DirectX SDK安装颜色变化

Question

我最近关注了 YouTube 上关于如何将 DirectX 安装到 Win32 中的教程。 当我之前运行它时，我得到了一个白色的窗口。安装 DirectX 后运行它时，我尝试使用 DirectX 更改颜色，但当它应该是青色时，我仍然得到一个白色窗口。

#include <Windows.h>
#include <iostream>
#include "wtypes.h"
#include "wtypes.h"
#include <d3d11.h>
#include <d3dx11.h>
#include <DxErr.h>

void GetDesktopResolution(int& horizontal, int& vertical)
{
    RECT desktop;
    const HWND hDesktop = GetDesktopWindow();
    GetWindowRect(hDesktop, &desktop);
    horizontal = desktop.right;
    vertical = desktop.bottom;
}

using namespace std;

HWND windowHandle;

LRESULT CALLBACK WndProc(HWND hwnd, UINT fMsg, WPARAM wParam, LPARAM lParam)
{
    switch (fMsg)
    {
    case WM_CLOSE:
        DestroyWindow(hwnd);
        break;
    case WM_DESTROY:
        PostQuitMessage(0);
        break;
    case WM_CHAR:
    {
        if (wParam == VK_ESCAPE)
        SendMessage(hwnd, WM_CLOSE, 0, 0);
        return 0;
    }
    default:
        return DefWindowProc(hwnd, fMsg, wParam, lParam);
    }
}

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE prevIstance, PSTR cmdLine, int showCmd)
{
    int horizontal = 0;
    int vertical = 0;
    bool success;
    int hres = 0;
    int vres = 0;
    GetDesktopResolution(horizontal, vertical);

    if (success = GetDesktopResolution)
    {
        hres = horizontal - 800;
        vres = vertical - 600;
    }

    const int result = MessageBoxA(0, "Would you like to play in \nFull-Screen Mode?", "When the Sun Sets", MB_ICONEXCLAMATION | MB_YESNOCANCEL);

    switch (result)
    {
    case IDYES:

        if (result == IDYES)
        {
            // FIRST WINDOW

            WNDCLASSEX fGame;

            fGame.cbSize = sizeof(WNDCLASSEX);
            fGame.cbClsExtra = 0;
            fGame.cbWndExtra = 0;
            fGame.hIconSm = 0;

            fGame.hInstance = hInstance;
            fGame.lpfnWndProc = WndProc;
            fGame.style = CS_HREDRAW | CS_VREDRAW;
            fGame.lpszClassName = L"WTSS1";
            fGame.lpszMenuName = 0;
            fGame.hCursor = LoadCursor(0, IDC_ARROW);
            fGame.hIcon = LoadIcon(0, IDI_APPLICATION);
            fGame.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);

            RegisterClassEx(&fGame);

            windowHandle = CreateWindowEx(WS_MAXIMIZEBOX, L"WTSS1", L"When the Sun Sets", WS_OVERLAPPEDWINDOW | WS_VISIBLE, 0, 0, 800 + hres, 600 + vres, 0, 0, hInstance, 0);

            SetWindowLong(windowHandle, GWL_STYLE, 0);

            if (windowHandle == 0)
            {
                MessageBoxA(0, "Error: The window has been configured incorrectly.", "When the Sun Sets", 0);
                return -1;
            }

            ShowWindow(windowHandle, showCmd);

            UpdateWindow(windowHandle);

            HRESULT hResult = S_OK;

            ID3D11Device*           m_pD3D11Device = 0;
            IDXGISwapChain*         m_pSwapChain = 0;
            ID3D11DeviceContext*    m_pD3D11Context = 0;
            D3D_FEATURE_LEVEL       FeatureLevelsSupported;

            D3D_FEATURE_LEVEL FeatureLevelsRequested[] =
            {
                    D3D_FEATURE_LEVEL_11_0,
                    D3D_FEATURE_LEVEL_10_1,
                    D3D_FEATURE_LEVEL_10_0,
                    D3D_FEATURE_LEVEL_9_3,
                    D3D_FEATURE_LEVEL_9_2,
                    D3D_FEATURE_LEVEL_9_1,
            };

            RECT dimensions;
            GetClientRect(windowHandle, &dimensions);
            LONG width = dimensions.right - dimensions.left;
            LONG height = dimensions.bottom - dimensions.top;

            DXGI_SWAP_CHAIN_DESC sd;
            ZeroMemory(&sd, sizeof(sd));
            sd.BufferCount = 1;
            sd.BufferDesc.Width = static_cast<unsigned int>(width);
            sd.BufferDesc.Height = static_cast<unsigned int>(height);
            sd.BufferDesc.Format = DXGI_FORMAT_R8G8B8A8_UNORM;
            sd.BufferDesc.RefreshRate.Numerator = 60;
            sd.BufferDesc.RefreshRate.Denominator = 1;
            sd.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;
            sd.OutputWindow = windowHandle;
            sd.SampleDesc.Count = 1;
            sd.SampleDesc.Quality = 0;
            sd.Windowed = TRUE;

            hResult = D3D11CreateDeviceAndSwapChain(NULL,
                D3D_DRIVER_TYPE_HARDWARE,
                NULL,
                0,
                FeatureLevelsRequested,
                3,
                D3D11_SDK_VERSION,
                &sd,
                &m_pSwapChain,
                &m_pD3D11Device,
                &FeatureLevelsSupported,
                &m_pD3D11Context);

            if (FAILED(hResult))
            {
                MessageBoxA(windowHandle, "Error: The Direct3D device has been configured incorrectly.", "When the Sun Sets", 0);
                return -1;
            }

            ID3D11RenderTargetView* m_pBackBufferTarget = 0;

            ID3D11Texture2D* backBufferTexture;
            hResult = m_pSwapChain->GetBuffer(0, __uuidof(ID3D11Texture2D), (LPVOID*)&backBufferTexture);

            if (FAILED(hResult))
            {
                MessageBoxA(windowHandle, "Error: The Direct3D device has been configured incorrectly.", "When the Sun Sets", 0);
                return -1;
            }

            hResult = m_pD3D11Device->CreateRenderTargetView(backBufferTexture, 0, &m_pBackBufferTarget);

            if (backBufferTexture)
            {
                backBufferTexture->Release(); 
                backBufferTexture = 0;
            }

            if (FAILED(hResult))
            {
                MessageBoxA(windowHandle, "Error: The Direct3D device has been configured incorrectly.", "When the Sun Sets", 0);
                return -1;
            }

            m_pD3D11Context->OMSetRenderTargets(1, &m_pBackBufferTarget, 0);

            D3D11_VIEWPORT vp;
            vp.Width = static_cast<float>(width);
            vp.Height = static_cast<float>(height);
            vp.MinDepth = 0.0f;
            vp.MaxDepth = 1.0f;
            vp.TopLeftX = 0;
            vp.TopLeftY = 0;
            m_pD3D11Context->RSSetViewports(1, &vp);

            if (m_pD3D11Context == 0)
            {
                MessageBoxA(windowHandle, "Error: The Direct3D device has been configured incorrectly.", "When the Sun Sets", 0);
                return -1;
            }

            float clearColor[4] = { 0.0f, 135/225.0f, 189/225.0f, 1.0f };

            m_pD3D11Context->ClearRenderTargetView(m_pBackBufferTarget, clearColor);

            m_pSwapChain->Present( 0, 0 );

            MSG fMsg;

            SecureZeroMemory(&fMsg, sizeof(MSG));
            int fReturnValue = 0;

            while ((fReturnValue = GetMessage(&fMsg, 0, 0, 0)) != 0)
            {
                if (fReturnValue == -1)
                {
                    MessageBoxA(windowHandle, "Error: The window has been configured incorrectly.", "When the Sun Sets", 0);
                }

                TranslateMessage(&fMsg);
                DispatchMessage(&fMsg);
            }

            if (m_pBackBufferTarget)
            {
                m_pBackBufferTarget->Release();
                m_pBackBufferTarget = 0;
            }

            if (m_pSwapChain)
            {
                m_pSwapChain->Release();
                m_pSwapChain = 0;
            }

            if (m_pD3D11Context)
            {
                m_pD3D11Context->Release();
                m_pD3D11Context = 0;
            }

            if (m_pD3D11Device)
            {
                m_pD3D11Device->Release();
                m_pD3D11Device = 0;
            }
        }
        break;

它明确指出：

            float clearColor[4] = { 0.0f, 135/225.0f, 189/225.0f, 1.0f };

            m_pD3D11Context->ClearRenderTargetView(m_pBackBufferTarget, clearColor);

            m_pSwapChain->Present( 0, 0 );

哪个应该给出一个青色窗口，不是吗？

提前致谢！

Answer 1

我尝试了代码，它对我有用。我得到一个青色窗口。但是，由于您只调用一次Present，它不会保持（完全）青色。您的WndProc，通过调用DefWindowProc，将使用您设置为(HBRUSH)(COLOR_WINDOW + 1)的窗口背景画笔擦除需要重新绘制的窗口部分。

要解决此问题，您需要做两件事。首先将fGame.hbrBackground 设置为0，所以WndProc 不再擦除窗口。接下来，更改您的消息循环，使其类似于以下内容（改编自 MSDN example）：

bool bGotMsg;
MSG  msg;
msg.message = WM_NULL;
PeekMessage(&msg, NULL, 0U, 0U, PM_NOREMOVE);

while (WM_QUIT != msg.message)
{
    // Process window events.
    // Use PeekMessage() so we can use idle time to render the scene. 
    bGotMsg = (PeekMessage(&msg, NULL, 0U, 0U, PM_REMOVE) != 0);

    if (bGotMsg)
    {
        // Translate and dispatch the message
        TranslateMessage(&msg);
        DispatchMessage(&msg);
    }
    else
    {
        Render();
    }
}

您需要将渲染窗口的代码（应该使其变为青色的部分）移动到上面示例中显示为Render() 的位置。具体来说，对ClearRenderTargetView 和Present 的调用。您可以将Render() 替换为对这两个函数的调用，或者将它们移动到一个名为Render 的函数中。

另外，if (success = GetDesktopResolution) 行并没有按照您显然认为的那样做。它为success 分配一个指向GetDesktopResolution 的函数指针，并且始终评估为真。您应该让GetDesktopResolution 返回一个值（不是void），具体取决于GetDesktopWindow 或GetWindowRect 是否失败，然后检查该值是否失败。