@SGaist My experience is different. The computer reported having DirectX 12 but it didn't work. Anyway, I am no longer worried about this particular computer.
Thanks

Nowadays the software renderer for WebGL works fine. I wonder if there is some easy way to detect if the video adapter is affected (probably intel && being "old") and if that's the case, to switch to software renderer, at run-time - maybe before initializing QApplication? in order to pass --enable-webgl-software-rendering parameter programmatically.

@dalamber

Set QT_LOGGING_RULES environment variable to 'qt.qpa.gl=true'.

Here's my log, I'm not sure how to interpret it. It seems to say it's disabling ANGLE and using OpenGL, but I'm not sure and it conflicts with what CodeXL tells me.

qt.qpa.gl: Qt: Using WGL and OpenGL from "opengl32.dll" qt.qpa.gl: QOpenGLStaticContext::create OpenGL: "Intel","Intel(R) HD Graphics 5500" default ContextFormat: v4.4 profile: QSurfaceFormat::OpenGLContextProfile(CompatibilityProfile) options: QFlags<QSurfaceFormat::FormatOption>(DeprecatedFunctions),SampleBuffers, Extension-API present Extensions: 200 qt.qpa.gl: Basic wglCreateContext gives version 4.4 qt.qpa.gl: OpenGL 2.0 entry points available qt.qpa.gl: GPU features: QSet("disable_angle") qt.qpa.gl: Disabling ANGLE: GpuDescription(vendorId=0x8086, deviceId=0x1616, subSysId=0x80c2103c, revision=9, driver: "igdumdim32.dll", version=20.19.15.4549, "Intel(R) HD Graphics 5500") qt.qpa.gl: QWindowsOpenGLTester::supportedRenderers GpuDescription(vendorId=0x8086, deviceId=0x1616, subSysId=0x80c2103c, revision=9, driver: "igdumdim32.dll", version=20.19.15.4549, "Intel(R) HD Graphics 5500") renderer: QFlags(0x1|0x20) qt.qpa.gl: QWindowsIntegration::createPlatformOpenGLContext QSurfaceFormat(version 2.0, options QFlags<QSurfaceFormat::FormatOption>(), depthBufferSize 24, redBufferSize -1, greenBufferSize -1, blueBufferSize -1, alphaBufferSize -1, stencilBufferSize 8, samples -1, swapBehavior QSurfaceFormat::SwapBehavior(DoubleBuffer), swapInterval 1, profile QSurfaceFormat::OpenGLContextProfile(NoProfile)) qt.qpa.gl: "ARB::choosePixelFormat Attributes: 0x2003 , 0x2027 , 0x2010 , 0x1 , 0x2001 , 0x1 , 0x2014 , 0x18 , 0x2011 , 0x1 , 0x2022 , 0x18 , 0x2013 , 0x202b , 0x201b , 0x8 , 0x2023 , 0x8 , 0x2041 , 0x0 , \n obtained px # 5 of 1 \n PIXELFORMATDESCRIPTOR dwFlags=0x8225 PFD_DRAW_TO_WINDOW PFD_SUPPORT_OPENGL PFD_SUPPORT_COMPOSITION PFD_DOUBLEBUFFER iPixelType=0 cColorBits=32 cRedBits=8 cRedShift=16 cGreenBits=8 cGreenShift=8 cBlueBits=8 cBlueShift=0 cDepthBits=24 cStencilBits=8 iLayerType=0 cAlphaBits=8 cAlphaShift=24 cAccumBits=64 cAccumRedBits=16 cAccumGreenBits=16 cAccumBlueBits=16 cAccumAlphaBits=16 " qt.qpa.gl: ARB::createContext Creating context version 2 . 0 3 attributes qt.qpa.gl: QWindowsGLContext::QWindowsGLContext 0x163adc0 ARB requested: QSurfaceFormat(version 2.0, options QFlags<QSurfaceFormat::FormatOption>(), depthBufferSize 24, redBufferSize -1, greenBufferSize -1, blueBufferSize -1, alphaBufferSize -1, stencilBufferSize 8, samples -1, swapBehavior QSurfaceFormat::SwapBehavior(DoubleBuffer), swapInterval 1, profile QSurfaceFormat::OpenGLContextProfile(NoProfile)) obtained # 5 ARB QSurfaceFormat(version 4.4, options QFlags<QSurfaceFormat::FormatOption>(DeprecatedFunctions), depthBufferSize 24, redBufferSize 8, greenBufferSize 8, blueBufferSize 8, alphaBufferSize 8, stencilBufferSize 8, samples 0, swapBehavior QSurfaceFormat::SwapBehavior(DoubleBuffer), swapInterval 1, profile QSurfaceFormat::OpenGLContextProfile(CompatibilityProfile)) PIXELFORMATDESCRIPTOR dwFlags=0x8225 PFD_DRAW_TO_WINDOW PFD_SUPPORT_OPENGL PFD_SUPPORT_COMPOSITION PFD_DOUBLEBUFFER iPixelType=0 cColorBits=32 cRedBits=8 cRedShift=16 cGreenBits=8 cGreenShift=8 cBlueBits=8 cBlueShift=0 cDepthBits=24 cStencilBits=8 iLayerType=0 cAlphaBits=8 cAlphaShift=24 cAccumBits=64 cAccumRedBits=16 cAccumGreenBits=16 cAccumBlueBits=16 cAccumAlphaBits=16 swap interval: 1 default: ContextFormat: v4.4 profile: QSurfaceFormat::OpenGLContextProfile(CompatibilityProfile) options: QFlags<QSurfaceFormat::FormatOption>(DeprecatedFunctions) HGLRC= 0x30000

One thing I note is that surprisingly my Intel GPU seems to be used rather than my AMD GPU.

Try changing Z:/disable_angle.txt to Z:\disable_angle.txt Note the backslash :) It's Windows, so this may be the culprit.

Apart from disable_angle (your config seems correct to me), try also setting disable_d3d11 and disable_d3d9.

I tried both of these things, but CodeXL still shows the same "D3D" symptoms.

I saw it and took some inspiration, but at the moment a cannot use all techniques of this example. I am working on city building game where there is lots of (moving) objects. In my worst performance test scenario I have slightly over 30 FPS (acceptable) but on gtx970, so I am little worried what will happen on worse cards.

Another interesting development: I tried running on another machine with the Qt toolchain installed, and the program worked. So it appears it is still reading something from the filesystem that is not on a regular Windows machine, but I don't know what that might be. I did package all the qmldir files needed for Qt Quick to work.