From 1af8ae30a1a596ecdbb454bddcaf70f4aa0b0300 Mon Sep 17 00:00:00 2001
From: Jakob Hellermann <jakob.hellermann@protonmail.com>
Date: Sun, 20 Mar 2022 13:16:21 +0100
Subject: [PATCH] add UpscalingPipelineKey

---
 crates/bevy_core_pipeline/Cargo.toml          |  4 +-
 crates/bevy_core_pipeline/src/lib.rs          |  2 +-
 .../bevy_core_pipeline/src/upscaling/mod.rs   | 40 ++++++++++++++++++-
 3 files changed, 42 insertions(+), 4 deletions(-)

diff --git a/crates/bevy_core_pipeline/Cargo.toml b/crates/bevy_core_pipeline/Cargo.toml
index 671645e40889c..db325f7e3a19e 100644
--- a/crates/bevy_core_pipeline/Cargo.toml
+++ b/crates/bevy_core_pipeline/Cargo.toml
@@ -23,4 +23,6 @@ bevy_core = { path = "../bevy_core", version = "0.7.0-dev" }
 bevy_ecs = { path = "../bevy_ecs", version = "0.7.0-dev" }
 bevy_render = { path = "../bevy_render", version = "0.7.0-dev" }
 bevy_utils = { path = "../bevy_utils", version = "0.7.0-dev" }
-bevy_reflect = { path = "../bevy_reflect", version = "0.7.0-dev" }
\ No newline at end of file
+bevy_reflect = { path = "../bevy_reflect", version = "0.7.0-dev" }
+
+bitflags = "1.2"
\ No newline at end of file
diff --git a/crates/bevy_core_pipeline/src/lib.rs b/crates/bevy_core_pipeline/src/lib.rs
index 1abd923c1df01..b6efaaa2d7221 100644
--- a/crates/bevy_core_pipeline/src/lib.rs
+++ b/crates/bevy_core_pipeline/src/lib.rs
@@ -18,6 +18,7 @@ pub use clear_pass_driver::*;
 pub use main_pass_2d::*;
 pub use main_pass_3d::*;
 pub use main_pass_driver::*;
+pub use upscaling::*;
 
 use std::ops::Range;
 
@@ -41,7 +42,6 @@ use bevy_render::{
 use tonemapping::TonemappingNode;
 use tonemapping::TonemappingPlugin;
 use upscaling::UpscalingNode;
-use upscaling::UpscalingPlugin;
 
 /// When used as a resource, sets the color that is used to clear the screen between frames.
 ///
diff --git a/crates/bevy_core_pipeline/src/upscaling/mod.rs b/crates/bevy_core_pipeline/src/upscaling/mod.rs
index 157a8d1636cd5..8ca7b085e3ed8 100644
--- a/crates/bevy_core_pipeline/src/upscaling/mod.rs
+++ b/crates/bevy_core_pipeline/src/upscaling/mod.rs
@@ -70,8 +70,43 @@ impl FromWorld for UpscalingPipeline {
     }
 }
 
+#[repr(u8)]
+pub enum UpscalingMode {
+    Filtering = 0,
+    Nearest = 1,
+}
+
+bitflags::bitflags! {
+    #[repr(transparent)]
+    pub struct UpscalingPipelineKey: u32 {
+        const NONE                         = 0;
+        const UPSCALING_MODE_RESERVED_BITS = UpscalingPipelineKey::UPSCALING_MODE_MASK_BITS << UpscalingPipelineKey::UPSCALING_MODE_SHIFT_BITS;
+    }
+}
+
+impl UpscalingPipelineKey {
+    const UPSCALING_MODE_MASK_BITS: u32 = 0b1111; // enough for 16 different modes
+    const UPSCALING_MODE_SHIFT_BITS: u32 = 32 - 4;
+
+    pub fn from_upscaling_mode(upscaling_mode: UpscalingMode) -> Self {
+        let upscaling_mode_bits = ((upscaling_mode as u32) & Self::UPSCALING_MODE_MASK_BITS)
+            << Self::UPSCALING_MODE_SHIFT_BITS;
+        UpscalingPipelineKey::from_bits(upscaling_mode_bits).unwrap()
+    }
+
+    pub fn upscaling_mode(&self) -> UpscalingMode {
+        let upscaling_mode_bits =
+            (self.bits >> Self::UPSCALING_MODE_SHIFT_BITS) & Self::UPSCALING_MODE_MASK_BITS;
+        match upscaling_mode_bits {
+            0 => UpscalingMode::Filtering,
+            1 => UpscalingMode::Nearest,
+            other => panic!("invalid upscaling mode bits in UpscalingPipelineKey: {other}"),
+        }
+    }
+}
+
 impl SpecializedPipeline for UpscalingPipeline {
-    type Key = ();
+    type Key = UpscalingPipelineKey;
 
     fn specialize(&self, _: Self::Key) -> RenderPipelineDescriptor {
         RenderPipelineDescriptor {
@@ -113,7 +148,8 @@ fn queue_upscaling_bind_groups(
     view_targets: Query<Entity, With<ExtractedView>>,
 ) {
     for entity in view_targets.iter() {
-        let pipeline = pipelines.specialize(&mut render_pipeline_cache, &upscaling_pipeline, ());
+        let key = UpscalingPipelineKey::from_upscaling_mode(UpscalingMode::Filtering);
+        let pipeline = pipelines.specialize(&mut render_pipeline_cache, &upscaling_pipeline, key);
 
         commands.entity(entity).insert(UpscalingTarget { pipeline });
     }