bevy/crates/bevy_render/src/gpu_component_array_buffer.rs
James O'Brien 4f1d9a6315
Reorder render sets, refactor bevy_sprite to take advantage (#9236)
This is a continuation of this PR: #8062 

# Objective

- Reorder render schedule sets to allow data preparation when phase item
order is known to support improved batching
- Part of the batching/instancing etc plan from here:
https://github.com/bevyengine/bevy/issues/89#issuecomment-1379249074
- The original idea came from @inodentry and proved to be a good one.
Thanks!
- Refactor `bevy_sprite` and `bevy_ui` to take advantage of the new
ordering

## Solution
- Move `Prepare` and `PrepareFlush` after `PhaseSortFlush` 
- Add a `PrepareAssets` set that runs in parallel with other systems and
sets in the render schedule.
  - Put prepare_assets systems in the `PrepareAssets` set
- If explicit dependencies are needed on Mesh or Material RenderAssets
then depend on the appropriate system.
- Add `ManageViews` and `ManageViewsFlush` sets between
`ExtractCommands` and Queue
- Move `queue_mesh*_bind_group` to the Prepare stage
  - Rename them to `prepare_`
- Put systems that prepare resources (buffers, textures, etc.) into a
`PrepareResources` set inside `Prepare`
- Put the `prepare_..._bind_group` systems into a `PrepareBindGroup` set
after `PrepareResources`
- Move `prepare_lights` to the `ManageViews` set
  - `prepare_lights` creates views and this must happen before `Queue`
  - This system needs refactoring to stop handling all responsibilities
- Gather lights, sort, and create shadow map views. Store sorted light
entities in a resource

- Remove `BatchedPhaseItem`
- Replace `batch_range` with `batch_size` representing how many items to
skip after rendering the item or to skip the item entirely if
`batch_size` is 0.
- `queue_sprites` has been split into `queue_sprites` for queueing phase
items and `prepare_sprites` for batching after the `PhaseSort`
  - `PhaseItem`s are still inserted in `queue_sprites`
- After sorting adjacent compatible sprite phase items are accumulated
into `SpriteBatch` components on the first entity of each batch,
containing a range of vertex indices. The associated `PhaseItem`'s
`batch_size` is updated appropriately.
- `SpriteBatch` items are then drawn skipping over the other items in
the batch based on the value in `batch_size`
- A very similar refactor was performed on `bevy_ui`
---

## Changelog

Changed:
- Reordered and reworked render app schedule sets. The main change is
that data is extracted, queued, sorted, and then prepared when the order
of data is known.
- Refactor `bevy_sprite` and `bevy_ui` to take advantage of the
reordering.

## Migration Guide
- Assets such as materials and meshes should now be created in
`PrepareAssets` e.g. `prepare_assets<Mesh>`
- Queueing entities to `RenderPhase`s continues to be done in `Queue`
e.g. `queue_sprites`
- Preparing resources (textures, buffers, etc.) should now be done in
`PrepareResources`, e.g. `prepare_prepass_textures`,
`prepare_mesh_uniforms`
- Prepare bind groups should now be done in `PrepareBindGroups` e.g.
`prepare_mesh_bind_group`
- Any batching or instancing can now be done in `Prepare` where the
order of the phase items is known e.g. `prepare_sprites`

 
## Next Steps
- Introduce some generic mechanism to ensure items that can be batched
are grouped in the phase item order, currently you could easily have
`[sprite at z 0, mesh at z 0, sprite at z 0]` preventing batching.
 - Investigate improved orderings for building the MeshUniform buffer
 - Implementing batching across the rest of bevy

---------

Co-authored-by: Robert Swain <robert.swain@gmail.com>
Co-authored-by: robtfm <50659922+robtfm@users.noreply.github.com>
2023-08-27 14:33:49 +00:00

59 lines
1.9 KiB
Rust

use crate::{
render_resource::{GpuArrayBuffer, GpuArrayBufferable},
renderer::{RenderDevice, RenderQueue},
Render, RenderApp, RenderSet,
};
use bevy_app::{App, Plugin};
use bevy_ecs::{
prelude::{Component, Entity},
schedule::IntoSystemConfigs,
system::{Commands, Query, Res, ResMut},
};
use std::marker::PhantomData;
/// This plugin prepares the components of the corresponding type for the GPU
/// by storing them in a [`GpuArrayBuffer`].
pub struct GpuComponentArrayBufferPlugin<C: Component + GpuArrayBufferable>(PhantomData<C>);
impl<C: Component + GpuArrayBufferable> Plugin for GpuComponentArrayBufferPlugin<C> {
fn build(&self, app: &mut App) {
if let Ok(render_app) = app.get_sub_app_mut(RenderApp) {
render_app.add_systems(
Render,
prepare_gpu_component_array_buffers::<C>.in_set(RenderSet::PrepareResources),
);
}
}
fn finish(&self, app: &mut App) {
if let Ok(render_app) = app.get_sub_app_mut(RenderApp) {
render_app.insert_resource(GpuArrayBuffer::<C>::new(
render_app.world.resource::<RenderDevice>(),
));
}
}
}
impl<C: Component + GpuArrayBufferable> Default for GpuComponentArrayBufferPlugin<C> {
fn default() -> Self {
Self(PhantomData::<C>)
}
}
fn prepare_gpu_component_array_buffers<C: Component + GpuArrayBufferable>(
mut commands: Commands,
render_device: Res<RenderDevice>,
render_queue: Res<RenderQueue>,
mut gpu_array_buffer: ResMut<GpuArrayBuffer<C>>,
components: Query<(Entity, &C)>,
) {
gpu_array_buffer.clear();
let entities = components
.iter()
.map(|(entity, component)| (entity, gpu_array_buffer.push(component.clone())))
.collect::<Vec<_>>();
commands.insert_or_spawn_batch(entities);
gpu_array_buffer.write_buffer(&render_device, &render_queue);
}