[OpenXRExtensionWrapper] allows implementing OpenXR extensions with GDExtension. The extension should be registered with [method register_extension_wrapper].
When [OpenXRInterface] is initialized as the primary interface and any [Viewport] has [member Viewport.use_xr] set to [code]true[/code], OpenXR will become involved in Godot's rendering process. If [member ProjectSettings.rendering/driver/threads/thread_model] is set to "Separate", Godot's renderer will run on its own thread, and special care must be taken in all [OpenXRExtensionWrapper]s in order to prevent crashes or unexpected behavior. Some virtual methods will be called on the render thread, and any data they access should not be directly written to on the main thread. This is to prevent two potential issues:
1. Changes intended for the next frame, taking effect on the current frame. When using the "Separate" thread model, the main thread will immediately start working on the next frame while the render thread may still be rendering the current frame. If the main thread changes anything used by the render thread directly, the change could end up being used one frame earlier than intended.
2. Reading and writing to the same data at the same time from different threads can lead to the render thread using data in an invalid state.
In most cases, the solution is to use [method RenderingServer.call_on_render_thread] to schedule [Callable]s to write to any data used on the render thread. When using the "Separate" thread model, these [Callable]s will run after the renderer finishes the current frame and before it starts rendering the next frame. When not using this mode, they'll run immediately, so it's recommended to always use [method RenderingServer.call_on_render_thread] in these cases, which will allow your code to do the right thing regardless of the thread model.
Any virtual methods that run on the render thread will be noted below.
[b]Note:[/b] This virtual method will be called on the render thread. Additionally, the data it returns will be used shortly after this method is called, so it needs to remain valid until the next time [method _on_pre_render] runs.
[b]Note:[/b] This virtual method will be called on the render thread. Additionally, the data it returns will be used shortly after this method is called, so it needs to remain valid until the next time [method _on_pre_render] runs.
Returns an integer that will be used to sort the given composition layer provided via [method _get_composition_layer]. Lower numbers will move the layer to the front of the list, and higher numbers to the end. The default projection layer has an order of [code]0[/code], so layers provided by this method should probably be above or below (but not exactly) [code]0[/code].
This will only be called if the extension previously registered itself with [method OpenXRAPIExtension.register_composition_layer_provider].
[b]Note:[/b] This virtual method will be called on the render thread. Additionally, the data it returns will be used shortly after this method is called, so it needs to remain valid until the next time [method _on_pre_render] runs.
Returns a [Dictionary] of OpenXR extensions related to this extension. The [Dictionary] should contain the name of the extension, mapped to a [code]bool *[/code] cast to an integer:
- If the [code]bool *[/code] is a [code]nullptr[/code] this extension is mandatory.
- If the [code]bool *[/code] points to a boolean, the boolean will be updated to [code]true[/code] if the extension is enabled.
Gets an array of [Dictionary]s that represent properties, just like [method Object._get_property_list], that will be added to [OpenXRCompositionLayer] nodes.
[b]Note:[/b] This virtual method will be called on the main thread, however, it will be called [i]before[/i] OpenXR becomes involved in rendering, so it is safe to write to data that will be used by the render thread.
Called when there is an OpenXR event to process. When implementing, return [code]true[/code] if the event was handled, return [code]false[/code] otherwise.
[b]Note:[/b] This virtual method will be called on the main thread, however, it will be called [i]before[/i] OpenXR becomes involved in rendering, so it is safe to write to data that will be used by the render thread.
[b]Note:[/b] This virtual method will be called on the main thread, however, it will be called [i]after[/i] OpenXR is done being involved in rendering, so it is safe to write to data that was used by the render thread.
Called as part of the OpenXR process handling. This happens right before general and physics processing steps of the main loop. During this step controller data is queried and made available to game logic.
Allows extensions to register additional controller metadata. This function is called even when the OpenXR API is not constructed as the metadata needs to be available to the editor.
Extensions should also provide metadata regardless of whether they are supported on the host system. The controller data is used to setup action maps for users who may have access to the relevant hardware.
[b]Note:[/b] This virtual method will be called on the main thread, however, it will be called [i]before[/i] OpenXR becomes involved in rendering, so it is safe to write to data that will be used by the render thread.
[b]Note:[/b] This virtual method will be called on the main thread, however, it will be called [i]after[/i] OpenXR is done being involved in rendering, so it is safe to write to data that was used by the render thread.
Called to allow an extension to print additional information about its view configuration, if applicable. This will only be called if verbose output is enabled.
[b]Note:[/b] This virtual method will be called on the render thread. Additionally, the data it returns will be used shortly after this method is called, so it needs to remain valid until the next time [method _on_pre_render] runs.
[b]Note:[/b] This virtual method will be called on the render thread. Additionally, the data it returns will be used shortly after this method is called, so it needs to remain valid until the next time [method _on_pre_render] runs.
[b]Note:[/b] This virtual method will be called on the render thread. Additionally, the data it returns will be used shortly after this method is called, so it needs to remain valid until the next time [method _on_pre_render] runs.
[b]Note:[/b] This virtual method will be called on the render thread. Additionally, the data it returns will be used shortly after this method is called, so it needs to remain valid until the next time [method _on_pre_render] runs.
