fix material shader example

examples/custom_material_shader.rs

@@ -0,0 +1,131 @@
+use bevy::prelude::*;
+
+fn main() {
+    App::build().add_defaults().setup(setup).run();
+}
+
+#[derive(Uniforms, Default)]
+struct MyMaterial {
+    pub color: Color,
+    #[uniform(ignore, shader_def)]
+    pub always_red: bool,
+}
+
+fn add_shader_to_render_graph(resources: &mut Resources) {
+    let mut render_graph = resources.get_mut::<RenderGraph>().unwrap();
+    let mut pipelines = resources
+        .get_mut::<AssetStorage<PipelineDescriptor>>()
+        .unwrap();
+    let mut shaders = resources.get_mut::<AssetStorage<Shader>>().unwrap();
+
+    render_graph
+        .build(&mut pipelines, &mut shaders)
+        .add_resource_provider(UniformResourceProvider::<MyMaterial>::new(true))
+        .add_pipeline_to_pass(resource_name::pass::MAIN, "MyMaterial", |builder| {
+            builder
+                .with_vertex_shader(Shader::from_glsl(
+                    ShaderStage::Vertex,
+                    r#"
+                    #version 450
+                    layout(location = 0) in vec4 Vertex_Position;
+                    layout(location = 0) out vec4 v_Position;
+                    layout(set = 0, binding = 0) uniform Camera {
+                        mat4 ViewProj;
+                    };
+                    layout(set = 1, binding = 0) uniform Object {
+                        mat4 Model;
+                    };
+                    void main() {
+                        v_Position = Model * Vertex_Position;
+                        gl_Position = ViewProj * v_Position;
+                    }
+                "#,
+                ))
+                .with_fragment_shader(Shader::from_glsl(
+                    ShaderStage::Fragment,
+                    r#"
+                    #version 450
+                    layout(location = 0) in vec4 v_Position;
+                    layout(location = 0) out vec4 o_Target;
+                    layout(set = 1, binding = 1) uniform MyMaterial_color {
+                        vec4 color;
+                    };
+                    void main() {
+                        o_Target = color;
+
+                    # ifdef MYMATERIAL_ALWAYS_RED
+                        o_Target = vec4(0.8, 0.0, 0.0, 1.0);
+                    # endif
+                    }
+                "#,
+                ))
+                .with_default_config();
+        });
+}
+
+fn setup(world: &mut World, resources: &mut Resources) {
+    // add our shader to the render graph
+    add_shader_to_render_graph(resources);
+
+    // create materials
+    let mut material_storage = AssetStorage::<MyMaterial>::new();
+    let green_material = material_storage.add(MyMaterial {
+        color: Color::rgb(0.0, 0.8, 0.0),
+        always_red: false,
+    });
+
+    let red_material = material_storage.add(MyMaterial {
+        color: Color::rgb(0.0, 0.0, 0.0),
+        always_red: true,
+    });
+
+    resources.insert(material_storage);
+
+    // batch materials to improve performance
+    let mut asset_batchers = resources.get_mut::<AssetBatchers>().unwrap();
+    asset_batchers.batch_types2::<Mesh, MyMaterial>();
+
+    // get a handle to our newly created shader pipeline
+    let mut pipeline_storage = resources
+        .get_mut::<AssetStorage<PipelineDescriptor>>()
+        .unwrap();
+    let pipeline_handle = pipeline_storage.get_named("MyMaterial").unwrap();
+
+    let mut mesh_storage = resources.get_mut::<AssetStorage<Mesh>>().unwrap();
+    let cube_handle = mesh_storage.add(Mesh::load(MeshType::Cube));
+
+    world
+        .build()
+        // cube
+        .add_entity(MeshMaterialEntity::<MyMaterial> {
+            mesh: cube_handle,
+            renderable: Renderable {
+                pipelines: vec![pipeline_handle],
+                ..Default::default()
+            },
+            material: green_material,
+            translation: Translation::new(-2.0, 0.0, 0.0),
+            ..Default::default()
+        })
+        // cube
+        .add_entity(MeshMaterialEntity::<MyMaterial> {
+            mesh: cube_handle,
+            renderable: Renderable {
+                pipelines: vec![pipeline_handle],
+                ..Default::default()
+            },
+            material: red_material,
+            translation: Translation::new(2.0, 0.0, 0.0),
+            ..Default::default()
+        })
+        // camera
+        .add_entity(CameraEntity {
+            local_to_world: LocalToWorld(Mat4::look_at_rh(
+                Vec3::new(3.0, 8.0, 5.0),
+                Vec3::new(0.0, 0.0, 0.0),
+                Vec3::new(0.0, 0.0, 1.0),
+            )),
+            ..Default::default()
+        })
+        .build();
+}