问题描述
我正在研究一个根据本文进行直接组合的项目：
Windows with C++ : High-Performance Window Layering Using the Windows Composition Engine
我能够重新创建示例，并且该示例正在运行。当前，我正在尝试将IDCompositionGaussianBlurEffect应用于我的Visual (variable: visual)，但是编译器会引发访问冲突异常。有什么方法可以使用直接合成将模糊效果应用于我的视觉效果。
例外：
Exception thrown at 0x6E695565 (dcomp.dll) in DirectComNoCom.exe: 0xC0000005: Access violation reading location 0x41200000.
此行抛出异常：
effect->SetStandardDeviation(10.0f);
这是完整代码：
#ifndef UNICODE
#define UNICODE
#endif
#include <windows.h>
#include <wrl.h>
using namespace Microsoft::WRL;
#include <dxgi1_3.h>
#include <d3d11_2.h>
#include <d2d1_2.h>
#include <d2d1_2helper.h>
#include <dcomp.h>
#pragma comment(lib,"dxgi")
#pragma comment(lib,"d3d11")
#pragma comment(lib,"d2d1")
#pragma comment(lib,"dcomp")
LRESULT CALLBACK WindowProc(HWND hwnd,UINT uMsg,WParaM wParam,LParaM lParam);
ComPtr<ID3D11Device> direct3dDevice;
ComPtr<IdxgiDevice> dxgiDevice;
ComPtr<IdxgiFactory2> dxFactory;
ComPtr<IdxgiSwapChain1> swapChain;
ComPtr<ID2D1Factory2> d2Factory;
ComPtr<ID2D1Device1> d2Device;
ComPtr<IDCompositionTarget> target;
struct ComException
{
HRESULT result;
ComException(HRESULT const value) :
result(value)
{}
};
void HR(HRESULT const result)
{
if (S_OK != result)
{
throw ComException(result);
}
}
void CreateVisual(HWND hwnd)
{
HR(D3D11CreateDevice(nullptr,// Adapter
D3D_DRIVER_TYPE_HARDWARE,nullptr,// Module
D3D11_CREATE_DEVICE_BGRA_SUPPORT,// Highest available feature level
D3D11_SDK_VERSION,&direct3dDevice,// Actual feature level
nullptr)); // Device context
HR(direct3dDevice.As(&dxgiDevice));
HR(CreatedxgiFactory2(
dxgi_CREATE_FACTORY_DEBUG,__uuidof(dxFactory),reinterpret_cast<void**>(dxFactory.GetAddressOf())));
dxgi_SWAP_CHAIN_DESC1 description = {};
description.Format = dxgi_FORMAT_B8G8R8A8_UnorM;
description.BufferUsage = dxgi_USAGE_RENDER_TARGET_OUTPUT;
description.SwapEffect = dxgi_SWAP_EFFECT_FLIP_SEQUENTIAL;
description.BufferCount = 2;
description.SampleDesc.Count = 1;
description.AlphaMode = dxgi_ALPHA_MODE_PREMULTIPLIED;
RECT rect = {};
GetClientRect(hwnd,&rect);
description.Width = rect.right - rect.left;
description.Height = rect.bottom - rect.top;
HR(dxFactory->CreateSwapChainForComposition(dxgiDevice.Get(),&description,// Don’t restrict
swapChain.GetAddressOf()));
D2D1_FACTORY_OPTIONS const options = { D2D1_DEBUG_LEVEL_@R_774_4045@ION };
HR(D2D1CreateFactory(D2D1_FACTORY_TYPE_SINGLE_THREADED,options,d2Factory.GetAddressOf()));
// Create the Direct2D device that links back to the Direct3D device
HR(d2Factory->CreateDevice(dxgiDevice.Get(),d2Device.GetAddressOf()));
// Create the Direct2D device context that is the actual render target
// and exposes drawing commands
ComPtr<ID2D1DeviceContext> dc;
HR(d2Device->CreateDeviceContext(D2D1_DEVICE_CONTEXT_OPTIONS_NONE,dc.GetAddressOf()));
// Retrieve the swap chain's back buffer
ComPtr<IdxgiSurface2> surface;
HR(swapChain->GetBuffer(
0,// index
__uuidof(surface),reinterpret_cast<void**>(surface.GetAddressOf())));
// Create a Direct2D bitmap that points to the swap chain surface
D2D1_BITMAP_PROPERTIES1 properties = {};
properties.pixelFormat.alphaMode = D2D1_ALPHA_MODE_PREMULTIPLIED;
properties.pixelFormat.format = dxgi_FORMAT_B8G8R8A8_UnorM;
properties.bitmapOptions = D2D1_BITMAP_OPTIONS_TARGET |
D2D1_BITMAP_OPTIONS_CANNOT_DRAW;
ComPtr<ID2D1Bitmap1> bitmap;
HR(dc->CreateBitmapFromdxgiSurface(surface.Get(),properties,bitmap.GetAddressOf()));
// Point the device context to the bitmap for rendering
dc->SetTarget(bitmap.Get());
// Draw something
dc->BeginDraw();
dc->Clear();
ComPtr<ID2D1SolidColorBrush> brush;
D2D1_COLOR_F const brushColor = D2D1::ColorF(0.18f,// red
0.55f,// green
0.34f,// blue
0.75f); // alpha
HR(dc->CreateSolidColorBrush(brushColor,brush.GetAddressOf()));
D2D1_POINT_2F const ellipseCenter = D2D1::Point2F(150.0f,// x
150.0f); // y
D2D1_ELLIPSE const ellipse = D2D1::Ellipse(ellipseCenter,100.0f,// x radius
100.0f); // y radius
dc->FillEllipse(ellipse,brush.Get());
HR(dc->EndDraw());
// Make the swap chain available to the composition engine
HR(swapChain->Present(1,// sync
0)); // flags
ComPtr<IDCompositionDevice> dcompDevice;
ComPtr<IDCompositionVisual> visual;
HR(DCompositionCreateDevice(
dxgiDevice.Get(),__uuidof(dcompDevice),reinterpret_cast<void**>(dcompDevice.GetAddressOf())));
ComPtr<IDCompositionDevice3> dcompDevice3;
dcompDevice->QueryInterface(__uuidof(IDCompositionDevice),(LPVOID*)&dcompDevice3);
ComPtr<IDCompositionGaussianBlurEffect> effect;
HR(dcompDevice3->CreateGaussianBlurEffect(&effect));
effect->SetStandardDeviation(10.0f);
HR(dcompDevice->CreateTargetForHwnd(hwnd,true,// Top most
target.GetAddressOf()));
HR(dcompDevice->CreateVisual(visual.GetAddressOf()));
HR(visual->SetContent(swapChain.Get()));
HR(target->SetRoot(visual.Get()));
HR(dcompDevice->Commit());
}
int WINAPI wWinMain(HINSTANCE hInstance,HINSTANCE,PWSTR pCmdLine,int nCmdshow)
{
// Register the window class.
const wchar_t CLASS_NAME[] = L"Sample Window Class";
WNDCLASS wc = { };
wc.lpfnWndProc = WindowProc;
wc.hInstance = hInstance;
wc.lpszClassName = CLASS_NAME;
RegisterClass(&wc);
// Create the window.
HWND hwnd = CreateWindowEx(WS_EX_norEDIRECTIONBITMAP,wc.lpszClassName,L"Sample",WS_OVERLAPPEDWINDOW | WS_VISIBLE,CW_USEDEFAULT,hInstance,nullptr);
if (hwnd == NULL)
{
return 0;
}
CreateVisual(hwnd);
ShowWindow(hwnd,nCmdshow);
// Run the message loop.
MSG msg = { };
while (GetMessage(&msg,NULL,0))
{
TranslateMessage(&msg);
dispatchMessage(&msg);
}
return 0;
}
LRESULT CALLBACK WindowProc(HWND hwnd,LParaM lParam)
{
switch (uMsg)
{
case WM_DESTROY:
PostQuitMessage(0);
return 0;
case WM_PAINT:
{
PAINTSTRUCT ps;
HDC hdc = BeginPaint(hwnd,&ps);
FillRect(hdc,&ps.rcPaint,(HBrush)(COLOR_WINDOW + 1));
EndPaint(hwnd,&ps);
}
return 0;
}
return DefWindowProc(hwnd,uMsg,wParam,lParam);
}
我尝试更改每段代码，但仍然抛出异常。我是Directx的新手，代码中的IDCompositionDevice3设备实际上是我自己创建的，我不知道它是对还是错，因为Microsoft提供的文档中没有太多描述。
这是完整的项目代码：Direct Composition Blur
解决方法
大概是使用WRL的ComPtr。要访问其内部接口指针，您需要调用GetAddressOf：
dcompDevice3->CreateGaussianBlurEffect(effect.GetAddressOf());
WRL的operator&在返回弱引用时是令人毛骨悚然的，它阻止了编译器捕获这种意外使用。
注意： C ++ / WinRT提供了一种更为安全的COM智能指针类型（winrt::com_ptr），但没有为您提供太多的COM支持。
,有两个问题：
1。dcomp的实现似乎很奇怪，因为它成功回答了这个问题，但是dcompDevice3实际上已经坏了，因此崩溃了：
ComPtr<IDCompositionDevice3> dcompDevice3;
HR(dcompDevice->QueryInterface(__uuidof(IDCompositionDevice),(LPVOID*)&dcompDevice3))
2。您的代码也很糟糕，应该是这样：
HR(DCompositionCreateDevice3( // only this factory can give you an IDCompositionDevice3 implementation
dxgiDevice.Get(),__uuidof(dcompDevice),reinterpret_cast<void**>(dcompDevice.GetAddressOf())));
ComPtr<IDCompositionDevice3> dcompDevice3;
HR(dcompDevice->QueryInterface(__uuidof(IDCompositionDevice3),(LPVOID*)&dcompDevice3)); // use IDCompositionDevice3 here
现在它至少应该继续工作。