Como criar uma árvore visual simples
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 uma árvore visual simples do Microsoft DirectComposition. O exemplo neste tópico cria e compõe uma árvore visual que consiste em um visual raiz e três visuais filho. O conteúdo do visual raiz é um bitmap azul-claro que serve como plano de fundo para os visuais filho. Esta ilustração mostra a composição criada pelo código de exemplo neste tópico.
O que você precisa saber
Tecnologias
Pré-requisitos
Conhecimento de:
- C/C++
- Microsoft Win32
- COM (Component Object Model)
Instruções
Etapa 1: inicializar os objetos de destino do dispositivo e da composição
Para obter mais informações, consulte Como inicializar o DirectComposition.
Etapa 2: Criar os objetos visuais e definir o conteúdo do bitmap
Use o método IDCompositionDevice::CreateVisual para criar os visuais e o método IDCompositionVisual::SetContent para definir o conteúdo de bitmap dos visuais.
Observação
No exemplo a seguir, o primeiro elemento da m_hBitmaps matriz contém o bitmap para o visual raiz e os elementos restantes contêm os bitmaps para os visuais filho.
#define NUM_VISUALS 4 // number of visuals in the composition
HBITMAP m_hBitmaps[NUM_VISUALS];
HRESULT hr = S_OK;
IDCompositionVisual *pVisuals[NUM_VISUALS]{ };
IDCompositionSurface *pSurface{ nullptr };
// Create a visual objects and set their content.
for (int i = 0; i < NUM_VISUALS; i++)
{
hr = m_pDevice->CreateVisual(&pVisuals[i]);
if (SUCCEEDED(hr))
{
// This application-defined function creates a DirectComposition
// surface and renders a GDI bitmap onto the surface.
hr = MyCreateGDIRenderedDCompSurface(m_hBitmaps[i], &pSurface);
if (SUCCEEDED(hr))
{
// Set the bitmap content.
hr = pVisuals[i]->SetContent(pSurface);
}
SafeRelease(&pSurface);
}
if (FAILED(hr))
{
goto Cleanup;
}
}
A função definida pelo aplicativo a seguir mostra como criar a superfície do Microsoft DirectComposition e renderizar um bitmap da GDI (Interface de Dispositivo Gráfico) do Windows para a 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;
POINT pointOffset = { };
hr = hBitmap ? S_OK : E_FAIL;
if (SUCCEEDED(hr))
{
// 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.
hr = m_pDevice->CreateSurface(bitmapWidth, bitmapHeight,
DXGI_FORMAT_B8G8R8A8_UNORM, DXGI_ALPHA_MODE_IGNORE, ppSurface);
}
hr = ppSurface ? S_OK : E_FAIL;
if (SUCCEEDED(hr))
{
hr = (*ppSurface)->BeginDraw(NULL, __uuidof(IDXGISurface1),
reinterpret_cast<void**>(&pDXGISurface), &pointOffset);
}
if (SUCCEEDED(hr))
{
pDXGISurface->GetDC(FALSE, &hSurfaceDC);
}
hr = hSurfaceDC ? S_OK : E_FAIL;
if (SUCCEEDED(hr))
{
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);
}
(*ppSurface)->EndDraw();
SafeRelease(&pDXGISurface);
return hr;
}
Etapa 3: Definir o visual raiz
Defina os deslocamentos horizontais e verticais do visual raiz e adicione-os à árvore visual chamando o método IDCompositionTarget::SetRoot .
float xPosRoot = 50.0;
float yPosRoot = 50.0;
// Set the horizontal and vertical position of the root visual.
pVisuals[0]->SetOffsetX(xPosRoot);
pVisuals[0]->SetOffsetY(yPosRoot);
// Set the root visual of the visual tree.
hr = m_pCompTarget->SetRoot(pVisuals[0]);
Etapa 4: Adicionar os visuais filho e confirmar a composição
Use métodos expostos pela interface IDCompositionVisual de cada visual filho para definir o conteúdo do bitmap e outras propriedades e, em seguida, use o método IDCompositionVisual::AddVisual do visual raiz para adicionar os visuais filho à raiz da árvore visual. Chame IDCompositionDevice::Commit para confirmar o lote de comandos no DirectComposition para processamento. A composição resultante aparece na janela de destino.
float xPosChild = 20.0f;
float yPosChild = 20.0f;
if (SUCCEEDED(hr))
{
// Set the positions of the child visuals and add them to the visual tree.
for (int i = 1; i < NUM_VISUALS; i++)
{
pVisuals[i]->SetOffsetX(xPosChild);
pVisuals[i]->SetOffsetY(
static_cast<float>((yPosChild * i) + (CHILD_BITMAP_HEIGHT * (i - 1))));
// Add the child visuals as children of the root visual.
pVisuals[0]->AddVisual(pVisuals[i], TRUE, nullptr);
}
}
// Commit the visual to be composed and displayed.
hr = m_pDevice->Commit();
Etapa 5: Liberar os objetos DirectComposition
Libere os objetos visuais assim que você não precisar mais deles. Esse próximo bit de código chama a macro SafeRelease definida pelo aplicativo para liberar os objetos visuais.
Cleanup:
// Free the visuals.
for (int i = 0; i < NUM_VISUALS; i++)
{
SafeRelease(&pVisuals[i]);
}
Além disso, lembre-se de liberar os objetos de destino do dispositivo e da composição antes que o aplicativo seja encerrado.
SafeRelease(&m_pD3D11Device);
SafeRelease(&m_pDevice);
SafeRelease(&m_pCompTarget);
Exemplo completo
// 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>
#include <dcomp.h>
#include <d3d11.h>
/******************************************************************
* *
* Macros *
* *
******************************************************************/
template<class Interface>
inline void
SafeRelease(
Interface **ppInterfaceToRelease
)
{
if (*ppInterfaceToRelease != NULL)
{
(*ppInterfaceToRelease)->Release();
(*ppInterfaceToRelease) = NULL;
}
}
#ifndef Assert
#if defined( DEBUG ) || defined( _DEBUG )
#define Assert(b) if (!(b)) {OutputDebugStringA("Assert: " #b "\n");}
#else
#define Assert(b)
#endif //DEBUG || _DEBUG
#endif
#ifndef HINST_THISCOMPONENT
EXTERN_C IMAGE_DOS_HEADER __ImageBase;
#define HINST_THISCOMPONENT ((HINSTANCE)&__ImageBase)
#endif
// Application-defined constants
#define NUM_VISUALS 4 // number of visuals in the composition
#define CHILD_BITMAP_HEIGHT 96 // height, in pixels, of a child visual
#define NUM_BITMAPS 4 // number of bitmaps in the composition
/******************************************************************
* *
* DemoApp *
* *
******************************************************************/
class DemoApp
{
public:
DemoApp();
~DemoApp();
HRESULT Initialize();
void RunMessageLoop();
private:
HRESULT InitializeDirectCompositionDevice();
HRESULT CreateResources();
void DiscardResources();
HRESULT OnClientClick();
HRESULT DemoApp::LoadResourceGDIBitmap(
PCWSTR resourceName,
HBITMAP &hbmp
);
HRESULT DemoApp::MyCreateGDIRenderedDCompSurface(HBITMAP hBitmap, IDCompositionSurface **ppSurface);
static LRESULT CALLBACK WndProc(
HWND hWnd,
UINT message,
WPARAM wParam,
LPARAM lParam
);
private:
HWND m_hwnd;
HBITMAP m_hBitmaps[NUM_VISUALS];
ID3D11Device *m_pD3D11Device;
IDCompositionDevice *m_pDevice;
IDCompositionTarget *m_pCompTarget;
};
// 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 a root visual and three child
// visuals. The root visual provides the background bitmap for the
// composition, and the three child visuals provide bitmaps that are
// composed on top of the root. All bitmaps are GDI.
#include "SimpleVisualTree.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_hBitmaps(),
m_pD3D11Device(nullptr),
m_pDevice(nullptr),
m_pCompTarget(nullptr)
{
}
/******************************************************************
* *
* Release resources. *
* *
******************************************************************/
DemoApp::~DemoApp()
{
SafeRelease(&m_pD3D11Device);
SafeRelease(&m_pDevice);
SafeRelease(&m_pCompTarget);
}
/*******************************************************************
* *
* 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 = NULL;
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;
IDXGIDevice *pDXGIDevice = nullptr;
// Create the D3D device object.
D3D11CreateDevice(
nullptr,
D3D_DRIVER_TYPE_HARDWARE,
NULL,
D3D11_CREATE_DEVICE_BGRA_SUPPORT,
NULL,
0,
D3D11_SDK_VERSION,
&m_pD3D11Device,
&featureLevelSupported,
NULL);
hr = (m_pD3D11Device == nullptr) ? E_UNEXPECTED : S_OK;
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_pDevice));
}
if (SUCCEEDED(hr))
{
// Create the composition target object.
hr = m_pDevice->CreateTargetForHwnd(m_hwnd, TRUE, &m_pCompTarget);
}
SafeRelease(&pDXGIDevice);
return hr;
}
/******************************************************************
* *
* This method creates the GDI bitmaps to be associated with *
* DirectComposition visual objects. *
* *
******************************************************************/
HRESULT DemoApp::CreateResources()
{
HRESULT hr = S_OK;
hr = LoadResourceGDIBitmap(L"Background", m_hBitmaps[0]);
hr = LoadResourceGDIBitmap(L"BlkKnight", m_hBitmaps[1]);
hr = LoadResourceGDIBitmap(L"BlkQueen", m_hBitmaps[2]);
hr = LoadResourceGDIBitmap(L"BlkRook", m_hBitmaps[3]);
return hr;
}
/******************************************************************
* *
* Discard device-specific resources. *
* *
******************************************************************/
void DemoApp::DiscardResources()
{
int i = 0;
while (i < NUM_VISUALS)
{
DeleteObject(m_hBitmaps[i++]);
}
}
/******************************************************************
* *
* 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 the client area of the main *
* window. This method builds a simple visual tree consisting of *
* a root visual and three child visuals. *
******************************************************************/
HRESULT DemoApp::OnClientClick()
{
HRESULT hr = S_OK;
IDCompositionVisual *pVisuals[NUM_VISUALS] = { };
IDCompositionSurface *pSurface = nullptr;
// Create a visual objects and set their content.
for (int i = 0; i < NUM_VISUALS; i++)
{
hr = m_pDevice->CreateVisual(&pVisuals[i]);
if (SUCCEEDED(hr))
{
// This application-defined function creates a DirectComposition
// surface and renders a GDI bitmap onto the surface.
hr = MyCreateGDIRenderedDCompSurface(m_hBitmaps[i], &pSurface);
if (SUCCEEDED(hr))
{
// Set the bitmap content.
hr = pVisuals[i]->SetContent(pSurface);
}
SafeRelease(&pSurface);
}
if (FAILED(hr))
{
goto Cleanup;
}
}
float xPosRoot = 50.0;
float yPosRoot = 50.0;
// Set the horizontal and vertical position of the root visual.
pVisuals[0]->SetOffsetX(xPosRoot);
pVisuals[0]->SetOffsetY(yPosRoot);
// Set the root visual of the visual tree.
hr = m_pCompTarget->SetRoot(pVisuals[0]);
float xPosChild = 20.0f;
float yPosChild = 20.0f;
if (SUCCEEDED(hr))
{
// Set the positions of the child visuals and add them to the visual tree.
for (int i = 1; i < NUM_VISUALS; i++)
{
pVisuals[i]->SetOffsetX(xPosChild);
pVisuals[i]->SetOffsetY(
static_cast<float>((yPosChild * i) + (CHILD_BITMAP_HEIGHT * (i - 1))));
// Add the child visuals as children of the root visual.
pVisuals[0]->AddVisual(pVisuals[i], TRUE, nullptr);
}
}
// Commit the visual to be composed and displayed.
hr = m_pDevice->Commit();
Cleanup:
// Free the visuals.
for (int i = 0; i < NUM_VISUALS; i++)
{
SafeRelease(&pVisuals[i]);
}
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();
}
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)
{
// Load the bitmap from the application resources.
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;
POINT pointOffset = { };
hr = hBitmap ? S_OK : E_FAIL;
if (SUCCEEDED(hr))
{
// 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.
hr = m_pDevice->CreateSurface(bitmapWidth, bitmapHeight,
DXGI_FORMAT_B8G8R8A8_UNORM, DXGI_ALPHA_MODE_IGNORE, ppSurface);
}
hr = ppSurface ? S_OK : E_FAIL;
if (SUCCEEDED(hr))
{
hr = (*ppSurface)->BeginDraw(NULL, __uuidof(IDXGISurface1),
reinterpret_cast<void**>(&pDXGISurface), &pointOffset);
}
if (SUCCEEDED(hr))
{
pDXGISurface->GetDC(FALSE, &hSurfaceDC);
}
hr = hSurfaceDC ? S_OK : E_FAIL;
if (SUCCEEDED(hr))
{
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);
}
(*ppSurface)->EndDraw();
SafeRelease(&pDXGISurface);
return hr;
}