From 60c72399e374f27164ae819297e6380e94e90393 Mon Sep 17 00:00:00 2001
From: robtfm <50659922+robtfm@users.noreply.github.com>
Date: Mon, 23 Oct 2023 10:03:28 +0100
Subject: [PATCH] rework it

---
 crates/bevy_core_pipeline/src/core_3d/mod.rs | 27 ++++++++++----------
 crates/bevy_core_pipeline/src/prepass/mod.rs |  1 +
 crates/bevy_pbr/src/prepass/mod.rs           | 15 +++++------
 3 files changed, 20 insertions(+), 23 deletions(-)

diff --git a/crates/bevy_core_pipeline/src/core_3d/mod.rs b/crates/bevy_core_pipeline/src/core_3d/mod.rs
index 9684899ffc7bd..5bee9f4c1cd41 100644
--- a/crates/bevy_core_pipeline/src/core_3d/mod.rs
+++ b/crates/bevy_core_pipeline/src/core_3d/mod.rs
@@ -381,9 +381,6 @@ pub fn extract_camera_prepass_phase(
         if camera.is_active {
             let mut entity = commands.get_or_spawn(entity);
 
-            // deferred requires depth
-            let depth_prepass = depth_prepass || deferred_prepass;
-
             if depth_prepass || normal_prepass || motion_vector_prepass {
                 entity.insert((
                     RenderPhase::<Opaque3dPrepass>::default(),
@@ -510,15 +507,17 @@ pub fn prepare_prepass_textures(
         (
             Entity,
             &ExtractedCamera,
-            Option<&DepthPrepass>,
-            Option<&NormalPrepass>,
-            Option<&MotionVectorPrepass>,
-            Option<&DeferredPrepass>,
+            Has<DepthPrepass>,
+            Has<NormalPrepass>,
+            Has<MotionVectorPrepass>,
+            Has<DeferredPrepass>,
         ),
-        (
+        Or<(
             With<RenderPhase<Opaque3dPrepass>>,
             With<RenderPhase<AlphaMask3dPrepass>>,
-        ),
+            With<RenderPhase<Opaque3dDeferred>>,
+            With<RenderPhase<AlphaMask3dDeferred>>,
+        )>,
     >,
 ) {
     let mut depth_textures = HashMap::default();
@@ -539,7 +538,7 @@ pub fn prepare_prepass_textures(
             height: physical_target_size.y,
         };
 
-        let cached_depth_texture = depth_prepass.is_some().then(|| {
+        let cached_depth_texture = depth_prepass.then(|| {
             depth_textures
                 .entry(camera.target.clone())
                 .or_insert_with(|| {
@@ -560,7 +559,7 @@ pub fn prepare_prepass_textures(
                 .clone()
         });
 
-        let cached_normals_texture = normal_prepass.is_some().then(|| {
+        let cached_normals_texture = normal_prepass.then(|| {
             normal_textures
                 .entry(camera.target.clone())
                 .or_insert_with(|| {
@@ -582,7 +581,7 @@ pub fn prepare_prepass_textures(
                 .clone()
         });
 
-        let cached_motion_vectors_texture = motion_vector_prepass.is_some().then(|| {
+        let cached_motion_vectors_texture = motion_vector_prepass.then(|| {
             motion_vectors_textures
                 .entry(camera.target.clone())
                 .or_insert_with(|| {
@@ -604,7 +603,7 @@ pub fn prepare_prepass_textures(
                 .clone()
         });
 
-        let cached_deferred_texture = deferred_prepass.is_some().then(|| {
+        let cached_deferred_texture = deferred_prepass.then(|| {
             deferred_textures
                 .entry(camera.target.clone())
                 .or_insert_with(|| {
@@ -626,7 +625,7 @@ pub fn prepare_prepass_textures(
                 .clone()
         });
 
-        let deferred_lighting_pass_id_texture = deferred_prepass.is_some().then(|| {
+        let deferred_lighting_pass_id_texture = deferred_prepass.then(|| {
             deferred_lighting_id_textures
                 .entry(camera.target.clone())
                 .or_insert_with(|| {
diff --git a/crates/bevy_core_pipeline/src/prepass/mod.rs b/crates/bevy_core_pipeline/src/prepass/mod.rs
index ba4de1952c82e..63b8c764af5ff 100644
--- a/crates/bevy_core_pipeline/src/prepass/mod.rs
+++ b/crates/bevy_core_pipeline/src/prepass/mod.rs
@@ -55,6 +55,7 @@ pub struct NormalPrepass;
 pub struct MotionVectorPrepass;
 
 /// If added to a [`crate::prelude::Camera3d`] then deferred materials will be rendered to the deferred gbuffer texture and will be available to subsequent passes.
+/// Note the default deferred lighting plugin also requires `DepthPrepass` to work correctly.
 #[derive(Component, Default, Reflect)]
 pub struct DeferredPrepass;
 
diff --git a/crates/bevy_pbr/src/prepass/mod.rs b/crates/bevy_pbr/src/prepass/mod.rs
index 54155ce385a0e..9761c186d1e64 100644
--- a/crates/bevy_pbr/src/prepass/mod.rs
+++ b/crates/bevy_pbr/src/prepass/mod.rs
@@ -810,9 +810,6 @@ pub fn queue_prepass_material_meshes<M: Material>(
             view_key |= MeshPipelineKey::MOTION_VECTOR_PREPASS;
         }
 
-        let mut opaque_phase_deferred = opaque_deferred_phase.as_mut();
-        let mut alpha_mask_phase_deferred = alpha_mask_deferred_phase.as_mut();
-
         let rangefinder = view.rangefinder3d();
 
         for visible_entity in &visible_entities.entities {
@@ -879,7 +876,7 @@ pub fn queue_prepass_material_meshes<M: Material>(
             match alpha_mode {
                 AlphaMode::Opaque => {
                     if deferred {
-                        opaque_phase_deferred
+                        opaque_deferred_phase
                             .as_mut()
                             .unwrap()
                             .add(Opaque3dDeferred {
@@ -890,8 +887,8 @@ pub fn queue_prepass_material_meshes<M: Material>(
                                 batch_range: 0..1,
                                 dynamic_offset: None,
                             });
-                    } else {
-                        opaque_phase.as_mut().unwrap().add(Opaque3dPrepass {
+                    } else if let Some(opaque_phase) = opaque_phase.as_mut() {
+                        opaque_phase.add(Opaque3dPrepass {
                             entity: *visible_entity,
                             draw_function: opaque_draw_prepass,
                             pipeline_id,
@@ -903,7 +900,7 @@ pub fn queue_prepass_material_meshes<M: Material>(
                 }
                 AlphaMode::Mask(_) => {
                     if deferred {
-                        alpha_mask_phase_deferred
+                        alpha_mask_deferred_phase
                             .as_mut()
                             .unwrap()
                             .add(AlphaMask3dDeferred {
@@ -914,8 +911,8 @@ pub fn queue_prepass_material_meshes<M: Material>(
                                 batch_range: 0..1,
                                 dynamic_offset: None,
                             });
-                    } else {
-                        alpha_mask_phase.as_mut().unwrap().add(AlphaMask3dPrepass {
+                    } else if let Some(alpha_mask_phase) = alpha_mask_phase.as_mut() {
+                        alpha_mask_phase.add(AlphaMask3dPrepass {
                             entity: *visible_entity,
                             draw_function: alpha_mask_draw_prepass,
                             pipeline_id,