I have made a program that draws meshes together with their wireframe.

There is z-fighting between the triangles and the line.

For solving this, I use depth biasing on the pipeline that draws the triangles.

I would have preferred to apply the inverse bias on the lines, since it would fit better my code organization. However, in the Vulkan spec, I only see depth bias referencing “polygons”:

25.9.3. Depth Bias The depth values of all fragments generated by the rasterization of a polygon can be biased (offset) by a single depth
bias value that is computed for that polygon.

That made me a bit sad.

But I gave it a chance and… it worked!
I was indeed able to apply the depth bias on the lines instead!

So I’m wondering, it this correct behaviour? Do lines also count as polygons? Or is it a bug in my Vulkan driver?

I’m using a Radeon RX6600.