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OpenGL [fixed by update qt to 5.1]performance of wglMakeCurrent[ work with QT5.0.2]

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hi, i am working with opengl and qt, but i find some performance problem about wglMakCurrent.

this is the test result which was captured by intel vtune.







i am not use QWidget not QGLWidget because i want to make the rendering code with a same style.

when i render a QT widget with directx9, i send the wid() to my render, and createdevice from this HWND.

if i need a child widget, i will create a new SwapChain for this new widget.

this framework work with directx perfect.


but there is a performance question when i make it work with opengl.


like directx, i send wid() to opengl render, and create a GLContext by this HWND. this is the initialize code:

                m_HDC = ::GetDC( m_BindWnd );

                PIXELFORMATDESCRIPTOR FormatDesc;
                memset(&FormatDesc, 0, sizeof(PIXELFORMATDESCRIPTOR));
                FormatDesc.nSize		= sizeof(PIXELFORMATDESCRIPTOR);
                FormatDesc.nVersion		= 1;
                FormatDesc.iPixelType	= PFD_TYPE_RGBA;
                FormatDesc.cColorBits	= 32;
                FormatDesc.cDepthBits	= 32;
                // FormatDesc.cStencilBits	= 0;
                FormatDesc.iLayerType	= PFD_MAIN_PLANE;

                INT PixelFormat = ChoosePixelFormat( m_HDC, &FormatDesc);
                if (PixelFormat && SetPixelFormat( m_HDC, PixelFormat, &FormatDesc) )
                    m_GLContext = wglCreateContext(m_HDC);

                    if ( m_GLContext && wglMakeCurrent(m_HDC, m_GLContext) )

         if a new qwidget created, i will do the same thing for this new qwidget.


        when i render them, i will call beginRender and endRender for these warpper object.

        in directx9, i will set the rendertarget to the one which is created by the swapchain.

        in opengl, i will call wglMakeCurrent in BeginRender, call wglMakeCurrent( NULL, NULL ) in EndRender. eg:

            void Viewport::SwapChain()
                if( m_GLContext && m_HDC )
                    ::SwapBuffers( m_HDC );
            void Viewport::BeginRender()
                X_ASSERT( m_HDC && m_GLContext );

                BOOL bRet = ::wglMakeCurrent( m_HDC, m_GLContext );

                X_ASSERT( bRet );
            void Viewport::EndRender()
                BOOL bRet = ::wglMakeCurrent( NULL, NULL );

                X_ASSERT( bRet );                

          all the codes are in main thread.  In addition to this, i have do nothing. 

          this will be very serious when i drag and move the window.





         this framework is work fine with normal window which is created by windows api.

         but when i use it work with qt, it does not work. work with dx fine....


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i have fixed this question with update qt to qt5.1 and use the offical release. dry.png

it works well now.biggrin.png

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