Add a project setting to control 3D line drawing thickness

[Calinou]

• Salvage of Add a project setting to control wireframe thickness #74387.
  Thanks @myaaaaaaaaa for the original implementation 🙂

This setting affects all lines drawn in 3D, including gizmos in the editor and debug draw options. This can be used to make debug drawing more visible, particularly when using a high-resolution viewport.

This relies on hardware support, so it's not available on all platforms and GPUs (see maximum supported line width). It's also only supported in the Forward+ and Mobile rendering methods.

This could technically be implemented in Compatibility with glLineWidth() (on desktop platforms only), but I haven't managed to do this yet.

• This closes Allow changing the line width of 3D gizmos godot-proposals#9299.

Preview

Line width = 1

Line width = 2

Line width = 1 with half-resolution viewport

Effective line width is identical to line width = 2. This shows how thicker lines are helpful on high-resolution viewports, such as hiDPI displays.

TODO

• Expose an editor setting to control line width in the editor while keeping the project setting for the running project.

[clayjohn]

If we want to expose this for GPUs that support it, we need to check for the wideLines feature and then properly warn users when its not available and fall back to a width of 1.0.

From the Vulkan spec:

wideLines specifies whether lines with width other than 1.0 are supported. If this feature is not enabled, the lineWidth member of the VkPipelineRasterizationStateCreateInfo structure must be 1.0 unless the VK_DYNAMIC_STATE_LINE_WIDTH dynamic state is enabled, in which case the lineWidth parameter to vkCmdSetLineWidth must be 1.0. When this feature is supported, the range and granularity of supported line widths are indicated by the lineWidthRange and lineWidthGranularity members of the VkPhysicalDeviceLimits structure, respectively.

[Calinou]

Rebased and tested again, it works as expected. Note that I didn't implement the wideLines check yet.

If we want to expose this for GPUs that support it, we need to check for the wideLines feature and then properly warn users when its not available and fall back to a width of 1.0.

I can see wideLines being mentioned here:

godot/drivers/vulkan/rendering_device_driver_vulkan.cpp

Line 569 in a308047

Error RenderingDeviceDriverVulkan::_check_device_features() {

The question is, how do I expose this information so it can be read in RenderSceneClustered and RenderSceneMobile? Preferably without adding Vulkan-specific checks to those classes, that is.

(Also, what about Direct3D 12? I suppose nearly all GPUs on D3D12 support line widths greater than 1.0 anyway.)

[clayjohn]

The question is, how do I expose this information so it can be read in RenderSceneClustered and RenderSceneMobile? Preferably without adding Vulkan-specific checks to those classes, that is.

Either through limit_get() or has_feature() I guess