bevy/examples/shader/hot_shader_reloading.rs
Carter Anderson 81b53d15d4 Make Commands and World apis consistent (#1703)
Resolves #1253 #1562

This makes the Commands apis consistent with World apis. This moves to a "type state" pattern (like World) where the "current entity" is stored in an `EntityCommands` builder.

In general this tends to cuts down on indentation and line count. It comes at the cost of needing to type `commands` more and adding more semicolons to terminate expressions.

I also added `spawn_bundle` to Commands because this is a common enough operation that I think its worth providing a shorthand.
2021-03-23 00:23:40 +00:00

80 lines
2.5 KiB
Rust

use bevy::{
prelude::*,
reflect::TypeUuid,
render::{
mesh::shape,
pipeline::{PipelineDescriptor, RenderPipeline},
render_graph::{base, AssetRenderResourcesNode, RenderGraph},
renderer::RenderResources,
shader::ShaderStages,
},
};
/// This example illustrates how to load shaders such that they can be
/// edited while the example is still running.
fn main() {
App::build()
.add_plugins(DefaultPlugins)
.add_asset::<MyMaterial>()
.add_startup_system(setup.system())
.run();
}
#[derive(RenderResources, Default, TypeUuid)]
#[uuid = "3bf9e364-f29d-4d6c-92cf-93298466c620"]
struct MyMaterial {
pub color: Color,
}
fn setup(
mut commands: Commands,
asset_server: ResMut<AssetServer>,
mut pipelines: ResMut<Assets<PipelineDescriptor>>,
mut meshes: ResMut<Assets<Mesh>>,
mut materials: ResMut<Assets<MyMaterial>>,
mut render_graph: ResMut<RenderGraph>,
) {
// Watch for changes
asset_server.watch_for_changes().unwrap();
// Create a new shader pipeline with shaders loaded from the asset directory
let pipeline_handle = pipelines.add(PipelineDescriptor::default_config(ShaderStages {
vertex: asset_server.load::<Shader, _>("shaders/hot.vert"),
fragment: Some(asset_server.load::<Shader, _>("shaders/hot.frag")),
}));
// Add an AssetRenderResourcesNode to our Render Graph. This will bind MyMaterial resources to
// our shader
render_graph.add_system_node(
"my_material",
AssetRenderResourcesNode::<MyMaterial>::new(true),
);
// Add a Render Graph edge connecting our new "my_material" node to the main pass node. This
// ensures "my_material" runs before the main pass
render_graph
.add_node_edge("my_material", base::node::MAIN_PASS)
.unwrap();
// Create a new material
let material = materials.add(MyMaterial {
color: Color::rgb(0.0, 0.8, 0.0),
});
// cube
commands
.spawn_bundle(MeshBundle {
mesh: meshes.add(Mesh::from(shape::Cube { size: 2.0 })),
render_pipelines: RenderPipelines::from_pipelines(vec![RenderPipeline::new(
pipeline_handle,
)]),
transform: Transform::from_xyz(0.0, 0.0, 0.0),
..Default::default()
})
.insert(material);
// camera
commands.spawn_bundle(PerspectiveCameraBundle {
transform: Transform::from_xyz(3.0, 5.0, -8.0).looking_at(Vec3::ZERO, Vec3::Y),
..Default::default()
});
}