Struct EntitySpecializationTickPair 

pub struct EntitySpecializationTickPair {
    pub system_tick: Tick,
    pub material_instances_tick: Tick,
}

Ticks that specify the last time an entity’s pipeline was specialized.

We need two different types of ticks here for a subtle reason. First, we need the Self::system_tick, which maps to Bevy’s SystemChangeTick, because that’s what we use in specialize_material_meshes to check whether pipelines need specialization. But we also need Self::material_instances_tick, which maps to the RenderMaterialInstances::current_change_tick. That’s because the latter only changes once per frame, which is a guarantee we need to handle the following case:

1. The app removes material A from a mesh and replaces it with material B. Both A and B are of different Material types entirely.

2. extract_entities_needs_specialization runs for material B and marks the mesh as up to date by recording the current tick.

3. sweep_entities_needing_specialization runs for material A and checks to ensure it’s safe to remove the EntitySpecializationTickPair for the mesh from the EntitySpecializationTicks. To do this, it needs to know whether extract_entities_needs_specialization for some different material (in this case, material B) ran earlier in the frame and updated the change tick, and to skip removing the EntitySpecializationTickPair if so. It can’t reliably use the Self::system_tick to determine this because the SystemChangeTick can be updated multiple times in the same frame. Instead, it needs a type of tick that’s updated only once per frame, after all materials’ versions of sweep_entities_needing_specialization have run. The RenderMaterialInstances tick satisfies this criterion, and so that’s what sweep_entities_needing_specialization uses.

Fields

system_tick: Tick

The standard Bevy system tick.

material_instances_tick: Tick

The tick in RenderMaterialInstances, which is updated in late_sweep_material_instances.

Trait Implementations

impl Clone for EntitySpecializationTickPair

fn clone(&self) -> EntitySpecializationTickPair

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for EntitySpecializationTickPair

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Copy for EntitySpecializationTickPair