From 75dcc9077cded2d560ff47db2cf6c72bed207294 Mon Sep 17 00:00:00 2001
From: Robin KAY <komadori@gekkou.co.uk>
Date: Mon, 8 Aug 2022 22:40:38 +0100
Subject: [PATCH] Add visible flag to Outline component.

---
 examples/shapes.rs |  4 ++++
 src/lib.rs         | 10 +++++++---
 src/uniforms.rs    | 48 ++++++++++++++++++++--------------------------
 3 files changed, 32 insertions(+), 30 deletions(-)

diff --git a/examples/shapes.rs b/examples/shapes.rs
index 6bdfdfe..42ddf9f 100644
--- a/examples/shapes.rs
+++ b/examples/shapes.rs
@@ -36,6 +36,7 @@ fn setup(
         material: materials.add(Color::rgb(0.3, 0.5, 0.3).into()),
         ..default()
     });
+
     let mut cube_mesh = Mesh::from(Cube { size: 1.0 });
     cube_mesh.generate_outline_normals().unwrap();
     commands
@@ -46,11 +47,13 @@ fn setup(
             ..default()
         })
         .insert(Outline {
+            visible: true,
             colour: Color::rgba(0.0, 1.0, 0.0, 1.0),
             width: 25.0,
         })
         .insert(OutlineStencil)
         .insert(Wobbles);
+
     commands
         .spawn_bundle(PbrBundle {
             mesh: meshes.add(Mesh::from(Torus {
@@ -65,6 +68,7 @@ fn setup(
             ..default()
         })
         .insert(Outline {
+            visible: true,
             colour: Color::rgba(1.0, 0.0, 1.0, 0.3),
             width: 15.0,
         })
diff --git a/src/lib.rs b/src/lib.rs
index 70abd8b..c128def 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -16,7 +16,10 @@ use crate::node::{OpaqueOutline, OutlineNode, StencilOutline, TransparentOutline
 use crate::pipeline::{
     OutlinePipeline, COMMON_SHADER_HANDLE, OUTLINE_SHADER_HANDLE, STENCIL_SHADER_HANDLE,
 };
-use crate::uniforms::{queue_outline_bind_group, OutlineFragmentUniform, OutlineVertexUniform};
+use crate::uniforms::{
+    extract_outline_uniforms, queue_outline_bind_group, OutlineFragmentUniform,
+    OutlineVertexUniform,
+};
 use crate::view_uniforms::{
     extract_outline_view_uniforms, queue_outline_view_bind_group, OutlineViewUniform,
 };
@@ -52,6 +55,8 @@ impl ExtractComponent for OutlineStencil {
 /// A component for rendering outlines around meshes.
 #[derive(Clone, Component)]
 pub struct Outline {
+    /// Enable rendering of the outline
+    pub visible: bool,
     /// Width of the outline in logical pixels
     pub width: f32,
     /// Colour of the outline
@@ -145,8 +150,6 @@ impl Plugin for OutlinePlugin {
         );
 
         app.add_plugin(ExtractComponentPlugin::<OutlineStencil>::extract_visible())
-            .add_plugin(ExtractComponentPlugin::<OutlineVertexUniform>::default())
-            .add_plugin(ExtractComponentPlugin::<OutlineFragmentUniform>::default())
             .add_plugin(UniformComponentPlugin::<OutlineVertexUniform>::default())
             .add_plugin(UniformComponentPlugin::<OutlineFragmentUniform>::default())
             .add_plugin(UniformComponentPlugin::<OutlineViewUniform>::default())
@@ -160,6 +163,7 @@ impl Plugin for OutlinePlugin {
             .add_render_command::<OpaqueOutline, DrawOutline>()
             .add_render_command::<TransparentOutline, DrawOutline>()
             .add_system_to_stage(RenderStage::Extract, extract_outline_view_uniforms)
+            .add_system_to_stage(RenderStage::Extract, extract_outline_uniforms)
             .add_system_to_stage(RenderStage::PhaseSort, sort_phase_system::<StencilOutline>)
             .add_system_to_stage(RenderStage::PhaseSort, sort_phase_system::<OpaqueOutline>)
             .add_system_to_stage(
diff --git a/src/uniforms.rs b/src/uniforms.rs
index 13ae787..612144b 100644
--- a/src/uniforms.rs
+++ b/src/uniforms.rs
@@ -1,17 +1,15 @@
 use bevy::{
-    ecs::{
-        query::QueryItem,
-        system::{
-            lifetimeless::{Read, SQuery, SRes},
-            SystemParamItem,
-        },
+    ecs::system::{
+        lifetimeless::{Read, SQuery, SRes},
+        SystemParamItem,
     },
     prelude::*,
     render::{
-        extract_component::{ComponentUniforms, DynamicUniformIndex, ExtractComponent},
+        extract_component::{ComponentUniforms, DynamicUniformIndex},
         render_phase::{EntityRenderCommand, RenderCommandResult, TrackedRenderPass},
         render_resource::{BindGroup, BindGroupDescriptor, BindGroupEntry, ShaderType},
         renderer::RenderDevice,
+        Extract,
     },
 };
 
@@ -22,35 +20,31 @@ pub struct OutlineVertexUniform {
     pub width: f32,
 }
 
-impl ExtractComponent for OutlineVertexUniform {
-    type Query = Read<Outline>;
-    type Filter = ();
-
-    fn extract_component(item: QueryItem<Self::Query>) -> Self {
-        OutlineVertexUniform { width: item.width }
-    }
-}
-
 #[derive(Clone, Component, ShaderType)]
 pub struct OutlineFragmentUniform {
     pub colour: Vec4,
 }
 
-impl ExtractComponent for OutlineFragmentUniform {
-    type Query = Read<Outline>;
-    type Filter = ();
-
-    fn extract_component(item: QueryItem<Self::Query>) -> Self {
-        OutlineFragmentUniform {
-            colour: item.colour.as_linear_rgba_f32().into(),
-        }
-    }
-}
-
 pub struct OutlineBindGroup {
     pub bind_group: BindGroup,
 }
 
+pub fn extract_outline_uniforms(mut commands: Commands, query: Extract<Query<(Entity, &Outline)>>) {
+    for (entity, outline) in query.iter() {
+        if !outline.visible || outline.colour.a() == 0.0 {
+            continue;
+        }
+        commands
+            .get_or_spawn(entity)
+            .insert(OutlineVertexUniform {
+                width: outline.width,
+            })
+            .insert(OutlineFragmentUniform {
+                colour: outline.colour.as_linear_rgba_f32().into(),
+            });
+    }
+}
+
 pub fn queue_outline_bind_group(
     mut commands: Commands,
     render_device: Res<RenderDevice>,