https://learn.microsoft.com/ko-kr/windows/win32/direct2d/direct2d-quickstart-with-device-context
按照上面的步骤，我输入了绘制矩形的 Direct2D 基本代码。但它并没有画出任何东西。原因是什么？
这是创建一个空工程并在工程属性中将子系统设置为WINDOW后的结果。
#pragma comment(lib, "D2D1.lib")
#pragma comment(lib, "D3D11.lib")
#pragma comment(lib, "DXGI.lib")
#pragma comment(lib, "dxguid.lib")
#include <windows.h>
#include <d2d1.h>
#include <d2d1helper.h>
#include <d2d1_1.h>
#include <d3d11.h>
#include <dxgi.h>
#include <dxgi1_2.h>
#include <wrl.h>
#include <wincodec.h>
using namespace D2D1;
using namespace Microsoft::WRL;
HINSTANCE g_hInst;
HWND hWndMain;
LPCTSTR lpszClass = TEXT("DeviceContext Test");
int m_dpi = 96;
ComPtr<ID2D1Factory1> m_d2dFactory;
D3D_FEATURE_LEVEL m_featureLevel;
ComPtr<ID2D1Device> m_d2dDevice;
ComPtr<ID2D1DeviceContext> m_d2dContext;
ComPtr<IDXGISwapChain1> m_swapChain;
ComPtr<ID2D1Bitmap1> m_d2dTargetBitmap;
ComPtr<ID3D11Device> device;
ComPtr<ID3D11DeviceContext> context;
ComPtr<IDXGIDevice1> dxgiDevice;
ComPtr<IDXGIAdapter> dxgiAdapter;
ComPtr<IDXGIFactory2> dxgiFactory;
ComPtr<ID3D11Texture2D> backBuffer;
ComPtr<IDXGISurface> dxgiBackBuffer;
void onInit();
void onPaint();
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
int APIENTRY WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance
, LPSTR lpszCmdParam, int nCmdShow)
{
HWND hWnd;
MSG Message;
WNDCLASS WndClass;
g_hInst = hInstance;
WndClass.cbClsExtra = 0;
WndClass.cbWndExtra = 0;
WndClass.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
WndClass.hCursor = LoadCursor(NULL, IDC_ARROW);
WndClass.hIcon = LoadIcon(NULL, IDI_APPLICATION);
WndClass.hInstance = hInstance;
WndClass.lpfnWndProc = WndProc;
WndClass.lpszClassName = lpszClass;
WndClass.lpszMenuName = NULL;
WndClass.style = CS_HREDRAW | CS_VREDRAW;
RegisterClass(&WndClass);
hWnd = CreateWindow(lpszClass, lpszClass, WS_OVERLAPPEDWINDOW,
//CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT,
1400, 500, 500, 500,
NULL, (HMENU)NULL, hInstance, NULL);
hWndMain = hWnd;
ShowWindow(hWnd, nCmdShow);
while (GetMessage(&Message, NULL, 0, 0)) {
TranslateMessage(&Message);
DispatchMessage(&Message);
}
return (int)Message.wParam;
}
LRESULT CALLBACK WndProc(HWND hWnd, UINT iMessage, WPARAM wParam, LPARAM lParam)
{
HDC hdc;
PAINTSTRUCT ps;
switch (iMessage) {
case WM_CREATE:
hWndMain = hWnd;
onInit();
return 0;
case WM_PAINT:
hdc = BeginPaint(hWnd, &ps);
EndPaint(hWnd, &ps);
onPaint();
InvalidateRect(hWnd, 0, 0);
return 0;
case WM_DESTROY:
PostQuitMessage(0);
return 0;
}
return(DefWindowProc(hWnd, iMessage, wParam, lParam));
}
void onPaint()
{
HRESULT res;
m_d2dContext->SetTarget(m_d2dTargetBitmap.Get());
auto size = m_d2dTargetBitmap->GetSize();
ComPtr<ID2D1SolidColorBrush> pBlackBrush;
res = m_d2dContext->CreateSolidColorBrush(
D2D1::ColorF(D2D1::ColorF::Black),
&pBlackBrush
);
m_d2dContext->BeginDraw();
D2D1_RECT_F rc;
rc.left = rc.top = 100;
rc.right = rc.bottom = 200;
m_d2dContext->DrawRectangle(rc, pBlackBrush.Get());
res = m_d2dContext->EndDraw();
RECT rect = { 0, 0, 400, 400 };
DXGI_PRESENT_PARAMETERS parameters;
parameters.DirtyRectsCount = 1;
parameters.pDirtyRects = ▭
parameters.pScrollOffset = 0;
parameters.pScrollRect = 0;
res = m_swapChain->Present1(1, 0, ¶meters);
}
void onInit()
{
D2D1_FACTORY_OPTIONS options;
options.debugLevel = D2D1_DEBUG_LEVEL_ERROR;
D2D1CreateFactory(D2D1_FACTORY_TYPE_SINGLE_THREADED, __uuidof(ID2D1Factory1), &options, &m_d2dFactory);
// This flag adds support for surfaces with a different color channel ordering than the API default.
// You need it for compatibility with Direct2D.
UINT creationFlags = D3D11_CREATE_DEVICE_BGRA_SUPPORT;
// This array defines the set of DirectX hardware feature levels this app supports.
// The ordering is important and you should preserve it.
// Don't forget to declare your app's minimum required feature level in its
// description. All apps are assumed to support 9.1 unless otherwise stated.
D3D_FEATURE_LEVEL featureLevels[] =
{
D3D_FEATURE_LEVEL_11_1,
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
};
// Create the DX11 API device object, and get a corresponding context.
D3D11CreateDevice(
nullptr, // specify null to use the default adapter
D3D_DRIVER_TYPE_HARDWARE,
0,
creationFlags, // optionally set debug and Direct2D compatibility flags
featureLevels, // list of feature levels this app can support
ARRAYSIZE(featureLevels), // number of possible feature levels
D3D11_SDK_VERSION,
&device, // returns the Direct3D device created
&m_featureLevel, // returns feature level of device created
&context // returns the device immediate context
);
// Obtain the underlying DXGI device of the Direct3D11 device.
device.As(&dxgiDevice);
// Obtain the Direct2D device for 2-D rendering.
m_d2dFactory->CreateDevice(dxgiDevice.Get(), &m_d2dDevice);
// Get Direct2D device's corresponding device context object.
m_d2dDevice->CreateDeviceContext(
D2D1_DEVICE_CONTEXT_OPTIONS_NONE,
&m_d2dContext
);
// Allocate a descriptor.
DXGI_SWAP_CHAIN_DESC1 swapChainDesc = { 0 };
swapChainDesc.Width = 0; // use automatic sizing
swapChainDesc.Height = 0;
swapChainDesc.Format = DXGI_FORMAT_B8G8R8A8_UNORM; // this is the most common swapchain format
swapChainDesc.Stereo = false;
swapChainDesc.SampleDesc.Count = 1; // don't use multi-sampling
swapChainDesc.SampleDesc.Quality = 0;
swapChainDesc.BufferUsage = DXGI_USAGE_RENDER_TARGET_OUTPUT;
swapChainDesc.BufferCount = 2; // use double buffering to enable flip
swapChainDesc.Scaling = DXGI_SCALING_NONE;
swapChainDesc.SwapEffect = DXGI_SWAP_EFFECT_FLIP_SEQUENTIAL; // all apps must use this SwapEffect
swapChainDesc.Flags = 0;
// Identify the physical adapter (GPU or card) this device is runs on.
dxgiDevice->GetAdapter(&dxgiAdapter);
// Get the factory object that created the DXGI device.
dxgiAdapter->GetParent(IID_PPV_ARGS(&dxgiFactory));
// Get the final swap chain for this window from the DXGI factory.
dxgiFactory->CreateSwapChainForHwnd(
device.Get(),
hWndMain,
&swapChainDesc,
nullptr, // allow on all displays
nullptr,
&m_swapChain
);
// Ensure that DXGI doesn't queue more than one frame at a time.
dxgiDevice->SetMaximumFrameLatency(1);
// Get the backbuffer for this window which is be the final 3D render target.
m_swapChain->GetBuffer(0, IID_PPV_ARGS(&backBuffer));
// Now we set up the Direct2D render target bitmap linked to the swapchain.
// Whenever we render to this bitmap, it is directly rendered to the
// swap chain associated with the window.
D2D1_BITMAP_PROPERTIES1 bitmapProperties =
BitmapProperties1(
D2D1_BITMAP_OPTIONS_TARGET | D2D1_BITMAP_OPTIONS_CANNOT_DRAW,
PixelFormat(DXGI_FORMAT_B8G8R8A8_UNORM, D2D1_ALPHA_MODE_IGNORE),
m_dpi,
m_dpi
);
// Direct2D needs the dxgi version of the backbuffer surface pointer.
m_swapChain->GetBuffer(0, IID_PPV_ARGS(&dxgiBackBuffer));
// Get a D2D surface from the DXGI back buffer to use as the D2D render target.
m_d2dContext->CreateBitmapFromDxgiSurface(
dxgiBackBuffer.Get(),
&bitmapProperties,
&m_d2dTargetBitmap
);
}
更新窗口后，尝试删除 InvalidateRect 行或将其更改为 ValidateRect(hwnd, NULL)。
如果你不使用BeginPaint() ... EndPaint()对，你一定要使用ValidateRect(hwnd, NULL)，否则窗口将不断生成WM_PAINT消息。 EndPaint() 内部执行 ValidateRect(hwnd, NULL)