Como inicializar o DirectComposition
Observação
Para aplicativos no Windows 10, é recomendável usar APIs Windows.UI.Composition em vez de DirectComposition. Para obter mais informações, consulte Modernizar seu aplicativo da área de trabalho usando a camada Visual.
Este tópico demonstra como criar e inicializar o conjunto mínimo de objetos Do Microsoft DirectComposition necessários para criar uma composição simples.
O que você precisa saber
Tecnologias
Pré-requisitos
- C/C++
- Microsoft Win32
- COM (Component Object Model)
Instruções
Etapa 1: Criar o objeto de dispositivo Direct3D
Use a função D3D11CreateDevice da API do Microsoft Direct3D para criar uma instância de um objeto de dispositivo que representa o adaptador de exibição.
ID3D11Device *m_pD3D11Device;
D3D_FEATURE_LEVEL featureLevelSupported;
// Create the D3D device object. The D3D11_CREATE_DEVICE_BGRA_SUPPORT
// flag enables rendering on surfaces using Direct2D.
hr = D3D11CreateDevice(
nullptr,
D3D_DRIVER_TYPE_HARDWARE,
NULL,
D3D11_CREATE_DEVICE_BGRA_SUPPORT,
NULL,
0,
D3D11_SDK_VERSION,
&m_pD3D11Device,
&featureLevelSupported,
nullptr);
Etapa 2: recuperar um ponteiro para o objeto DXGI
Use o método QueryInterface para recuperar o ponteiro IDXGIDevice do objeto de dispositivo Direct3D. O DirectComposition usará o objeto DXGI (Microsoft DirectX Graphics Infrastructure) para criar todos os objetos surface para o dispositivo DirectComposition.
IDXGIDevice *pDXGIDevice = nullptr;
// Check the result of calling D3D11CreateDriver.
if (SUCCEEDED(hr))
{
// Create the DXGI device used to create bitmap surfaces.
hr = m_pD3D11Device->QueryInterface(&pDXGIDevice);
}
Etapa 3: Criar o objeto de dispositivo DirectComposition
Use a função DCompositionCreateDevice para criar uma instância do objeto de dispositivo DirectComposition, especificando o ponteiro IDXGIDevice recuperado na etapa anterior. A função recupera um ponteiro IDCompositionDevice usado para criar todos os outros objetos DirectComposition usados em uma composição.
IDCompositionDevice *m_pDCompDevice;
if (SUCCEEDED(hr))
{
// Create the DirectComposition device object.
hr = DCompositionCreateDevice(pDXGIDevice,
__uuidof(IDCompositionDevice),
reinterpret_cast<void **>(&m_pDCompDevice));
}
Etapa 4: Criar o objeto de destino de composição
Use o método IDCompositionDevice::CreateTargetForHwnd para criar uma instância do objeto de destino de composição. Chamar CreateTargetForHwnd associa o objeto de dispositivo à janela do aplicativo que exibirá a composição.
IDCompositionTarget *m_pDCompTarget;
if (SUCCEEDED(hr))
{
// Create the composition target object based on the
// specified application window.
hr = m_pDCompDevice->CreateTargetForHwnd(m_hwnd, TRUE, &m_pDCompTarget);
}
Etapa 5: Criar um objeto visual
Use o método IDCompositionDevice::CreateVisual para criar um objeto visual. O método recupera um ponteiro IDCompositionVisual usado para definir as propriedades do visual. Para obter mais informações, consulte Propriedades de um objeto visual.
IDCompositionVisual *pVisual = nullptr;
// Create a visual object.
hr = m_pDCompDevice->CreateVisual(&pVisual);
Etapa 6: Criar uma superfície de composição e renderizar um bitmap para a superfície
Crie um ponteiro IDCompositionSurface .
IDCompositionSurface *pSurface = nullptr;
if (SUCCEEDED(hr))
{
// Create a composition surface and render a GDI bitmap
// to the surface.
hr = MyCreateGDIRenderedDCompSurface(m_hBitmap, &pSurface);
}
A função a seguir cria uma superfície do Microsoft DirectComposition e desenha o bitmap na superfície.
// MyCreateGDIRenderedDCompSurface - Creates a DirectComposition surface and
// copies the bitmap to the surface.
//
// Parameters:
// hBitmap - a GDI bitmap.
// ppSurface - the composition surface object.
//
HRESULT DemoApp::MyCreateGDIRenderedDCompSurface(HBITMAP hBitmap,
IDCompositionSurface **ppSurface)
{
HRESULT hr = S_OK;
int bitmapWidth = 0;
int bitmapHeight = 0;
int bmpSize = 0;
BITMAP bmp = { };
HBITMAP hBitmapOld = NULL;
HDC hSurfaceDC = NULL;
HDC hBitmapDC = NULL;
IDXGISurface1 *pDXGISurface = nullptr;
IDCompositionSurface *pDCSurface = nullptr;
POINT pointOffset = { };
if (ppSurface == nullptr)
return E_INVALIDARG;
// Get information about the bitmap.
bmpSize = GetObject(hBitmap, sizeof(BITMAP), &bmp);
hr = bmpSize ? S_OK : E_FAIL;
if (SUCCEEDED(hr))
{
// Save the bitmap dimensions.
bitmapWidth = bmp.bmWidth;
bitmapHeight = bmp.bmHeight;
// Create a DirectComposition-compatible surface that is the same size
// as the bitmap. The DXGI_FORMAT_B8G8R8A8_UNORM flag is required for
// rendering on the surface using GDI via GetDC.
hr = m_pDCompDevice->CreateSurface(bitmapWidth, bitmapHeight,
DXGI_FORMAT_B8G8R8A8_UNORM, DXGI_ALPHA_MODE_IGNORE, &pDCSurface);
}
if (SUCCEEDED(hr))
{
// Begin rendering to the surface.
hr = pDCSurface->BeginDraw(NULL, __uuidof(IDXGISurface1),
reinterpret_cast<void**>(&pDXGISurface), &pointOffset);
}
if (SUCCEEDED(hr))
{
// Get the device context (DC) for the surface.
hr = pDXGISurface->GetDC(FALSE, &hSurfaceDC);
}
if (SUCCEEDED(hr))
{
// Create a compatible DC and select the surface
// into the DC.
hBitmapDC = CreateCompatibleDC(hSurfaceDC);
if (hBitmapDC != NULL)
{
hBitmapOld = (HBITMAP)SelectObject(hBitmapDC, hBitmap);
BitBlt(hSurfaceDC, pointOffset.x, pointOffset.y,
bitmapWidth, bitmapHeight, hBitmapDC, 0, 0, SRCCOPY);
if (hBitmapOld)
{
SelectObject(hBitmapDC, hBitmapOld);
}
DeleteDC(hBitmapDC);
}
pDXGISurface->ReleaseDC(NULL);
}
// End the rendering.
pDCSurface->EndDraw();
*ppSurface = pDCSurface;
// Call an application-defined macro to free the surface pointer.
SafeRelease(&pDXGISurface);
return hr;
}
Etapa 7: Associar a superfície ao visual e definir as propriedades do objeto visual
Chame os métodos da interface IDCompositionVisual do objeto visual para definir as propriedades do visual.
Este próximo exemplo define o conteúdo do bitmap para o visual e a posição horizontal e vertical do visual em relação ao canto superior esquerdo do contêiner. Como é o visual raiz, o contêiner para esse visual é a janela de destino de composição.
if (SUCCEEDED(hr))
{
// Set the bitmap content of the visual.
hr = pVisual->SetContent(pSurface);
}
if (SUCCEEDED(hr))
{
// Set the horizontal and vertical position of the visual relative
// to the upper-left corner of the composition target window.
hr = pVisual->SetOffsetX(xOffset);
if (SUCCEEDED(hr))
{
hr = pVisual->SetOffsetY(yOffset);
}
}
Etapa 8: Definir o visual raiz da árvore visual
Defina o visual raiz da árvore visual chamando o método IDCompositionTarget::SetRoot .
if (SUCCEEDED(hr))
{
// Set the visual to be the root of the visual tree.
hr = m_pDCompTarget->SetRoot(pVisual);
}
Etapa 9: Confirmar a composição
Chame o método IDCompositionDevice::Commit para confirmar o lote de comandos no DirectComposition para processamento. A composição resultante aparece na janela de destino.
if (SUCCEEDED(hr))
{
// Commit the visual to be composed and displayed.
hr = m_pDCompDevice->Commit();
}
Etapa 10: Liberar os objetos DirectComposition
É uma boa prática de programação liberar objetos visuais assim que você não precisar mais deles. O exemplo a seguir chama a macro SafeRelease definida pelo aplicativo para liberar o objeto visual.
// Free the visual.
SafeRelease(&pVisual);
Além disso, lembre-se de liberar o objeto DXGI, o objeto do dispositivo e o objeto de destino de composição antes da saída do aplicativo.
SafeRelease(&pDXGIDevice);
SafeRelease(&m_pDCompDevice);
SafeRelease(&m_pDCompTarget);
SafeRelease(&m_pD3D11Device);
Exemplo completo
//
// SimpleComposition.h
//
// THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF
// ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO
// THE IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A
// PARTICULAR PURPOSE.
//
// Copyright (c) Microsoft Corporation. All rights reserved
#pragma once
// Modify the following definitions if you need to target a platform prior to the ones specified below.
#ifndef WINVER // Allow use of features specific to Windows 7 or later.
#define WINVER 0x0700 // Change this to the appropriate value to target other versions of Windows.
#endif
#ifndef _WIN32_WINNT // Allow use of features specific to Windows 7 or later.
#define _WIN32_WINNT 0x0700 // Change this to the appropriate value to target other versions of Windows.
#endif
#ifndef UNICODE
#define UNICODE
#endif
#define WIN32_LEAN_AND_MEAN // Exclude rarely-used items from Windows headers
// Windows Header Files:
#include <windows.h>
// C RunTime Header Files
#include <math.h>
// DirectComposition Header Files
#include <dcomp.h>
// Direct3D Header Files
#include <d3d11.h>
/******************************************************************
* *
* Macros *
* *
******************************************************************/
template<class Interface>
inline void
SafeRelease(
Interface **ppInterfaceToRelease
)
{
if (*ppInterfaceToRelease != NULL)
{
(*ppInterfaceToRelease)->Release();
(*ppInterfaceToRelease) = NULL;
}
}
#ifndef HINST_THISCOMPONENT
EXTERN_C IMAGE_DOS_HEADER __ImageBase;
#define HINST_THISCOMPONENT ((HINSTANCE)&__ImageBase)
#endif
/******************************************************************
* *
* DemoApp *
* *
******************************************************************/
class DemoApp
{
public:
DemoApp();
~DemoApp();
HRESULT Initialize();
void RunMessageLoop();
private:
HRESULT InitializeDirectCompositionDevice();
HRESULT CreateResources();
void DiscardResources();
HRESULT OnClientClick();
HRESULT LoadResourceGDIBitmap(
PCWSTR resourceName,
HBITMAP &hbmp
);
HRESULT MyCreateGDIRenderedDCompSurface(HBITMAP hBitmap,
IDCompositionSurface **ppSurface);
static LRESULT CALLBACK WndProc(
HWND hWnd,
UINT message,
WPARAM wParam,
LPARAM lParam
);
private:
HWND m_hwnd;
HBITMAP m_hBitmap;
ID3D11Device *m_pD3D11Device;
IDCompositionDevice *m_pDCompDevice;
IDCompositionTarget *m_pDCompTarget;
};
//
// SimpleComposition.cpp
//
// THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF
// ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO
// THE IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A
// PARTICULAR PURPOSE.
//
// Copyright (c) Microsoft Corporation. All rights reserved
// Instructions: Right-click in the client area to cause DirectCompostion
// to create a simple composition consisting of a single GDI bitmap.
#include "SimpleComposition.h"
/******************************************************************
* *
* The application entry point. *
* *
******************************************************************/
int WINAPI WinMain(
HINSTANCE /* hInstance */,
HINSTANCE /* hPrevInstance */,
LPSTR /* lpCmdLine */,
int /* nCmdShow */
)
{
// Ignore the return value because we want to run the program even in the
// unlikely event that HeapSetInformation fails.
HeapSetInformation(NULL, HeapEnableTerminationOnCorruption, NULL, 0);
if (SUCCEEDED(CoInitialize(NULL)))
{
{
DemoApp app;
if (SUCCEEDED(app.Initialize()))
{
app.RunMessageLoop();
}
}
CoUninitialize();
}
return 0;
}
/******************************************************************
* *
* DemoApp::DemoApp constructor *
* *
* Initialize member data. *
* *
******************************************************************/
DemoApp::DemoApp() :
m_hwnd(NULL),
m_hBitmap(NULL),
m_pDCompDevice(nullptr),
m_pDCompTarget(nullptr),
m_pD3D11Device(nullptr)
{
}
/******************************************************************
* *
* Release resources. *
* *
******************************************************************/
DemoApp::~DemoApp()
{
SafeRelease(&m_pDCompDevice);
SafeRelease(&m_pDCompTarget);
SafeRelease(&m_pD3D11Device);
}
/*******************************************************************
* *
* Create the application window. *
* *
*******************************************************************/
HRESULT DemoApp::Initialize()
{
HRESULT hr;
// Register the window class.
WNDCLASSEX wcex = { sizeof(WNDCLASSEX) };
wcex.style = CS_HREDRAW | CS_VREDRAW;
wcex.lpfnWndProc = DemoApp::WndProc;
wcex.cbClsExtra = 0;
wcex.cbWndExtra = sizeof(LONG_PTR);
wcex.hInstance = HINST_THISCOMPONENT;
wcex.hbrBackground = (HBRUSH)(COLOR_WINDOW+1);;
wcex.lpszMenuName = nullptr;
wcex.hCursor = LoadCursor(NULL, IDC_ARROW);
wcex.lpszClassName = L"DirectCompDemoApp";
RegisterClassEx(&wcex);
// Create the application window.
//
// Because the CreateWindow function takes its size in pixels, we
// obtain the system DPI and use it to scale the window size.
int dpiX = 0;
int dpiY = 0;
HDC hdc = GetDC(NULL);
if (hdc)
{
dpiX = GetDeviceCaps(hdc, LOGPIXELSX);
dpiY = GetDeviceCaps(hdc, LOGPIXELSY);
ReleaseDC(NULL, hdc);
}
m_hwnd = CreateWindow(
L"DirectCompDemoApp",
L"DirectComposition Demo Application",
WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT,
CW_USEDEFAULT,
static_cast<UINT>(ceil(640.f * dpiX / 96.f)),
static_cast<UINT>(ceil(480.f * dpiY / 96.f)),
NULL,
NULL,
HINST_THISCOMPONENT,
this
);
hr = m_hwnd ? S_OK : E_FAIL;
if (SUCCEEDED(hr))
{
ShowWindow(m_hwnd, SW_SHOWNORMAL);
UpdateWindow(m_hwnd);
// Initialize DirectComposition resources, such as the
// device object and composition target object.
hr = InitializeDirectCompositionDevice();
}
if (SUCCEEDED(hr))
{
hr = CreateResources();
}
return hr;
}
/******************************************************************
* *
* This method creates the DirectComposition device object and *
* and the composition target object. These objects endure for *
* the lifetime of the application. *
* *
******************************************************************/
HRESULT DemoApp::InitializeDirectCompositionDevice()
{
HRESULT hr = S_OK;
D3D_FEATURE_LEVEL featureLevelSupported;
// Create the D3D device object. The D3D11_CREATE_DEVICE_BGRA_SUPPORT
// flag enables rendering on surfaces using Direct2D.
hr = D3D11CreateDevice(
nullptr,
D3D_DRIVER_TYPE_HARDWARE,
NULL,
D3D11_CREATE_DEVICE_BGRA_SUPPORT,
NULL,
0,
D3D11_SDK_VERSION,
&m_pD3D11Device,
&featureLevelSupported,
nullptr);
IDXGIDevice *pDXGIDevice = nullptr;
// Check the result of calling D3D11CreateDriver.
if (SUCCEEDED(hr))
{
// Create the DXGI device used to create bitmap surfaces.
hr = m_pD3D11Device->QueryInterface(&pDXGIDevice);
}
if (SUCCEEDED(hr))
{
// Create the DirectComposition device object.
hr = DCompositionCreateDevice(pDXGIDevice,
__uuidof(IDCompositionDevice),
reinterpret_cast<void **>(&m_pDCompDevice));
}
if (SUCCEEDED(hr))
{
// Create the composition target object based on the
// specified application window.
hr = m_pDCompDevice->CreateTargetForHwnd(m_hwnd, TRUE, &m_pDCompTarget);
}
SafeRelease(&pDXGIDevice);
return hr;
}
/******************************************************************
* *
* This method creates the GDI bitmap that the application gives *
* to DirectComposition to be composed. *
* *
******************************************************************/
HRESULT DemoApp::CreateResources()
{
HRESULT hr = S_OK;
hr = LoadResourceGDIBitmap(L"Logo", m_hBitmap);
return hr;
}
/******************************************************************
* *
* Discard device-specific resources. *
* *
******************************************************************/
void DemoApp::DiscardResources()
{
DeleteObject(m_hBitmap);
}
/******************************************************************
* *
* The main window's message loop. *
* *
******************************************************************/
void DemoApp::RunMessageLoop()
{
MSG msg;
while (GetMessage(&msg, NULL, 0, 0))
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
}
/******************************************************************
* *
* Called whenever the user clicks in client area of the main *
* window. This method builds a simple visual tree and passes it *
* to DirectComposition.
* *
******************************************************************/
HRESULT DemoApp::OnClientClick()
{
HRESULT hr = S_OK;
float xOffset = 20; // horizonal position of visual
float yOffset = 20; // vertical position of visual
IDCompositionVisual *pVisual = nullptr;
// Create a visual object.
hr = m_pDCompDevice->CreateVisual(&pVisual);
IDCompositionSurface *pSurface = nullptr;
if (SUCCEEDED(hr))
{
// Create a composition surface and render a GDI bitmap
// to the surface.
hr = MyCreateGDIRenderedDCompSurface(m_hBitmap, &pSurface);
}
if (SUCCEEDED(hr))
{
// Set the bitmap content of the visual.
hr = pVisual->SetContent(pSurface);
}
if (SUCCEEDED(hr))
{
// Set the horizontal and vertical position of the visual relative
// to the upper-left corner of the composition target window.
hr = pVisual->SetOffsetX(xOffset);
if (SUCCEEDED(hr))
{
hr = pVisual->SetOffsetY(yOffset);
}
}
if (SUCCEEDED(hr))
{
// Set the visual to be the root of the visual tree.
hr = m_pDCompTarget->SetRoot(pVisual);
}
if (SUCCEEDED(hr))
{
// Commit the visual to be composed and displayed.
hr = m_pDCompDevice->Commit();
}
// Free the visual.
SafeRelease(&pVisual);
return hr;
}
/******************************************************************
* *
* The window's message handler. *
* *
******************************************************************/
LRESULT CALLBACK DemoApp::WndProc(HWND hwnd, UINT message,
WPARAM wParam, LPARAM lParam)
{
LRESULT result = 0;
if (message == WM_CREATE)
{
LPCREATESTRUCT pcs = (LPCREATESTRUCT)lParam;
DemoApp *pDemoApp = (DemoApp *)pcs->lpCreateParams;
::SetWindowLongPtrW(
hwnd,
GWLP_USERDATA,
PtrToUlong(pDemoApp)
);
result = 1;
}
else
{
DemoApp *pDemoApp = reinterpret_cast<DemoApp *>(static_cast<LONG_PTR>(
::GetWindowLongPtrW(
hwnd,
GWLP_USERDATA
)));
bool wasHandled = false;
if (pDemoApp)
{
switch (message)
{
case WM_LBUTTONDOWN:
{
pDemoApp->OnClientClick();
}
wasHandled = true;
result = 0;
break;
case WM_DISPLAYCHANGE:
{
InvalidateRect(hwnd, NULL, FALSE);
}
wasHandled = true;
result = 0;
break;
case WM_DESTROY:
{
PostQuitMessage(0);
pDemoApp->DiscardResources();
}
wasHandled = true;
result = 1;
break;
}
}
if (!wasHandled)
{
result = DefWindowProc(hwnd, message, wParam, lParam);
}
}
return result;
}
/******************************************************************
* *
* This method loads the specified GDI bitmap from the *
* application resources, creates a new bitmap that is in a *
* format that DirectComposition can use, and copies the contents *
* of the original bitmap to the new bitmap. *
* *
******************************************************************/
HRESULT DemoApp::LoadResourceGDIBitmap(PCWSTR resourceName, HBITMAP &hbmp)
{
hbmp = static_cast<HBITMAP>(LoadImageW(HINST_THISCOMPONENT, resourceName,
IMAGE_BITMAP, 0, 0, LR_DEFAULTCOLOR));
return hbmp ? S_OK : E_FAIL;
}
// MyCreateGDIRenderedDCompSurface - Creates a DirectComposition surface and
// copies the bitmap to the surface.
//
// Parameters:
// hBitmap - a GDI bitmap.
// ppSurface - the composition surface object.
//
HRESULT DemoApp::MyCreateGDIRenderedDCompSurface(HBITMAP hBitmap,
IDCompositionSurface **ppSurface)
{
HRESULT hr = S_OK;
int bitmapWidth = 0;
int bitmapHeight = 0;
int bmpSize = 0;
BITMAP bmp = { };
HBITMAP hBitmapOld = NULL;
HDC hSurfaceDC = NULL;
HDC hBitmapDC = NULL;
IDXGISurface1 *pDXGISurface = nullptr;
IDCompositionSurface *pDCSurface = nullptr;
POINT pointOffset = { };
if (ppSurface == nullptr)
return E_INVALIDARG;
// Get information about the bitmap.
bmpSize = GetObject(hBitmap, sizeof(BITMAP), &bmp);
hr = bmpSize ? S_OK : E_FAIL;
if (SUCCEEDED(hr))
{
// Save the bitmap dimensions.
bitmapWidth = bmp.bmWidth;
bitmapHeight = bmp.bmHeight;
// Create a DirectComposition-compatible surface that is the same size
// as the bitmap. The DXGI_FORMAT_B8G8R8A8_UNORM flag is required for
// rendering on the surface using GDI via GetDC.
hr = m_pDCompDevice->CreateSurface(bitmapWidth, bitmapHeight,
DXGI_FORMAT_B8G8R8A8_UNORM, DXGI_ALPHA_MODE_IGNORE, &pDCSurface);
}
if (SUCCEEDED(hr))
{
// Begin rendering to the surface.
hr = pDCSurface->BeginDraw(NULL, __uuidof(IDXGISurface1),
reinterpret_cast<void**>(&pDXGISurface), &pointOffset);
}
if (SUCCEEDED(hr))
{
// Get the device context (DC) for the surface.
hr = pDXGISurface->GetDC(FALSE, &hSurfaceDC);
}
if (SUCCEEDED(hr))
{
// Create a compatible DC and select the surface
// into the DC.
hBitmapDC = CreateCompatibleDC(hSurfaceDC);
if (hBitmapDC != NULL)
{
hBitmapOld = (HBITMAP)SelectObject(hBitmapDC, hBitmap);
BitBlt(hSurfaceDC, pointOffset.x, pointOffset.y,
bitmapWidth, bitmapHeight, hBitmapDC, 0, 0, SRCCOPY);
if (hBitmapOld)
{
SelectObject(hBitmapDC, hBitmapOld);
}
DeleteDC(hBitmapDC);
}
pDXGISurface->ReleaseDC(NULL);
}
// End the rendering.
pDCSurface->EndDraw();
*ppSurface = pDCSurface;
// Call an application-defined macro to free the surface pointer.
SafeRelease(&pDXGISurface);
return hr;
}
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