VertexShaderManager: Only look for freelook config changes if we're using freelook

[iwubcode]

Another attempt to fix 12157. I made the assumption that pulling from our onion config system was relatively fast but that doesn't seem to be the case from testing that fifolog (4fps difference)

[iwubcode]

I'd love to hear from other devs on how they handle config changes that can occur at any time?

[delroth]

Snapshot at the beginning of the frame? It doesn't make sense to change this setting mid-rendering anyway.

[delroth]

Also: Config::AddConfigChangedCallback means you don't even have to snapshot, you can update the local version when it gets set.

[JosJuice]

I'd love to hear from other devs on how they handle config changes that can occur at any time?

This function is called on config change and writes the current config values to g_Config, which is then copied to g_ActiveConfig when a new frame starts:

dolphin/Source/Core/VideoCommon/VideoConfig.cpp

Line 60 in a63510a

void VideoConfig::Refresh()

[iwubcode]

Thank you both. This is useful.

I'm going to be moving these settings out of the graphics/video config in #8867 so I was curious how that was working. Despite having looked at VideoConfig.cpp so many times, I didn't even notice that AddConfigChangedCallback!

For now though, I will add this setting to VideoConfig.cpp so I don't need to query it every time when freelook is enabled.

[iwubcode]

@delroth / @JosJuice - updated, let me know what you think

[stenzek]

LGTM otherwise. I think the CheckForConfigChanges() method makes more sense though.

[iwubcode]

Thanks @stenzek , updated per your suggestion.

[stenzek]

Does this function have to run every frame? Could you save the old freelook control type/freelook enable and only run it when that changes? e.g.

const bool old_freelook = g_ActiveConfig.bFreeLook;
const int old_freelook_control_type = g_ActiveConfig.iFreelookControlType;

if (old_freelook != g_ActiveConfig.bFreeLook || old_freelook_control_type != g_ActiveConfig.iFreelookControlType)
{
  g_freelook_camera.SetControlType(g_ActiveConfig.iFreelookControlType);
}

[iwubcode]

It doesn't have to but what's the point of all this checking? It doesn't really matter that function is called so often because the actual function already bails if there are no changes. The whole point is to just get the new value from configuration.

[stenzek]

Oh, I didn't see the check here: https://github.com/dolphin-emu/dolphin/blob/master/Source/Core/VideoCommon/FreeLookCamera.cpp#L179

I misremembered it unconditionally reallocating it. In that case, it's fine as-is.