Emulator

I managed to figure out where the issue began and have also recorded a video, showing the issue in action.

https://www.youtube.com/watch?v=nGVbId0DfqY

4.0-4674 worked fine
4.0-4699 wouldn't run the game in any playable fashion
4.0-4701 is where the issue arose

Cheers!

This happens on my computer too, though?

If you think it's an actual bug with the shader then compare it with the D3D backend. Compare the performance to OGL and also check if there was any regression of performance on D3D since the merge.

I don't think it's a bug within the shader; I'm just saying it's not because of Intel HD.

Wouldn't this also have an effect on the in-game performance, though? If it were simply an issue with OpenGL? This only occurs when the map is pulled up, which I'd assume (with my limited knowledge) wouldn't put nearly as much stress on the GPU.

If it helps, I'll try it out with the software renderer when I get home and report back.

Actually, what led me to believe it was a line-width regression is because line-width is only used during that menu. Basically, the game is using a relatively hard to emulate effect (at least in this case, Line-width) a lot in one particular screen.

The rest of the game wouldn't be affected for the exact reason that it doesn't use line-width as heavily.

@veegee

The software renderer is useless as far as performance benchmarks go, it's just there for accuracy tests.

And the geometry shader stage is disabled unless there are lines on the screen. As soon as you pull up the map the geometry stage is activated on your GPU and that causes it to slow down. Unfortunately from now on we will rely on the geometry shader stage so we can't simply solve the reduction in performance.

@JMC4789

So you're saying even a high-end GPU slows down significantly? That would be interesting, since that may indicate some other bottleneck such as uniforms being uploaded too often.

Yeah; my GTX 760 is getting wrecked down to 47 fps. I can try it on my brother's GTX 970 sometime; but on my GTX 560m it's like, no chance, 10 - 15 fps.

Even on a GTX 1060 6GB + OpenGL the map rendering is slow in some areas; notably Chozo Ruins and Phaedrana Drifts. With Vulkan this particular shader is much faster and there's no slowdown when accessing the map.