275,6 @@ void print_output(
             printf("%f, ", outputData[i]);
         }
         printf("\n");
-
-        renderer->unmap(structuredBuffer);
     }
 }
 
@@ -321,10 +329,10 @@ void printInitialValues_0(FixedArray<float, 4> _0, int32_t _1)
     printInitialValues((float*)&_0, _1);
 }
 
-void dispatchComputation_0(gfx_Renderer_0* _0, gfx_PipelineState_0* _1, gfx_PipelineLayout_0* _2, gfx_DescriptorSet_0* _3, unsigned int gridDimsX, unsigned int gridDimsY, unsigned int gridDimsZ)
+void dispatchComputation_0(gfx_CommandQueue_0* _0, gfx_PipelineState_0* _1, gfx_PipelineLayout_0* _2, gfx_DescriptorSet_0* _3, unsigned int gridDimsX, unsigned int gridDimsY, unsigned int gridDimsZ)
 {
     dispatchComputation(
-        (gfx::IRenderer*)_0,
+        (gfx::ICommandQueue*)_0,
         (gfx::IPipelineState*)_1,
         (gfx::IPipelineLayout*)_2,
         (gfx::IDescriptorSet*)_3,
@@ -343,9 +351,9 @@ gfx_BufferResource_0* unconvertBuffer_0(RWStructuredBuffer<float> _0) {
     return (gfx_BufferResource_0*)(_0.data);
 }
 
-void print_output_0(gfx_Renderer_0* _0, gfx_BufferResource_0* _1, int32_t _2)
+void print_output_0(gfx_CommandQueue_0* _0, gfx_BufferResource_0* _1, int32_t _2)
 {
-    print_output((gfx::IRenderer*)_0, (gfx::IBufferResource*)_1, _2);
+    print_output((gfx::ICommandQueue*)_0, (gfx::IBufferResource*)_1, _2);
 }
 
 // This "inner" main function is used by the platform abstraction
@@ -368,3 +376,5 @@ void innerMain(ApplicationContext* context)
 // invoke the `innerMain` above.
 //
 GFX_CONSOLE_MAIN(innerMain)
+
+#endif
diff --git a/examples/heterogeneous-hello-world/shader.cpp b/examples/experimental/heterogeneous-hello-world/shader.cpp
index 640e8aa3c..5a8dd7815 100644
--- a/examples/heterogeneous-hello-world/shader.cpp
+++ b/examples/experimental/heterogeneous-hello-world/shader.cpp
@@ -1,3 +1,4 @@
+#if 0
 #include "../../prelude/slang-cpp-prelude.h"
 
 
@@ -140,6 +141,7 @@ bool executeComputation_0()
 
     gfx_Window_0* _S9 = createWindow_0(int(1024), int(768));
     gfx_Renderer_0* _S10 = createRenderer_0(int(1024), int(768), _S9);
+    gfx_CommandQueue_0* _
     gfx_BufferResource_0* _S11 = createStructuredBuffer_0(_S10, initialArray_0);
     Vector<uint32_t, 3> _S12 = make_VecU3(uint32_t(int(4)), uint32_t(int(1)), uint32_t(int(1)));
     RWStructuredBuffer<float> _S13 = convertBuffer_0(_S11);
@@ -192,3 +194,4 @@ void computeMain(ComputeVaryingInput* varyingInput, void* entryPointParams, void
         }
     }
 }
+#endif
diff --git a/examples/heterogeneous-hello-world/shader.slang b/examples/experimental/heterogeneous-hello-world/shader.slang
index 47c883b39..47c883b39 100644
--- a/examples/heterogeneous-hello-world/shader.slang
+++ b/examples/experimental/heterogeneous-hello-world/shader.slang
diff --git a/examples/model-viewer/README.md b/examples/experimental/model-viewer/README.md
index a350a48a2..a350a48a2 100644
--- a/examples/model-viewer/README.md
+++ b/examples/experimental/model-viewer/README.md
diff --git a/examples/model-viewer/cube.mtl b/examples/experimental/model-viewer/cube.mtl
index 6c8eeb10b..6c8eeb10b 100644
--- a/examples/model-viewer/cube.mtl
+++ b/examples/experimental/model-viewer/cube.mtl
diff --git a/examples/model-viewer/main.cpp b/examples/experimental/model-viewer/main.cpp
index c9693e529..d4bc21776 100644
--- a/examples/model-viewer/main.cpp
+++ b/examples/experimental/model-viewer/main.cpp
@@ -1,3 +1,9 @@
+// This example is out of date and currently disabled from build.
+// The `gfx` layer has been refactored with a new shader-object model
+// that will greatly simplify shader binding and specialization.
+// This example should be updated to use the shader-object API in `gfx`.
+
+#if 0
 // main.cpp
 
 //
@@ -2214,7 +2220,6 @@ Result initialize()
 //
 void renderFrame()
 {
-    gRenderer->beginFrame();
     gui->beginFrame();
 
     // In order to see that things are rendering properly we need some
@@ -2402,10 +2407,6 @@ void renderFrame()
 
     ImGui::End();
 
-    gui->endFrame();
-
-    gRenderer->makeSwapchainImagePresentable(gSwapchain);
-    gRenderer->endFrame();
     gSwapchain->present();
 
 }
@@ -2441,3 +2442,5 @@ void innerMain(ApplicationContext* context)
     app.finalize();
 }
 GFX_UI_MAIN(innerMain)
+
+#endif
diff --git a/examples/model-viewer/shaders.slang b/examples/experimental/model-viewer/shaders.slang
index 15ce0120d..15ce0120d 100644
--- a/examples/model-viewer/shaders.slang
+++ b/examples/experimental/model-viewer/shaders.slang
diff --git a/examples/gpu-printing/main.cpp b/examples/gpu-printing/main.cpp
index 4f79147f6..63eb31a82 100644
--- a/examples/gpu-printing/main.cpp
+++ b/examples/gpu-printing/main.cpp
@@ -175,19 +175,26 @@ Result execute()
     printBufferViewDesc.type = IResourceView::Type::UnorderedAccess;
     auto printBufferView = gRenderer->createBufferView(printBuffer, printBufferViewDesc);
 
+    ICommandQueue::Desc queueDesc = {ICommandQueue::QueueType::Graphics};
+    auto queue = gRenderer->createCommandQueue(queueDesc);
+    auto commandBuffer = queue->createCommandBuffer();
+    auto encoder = commandBuffer->encodeComputeCommands();
     // TODO: need to copy a zero into the start of the print buffer!
 
     gDescriptorSet->setResource(0, 0, printBufferView);
-    gRenderer->setDescriptorSet(PipelineType::Compute, gPipelineLayout, 0, gDescriptorSet);
-
-    gRenderer->setPipelineState(gPipelineState);
-    gRenderer->dispatchCompute(1, 1, 1);
+    encoder->setDescriptorSet(gPipelineLayout, 0, gDescriptorSet);
 
+    encoder->setPipelineState(gPipelineState);
+    encoder->dispatchCompute(1, 1, 1);
+    encoder->endEncoding();
+    commandBuffer->close();
+    queue->executeCommandBuffer(commandBuffer);
     // TODO: need to copy from the print buffer to a staging buffer...
 
-    auto printBufferData = (uint32_t*) gRenderer->map(printBuffer, MapFlavor::HostRead);
+    ComPtr<ISlangBlob> blob;
+    gRenderer->readBufferResource(printBuffer, 0, printBufferSize, blob.writeRef());
 
-    gGPUPrinting.processGPUPrintCommands(printBufferData, printBufferSize);
+    gGPUPrinting.processGPUPrintCommands(blob->getBufferPointer(), printBufferSize);
 
     return SLANG_OK;
 }
diff --git a/examples/hello-world/main.cpp b/examples/hello-world/main.cpp
index f0ea3eb2a..47016b48d 100644
--- a/examples/hello-world/main.cpp
+++ b/examples/hello-world/main.cpp
@@ -219,6 +219,8 @@ 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
@@ -246,6 +248,10 @@ Slang::Result initialize()
     gfx::Result res = gfxCreateRenderer(&rendererDesc, gRenderer.writeRef());
     if(SLANG_FAILED(res)) return res;
 
+    ICommandQueue::Desc queueDesc = {};
+    queueDesc.type = ICommandQueue::QueueType::Graphics;
+    gQueue = gRenderer->createCommandQueue(queueDesc);
+
     // Now we will create objects needed to configur the "input assembler"
     // (IA) stage of the D3D pipeline.
     //
@@ -316,6 +322,7 @@ Slang::Result initialize()
     swapchainDesc.width = gWindowWidth;
     swapchainDesc.height = gWindowHeight;
     swapchainDesc.imageCount = kSwapchainImageCount;
+    swapchainDesc.queue = gQueue;
     gSwapchain = gRenderer->createSwapchain(
         swapchainDesc, gfx::WindowHandle::FromHwnd(getPlatformWindowHandle(gWindow)));
 
@@ -331,7 +338,7 @@ Slang::Result initialize()
 
     for (uint32_t i = 0; i < kSwapchainImageCount; i++)
     {
-        gfx::ITextureResource::Desc depthBufferDesc;
+        gfx::ITextureResource::Desc depthBufferDesc = {};
         depthBufferDesc.setDefaults(gfx::IResource::Usage::DepthWrite);
         depthBufferDesc.init2D(
             gfx::IResource::Type::Texture2D,
@@ -345,23 +352,21 @@ Slang::Result initialize()
         ComPtr<gfx::ITextureResource> colorBuffer;
         gSwapchain->getImage(i, colorBuffer.writeRef());
 
-        gfx::IResourceView::Desc colorBufferViewDesc;
-        memset(&colorBufferViewDesc, 0, sizeof(colorBufferViewDesc));
+        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 =
             gRenderer->createTextureView(colorBuffer.get(), colorBufferViewDesc);
 
-        gfx::IResourceView::Desc depthBufferViewDesc;
-        memset(&depthBufferViewDesc, 0, sizeof(depthBufferViewDesc));
+        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 =
             gRenderer->createTextureView(depthBufferResource.get(), depthBufferViewDesc);
 
-        gfx::IFramebuffer::Desc framebufferDesc;
+        gfx::IFramebuffer::Desc framebufferDesc = {};
         framebufferDesc.renderTargetCount = 1;
         framebufferDesc.depthStencilView = dsv.get();
         framebufferDesc.renderTargetViews = rtv.readRef();
@@ -383,6 +388,23 @@ Slang::Result initialize()
 
     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 = gRenderer->createRenderPassLayout(renderPassDesc);
+
     // Once we've initialized all the graphics API objects,
     // it is time to show our application window and start rendering.
     //
@@ -398,22 +420,16 @@ Slang::Result initialize()
 //
 void renderFrame()
 {
-    gRenderer->beginFrame();
     uint32_t frameBufferIndex = gSwapchain->acquireNextImage();
-    gRenderer->setFramebuffer(gFramebuffers[frameBufferIndex]);
+
+    ComPtr<ICommandBuffer> commandBuffer = gQueue->createCommandBuffer();
+    auto renderEncoder = commandBuffer->encodeRenderCommands(gRenderPass, gFramebuffers[frameBufferIndex]);
 
     gfx::Viewport viewport = {};
     viewport.maxZ = 1.0f;
     viewport.extentX = (float)gWindowWidth;
     viewport.extentY = (float)gWindowHeight;
-    gRenderer->setViewportAndScissor(viewport);
-
-
-    // We start by clearing our framebuffer, which only has a color target.
-    //
-    static const float kClearColor[] = { 0.25, 0.25, 0.25, 1.0 };
-    gRenderer->setClearColor(kClearColor);
-    gRenderer->clearFrame();
+    renderEncoder->setViewportAndScissor(viewport);
 
     // We will update the model-view-projection matrix that is passed
     // into the shader code via the `Uniforms` buffer on a per-frame
@@ -485,31 +501,31 @@ void renderFrame()
     // PSO, binding our root shader object to it (which references
     // the `Uniforms` buffer that will filled in above).
     //
-    gRenderer->setPipelineState(gPipelineState);
-    gRenderer->bindRootShaderObject(PipelineType::Graphics, gRootObject);
+    renderEncoder->setPipelineState(gPipelineState);
+    renderEncoder->bindRootShaderObject(gRootObject);
 
     // We also need to set up a few pieces of fixed-function pipeline
     // state that are not bound by the pipeline state above.
     //
-    gRenderer->setVertexBuffer(0, gVertexBuffer, sizeof(Vertex));
-    gRenderer->setPrimitiveTopology(PrimitiveTopology::TriangleList);
+    renderEncoder->setVertexBuffer(0, gVertexBuffer, sizeof(Vertex));
+    renderEncoder->setPrimitiveTopology(PrimitiveTopology::TriangleList);
 
     // Finally, we are ready to issue a draw call for a single triangle.
     //
-    gRenderer->draw(3);
+    renderEncoder->draw(3);
+    renderEncoder->endEncoding();
+    commandBuffer->close();
+    gQueue->executeCommandBuffer(commandBuffer);
 
     // With that, we are done drawing for one frame, and ready for the next.
     //
-    gRenderer->makeSwapchainImagePresentable(gSwapchain);
-
-    gRenderer->endFrame();
-
     gSwapchain->present();
 }
 
 void finalize()
 {
-    gRenderer->waitForGpu();
+    gQueue->wait();
+    gSwapchain = nullptr;
     destroyWindow(gWindow);
 }
 
diff --git a/examples/model-viewer/cube.obj b/examples/model-viewer/cube.obj
deleted file mode 100644
index 2f7de8a92..000000000
--- a/examples/model-viewer/cube.obj
+++ /dev/null
@@ -1,43 +0,0 @@
-mtllib cube.mtl
-o Cube
-v  1.000000 -1.000000 -1.000000
-v  1.000000 -1.000000  1.000000
-v -1.000000 -1.000000  1.000000
-v -1.000000 -1.000000 -1.000000
-v  1.000000  1.000000 -1.000000
-v  1.000000  1.000000  1.000000
-v -1.000000  1.000000  1.000000
-v -1.000000  1.000000 -1.000000
-vn  0.000000 -1.000000  0.000000
-vn  0.000000  1.000000  0.000000
-vn  1.000000  0.000000  0.000000
-vn  0.000000  0.000000  1.000000
-vn -1.000000  0.000000  0.000000
-vn  0.000000  0.000000 -1.000000
-
-v -10 -1 -10
-v  10 -1 -10
-v  10 -1  10
-v -10 -1  10
-vn 0 1 0
-
-usemtl Red
-s off
-f 2//3 6//3 5//3 1//3
-f 4//5 8//5 7//5 3//5
-
-usemtl Green
-s off
-f 4//1 3//1 2//1 1//1
-f 6//2 7//2 8//2 5//2
-
-usemtl Blue
-s off
-f 3//4 7//4 6//4 2//4
-f 8//6 4//6 1//6 5//6
-
-o Ground
-usemtl Ground
-s off
-f 9//7 10//7 11//7 12//7
-
diff --git a/examples/shader-object/main.cpp b/examples/shader-object/main.cpp
index 9b1b4de72..d368cd9aa 100644
--- a/examples/shader-object/main.cpp
+++ b/examples/shader-object/main.cpp
@@ -136,7 +136,7 @@ int main()
     // interacting with the graphics API.
     Slang::ComPtr<gfx::IRenderer> renderer;
     IRenderer::Desc rendererDesc = {};
-    rendererDesc.rendererType = RendererType::CUDA;
+    rendererDesc.rendererType = RendererType::DirectX11;
     SLANG_RETURN_ON_FAIL(gfxCreateRenderer(&rendererDesc, renderer.writeRef()));
 
     // Now we can load the shader code.
@@ -146,7 +146,7 @@ int main()
     slang::ProgramLayout* slangReflection;
     SLANG_RETURN_ON_FAIL(loadShaderProgram(renderer, shaderProgram, slangReflection));
 
-    // Create a pipelien state with the loaded shader.
+    // Create a pipeline state with the loaded shader.
     gfx::ComputePipelineStateDesc pipelineDesc = {};
     pipelineDesc.program = shaderProgram.get();
     ComPtr<gfx::IPipelineState> pipelineState;
@@ -211,17 +211,26 @@ int main()
 
     // We have set up all required parameters in entry-point object, now it is time
     // to bind the pipeline and root object and launch the kernel.
-    renderer->beginFrame();
-    renderer->setPipelineState(pipelineState);
-    SLANG_RETURN_ON_FAIL(renderer->bindRootShaderObject(gfx::PipelineType::Compute, rootObject));
-    renderer->dispatchCompute(1, 1, 1);
-    renderer->endFrame();
+    {
+        ICommandQueue::Desc queueDesc = {ICommandQueue::QueueType::Graphics};
+        auto queue = renderer->createCommandQueue(queueDesc);
+        auto commandBuffer = queue->createCommandBuffer();
+        auto encoder = commandBuffer->encodeComputeCommands();
+        encoder->setPipelineState(pipelineState);
+        encoder->bindRootShaderObject(rootObject);
+        encoder->dispatchCompute(1, 1, 1);
+        encoder->endEncoding();
+        commandBuffer->close();
+        queue->executeCommandBuffer(commandBuffer);
+        queue->wait();
+    }
     // Read back the results.
-    renderer->waitForGpu();
-    float* result = (float*)renderer->map(numbersBuffer, gfx::MapFlavor::HostRead);
+    ComPtr<ISlangBlob> resultBlob;
+    SLANG_RETURN_ON_FAIL(renderer->readBufferResource(
+        numbersBuffer, 0, numberCount * sizeof(float), resultBlob.writeRef()));
+    auto result = reinterpret_cast<const float*>(resultBlob->getBufferPointer());
     for (int i = 0; i < numberCount; i++)
         printf("%f\n", result[i]);
-    renderer->unmap(numbersBuffer);
 
     return SLANG_OK;
 }
diff --git a/examples/shader-toy/main.cpp b/examples/shader-toy/main.cpp
index 697bb1044..0d058fa2c 100644
--- a/examples/shader-toy/main.cpp
+++ b/examples/shader-toy/main.cpp
@@ -339,6 +339,8 @@ ComPtr<gfx::IDescriptorSet> gDescriptorSet;
 ComPtr<gfx::IBufferResource> gVertexBuffer;
 ComPtr<gfx::ISwapchain> gSwapchain;
 Slang::List<ComPtr<gfx::IFramebuffer>> gFramebuffers;
+ComPtr<gfx::IRenderPassLayout> gRenderPass;
+ComPtr<gfx::ICommandQueue> gQueue;
 
 Result initialize()
 {
@@ -355,6 +357,10 @@ Result initialize()
     Result res = gfxCreateRenderer(&rendererDesc, gRenderer.writeRef());
     if(SLANG_FAILED(res)) return res;
 
+    ICommandQueue::Desc queueDesc = {};
+    queueDesc.type = ICommandQueue::QueueType::Graphics;
+    gQueue = gRenderer->createCommandQueue(queueDesc);
+
     int constantBufferSize = sizeof(Uniforms);
 
     IBufferResource::Desc constantBufferDesc;
@@ -423,6 +429,7 @@ Result initialize()
     swapchainDesc.width = gWindowWidth;
     swapchainDesc.height = gWindowHeight;
     swapchainDesc.imageCount = kSwapchainImageCount;
+    swapchainDesc.queue = gQueue;
     gSwapchain = gRenderer->createSwapchain(
         swapchainDesc, gfx::WindowHandle::FromHwnd(getPlatformWindowHandle(gWindow)));
 
@@ -489,6 +496,24 @@ Result initialize()
 
     gPipelineState = pipelineState;
 
+    // Create render pass.
+    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 = gRenderer->createRenderPassLayout(renderPassDesc);
+
     showWindow(gWindow);
 
     return SLANG_OK;
@@ -506,26 +531,18 @@ uint64_t startTime = 0;
 
 void renderFrame()
 {
-    gRenderer->beginFrame();
     auto frameIndex = gSwapchain->acquireNextImage();
-    gRenderer->setFramebuffer(gFramebuffers[frameIndex]);
+    auto commandBuffer = gQueue->createCommandBuffer();
     if( firstTime )
     {
         startTime = getCurrentTime();
         firstTime = false;
     }
 
-    gfx::Viewport viewport = {};
-    viewport.maxZ = 1.0f;
-    viewport.extentX = (float)gWindowWidth;
-    viewport.extentY = (float)gWindowHeight;
-    gRenderer->setViewportAndScissor(viewport);
-
-    static const float kClearColor[] = { 0.25, 0.25, 0.25, 1.0 };
-    gRenderer->setClearColor(kClearColor);
-    gRenderer->clearFrame();
+    // Update uniform buffer.
+    auto uploadEncoder = commandBuffer->encodeResourceCommands();
 
-    if(Uniforms* uniforms = (Uniforms*) gRenderer->map(gConstantBuffer, MapFlavor::WriteDiscard))
+    Uniforms uniforms = {};
     {
         bool isMouseClick = isMouseDown && !wasMouseDown;
         wasMouseDown = isMouseDown;
@@ -536,35 +553,41 @@ void renderFrame()
             clickMouseY = lastMouseY;
         }
 
-        uniforms->iMouse[0] = lastMouseX;
-        uniforms->iMouse[1] = lastMouseY;
-        uniforms->iMouse[2] = isMouseDown ? clickMouseX : -clickMouseX;
-        uniforms->iMouse[3] = isMouseClick ? clickMouseY : -clickMouseY;
-        uniforms->iTime = float( double(getCurrentTime() - startTime) / double(getTimerFrequency()) );
-        uniforms->iResolution[0] = float(gWindowWidth);
-        uniforms->iResolution[1] = float(gWindowHeight);
+        uniforms.iMouse[0] = lastMouseX;
+        uniforms.iMouse[1] = lastMouseY;
+        uniforms.iMouse[2] = isMouseDown ? clickMouseX : -clickMouseX;
+        uniforms.iMouse[3] = isMouseClick ? clickMouseY : -clickMouseY;
+        uniforms.iTime = float( double(getCurrentTime() - startTime) / double(getTimerFrequency()) );
+        uniforms.iResolution[0] = float(gWindowWidth);
+        uniforms.iResolution[1] = float(gWindowHeight);
 
-        gRenderer->unmap(gConstantBuffer);
+        uploadEncoder->uploadBufferData(gConstantBuffer, 0, sizeof(Uniforms), &uniforms);
     }
+    uploadEncoder->endEncoding();
 
-    gRenderer->setPipelineState(gPipelineState);
-    gRenderer->setDescriptorSet(PipelineType::Graphics, gPipelineLayout, 0, gDescriptorSet);
-
-    gRenderer->setVertexBuffer(0, gVertexBuffer, sizeof(FullScreenTriangle::Vertex));
-    gRenderer->setPrimitiveTopology(PrimitiveTopology::TriangleList);
-
-    gRenderer->draw(3);
-
-    gRenderer->makeSwapchainImagePresentable(gSwapchain);
-
-    gRenderer->endFrame();
+    // Encode render commands.
+    auto encoder = commandBuffer->encodeRenderCommands(gRenderPass, gFramebuffers[frameIndex]);
 
+    gfx::Viewport viewport = {};
+    viewport.maxZ = 1.0f;
+    viewport.extentX = (float)gWindowWidth;
+    viewport.extentY = (float)gWindowHeight;
+    encoder->setViewportAndScissor(viewport);
+    encoder->setPipelineState(gPipelineState);
+    encoder->setDescriptorSet(gPipelineLayout, 0, gDescriptorSet);
+    encoder->setVertexBuffer(0, gVertexBuffer, sizeof(FullScreenTriangle::Vertex));
+    encoder->setPrimitiveTopology(PrimitiveTopology::TriangleList);
+    encoder->draw(3);
+    encoder->endEncoding();
+    commandBuffer->close();
+
+    gQueue->executeCommandBuffer(commandBuffer);
     gSwapchain->present();
 }
 
 void finalize()
 {
-    gRenderer->waitForGpu();
+    gQueue->wait();
     destroyWindow(gWindow);
 }