From b2e85a6f2e9c570ae7599bdce166c50403f15bb0 Mon Sep 17 00:00:00 2001
From: Ryan Butler <thebutlah@gmail.com>
Date: Sat, 7 Oct 2023 17:35:12 +0200
Subject: [PATCH] Use ExtractResource trait for EguiManagedTextures and
 EguiUserTextures (#210)

Co-authored-by: mvlabat <mvlabat@gmail.com>
---
 src/lib.rs            | 12 +++++-----
 src/render_systems.rs | 52 ++++++++++++++++++++++---------------------
 2 files changed, 32 insertions(+), 32 deletions(-)

diff --git a/src/lib.rs b/src/lib.rs
index f5d5d8fd5..38564292a 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -62,7 +62,7 @@ pub use egui;
 
 use crate::{
     egui_node::{EguiPipeline, EGUI_SHADER_HANDLE},
-    render_systems::EguiTransforms,
+    render_systems::{EguiTransforms, ExtractedEguiManagedTextures},
     systems::*,
 };
 #[cfg(all(feature = "manage_clipboard", not(target_arch = "wasm32")))]
@@ -471,7 +471,7 @@ impl<'w, 's> EguiContexts<'w, 's> {
 pub struct EguiMousePosition(pub Option<(Entity, egui::Vec2)>);
 
 /// A resource for storing `bevy_egui` user textures.
-#[derive(Clone, Resource, Default)]
+#[derive(Clone, Resource, Default, ExtractResource)]
 pub struct EguiUserTextures {
     textures: HashMap<Handle<Image>, u64>,
     last_texture_id: u64,
@@ -579,6 +579,8 @@ impl Plugin for EguiPlugin {
         world.init_resource::<EguiUserTextures>();
         world.init_resource::<EguiMousePosition>();
         world.insert_resource(TouchId::default());
+        app.add_plugins(ExtractResourcePlugin::<EguiUserTextures>::default());
+        app.add_plugins(ExtractResourcePlugin::<ExtractedEguiManagedTextures>::default());
         app.add_plugins(ExtractResourcePlugin::<EguiSettings>::default());
         app.add_plugins(ExtractComponentPlugin::<EguiContext>::default());
         app.add_plugins(ExtractComponentPlugin::<WindowSize>::default());
@@ -650,11 +652,7 @@ impl Plugin for EguiPlugin {
                 .init_resource::<EguiTransforms>()
                 .add_systems(
                     ExtractSchedule,
-                    (
-                        render_systems::setup_new_windows_render_system,
-                        render_systems::extract_egui_textures_system,
-                    )
-                        .into_configs(),
+                    render_systems::setup_new_windows_render_system,
                 )
                 .add_systems(
                     Render,
diff --git a/src/render_systems.rs b/src/render_systems.rs
index eb2136b8f..7b6887bca 100644
--- a/src/render_systems.rs
+++ b/src/render_systems.rs
@@ -4,8 +4,10 @@ use crate::{
 };
 use bevy::{
     asset::HandleId,
+    ecs::system::SystemParam,
     prelude::*,
     render::{
+        extract_resource::ExtractResource,
         render_asset::RenderAssets,
         render_graph::RenderGraph,
         render_resource::{
@@ -21,6 +23,21 @@ use bevy::{
     utils::HashMap,
 };
 
+/// Extracted Egui settings.
+#[derive(Resource, Deref, DerefMut, Default)]
+pub struct ExtractedEguiSettings(pub EguiSettings);
+
+/// The extracted version of [`EguiManagedTextures`].
+#[derive(Debug, Resource)]
+pub struct ExtractedEguiManagedTextures(pub HashMap<(Entity, u64), Handle<Image>>);
+impl ExtractResource for ExtractedEguiManagedTextures {
+    type Source = EguiManagedTextures;
+
+    fn extract_resource(source: &Self::Source) -> Self {
+        Self(source.iter().map(|(k, v)| (*k, v.handle.clone())).collect())
+    }
+}
+
 /// Corresponds to Egui's [`egui::TextureId`].
 #[derive(Debug, PartialEq, Eq, Hash)]
 pub enum EguiTextureId {
@@ -31,24 +48,26 @@ pub enum EguiTextureId {
 }
 
 /// Extracted Egui textures.
-#[derive(Resource, Default)]
-pub struct ExtractedEguiTextures {
+#[derive(SystemParam)]
+pub struct ExtractedEguiTextures<'w> {
     /// Maps Egui managed texture ids to Bevy image handles.
-    pub egui_textures: HashMap<(Entity, u64), Handle<Image>>,
+    pub egui_textures: Res<'w, ExtractedEguiManagedTextures>,
     /// Maps Bevy managed texture handles to Egui user texture ids.
-    pub user_textures: HashMap<Handle<Image>, u64>,
+    pub user_textures: Res<'w, EguiUserTextures>,
 }
 
-impl ExtractedEguiTextures {
+impl ExtractedEguiTextures<'_> {
     /// Returns an iterator over all textures (both Egui and Bevy managed).
     pub fn handles(&self) -> impl Iterator<Item = (EguiTextureId, HandleId)> + '_ {
         self.egui_textures
+            .0
             .iter()
-            .map(|(&(window, texture_id), handle)| {
-                (EguiTextureId::Managed(window, texture_id), handle.id())
+            .map(|(&(window, texture_id), managed_tex)| {
+                (EguiTextureId::Managed(window, texture_id), managed_tex.id())
             })
             .chain(
                 self.user_textures
+                    .textures
                     .iter()
                     .map(|(handle, id)| (EguiTextureId::User(*id), handle.id())),
             )
@@ -74,23 +93,6 @@ pub fn setup_new_windows_render_system(
     }
 }
 
-/// Extracts Egui textures.
-pub fn extract_egui_textures_system(
-    mut commands: Commands,
-    egui_user_textures: Extract<Res<EguiUserTextures>>,
-    egui_managed_textures: Extract<Res<EguiManagedTextures>>,
-) {
-    commands.insert_resource(ExtractedEguiTextures {
-        egui_textures: egui_managed_textures
-            .iter()
-            .map(|(&(window_id, texture_id), managed_texture)| {
-                ((window_id, texture_id), managed_texture.handle.clone())
-            })
-            .collect(),
-        user_textures: egui_user_textures.textures.clone(),
-    });
-}
-
 /// Describes the transform buffer.
 #[derive(Resource, Default)]
 pub struct EguiTransforms {
@@ -176,7 +178,7 @@ pub struct EguiTextureBindGroups(pub HashMap<EguiTextureId, BindGroup>);
 /// Queues bind groups.
 pub fn queue_bind_groups_system(
     mut commands: Commands,
-    egui_textures: Res<ExtractedEguiTextures>,
+    egui_textures: ExtractedEguiTextures,
     render_device: Res<RenderDevice>,
     gpu_images: Res<RenderAssets<Image>>,
     egui_pipeline: Res<EguiPipeline>,