Details
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Suggestion
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Resolution: Duplicate
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P3: Somewhat important
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None
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6.2.4
Description
Even though it is documented that "the scene graph will choose the graphics API to use based on the platform" (https://doc.qt.io/qt-6/qquickwindow.html#setGraphicsApi), it would be nice if Qt on Windows can auto-detect the supported D3D feature levels and fall back to OpenGL if Shader Model 5.0 isn't available.
With QSG_INFO=1 and QSG_RHI_DEBUG_LAYER=1, an old graphics card might produce this...
[1756] qt.scenegraph.general: Using QRhi with backend D3D11 [1756] Graphics API debug/validation layers: 1 [1756] QRhi profiling and debug markers: 0 [1756] Shader/pipeline cache collection: 0 [1756] qt.scenegraph.general: threaded render loop [1756] qt.scenegraph.general: Using sg animation driver [1756] qt.scenegraph.general: Animation Driver: using vsync: 16.66 ms [1756] qt.scenegraph.general: Using sg animation driver [1756] qt.scenegraph.general: Animation Driver: using vsync: 16.66 ms [1756] qt.rhi.general: FLIP_* swapchain supported = true, ALLOW_TEARING supported = true [1756] qt.rhi.general: Default swap effect: FLIP_SEQUENTIAL [1756] qt.rhi.general: Adapter 0: 'NVIDIA GeForce GTS 250' (vendor 0x10DE device 0x615 flags 0x0) [1756] qt.rhi.general: using this adapter [1756] qt.rhi.general: Adapter 1: 'Microsoft Basic Render Driver' (vendor 0x1414 device 0x8C flags 0x2) [1756] qt.scenegraph.general: MSAA sample count for the swapchain is 1. Alpha channel requested = no. [1756] qt.scenegraph.general: rhi texture atlas dimensions: 512x512 [1756] D3D11 ERROR: ID3D11Device::CreateVertexShader: Shader must be vs_4_0. Shader version provided: vs_5_0 [ STATE_CREATION ERROR #167: CREATEVERTEXSHADER_INVALIDSHADERTYPE] [1756] Failed to create vertex shader: Error 0x80070057: ???????? ????? ???????. [1756] Failed to build graphics pipeline state
...whereas the OpenGL backend can work. In other words, an app could run fine in Qt 5 (default: OpenGL) but fail in Qt 6 (default: D3D11)
One mechanism for such detection is described at https://stackoverflow.com/questions/22223859/find-out-directx-version (call D3D11CreateDeviceAndSwapChain() with D3D_FEATURE_LEVEL_11_0 and see if it succeeds)
Attachments
Issue Links
- duplicates
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QTBUG-78648 RHI: Does not work with Windows10 inside VMWare (Fusion)
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- Open
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