bevy/examples/shader/shader_material_glsl.rs
Alice Cecile de004da8d5
Rename bevy_render::Color to LegacyColor (#12069)
# Objective

The migration process for `bevy_color` (#12013) will be fairly involved:
there will be hundreds of affected files, and a large number of APIs.

## Solution

To allow us to proceed granularly, we're going to keep both
`bevy_color::Color` (new) and `bevy_render::Color` (old) around until
the migration is complete.

However, simply doing this directly is confusing! They're both called
`Color`, making it very hard to tell when a portion of the code has been
ported.

As discussed in #12056, by renaming the old `Color` type, we can make it
easier to gradually migrate over, one API at a time.

## Migration Guide

THIS MIGRATION GUIDE INTENTIONALLY LEFT BLANK.

This change should not be shipped to end users: delete this section in
the final migration guide!

---------

Co-authored-by: Alice Cecile <alice.i.cecil@gmail.com>
2024-02-24 21:35:32 +00:00

88 lines
2.7 KiB
Rust

//! A shader that uses the GLSL shading language.
use bevy::{
pbr::{MaterialPipeline, MaterialPipelineKey},
prelude::*,
reflect::TypePath,
render::{
mesh::MeshVertexBufferLayout,
render_resource::{
AsBindGroup, RenderPipelineDescriptor, ShaderRef, SpecializedMeshPipelineError,
},
},
};
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: LegacyColor::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: LegacyColor,
#[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 {
"shaders/custom_material.vert".into()
}
fn fragment_shader() -> ShaderRef {
"shaders/custom_material.frag".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: &MeshVertexBufferLayout,
_key: MaterialPipelineKey<Self>,
) -> Result<(), SpecializedMeshPipelineError> {
descriptor.vertex.entry_point = "main".into();
descriptor.fragment.as_mut().unwrap().entry_point = "main".into();
Ok(())
}
}