2 files changed, 485 insertions, 0 deletions

diff --git a/hello/CMakeLists.txt b/hello/CMakeLists.txt
new file mode 100644
index 0000000..3d059f0
--- /dev/null
+++ b/hello/CMakeLists.txt
@@ -0,0 +1,12 @@
+cmake_minimum_required(VERSION 3.20)
+
+project(hello)
+
+add_executable(hello
+    main.c)
+
+target_link_libraries(hello PRIVATE
+   app
+   dxg)
+
+install_agility_sdk(${CMAKE_CURRENT_BINARY_DIR})
diff --git a/hello/main.c b/hello/main.c
new file mode 100644
index 0000000..309a8c9
--- /dev/null
+++ b/hello/main.c
@@ -0,0 +1,473 @@
+#include <dxg/dxcommon.h>
+#include <dxwindow.h>
+
+#include <assert.h>
+#include <stdio.h>
+
+#define SWAP_CHAIN_BUFFER_COUNT 2 // Double-buffering.
+
+typedef struct D3DSettings
+{
+    int width;
+    int height;
+} D3DSettings;
+
+typedef struct D3D {
+    Window*     pWindow;
+    D3DSettings settings;
+
+    IDXGIFactory4* pDxgiFactory;
+    ID3D12Device*  pDevice;
+
+    ID3D12CommandQueue*        pCommandQueue;
+    ID3D12CommandAllocator*    pCommandAllocator;
+    ID3D12GraphicsCommandList* pCommandList;
+
+    IDXGISwapChain3* pSwapChain;
+
+    ID3D12DescriptorHeap* pRtvHeap;
+    ID3D12DescriptorHeap* pDsvHeap;
+
+    ID3D12Resource* pSwapChainBuffer[SWAP_CHAIN_BUFFER_COUNT];
+    ID3D12Resource* pDepthStencilBuffer;
+
+    ID3D12Fence* pFence;
+    HANDLE       fence_event;
+    UINT64       fence_value;
+
+    UINT rtv_descriptor_size;
+    UINT dsv_descriptor_size;
+    UINT cbv_descriptor_size;
+} D3D;
+
+static D3D12_CPU_DESCRIPTOR_HANDLE d3d_get_current_back_buffer_view(const D3D* d3d) {
+    assert(d3d);
+    assert(d3d->pSwapChain);
+    assert(d3d->pRtvHeap);
+    assert(d3d->rtv_descriptor_size > 0);
+    D3D12_CPU_DESCRIPTOR_HANDLE rtv_handle;
+    d3d->pRtvHeap->lpVtbl->GetCPUDescriptorHandleForHeapStart(d3d->pRtvHeap, &rtv_handle);
+    return CD3DX12_CPU_DESCRIPTOR_HANDLE(
+        rtv_handle,
+        d3d->pSwapChain->lpVtbl->GetCurrentBackBufferIndex(d3d->pSwapChain),
+        d3d->rtv_descriptor_size);
+}
+
+static ID3D12Resource* d3d_get_current_back_buffer(const D3D* d3d) {
+    assert(d3d);
+    assert(d3d->pSwapChain);
+    assert(d3d->pSwapChainBuffer);
+    return d3d->pSwapChainBuffer[d3d->pSwapChain->lpVtbl->GetCurrentBackBufferIndex(d3d->pSwapChain)];
+}
+
+static D3D12_CPU_DESCRIPTOR_HANDLE d3d_get_depth_stencil_view(D3D* d3d) {
+    assert(d3d);
+    assert(d3d->pDsvHeap);
+    D3D12_CPU_DESCRIPTOR_HANDLE handle;
+    d3d->pDsvHeap->lpVtbl->GetCPUDescriptorHandleForHeapStart(d3d->pDsvHeap, &handle);
+    return handle;
+}
+
+/// Creates the application's swap chain.
+///
+/// This method can be called multiple times to re-create the swap chain.
+static void d3d_create_swap_chain(D3D* d3d) {
+    assert(d3d);
+    assert(d3d->pDxgiFactory);
+    assert(d3d->pCommandQueue);
+    assert(d3d->pWindow);
+
+    SafeRelease(d3d->pSwapChain);
+
+    DXGI_SWAP_CHAIN_DESC1 desc = (DXGI_SWAP_CHAIN_DESC1){
+        .Width  = (UINT)(d3d->settings.width),
+        .Height = (UINT)(d3d->settings.height),
+        .Format = DXGI_FORMAT_R8G8B8A8_UNORM,
+        .SampleDesc = (DXGI_SAMPLE_DESC){
+            .Count   = 1,
+            .Quality = 0,
+        },
+        .BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT,
+        .BufferCount = SWAP_CHAIN_BUFFER_COUNT,
+        .SwapEffect  = DXGI_SWAP_EFFECT_FLIP_DISCARD,
+    };
+    IDXGISwapChain1* pSwapChain = 0;
+    TrapIfFailed(d3d->pDxgiFactory->lpVtbl->CreateSwapChainForHwnd(
+        d3d->pDxgiFactory,
+        (IUnknown*)d3d->pCommandQueue,  // Swap chain uses queue to perform flush.
+        window_handle(d3d->pWindow),
+        &desc,
+        /*pFullScreenDesc=*/0,  // Running in windowed mode.
+        /*pRestrictToOutput=*/0,
+        &pSwapChain));
+    //TrapIfFailed(pSwapChain.As(&d3d->pSwapChain));
+    d3d->pSwapChain = (IDXGISwapChain3*)pSwapChain;
+}
+
+/// Creates RTVs for all of the swap chain's buffers.
+static void d3d_create_swap_chain_buffer_render_target_views(D3D* d3d) {
+    assert(d3d);
+    assert(d3d->pDevice);
+    assert(d3d->pSwapChain);
+    assert(d3d->pSwapChainBuffer);
+    assert(d3d->pRtvHeap);
+    assert(d3d->rtv_descriptor_size > 0);
+
+    // Create the new buffer views.
+    D3D12_CPU_DESCRIPTOR_HANDLE rtv_heap_handle;
+    d3d->pRtvHeap->lpVtbl->GetCPUDescriptorHandleForHeapStart(d3d->pRtvHeap, &rtv_heap_handle);
+    for (int i = 0; i < SWAP_CHAIN_BUFFER_COUNT; ++i)
+    {
+        TrapIfFailed(d3d->pSwapChain->lpVtbl->GetBuffer(
+            d3d->pSwapChain, i, &IID_ID3D12Resource, &d3d->pSwapChainBuffer[i]));
+
+        d3d->pDevice->lpVtbl->CreateRenderTargetView(
+            d3d->pDevice, d3d->pSwapChainBuffer[i], /*pDesc=*/0, rtv_heap_handle);
+
+        rtv_heap_handle = OFFSET_HANDLE(rtv_heap_handle, 1, d3d->rtv_descriptor_size);
+    }
+}
+
+/// Creates a depth/stencil buffer and its view.
+static void d3d_create_depth_stencil_buffer_and_view(D3D* d3d) {
+    assert(d3d);
+    assert(d3d->pDevice);
+
+    const D3D12_RESOURCE_DESC depth_stencil_desc = (D3D12_RESOURCE_DESC){
+        .Dimension        = D3D12_RESOURCE_DIMENSION_TEXTURE2D,
+        .Alignment        = 0,
+        .Width            = (UINT64)(d3d->settings.width),
+        .Height           = (UINT)(d3d->settings.height),
+        .DepthOrArraySize = 1,
+        .MipLevels        = 1,
+        .Format           = DXGI_FORMAT_D24_UNORM_S8_UINT,
+        .SampleDesc       = (DXGI_SAMPLE_DESC){
+            .Count   = 1,
+            .Quality = 0,
+        },
+        .Layout = D3D12_TEXTURE_LAYOUT_UNKNOWN,
+        .Flags  = D3D12_RESOURCE_FLAG_ALLOW_DEPTH_STENCIL,
+    };
+    const D3D12_CLEAR_VALUE opt_clear_value = (D3D12_CLEAR_VALUE){
+        .Format       = depth_stencil_desc.Format,
+        .DepthStencil = (D3D12_DEPTH_STENCIL_VALUE){
+            .Depth    = 1.0f,
+            .Stencil  = 0,
+        },
+    };
+    const D3D12_HEAP_PROPERTIES depth_stencil_heap_properties = (D3D12_HEAP_PROPERTIES){
+        .Type                 = D3D12_HEAP_TYPE_DEFAULT,
+        .CPUPageProperty      = D3D12_CPU_PAGE_PROPERTY_UNKNOWN,
+        .MemoryPoolPreference = D3D12_MEMORY_POOL_UNKNOWN,
+        .CreationNodeMask     = 1,
+        .VisibleNodeMask      = 1,
+    };
+    TrapIfFailed(d3d->pDevice->lpVtbl->CreateCommittedResource(
+        d3d->pDevice,
+        &depth_stencil_heap_properties,
+        D3D12_HEAP_FLAG_NONE,
+        &depth_stencil_desc,
+        D3D12_RESOURCE_STATE_COMMON,
+        &opt_clear_value,
+        &IID_ID3D12Resource,
+        &d3d->pDepthStencilBuffer));
+
+    d3d->pDevice->lpVtbl->CreateDepthStencilView(
+        d3d->pDevice,
+        d3d->pDepthStencilBuffer,
+        /*pDesc=*/0,
+        d3d_get_depth_stencil_view(d3d));
+}
+
+/// Creates RTV and DSV descriptor heaps.
+static void d3d_create_descriptor_heaps(D3D* d3d) {
+    assert(d3d);
+    assert(d3d->pDevice);
+
+    // The RTV heap must hold as many descriptors as we have buffers in the
+    // swap chain.
+    const D3D12_DESCRIPTOR_HEAP_DESC rtv_heap_desc  = (D3D12_DESCRIPTOR_HEAP_DESC){
+        .Type           = D3D12_DESCRIPTOR_HEAP_TYPE_RTV,
+        .NumDescriptors = SWAP_CHAIN_BUFFER_COUNT,
+        .Flags          = D3D12_DESCRIPTOR_HEAP_FLAG_NONE,
+        .NodeMask       = 0,
+    };
+    TrapIfFailed(d3d->pDevice->lpVtbl->CreateDescriptorHeap(
+        d3d->pDevice, &rtv_heap_desc, &IID_ID3D12DescriptorHeap, &d3d->pRtvHeap));
+
+    // For the depth/stencil buffer, we just need one view.
+    const D3D12_DESCRIPTOR_HEAP_DESC dsv_heap_desc = (D3D12_DESCRIPTOR_HEAP_DESC){
+        .Type           = D3D12_DESCRIPTOR_HEAP_TYPE_DSV,
+        .NumDescriptors = 1,
+        .Flags          = D3D12_DESCRIPTOR_HEAP_FLAG_NONE,
+        .NodeMask       = 0,
+    };
+    TrapIfFailed(d3d->pDevice->lpVtbl->CreateDescriptorHeap(
+        d3d->pDevice, &dsv_heap_desc, &IID_ID3D12DescriptorHeap, &d3d->pDsvHeap));
+}
+
+static void d3d_init(D3D* d3d, Window* pWindow, const D3DSettings* pSettings) {
+    assert(d3d);
+    assert(pWindow);
+    assert(pSettings);
+
+    d3d->pWindow  = pWindow;
+    d3d->settings = *pSettings;
+
+    UINT dxgiFactoryFlags = 0;
+#ifndef NDEBUG
+    ID3D12Debug* pDebug = NULL;
+    TrapIfFailed(D3D12GetDebugInterface(&IID_ID3D12Debug, (&pDebug)));
+    pDebug->lpVtbl->EnableDebugLayer(pDebug);
+    dxgiFactoryFlags |= DXGI_CREATE_FACTORY_DEBUG;
+#endif
+    TrapIfFailed(CreateDXGIFactory2(
+        dxgiFactoryFlags, &IID_IDXGIFactory4, &d3d->pDxgiFactory));
+
+    // Prevent Alt+Enter from going into fullscreen.
+    TrapIfFailed(d3d->pDxgiFactory->lpVtbl->MakeWindowAssociation(
+        d3d->pDxgiFactory,
+        window_handle(d3d->pWindow),
+        DXGI_MWA_NO_ALT_ENTER));
+
+    TrapIfFailed(D3D12CreateDevice(
+        /*pAdapter=*/0, // Default adapter.
+        D3D_FEATURE_LEVEL_11_0,
+        &IID_ID3D12Device,
+        &d3d->pDevice));
+
+    d3d->rtv_descriptor_size = d3d->pDevice->lpVtbl->GetDescriptorHandleIncrementSize(
+        d3d->pDevice,
+        D3D12_DESCRIPTOR_HEAP_TYPE_RTV);
+    d3d->dsv_descriptor_size = d3d->pDevice->lpVtbl->GetDescriptorHandleIncrementSize(
+        d3d->pDevice,
+        D3D12_DESCRIPTOR_HEAP_TYPE_DSV);
+    d3d->cbv_descriptor_size = d3d->pDevice->lpVtbl->GetDescriptorHandleIncrementSize(
+        d3d->pDevice,
+        D3D12_DESCRIPTOR_HEAP_TYPE_CBV_SRV_UAV);
+
+    const D3D12_COMMAND_QUEUE_DESC queue_desc = (D3D12_COMMAND_QUEUE_DESC){
+        .Type  = D3D12_COMMAND_LIST_TYPE_DIRECT,
+        .Flags = D3D12_COMMAND_QUEUE_FLAG_NONE,
+    };
+    TrapIfFailed(d3d->pDevice->lpVtbl->CreateCommandQueue(
+        d3d->pDevice,
+        &queue_desc,
+        &IID_ID3D12CommandQueue,
+        &d3d->pCommandQueue));
+
+    // The command allocator is the memory backing for the command list.
+    // It is in the allocator's memory where the commands are stored.
+    TrapIfFailed(d3d->pDevice->lpVtbl->CreateCommandAllocator(
+        d3d->pDevice,
+        queue_desc.Type,
+        &IID_ID3D12CommandAllocator,
+        &d3d->pCommandAllocator));
+
+    TrapIfFailed(d3d->pDevice->lpVtbl->CreateCommandList(
+        d3d->pDevice,
+        /*nodeMask=*/0,
+        queue_desc.Type,
+        d3d->pCommandAllocator,
+        /*pInitialState=*/NULL,  // Pipeline state.
+        &IID_ID3D12CommandList,
+        &d3d->pCommandList));
+
+    // Command lists are in the "open" state after they are created. It is
+    // easier to assume that they start in the "closed" state at each
+    // iteration of the main loop, however. The Reset() method, which we'll
+    // use later, also expects the command list to be closed.
+    TrapIfFailed(d3d->pCommandList->lpVtbl->Close(d3d->pCommandList));
+
+    d3d_create_descriptor_heaps(d3d);
+
+    d3d_create_swap_chain(d3d);
+    d3d_create_swap_chain_buffer_render_target_views(d3d);
+    d3d_create_depth_stencil_buffer_and_view(d3d);
+
+    TrapIfFailed(d3d->pDevice->lpVtbl->CreateFence(
+        d3d->pDevice,
+        d3d->fence_value,
+        D3D12_FENCE_FLAG_NONE,
+        &IID_ID3D12Fence,
+        &d3d->pFence));
+
+    if ((d3d->fence_event = CreateEvent(NULL, FALSE, FALSE, NULL)) == NULL) {
+        TrapIfFailed(HRESULT_FROM_WIN32(GetLastError()));
+    }
+}
+
+void d3d_destroy(D3D* d3d) {
+    assert(d3d);
+    SafeRelease(d3d->pCommandList);
+    SafeRelease(d3d->pCommandAllocator);
+    SafeRelease(d3d->pCommandQueue);
+    // Swap chain buffers are owned by the swap chain.
+    SafeRelease(d3d->pDepthStencilBuffer);
+    SafeRelease(d3d->pSwapChain);
+    SafeRelease(d3d->pRtvHeap);
+    SafeRelease(d3d->pDsvHeap);
+    SafeRelease(d3d->pFence);
+    SafeRelease(d3d->pDevice);
+    SafeRelease(d3d->pDxgiFactory);
+    CloseHandle(d3d->fence_event);
+}
+
+static void d3d_populate_command_list(D3D* d3d) {
+    assert(d3d);
+    assert(d3d->pCommandAllocator);
+    assert(d3d->pCommandList);
+
+    /// Note that we skip the following two items:
+    ///
+    ///   1. RSSetViewports()
+    ///   2. OMSetRenderTargets()
+    ///
+    /// This application does not render anything useful, it simply clears
+    /// the back buffer and depth/stencil view. Clearing both resources
+    /// does not require a viewport to be set or the OM (output-merger
+    /// stage) to be configured.
+
+    // A command allocator can only be reset when its associated command
+    // lists are finished executing on the GPU. This requires
+    // synchronisation.
+    TrapIfFailed(d3d->pCommandAllocator->lpVtbl->Reset(d3d->pCommandAllocator));
+
+    // A command list can be reset as soon as it is executed with
+    // ExecuteCommandList(). Reset() does require that the command list is
+    // in a "closed" state, however, which is why we Close() it right away
+    // after creation.
+    TrapIfFailed(d3d->pCommandList->lpVtbl->Reset(
+        d3d->pCommandList,
+        d3d->pCommandAllocator,
+        /*pInitialState=*/NULL));
+
+    // Indicate that we intend to use the back buffer as a render target and
+    // depth/stencil for writing.
+    const D3D12_RESOURCE_BARRIER render_barriers[] = {
+        CD3DX12_RESOURCE_BARRIER_Transition(
+            d3d_get_current_back_buffer(d3d),
+            D3D12_RESOURCE_STATE_PRESENT,
+            D3D12_RESOURCE_STATE_RENDER_TARGET),
+        CD3DX12_RESOURCE_BARRIER_Transition(
+            d3d->pDepthStencilBuffer,
+            D3D12_RESOURCE_STATE_PRESENT,
+            D3D12_RESOURCE_STATE_DEPTH_WRITE)
+    };
+    d3d->pCommandList->lpVtbl->ResourceBarrier(d3d->pCommandList, COUNTOF(render_barriers), render_barriers);
+
+    // Record commands.
+    const float clear_colour[] = { 0.0f, 0.502f, 0.494f, 0.0f };
+    d3d->pCommandList->lpVtbl->ClearRenderTargetView(
+        d3d->pCommandList,
+        d3d_get_current_back_buffer_view(d3d),
+        clear_colour,
+        0,  // Number of rectangles in the following array.
+        0); // No rectangles; clear the entire resource.
+
+    d3d->pCommandList->lpVtbl->ClearDepthStencilView(
+        d3d->pCommandList,
+        d3d_get_depth_stencil_view(d3d),
+        D3D12_CLEAR_FLAG_DEPTH | D3D12_CLEAR_FLAG_STENCIL,
+        1.0f, // Depth.
+        0,    // Stencil.
+        0,    // Number of rectangles in the following array.
+        0);   // No rectangles; clear the entire resource view.
+
+    // Indicate that we now intend to use the back buffer and depth/stencil
+    // buffer to present.
+    const D3D12_RESOURCE_BARRIER present_barriers[] = {
+        CD3DX12_RESOURCE_BARRIER_Transition(
+            d3d_get_current_back_buffer(d3d),
+            D3D12_RESOURCE_STATE_RENDER_TARGET,
+            D3D12_RESOURCE_STATE_PRESENT),
+        CD3DX12_RESOURCE_BARRIER_Transition(
+            d3d->pDepthStencilBuffer,
+            D3D12_RESOURCE_STATE_DEPTH_WRITE,
+            D3D12_RESOURCE_STATE_PRESENT)
+    };
+    d3d->pCommandList->lpVtbl->ResourceBarrier(d3d->pCommandList, COUNTOF(present_barriers), present_barriers);
+
+    // A command list must be closed before it can be executed.
+    TrapIfFailed(d3d->pCommandList->lpVtbl->Close(d3d->pCommandList));
+}
+
+static void d3d_wait_for_previous_frame(D3D* d3d) {
+    assert(d3d);
+    assert(d3d->pFence);
+    assert(d3d->pCommandQueue);
+
+    // Advance the fence value to mark commands up to this fence point.
+    d3d->fence_value++;
+
+    // The command queue will signal the new fence value when all commands up to
+    // this point have finished execution.
+    TrapIfFailed(d3d->pCommandQueue->lpVtbl->Signal(
+        d3d->pCommandQueue, d3d->pFence, d3d->fence_value));
+
+    // Wait for commands to finish execution.
+    // It is possible that execution has already finished by the time we
+    // get here, so first check the fence's completed value.
+    if (d3d->pFence->lpVtbl->GetCompletedValue(d3d->pFence) < d3d->fence_value) {
+        // Commands are still being executed. Configure a Windows event
+        // and wait for it. The event fires when the commands have finished
+        // execution.
+
+        // Indicate that |fence_event| is to be fired when |fence|
+        // reaches the new fence value.
+        TrapIfFailed(d3d->pFence->lpVtbl->SetEventOnCompletion(
+            d3d->pFence, d3d->fence_value, d3d->fence_event));
+
+        // Will wake up when the fence takes on the new fence value.
+        WaitForSingleObject(d3d->fence_event, INFINITE);
+    }
+}
+
+static void d3d_render(D3D* d3d) {
+    assert(d3d);
+    assert(d3d->pCommandQueue);
+    assert(d3d->pSwapChain);
+
+    d3d_populate_command_list(d3d);
+
+    ID3D12CommandList* command_lists[] = { (ID3D12CommandList*)d3d->pCommandList };
+    d3d->pCommandQueue->lpVtbl->ExecuteCommandLists(
+        d3d->pCommandQueue, _countof(command_lists), command_lists);
+
+    TrapIfFailed(d3d->pSwapChain->lpVtbl->Present(
+        d3d->pSwapChain, /*SyncInterval=*/1, /*Flags=*/0));
+
+    // It is not efficient to wait for the frame to complete here, but it
+    // is simple and sufficient for this application.
+    d3d_wait_for_previous_frame(d3d);
+}
+
+int main(int argc, const char** argv) {
+    const D3DSettings settings = (D3DSettings){
+        .width  = 1920,
+        .height = 1200,
+    };
+
+    if (!window_global_init()) {
+        TRAP("Failed to initialise the window subsystem");
+    }
+
+    Window* window = window_init(settings.width, settings.height, "D3D Application");
+    if (!window) {
+        TRAP(window_get_error());
+    }
+
+    D3D d3d = {0};
+    d3d_init(&d3d, window, &settings);
+
+    while (!window_should_close(window))
+    {
+        window_update(window);
+        d3d_render(&d3d);
+        Sleep(10);
+    }
+
+    d3d_destroy(&d3d);
+    window_global_quit();
+    return 0;
+}