Lorien is constantly rendering frames, so it is not power efficient

[toboil-features]

Lorien version: 0.7.0-dev

OS/device including version: NVIDIA with proprietary driver 555.58.02

Issue description: Lorien as of latest commit constantly consumes GPU power just to draw the same frame if you are in the app and do nothing.

Steps to reproduce:

1. Open app
2. Draw something
3. Do nothing and check GPU utilization

[mbrlabs]

Nothing i can do about that unfortunately; that's how Godot works. If the app is not in focus it will slow rendering down though.

[Zacrain]

Issue description: Lorien as of latest commit constantly consumes GPU power just to draw the same frame if you are in the app and do nothing.

Since Lorien is made with Godot, a game engine, it renders an image based upon the allowed FPS settings of Lorien and may also be further limited by your GPU's driver settings.

In Lorien you can set limits here in the settings:

If you've got an AMD based GPU you may profit from the "Radeon Chill" setting, which adjusts the FPS within a user-configured range depending on "how much is happening", which can greatly reduce power consumption of Vulkan nad DirectX applications. Since Godot was designed towards the Vulkan-API this should work (haven't tested it personally though). See here for the AMD settings: https://www.amd.com/en/products/software/adrenalin/radeon-software-chill.html

Nvidia unfortunately has no similar feature as far as I know, although you can specify maximum allowed fps in foreground and background via the driver settings. (Which is not really necessary since Lorien has its own settings you can use.)

Nothing i can do about that unfortunately; that's how Godot works. If the app is not in focus it will slow rendering down though.

I think it might be not a bad idea to explore whether Lorien can be optimized though. Considering that the Godot Editor is buit with the Godot engine as well and doesn't have noticeable GPU loads on my system, there might be a way. Lorien appears to be a simple enough application that such performance impacts might be avoidable.

[mbrlabs]

Since Godot was designed towards the Vulkan-API this should work (haven't tested it personally though).

Lorien uses the Compatibility renderer (OpenGL 3.3) in order to also run on low end devices. You can switch to one of the Vulkan backends with a command line argument though (can't be in settings because the renderer needs to be set before launch).

I might have an idea how to improve things though. The reason it's always drawing at the full speed is because the number of refreshes per second affect how smooth the drawn line is. Lower refresh rate -> choppy line. However i think we can add a third fps setting for when the app is in foreground but only in "UI mode" and not drawing.

• Idle fps / UI mode (default 30)
• Draw/Pan/Zoom mode (default 144)
• Background fps for when out of focus (default 10)

It's a pretty easy fix. I'll draft a PR so you guys can test it before i merge.

[mbrlabs]

The implementation is even simpler. I first went with the 3 fps modes (idle, draw, background), but the current foreground/background fps settings are enough to implement this and not confuse the user.

You can test here with the CI builds: #306

[toboil-features]

Which CLI argument to use to make Lorien run using Vulkan? Can't find one in --help. Edit: Tried --display-driver wayland vulkan but MangoHUD still shows Lorien using OpenGL.

[toboil-features]

To be honest, now it is far better than before.

[mbrlabs]

Which CLI argument to use to make Lorien run using Vulkan? Can't find that one in --help now. Edit: Tried --display-driver wayland vulkan but MangoHUD still shows Lorien using OpenGL.

Should be --rendering-method forward_plus|mobile|gl_compatibility (https://docs.godotengine.org/en/stable/tutorials/editor/command_line_tutorial.html)

• forward_plus and mobile use Vulkan
• gl_compatibility is OpenGL