Details
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Bug
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Resolution: Done
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P2: Important
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5.14.0 Beta 1
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None
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Qt5-master
Rpi4/VideocoreVI with latest RaspbianOS (Debian buster)/arm32
Mesa 19.3.0-devel (at least git-2d5edf2558)
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ba2ee2875aadc5e5c84e4dd6dec3dbb106a275ce (qt/qtbase/5.13)
Description
With introduction of OpenGL ES 3.1(in Mesa 2019.3-devel) on Raspberry Pi 4/VideoCoreVI hardware it's possible to run Compute Shaders, including computegles31 example from qtbase/opengl.
Unfortunately, Rpi4/VideoCoreVI hardware is quite limited, in particular MAX_COMPUTE_WORK_GROUP_INVOCATIONS is only 256(16*16), while computegles31 example required 1024(32x32).
Changing COMPUTEPATCHSIZE parameter(both in GLES shader and ++ code) from 32 to 16 make it possible to run computegles31 example on RPi4/VideoCoreVI (and may be some other hardware, like Vivante GPU).
Technically it's a really minor bug, while it can negatively affect a new Qt users/students with limited knowledge about GL/GLES/Compute shaders.
Attachments
For Gerrit Dashboard: QTBUG-79374 | ||||||
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# | Subject | Branch | Project | Status | CR | V |
278565,6 | Fix computegles31 example crashing on Pi4 | 5.13 | qt/qtbase | Status: MERGED | +2 | 0 |