Lines: workaround for WebGL/Linux bug #24
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vidaaudrey
approved these changes
Dec 14, 2018
brianc
approved these changes
Dec 14, 2018
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A couple users reported bugs with line rendering on certain Linux laptops. I was able to narrow it down to a problem with
stride/offsetwhen multiple vertex attributes are views on the same underlying buffer.This pure-regl example demonstrates the problem. It renders a simple moving average of some data: https://codepen.io/anon/pen/maVppw?editors=0010
On a Mac and some other platforms, this renders as expected (green = stride of 4 bytes, red = stride of 8 bytes):
However on the affected hardware, the result differs:
This is consistent between Chrome & Firefox, so it seems like it might a graphics driver/hardware bug.
The problem seems to occur when 3 or 4 attributes are using the same buffer, but not with only 2, so we can work around it by taking a slight perf hit to upload 2 copies of the same data into two buffers so that each has only two attributes reading from it.