# Objective
- Currently, the render graph slots are only used to pass the
view_entity around. This introduces significant boilerplate for very
little value. Instead of using slots for this, make the view_entity part
of the `RenderGraphContext`. This also means we won't need to have
`IN_VIEW` on every node and and we'll be able to use the default impl of
`Node::input()`.
## Solution
- Add `view_entity: Option<Entity>` to the `RenderGraphContext`
- Update all nodes to use this instead of entity slot input
---
## Changelog
- Add optional `view_entity` to `RenderGraphContext`
## Migration Guide
You can now get the view_entity directly from the `RenderGraphContext`.
When implementing the Node:
```rust
// 0.10
struct FooNode;
impl FooNode {
const IN_VIEW: &'static str = "view";
}
impl Node for FooNode {
fn input(&self) -> Vec<SlotInfo> {
vec![SlotInfo::new(Self::IN_VIEW, SlotType::Entity)]
}
fn run(
&self,
graph: &mut RenderGraphContext,
// ...
) -> Result<(), NodeRunError> {
let view_entity = graph.get_input_entity(Self::IN_VIEW)?;
// ...
Ok(())
}
}
// 0.11
struct FooNode;
impl Node for FooNode {
fn run(
&self,
graph: &mut RenderGraphContext,
// ...
) -> Result<(), NodeRunError> {
let view_entity = graph.view_entity();
// ...
Ok(())
}
}
```
When adding the node to the graph, you don't need to specify a slot_edge
for the view_entity.
```rust
// 0.10
let mut graph = RenderGraph::default();
graph.add_node(FooNode::NAME, node);
let input_node_id = draw_2d_graph.set_input(vec![SlotInfo::new(
graph::input::VIEW_ENTITY,
SlotType::Entity,
)]);
graph.add_slot_edge(
input_node_id,
graph::input::VIEW_ENTITY,
FooNode::NAME,
FooNode::IN_VIEW,
);
// add_node_edge ...
// 0.11
let mut graph = RenderGraph::default();
graph.add_node(FooNode::NAME, node);
// add_node_edge ...
```
## Notes
This PR paired with #8007 will help reduce a lot of annoying boilerplate
with the render nodes. Depending on which one gets merged first. It will
require a bit of clean up work to make both compatible.
I tagged this as a breaking change, because using the old system to get
the view_entity will break things because it's not a node input slot
anymore.
## Notes for reviewers
A lot of the diffs are just removing the slots in every nodes and graph
creation. The important part is mostly in the
graph_runner/CameraDriverNode.
# Objective
`RenderContext`, the core abstraction for running the render graph, currently only supports recording one `CommandBuffer` across the entire render graph. This means the entire buffer must be recorded sequentially, usually via the render graph itself. This prevents parallelization and forces users to only encode their commands in the render graph.
## Solution
Allow `RenderContext` to store a `Vec<CommandBuffer>` that it progressively appends to. By default, the context will not have a command encoder, but will create one as soon as either `begin_tracked_render_pass` or the `command_encoder` accesor is first called. `RenderContext::add_command_buffer` allows users to interrupt the current command encoder, flush it to the vec, append a user-provided `CommandBuffer` and reset the command encoder to start a new buffer. Users or the render graph will call `RenderContext::finish` to retrieve the series of buffers for submitting to the queue.
This allows users to encode their own `CommandBuffer`s outside of the render graph, potentially in different threads, and store them in components or resources.
Ideally, in the future, the core pipeline passes can run in `RenderStage::Render` systems and end up saving the completed command buffers to either `Commands` or a field in `RenderPhase`.
## Alternatives
The alternative is to use to use wgpu's `RenderBundle`s, which can achieve similar results; however it's not universally available (no OpenGL, WebGL, and DX11).
---
## Changelog
Added: `RenderContext::new`
Added: `RenderContext::add_command_buffer`
Added: `RenderContext::finish`
Changed: `RenderContext::render_device` is now private. Use the accessor `RenderContext::render_device()` instead.
Changed: `RenderContext::command_encoder` is now private. Use the accessor `RenderContext::command_encoder()` instead.
Changed: `RenderContext` now supports adding external `CommandBuffer`s for inclusion into the render graphs. These buffers can be encoded outside of the render graph (i.e. in a system).
## Migration Guide
`RenderContext`'s fields are now private. Use the accessors on `RenderContext` instead, and construct it with `RenderContext::new`.
# Objective
`add_node_edge` and `add_slot_edge` are fallible methods, but are always used with `.unwrap()`.
`input_node` is often unwrapped as well.
This points to having an infallible behaviour as default, with an alternative fallible variant if needed.
Improves readability and ergonomics.
## Solution
- Change `add_node_edge` and `add_slot_edge` to panic on error.
- Change `input_node` to panic on `None`.
- Add `try_add_node_edge` and `try_add_slot_edge` in case fallible methods are needed.
- Add `get_input_node` to still be able to get an `Option`.
---
## Changelog
### Added
- `try_add_node_edge`
- `try_add_slot_edge`
- `get_input_node`
### Changed
- `add_node_edge` is now infallible (panics on error)
- `add_slot_edge` is now infallible (panics on error)
- `input_node` now panics on `None`
## Migration Guide
Remove `.unwrap()` from `add_node_edge` and `add_slot_edge`.
For cases where the error was handled, use `try_add_node_edge` and `try_add_slot_edge` instead.
Remove `.unwrap()` from `input_node`.
For cases where the option was handled, use `get_input_node` instead.
Co-authored-by: Torstein Grindvik <52322338+torsteingrindvik@users.noreply.github.com>
# Objective
Currently, providing the wrong number of inputs to a render graph node triggers this assertion:
```
thread 'main' panicked at 'assertion failed: `(left == right)`
left: `1`,
right: `2`', /[redacted]/bevy/crates/bevy_render/src/renderer/graph_runner.rs:164:13
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
```
This does not provide the user any context.
## Solution
Add a new `RenderGraphRunnerError` variant to handle this case. The new message looks like this:
```
ERROR bevy_render::renderer: Error running render graph:
ERROR bevy_render::renderer: > node (name: 'Some("outline_pass")') has 2 input slots, but was provided 1 values
```
---
## Changelog
### Changed
`RenderGraphRunnerError` now has a new variant, `MismatchedInputCount`.
## Migration Guide
Exhaustive matches on `RenderGraphRunnerError` will need to add a branch to handle the new `MismatchedInputCount` variant.
Tracing added support for "inline span entering", which cuts down on a lot of complexity:
```rust
let span = info_span!("my_span").entered();
```
This adapts our code to use this pattern where possible, and updates our docs to recommend it.
This produces equivalent tracing behavior. Here is a side by side profile of "before" and "after" these changes.
This makes the [New Bevy Renderer](#2535) the default (and only) renderer. The new renderer isn't _quite_ ready for the final release yet, but I want as many people as possible to start testing it so we can identify bugs and address feedback prior to release.
The examples are all ported over and operational with a few exceptions:
* I removed a good portion of the examples in the `shader` folder. We still have some work to do in order to make these examples possible / ergonomic / worthwhile: #3120 and "high level shader material plugins" are the big ones. This is a temporary measure.
* Temporarily removed the multiple_windows example: doing this properly in the new renderer will require the upcoming "render targets" changes. Same goes for the render_to_texture example.
* Removed z_sort_debug: entity visibility sort info is no longer available in app logic. we could do this on the "render app" side, but i dont consider it a priority.
