#[Solved] OpenGL Graphics issues on other computers

1 messages · Page 1 of 1 (latest)

mint pecan
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I've been making a small paint-like program using OpenGL 4.5
While in my computer all seems right, once I gave the program to some friends of mine, there seems to be a big vertex explosion like problem.
What things can usually cause this type of problems? I would like some advice to what to check or how to even debug something like this.

Some aditional info:
The program seems to work fine on both a Nvidia gpu computer in windows and linux, as well on a AMD apu laptop with linux.
My friends both have a AMD gpu, both have graphical problems.
I use OpenGL with Direct State Access and Vertex Pulling in the shaders.

image.png image.png
tiny inlet
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What's your draw mode, and are you setting a line width?

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Looks like the program collects a stroke as a list of points and renders that as a LINE primitive, then draws a circle-cap centered at the final point in the stroke.

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This is a very interesting section. The top-left triangle of the button background is malformed, and the "Wh" in "White" are then stretched out to the right.

image.png
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But it's not that simple, an irregular section of the quad is malformed. Not simply the top-left tri.

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Which suggests undefined behavior in the rasterizer.

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Have you developed the app with the debug extension and message callback hooked up? It should alert you of various issues, but it can't predict hardware limits of other cards.

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May as well share the repo, this could be anything from where I sit.

mint pecan
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I will upload it to my repo and pass it in a moment

mint pecan
mint pecan
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Found the error!

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It was a read/write problem.
I was reusing a Shader Storage Buffer, putting in new vertex data to avoid creating new buffers for every draw.
I forgot to put a gl.Finish() or a memory barrier between draws, so the buffer was being written before the draw was finished (for some reason not in Nvidia).