bevy/examples/shader/shader_material_glsl.rs
Kornel 435d9bc02c
Highlight dependency on shader files in examples (#13824)
The examples won't work when copy-pasted to another project, without
also copying their shader files. This change adds constants at the top
of the files to bring attention to the dependencies.

Follow up to
[#13624](https://github.com/bevyengine/bevy/pull/13624#issuecomment-2143872791)
2024-06-12 14:16:01 +00:00

92 lines
2.9 KiB
Rust

//! A shader that uses the GLSL shading language.
use bevy::{
pbr::{MaterialPipeline, MaterialPipelineKey},
prelude::*,
reflect::TypePath,
render::{
mesh::MeshVertexBufferLayoutRef,
render_resource::{
AsBindGroup, RenderPipelineDescriptor, ShaderRef, SpecializedMeshPipelineError,
},
},
};
/// This example uses shader source files from the assets subdirectory
const VERTEX_SHADER_ASSET_PATH: &str = "shaders/custom_material.vert";
const FRAGMENT_SHADER_ASSET_PATH: &str = "shaders/custom_material.frag";
fn main() {
App::new()
.add_plugins((DefaultPlugins, MaterialPlugin::<CustomMaterial>::default()))
.add_systems(Startup, setup)
.run();
}
/// set up a simple 3D scene
fn setup(
mut commands: Commands,
mut meshes: ResMut<Assets<Mesh>>,
mut materials: ResMut<Assets<CustomMaterial>>,
asset_server: Res<AssetServer>,
) {
// cube
commands.spawn(MaterialMeshBundle {
mesh: meshes.add(Cuboid::default()),
transform: Transform::from_xyz(0.0, 0.5, 0.0),
material: materials.add(CustomMaterial {
color: LinearRgba::BLUE,
color_texture: Some(asset_server.load("branding/icon.png")),
alpha_mode: AlphaMode::Blend,
}),
..default()
});
// camera
commands.spawn(Camera3dBundle {
transform: Transform::from_xyz(-2.0, 2.5, 5.0).looking_at(Vec3::ZERO, Vec3::Y),
..default()
});
}
// This is the struct that will be passed to your shader
#[derive(Asset, TypePath, AsBindGroup, Clone)]
struct CustomMaterial {
#[uniform(0)]
color: LinearRgba,
#[texture(1)]
#[sampler(2)]
color_texture: Option<Handle<Image>>,
alpha_mode: AlphaMode,
}
/// The Material trait is very configurable, but comes with sensible defaults for all methods.
/// You only need to implement functions for features that need non-default behavior. See the Material api docs for details!
/// When using the GLSL shading language for your shader, the specialize method must be overridden.
impl Material for CustomMaterial {
fn vertex_shader() -> ShaderRef {
VERTEX_SHADER_ASSET_PATH.into()
}
fn fragment_shader() -> ShaderRef {
FRAGMENT_SHADER_ASSET_PATH.into()
}
fn alpha_mode(&self) -> AlphaMode {
self.alpha_mode
}
// Bevy assumes by default that vertex shaders use the "vertex" entry point
// and fragment shaders use the "fragment" entry point (for WGSL shaders).
// GLSL uses "main" as the entry point, so we must override the defaults here
fn specialize(
_pipeline: &MaterialPipeline<Self>,
descriptor: &mut RenderPipelineDescriptor,
_layout: &MeshVertexBufferLayoutRef,
_key: MaterialPipelineKey<Self>,
) -> Result<(), SpecializedMeshPipelineError> {
descriptor.vertex.entry_point = "main".into();
descriptor.fragment.as_mut().unwrap().entry_point = "main".into();
Ok(())
}
}