133 lines
4.1 KiB
Rust
133 lines
4.1 KiB
Rust
use bevy::{
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prelude::*,
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reflect::TypeUuid,
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render::{
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mesh::shape,
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pipeline::{PipelineDescriptor, RenderPipeline},
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render_graph::{base, AssetRenderResourcesNode, RenderGraph},
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renderer::RenderResources,
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shader::{asset_shader_defs_system, ShaderDefs, ShaderStage, ShaderStages},
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},
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};
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/// This example illustrates how to create a custom material asset that uses "shader defs" and a shader that uses that material.
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/// In Bevy, "shader defs" are a way to selectively enable parts of a shader based on values set in a component or asset.
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fn main() {
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App::build()
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.add_plugins(DefaultPlugins)
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.add_asset::<MyMaterial>()
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.add_startup_system(setup.system())
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.add_system_to_stage(
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stage::POST_UPDATE,
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asset_shader_defs_system::<MyMaterial>.system(),
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)
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.run();
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}
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#[derive(RenderResources, ShaderDefs, Default, TypeUuid)]
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#[uuid = "620f651b-adbe-464b-b740-ba0e547282ba"]
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struct MyMaterial {
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pub color: Color,
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#[render_resources(ignore)]
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#[shader_def]
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pub always_blue: bool,
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}
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const VERTEX_SHADER: &str = r#"
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#version 450
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layout(location = 0) in vec3 Vertex_Position;
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layout(set = 0, binding = 0) uniform Camera {
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mat4 ViewProj;
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};
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layout(set = 1, binding = 0) uniform Transform {
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mat4 Model;
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};
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void main() {
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gl_Position = ViewProj * Model * vec4(Vertex_Position, 1.0);
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}
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"#;
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const FRAGMENT_SHADER: &str = r#"
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#version 450
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layout(location = 0) out vec4 o_Target;
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layout(set = 2, binding = 0) uniform MyMaterial_color {
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vec4 color;
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};
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void main() {
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o_Target = color;
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# ifdef MYMATERIAL_ALWAYS_BLUE
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o_Target = vec4(0.0, 0.0, 0.8, 1.0);
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# endif
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}
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"#;
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fn setup(
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commands: &mut Commands,
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mut pipelines: ResMut<Assets<PipelineDescriptor>>,
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mut shaders: ResMut<Assets<Shader>>,
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mut meshes: ResMut<Assets<Mesh>>,
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mut materials: ResMut<Assets<MyMaterial>>,
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mut render_graph: ResMut<RenderGraph>,
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) {
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// Create a new shader pipeline
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let pipeline_handle = pipelines.add(PipelineDescriptor::default_config(ShaderStages {
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vertex: shaders.add(Shader::from_glsl(ShaderStage::Vertex, VERTEX_SHADER)),
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fragment: Some(shaders.add(Shader::from_glsl(ShaderStage::Fragment, FRAGMENT_SHADER))),
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}));
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// Add an AssetRenderResourcesNode to our Render Graph. This will bind MyMaterial resources to our shader
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render_graph.add_system_node(
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"my_material",
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AssetRenderResourcesNode::<MyMaterial>::new(true),
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);
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// 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
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render_graph
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.add_node_edge("my_material", base::node::MAIN_PASS)
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.unwrap();
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// Create a green material
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let green_material = materials.add(MyMaterial {
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color: Color::rgb(0.0, 0.8, 0.0),
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always_blue: false,
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});
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// Create a blue material, which uses our "always_blue" shader def
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let blue_material = materials.add(MyMaterial {
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color: Color::rgb(0.0, 0.0, 0.0),
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always_blue: true,
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});
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// Create a cube mesh which will use our materials
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let cube_handle = meshes.add(Mesh::from(shape::Cube { size: 2.0 }));
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commands
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// cube
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.spawn(MeshBundle {
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mesh: cube_handle.clone(),
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render_pipelines: RenderPipelines::from_pipelines(vec![RenderPipeline::new(
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pipeline_handle.clone(),
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)]),
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transform: Transform::from_xyz(-2.0, 0.0, 0.0),
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..Default::default()
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})
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.with(green_material)
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// cube
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.spawn(MeshBundle {
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mesh: cube_handle,
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render_pipelines: RenderPipelines::from_pipelines(vec![RenderPipeline::new(
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pipeline_handle,
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)]),
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transform: Transform::from_xyz(2.0, 0.0, 0.0),
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..Default::default()
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})
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.with(blue_material)
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// camera
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.spawn(Camera3dBundle {
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transform: Transform::from_xyz(3.0, 5.0, -8.0)
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.looking_at(Vec3::default(), Vec3::unit_y()),
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..Default::default()
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});
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}
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