Add description for rendering/limits/spatial_indexer/threaded_cull_minimum_instances

[ecmjohnson]

Adds a description for the property rendering/limits/spatial_indexer/threaded_cull_minimum_instances based on my reading of its use in renderer_scene_cull.cpp.

Accessing:

godot/servers/rendering/renderer_scene_cull.cpp

Line 4164 in 2d0ee20

thread_cull_threshold = GLOBAL_GET("rendering/limits/spatial_indexer/threaded_cull_minimum_instances");

Using:

godot/servers/rendering/renderer_scene_cull.cpp

Lines 3028 to 3033 in 2d0ee20

	if (visibility_cull_data.cull_count > thread_cull_threshold) {
	WorkerThreadPool::GroupID group_task = WorkerThreadPool::get_singleton()->add_template_group_task(this, &RendererSceneCull::_visibility_cull_threaded, &visibility_cull_data, WorkerThreadPool::get_singleton()->get_thread_count(), -1, true, SNAME("VisibilityCullInstances"));
	WorkerThreadPool::get_singleton()->wait_for_group_task_completion(group_task);
	} else {
	_visibility_cull(visibility_cull_data, visibility_cull_data.cull_offset, visibility_cull_data.cull_offset + visibility_cull_data.cull_count);
	}

godot/servers/rendering/renderer_scene_cull.cpp

Lines 3129 to 3145 in 2d0ee20

	if (cull_to > thread_cull_threshold) {
	//multiple threads
	for (InstanceCullResult &thread : scene_cull_result_threads) {
	thread.clear();
	}
	WorkerThreadPool::GroupID group_task = WorkerThreadPool::get_singleton()->add_template_group_task(this, &RendererSceneCull::_scene_cull_threaded, &cull_data, scene_cull_result_threads.size(), -1, true, SNAME("RenderCullInstances"));
	WorkerThreadPool::get_singleton()->wait_for_group_task_completion(group_task);
	for (InstanceCullResult &thread : scene_cull_result_threads) {
	scene_cull_result.append_from(thread);
	}
	} else {
	//single threaded
	_scene_cull(cull_data, scene_cull_result, cull_from, cull_to);
	}

[clayjohn]

Looks great!

[YuriSizov]

Thanks!

[YuriSizov]

Cherry-picked for 4.2.2.

[YuriSizov]

Cherry-picked for 4.1.4.