draw.cpp

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// SPDX-License-Identifier: GPL-3.0-only
 
#include "draw/draw.hpp"
 
#include "imgui.h"
#include "backends/imgui_impl_win32.h"
#include "backends/imgui_impl_dx12.h"
 
#include "implot.h"
 
#include <d3d12.h>
#include <dxgi1_4.h>
#include <tchar.h>
 
#ifdef _DEBUG
#define DX12_ENABLE_DEBUG_LAYER
#endif
 
#ifdef DX12_ENABLE_DEBUG_LAYER
#include <dxgidebug.h>
#pragma comment(lib, "dxguid.lib")
#endif
 
struct FrameContext
{
    ID3D12CommandAllocator* CommandAllocator;
    UINT64                  FenceValue;
};
 
// Data
static int const                    NUM_FRAMES_IN_FLIGHT = 3;
static FrameContext                 g_frameContext[NUM_FRAMES_IN_FLIGHT] = {};
static UINT                         g_frameIndex = 0;
 
static int const                    NUM_BACK_BUFFERS = 3;
static IDXGIAdapter3*               g_adapter = nullptr;
static ID3D12Device*                g_pd3dDevice = nullptr;
static ID3D12DescriptorHeap*        g_pd3dRtvDescHeap = nullptr;
static ID3D12DescriptorHeap*        g_pd3dSrvDescHeap = nullptr;
static ID3D12CommandQueue*          g_pd3dCommandQueue = nullptr;
static ID3D12GraphicsCommandList*   g_pd3dCommandList = nullptr;
static ID3D12Fence*                 g_fence = nullptr;
static HANDLE                       g_fenceEvent = nullptr;
static UINT64                       g_fenceLastSignaledValue = 0;
static IDXGISwapChain3*             g_pSwapChain = nullptr;
static HANDLE                       g_hSwapChainWaitableObject = nullptr;
static ID3D12Resource*              g_mainRenderTargetResource[NUM_BACK_BUFFERS] = {};
static D3D12_CPU_DESCRIPTOR_HANDLE  g_mainRenderTargetDescriptor[NUM_BACK_BUFFERS] = {};
 
static WNDCLASSEXW wc;
static HWND hwnd;
 
// Forward declarations of helper functions
bool CreateDeviceD3D(HWND hWnd);
void CleanupDeviceD3D();
void CreateRenderTarget();
void CleanupRenderTarget();
void WaitForLastSubmittedFrame();
FrameContext* WaitForNextFrameResources();
LRESULT WINAPI WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam);
 
// Helper functions
bool CreateDeviceD3D(HWND hWnd, bool use_warp_adapter)
{
    // Setup swap chain
    DXGI_SWAP_CHAIN_DESC1 sd;
    {
        ZeroMemory(&sd, sizeof(sd));
        sd.BufferCount = NUM_BACK_BUFFERS;
        sd.Width = 0;
        sd.Height = 0;
        sd.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
        sd.Flags = DXGI_SWAP_CHAIN_FLAG_FRAME_LATENCY_WAITABLE_OBJECT;
        sd.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;
        sd.SampleDesc.Count = 1;
        sd.SampleDesc.Quality = 0;
        sd.SwapEffect = DXGI_SWAP_EFFECT_FLIP_DISCARD;
        sd.AlphaMode = DXGI_ALPHA_MODE_UNSPECIFIED;
        sd.Scaling = DXGI_SCALING_STRETCH;
        sd.Stereo = FALSE;
    }
 
    // [DEBUG] Enable debug interface
#ifdef DX12_ENABLE_DEBUG_LAYER
    ID3D12Debug* pdx12Debug = nullptr;
    if (SUCCEEDED(D3D12GetDebugInterface(IID_PPV_ARGS(&pdx12Debug))))
        pdx12Debug->EnableDebugLayer();
#endif
 
    if (use_warp_adapter)
    {
        IDXGIFactory4* dxgiFactory = nullptr;
        if (CreateDXGIFactory1(IID_PPV_ARGS(&dxgiFactory)) != S_OK)
            return false;
        if (dxgiFactory->EnumWarpAdapter(IID_PPV_ARGS(&g_adapter)) != S_OK)
            return false;
        dxgiFactory->Release();
    }
 
    // Create device
    D3D_FEATURE_LEVEL featureLevel = D3D_FEATURE_LEVEL_11_0;
    if (D3D12CreateDevice(g_adapter, featureLevel, IID_PPV_ARGS(&g_pd3dDevice)) != S_OK)
        return false;
 
    // [DEBUG] Setup debug interface to break on any warnings/errors
#ifdef DX12_ENABLE_DEBUG_LAYER
    if (pdx12Debug != nullptr)
    {
        ID3D12InfoQueue* pInfoQueue = nullptr;
        g_pd3dDevice->QueryInterface(IID_PPV_ARGS(&pInfoQueue));
        pInfoQueue->SetBreakOnSeverity(D3D12_MESSAGE_SEVERITY_ERROR, true);
        pInfoQueue->SetBreakOnSeverity(D3D12_MESSAGE_SEVERITY_CORRUPTION, true);
        pInfoQueue->SetBreakOnSeverity(D3D12_MESSAGE_SEVERITY_WARNING, true);
        pInfoQueue->Release();
        pdx12Debug->Release();
    }
#endif
 
    {
        D3D12_DESCRIPTOR_HEAP_DESC desc = {};
        desc.Type = D3D12_DESCRIPTOR_HEAP_TYPE_RTV;
        desc.NumDescriptors = NUM_BACK_BUFFERS;
        desc.Flags = D3D12_DESCRIPTOR_HEAP_FLAG_NONE;
        desc.NodeMask = 1;
        if (g_pd3dDevice->CreateDescriptorHeap(&desc, IID_PPV_ARGS(&g_pd3dRtvDescHeap)) != S_OK)
            return false;
 
        SIZE_T rtvDescriptorSize = g_pd3dDevice->GetDescriptorHandleIncrementSize(D3D12_DESCRIPTOR_HEAP_TYPE_RTV);
        D3D12_CPU_DESCRIPTOR_HANDLE rtvHandle = g_pd3dRtvDescHeap->GetCPUDescriptorHandleForHeapStart();
        for (UINT i = 0; i < NUM_BACK_BUFFERS; i++)
        {
            g_mainRenderTargetDescriptor[i] = rtvHandle;
            rtvHandle.ptr += rtvDescriptorSize;
        }
    }
 
    {
        D3D12_DESCRIPTOR_HEAP_DESC desc = {};
        desc.Type = D3D12_DESCRIPTOR_HEAP_TYPE_CBV_SRV_UAV;
        desc.NumDescriptors = 1;
        desc.Flags = D3D12_DESCRIPTOR_HEAP_FLAG_SHADER_VISIBLE;
        if (g_pd3dDevice->CreateDescriptorHeap(&desc, IID_PPV_ARGS(&g_pd3dSrvDescHeap)) != S_OK)
            return false;
    }
 
    {
        D3D12_COMMAND_QUEUE_DESC desc = {};
        desc.Type = D3D12_COMMAND_LIST_TYPE_DIRECT;
        desc.Flags = D3D12_COMMAND_QUEUE_FLAG_NONE;
        desc.NodeMask = 1;
        if (g_pd3dDevice->CreateCommandQueue(&desc, IID_PPV_ARGS(&g_pd3dCommandQueue)) != S_OK)
            return false;
    }
 
    for (UINT i = 0; i < NUM_FRAMES_IN_FLIGHT; i++)
        if (g_pd3dDevice->CreateCommandAllocator(D3D12_COMMAND_LIST_TYPE_DIRECT, IID_PPV_ARGS(&g_frameContext[i].CommandAllocator)) != S_OK)
            return false;
 
    if (g_pd3dDevice->CreateCommandList(0, D3D12_COMMAND_LIST_TYPE_DIRECT, g_frameContext[0].CommandAllocator, nullptr, IID_PPV_ARGS(&g_pd3dCommandList)) != S_OK ||
        g_pd3dCommandList->Close() != S_OK)
        return false;
 
    if (g_pd3dDevice->CreateFence(0, D3D12_FENCE_FLAG_NONE, IID_PPV_ARGS(&g_fence)) != S_OK)
        return false;
 
    g_fenceEvent = CreateEvent(nullptr, FALSE, FALSE, nullptr);
    if (g_fenceEvent == nullptr)
        return false;
 
    {
        IDXGIFactory4* dxgiFactory = nullptr;
        IDXGISwapChain1* swapChain1 = nullptr;
        if (CreateDXGIFactory1(IID_PPV_ARGS(&dxgiFactory)) != S_OK)
            return false;
        if (dxgiFactory->CreateSwapChainForHwnd(g_pd3dCommandQueue, hWnd, &sd, nullptr, nullptr, &swapChain1) != S_OK)
            return false;
        if (swapChain1->QueryInterface(IID_PPV_ARGS(&g_pSwapChain)) != S_OK)
            return false;
        swapChain1->Release();
        dxgiFactory->Release();
        g_pSwapChain->SetMaximumFrameLatency(NUM_BACK_BUFFERS);
        g_hSwapChainWaitableObject = g_pSwapChain->GetFrameLatencyWaitableObject();
    }
 
    CreateRenderTarget();
    return true;
}
 
void CleanupDeviceD3D()
{
    CleanupRenderTarget();
    if (g_pSwapChain) { g_pSwapChain->SetFullscreenState(false, nullptr); g_pSwapChain->Release(); g_pSwapChain = nullptr; }
    if (g_hSwapChainWaitableObject != nullptr) { CloseHandle(g_hSwapChainWaitableObject); }
    for (UINT i = 0; i < NUM_FRAMES_IN_FLIGHT; i++)
        if (g_frameContext[i].CommandAllocator) { g_frameContext[i].CommandAllocator->Release(); g_frameContext[i].CommandAllocator = nullptr; }
    if (g_pd3dCommandQueue) { g_pd3dCommandQueue->Release(); g_pd3dCommandQueue = nullptr; }
    if (g_pd3dCommandList) { g_pd3dCommandList->Release(); g_pd3dCommandList = nullptr; }
    if (g_pd3dRtvDescHeap) { g_pd3dRtvDescHeap->Release(); g_pd3dRtvDescHeap = nullptr; }
    if (g_pd3dSrvDescHeap) { g_pd3dSrvDescHeap->Release(); g_pd3dSrvDescHeap = nullptr; }
    if (g_fence) { g_fence->Release(); g_fence = nullptr; }
    if (g_fenceEvent) { CloseHandle(g_fenceEvent); g_fenceEvent = nullptr; }
    if (g_pd3dDevice) { g_pd3dDevice->Release(); g_pd3dDevice = nullptr; }
 
#ifdef DX12_ENABLE_DEBUG_LAYER
    IDXGIDebug1* pDebug = nullptr;
    if (SUCCEEDED(DXGIGetDebugInterface1(0, IID_PPV_ARGS(&pDebug))))
    {
        pDebug->ReportLiveObjects(DXGI_DEBUG_ALL, DXGI_DEBUG_RLO_SUMMARY);
        pDebug->Release();
    }
#endif
 
    if (g_adapter) { g_adapter->Release(); g_adapter = nullptr; }
}
 
void CreateRenderTarget()
{
    for (UINT i = 0; i < NUM_BACK_BUFFERS; i++)
    {
        ID3D12Resource* pBackBuffer = nullptr;
        g_pSwapChain->GetBuffer(i, IID_PPV_ARGS(&pBackBuffer));
        g_pd3dDevice->CreateRenderTargetView(pBackBuffer, nullptr, g_mainRenderTargetDescriptor[i]);
        g_mainRenderTargetResource[i] = pBackBuffer;
    }
}
 
void CleanupRenderTarget()
{
    WaitForLastSubmittedFrame();
 
    for (UINT i = 0; i < NUM_BACK_BUFFERS; i++)
        if (g_mainRenderTargetResource[i]) { g_mainRenderTargetResource[i]->Release(); g_mainRenderTargetResource[i] = nullptr; }
}
 
void WaitForLastSubmittedFrame()
{
    FrameContext* frameCtx = &g_frameContext[g_frameIndex % NUM_FRAMES_IN_FLIGHT];
 
    UINT64 fenceValue = frameCtx->FenceValue;
    if (fenceValue == 0)
        return; // No fence was signaled
 
    frameCtx->FenceValue = 0;
    if (g_fence->GetCompletedValue() >= fenceValue)
        return;
 
    g_fence->SetEventOnCompletion(fenceValue, g_fenceEvent);
    WaitForSingleObject(g_fenceEvent, INFINITE);
}
 
FrameContext* WaitForNextFrameResources()
{
    UINT nextFrameIndex = g_frameIndex + 1;
    g_frameIndex = nextFrameIndex;
 
    HANDLE waitableObjects[] = { g_hSwapChainWaitableObject, nullptr };
    DWORD numWaitableObjects = 1;
 
    FrameContext* frameCtx = &g_frameContext[nextFrameIndex % NUM_FRAMES_IN_FLIGHT];
    UINT64 fenceValue = frameCtx->FenceValue;
    if (fenceValue != 0) // means no fence was signaled
    {
        frameCtx->FenceValue = 0;
        g_fence->SetEventOnCompletion(fenceValue, g_fenceEvent);
        waitableObjects[1] = g_fenceEvent;
        numWaitableObjects = 2;
    }
 
    WaitForMultipleObjects(numWaitableObjects, waitableObjects, TRUE, INFINITE);
 
    return frameCtx;
}
 
// Forward declare message handler from imgui_impl_win32.cpp
extern IMGUI_IMPL_API LRESULT ImGui_ImplWin32_WndProcHandler(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam);
 
// Win32 message handler
// You can read the io.WantCaptureMouse, io.WantCaptureKeyboard flags to tell if dear imgui wants to use your inputs.
// - When io.WantCaptureMouse is true, do not dispatch mouse input data to your main application, or clear/overwrite your copy of the mouse data.
// - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application, or clear/overwrite your copy of the keyboard data.
// Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.
LRESULT WINAPI WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
{
    if (ImGui_ImplWin32_WndProcHandler(hWnd, msg, wParam, lParam))
        return true;
 
    switch (msg)
    {
    case WM_SIZE:
        if (g_pd3dDevice != nullptr && wParam != SIZE_MINIMIZED)
        {
            WaitForLastSubmittedFrame();
            CleanupRenderTarget();
            HRESULT result = g_pSwapChain->ResizeBuffers(0, (UINT)LOWORD(lParam), (UINT)HIWORD(lParam), DXGI_FORMAT_UNKNOWN, DXGI_SWAP_CHAIN_FLAG_FRAME_LATENCY_WAITABLE_OBJECT);
            CTASSERT(SUCCEEDED(result) && "Failed to resize swapchain.");
            CreateRenderTarget();
        }
        return 0;
    case WM_SYSCOMMAND:
        if ((wParam & 0xfff0) == SC_KEYMENU) // Disable ALT application menu
            return 0;
        break;
    case WM_DESTROY:
        ::PostQuitMessage(0);
        return 0;
    }
    return ::DefWindowProcW(hWnd, msg, wParam, lParam);
}
 
bool draw::create(const config_t& config)
{
    // Create application window
    //ImGui_ImplWin32_EnableDpiAwareness();
    wc = { sizeof(wc), CS_CLASSDC, WndProc, 0L, 0L, GetModuleHandle(nullptr), nullptr, nullptr, nullptr, nullptr, L"ImGui Example", nullptr };
    ::RegisterClassExW(&wc);
    hwnd = ::CreateWindowW(wc.lpszClassName, config.title, WS_OVERLAPPEDWINDOW, 100, 100, 1280, 800, nullptr, nullptr, wc.hInstance, nullptr);
 
    // center window
    RECT rc;
    GetWindowRect(hwnd, &rc);
    int xPos = (GetSystemMetrics(SM_CXSCREEN) - rc.right) / 2;
    int yPos = (GetSystemMetrics(SM_CYSCREEN) - rc.bottom) / 2;
    SetWindowPos(hwnd, 0, xPos, yPos, 0, 0, SWP_NOZORDER | SWP_NOSIZE);
 
    // Initialize Direct3D
    if (!CreateDeviceD3D(hwnd, !config.hwaccel))
    {
        CleanupDeviceD3D();
        ::UnregisterClassW(wc.lpszClassName, wc.hInstance);
        return false;
    }
 
    // Show the window
    ::ShowWindow(hwnd, SW_SHOWDEFAULT);
    ::UpdateWindow(hwnd);
 
    // Setup Dear ImGui context
    IMGUI_CHECKVERSION();
    ImGui::CreateContext();
    ImGuiIO& io = ImGui::GetIO(); (void)io;
    io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
    io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls
    io.ConfigFlags |= ImGuiConfigFlags_DockingEnable;         // Enable Docking
    io.ConfigFlags |= ImGuiConfigFlags_ViewportsEnable;       // Enable Multi-Viewport / Platform Windows
    //io.ConfigViewportsNoAutoMerge = true;
    //io.ConfigViewportsNoTaskBarIcon = true;
 
    ImPlot::CreateContext();
 
    // Setup Dear ImGui style
    ImGui::StyleColorsDark();
    ImPlot::StyleColorsDark();
    //ImGui::StyleColorsLight();
 
    // When viewports are enabled we tweak WindowRounding/WindowBg so platform windows can look identical to regular ones.
    ImGuiStyle& style = ImGui::GetStyle();
    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
    {
        style.WindowRounding = 0.0f;
        style.Colors[ImGuiCol_WindowBg].w = 1.0f;
    }
 
    // Setup Platform/Renderer backends
    ImGui_ImplWin32_Init(hwnd);
    ImGui_ImplDX12_Init(g_pd3dDevice, NUM_FRAMES_IN_FLIGHT,
        DXGI_FORMAT_R8G8B8A8_UNORM, g_pd3dSrvDescHeap,
        g_pd3dSrvDescHeap->GetCPUDescriptorHandleForHeapStart(),
        g_pd3dSrvDescHeap->GetGPUDescriptorHandleForHeapStart());
 
    // Load Fonts
    // - If no fonts are loaded, dear imgui will use the default font. You can also load multiple fonts and use ImGui::PushFont()/PopFont() to select them.
    // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
    // - If the file cannot be loaded, the function will return a nullptr. Please handle those errors in your application (e.g. use an assertion, or display an error and quit).
    // - The fonts will be rasterized at a given size (w/ oversampling) and stored into a texture when calling ImFontAtlas::Build()/GetTexDataAsXXXX(), which ImGui_ImplXXXX_NewFrame below will call.
    // - Use '#define IMGUI_ENABLE_FREETYPE' in your imconfig file to use Freetype for higher quality font rendering.
    // - Read 'docs/FONTS.md' for more instructions and details.
    // - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
    //io.Fonts->AddFontDefault();
    //io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\segoeui.ttf", 18.0f);
    //io.Fonts->AddFontFromFileTTF("../../misc/fonts/DroidSans.ttf", 16.0f);
    //io.Fonts->AddFontFromFileTTF("../../misc/fonts/Roboto-Medium.ttf", 16.0f);
    //io.Fonts->AddFontFromFileTTF("../../misc/fonts/Cousine-Regular.ttf", 15.0f);
    //ImFont* font = io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\ArialUni.ttf", 18.0f, nullptr, io.Fonts->GetGlyphRangesJapanese());
    //IM_ASSERT(font != nullptr);
 
    return true;
}
 
void draw::destroy()
{
    WaitForLastSubmittedFrame();
 
    // Cleanup
    ImGui_ImplDX12_Shutdown();
    ImGui_ImplWin32_Shutdown();
    ImPlot::DestroyContext();
    ImGui::DestroyContext();
 
    CleanupDeviceD3D();
    ::DestroyWindow(hwnd);
    ::UnregisterClassW(wc.lpszClassName, wc.hInstance);
}
 
bool draw::begin_frame()
{
    // Poll and handle messages (inputs, window resize, etc.)
    // See the WndProc() function below for our to dispatch events to the Win32 backend.
    MSG msg;
    bool done = false;
    while (::PeekMessage(&msg, nullptr, 0U, 0U, PM_REMOVE))
    {
        ::TranslateMessage(&msg);
        ::DispatchMessage(&msg);
        if (msg.message == WM_QUIT)
            done = true;
    }
    if (done)
        return false;
 
    // Start the Dear ImGui frame
    ImGui_ImplDX12_NewFrame();
    ImGui_ImplWin32_NewFrame();
    ImGui::NewFrame();
 
    return true;
}
 
void draw::close()
{
    ::PostMessage(hwnd, WM_CLOSE, 0, 0);
}
 
void draw::end_frame()
{
    ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
 
    // Rendering
    ImGui::Render();
 
    FrameContext* frameCtx = WaitForNextFrameResources();
    UINT backBufferIdx = g_pSwapChain->GetCurrentBackBufferIndex();
    frameCtx->CommandAllocator->Reset();
 
    D3D12_RESOURCE_BARRIER barrier = {};
    barrier.Type                   = D3D12_RESOURCE_BARRIER_TYPE_TRANSITION;
    barrier.Flags                  = D3D12_RESOURCE_BARRIER_FLAG_NONE;
    barrier.Transition.pResource   = g_mainRenderTargetResource[backBufferIdx];
    barrier.Transition.Subresource = D3D12_RESOURCE_BARRIER_ALL_SUBRESOURCES;
    barrier.Transition.StateBefore = D3D12_RESOURCE_STATE_PRESENT;
    barrier.Transition.StateAfter  = D3D12_RESOURCE_STATE_RENDER_TARGET;
    g_pd3dCommandList->Reset(frameCtx->CommandAllocator, nullptr);
    g_pd3dCommandList->ResourceBarrier(1, &barrier);
 
    // Render Dear ImGui graphics
    const float clear_color_with_alpha[4] = { clear_color.x * clear_color.w, clear_color.y * clear_color.w, clear_color.z * clear_color.w, clear_color.w };
    g_pd3dCommandList->ClearRenderTargetView(g_mainRenderTargetDescriptor[backBufferIdx], clear_color_with_alpha, 0, nullptr);
    g_pd3dCommandList->OMSetRenderTargets(1, &g_mainRenderTargetDescriptor[backBufferIdx], FALSE, nullptr);
    g_pd3dCommandList->SetDescriptorHeaps(1, &g_pd3dSrvDescHeap);
    ImGui_ImplDX12_RenderDrawData(ImGui::GetDrawData(), g_pd3dCommandList);
    barrier.Transition.StateBefore = D3D12_RESOURCE_STATE_RENDER_TARGET;
    barrier.Transition.StateAfter  = D3D12_RESOURCE_STATE_PRESENT;
    g_pd3dCommandList->ResourceBarrier(1, &barrier);
    g_pd3dCommandList->Close();
 
    g_pd3dCommandQueue->ExecuteCommandLists(1, (ID3D12CommandList* const*)&g_pd3dCommandList);
 
    ImGuiIO& io = ImGui::GetIO();
 
    // Update and Render additional Platform Windows
    if (io.ConfigFlags & ImGuiConfigFlags_ViewportsEnable)
    {
        ImGui::UpdatePlatformWindows();
        ImGui::RenderPlatformWindowsDefault(nullptr, (void*)g_pd3dCommandList);
    }
 
    g_pSwapChain->Present(1, 0); // Present with vsync
    //g_pSwapChain->Present(0, 0); // Present without vsync
 
    UINT64 fenceValue = g_fenceLastSignaledValue + 1;
    g_pd3dCommandQueue->Signal(g_fence, fenceValue);
    g_fenceLastSignaledValue = fenceValue;
    frameCtx->FenceValue = fenceValue;
}