Adaptive Outline

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "bevy_outline_post_process"
-version = "0.1.3"
+version = "0.2.0"
 edition = "2021"
 
 [dependencies.bevy]

README.md

@@ -5,7 +5,7 @@
 ![Build](https://img.shields.io/github/actions/workflow/status/exvacuum/bevy_outline_post_process/rust.yml)
 [![Docs](https://img.shields.io/website?url=https%3A%2F%2Fexvacuum.github.io%2Fbevy_outline_post_process%2F&label=docs)](https://exvacuum.github.io/bevy_outline_post_process)
 
-A plugin for the [Bevy](https://bevyengine.org) engine which adds an outline post-processing effect.
+A plugin for the [Bevy](https://bevyengine.org) engine which adds an outline post-processing effect. Optionally supports adaptive outlining, so darker areas are outlined in white rather than black, based on luminance.
 
 Note: This is a full-screen post process effect and cannot be enabled/disabled for specific objects.
 
@@ -14,16 +14,13 @@ Note: This is a full-screen post process effect and cannot be enabled/disabled f
 ![](./doc/screenshot_smooth.png)
 Configuration Used:
 ```rs
-bevy_outline_post_process::components::OutlinePostProcessSettings {
-    weight: 2.0,
-    threshold: 0.0,
-}
+bevy_outline_post_process::components::OutlinePostProcessSettings::new(2.0, 0.0, false);
 ```
 ## Compatibility
 
 | Crate Version | Bevy Version |
 |---            |---           |
-| 0.1           | 0.13         |
+| 0.2           | 0.13         |
 
 ## Installation
 
@@ -56,10 +53,7 @@ When spawning a camera:
 commands.spawn((
     // Camera3dBundle...
     NormalPrepass,
-    bevy_outline_post_process::components::OutlinePostProcessSettings {
-        weight: 2.0,
-        threshold: 0.0,
-    }
+    bevy_outline_post_process::components::OutlinePostProcessSettings::new(2.0, 0.0, false);
 ));
 ```
 

assets/shaders/outline_post_process.wgsl

@@ -3,9 +3,7 @@
 struct OutlinePostProcessSettings {
 	weight: f32,
 	threshold: f32,
-#ifdef SIXTEEN_BYTE_ALIGNMENT
-	_padding: vec2<f32>,
-#endif
+    adaptive: u32,
 }
 
 @group(0) @binding(0) var screen_texture: texture_2d<f32>;
@@ -39,7 +37,11 @@ fn fragment(
 
     let delta_clipped = clamp((delta_raw * 2.0) - settings.threshold, 0.0, 1.0);
 
-    let outline = vec4f(delta_clipped, delta_clipped, delta_clipped, 0.0);
+    var outline = vec4f(delta_clipped, delta_clipped, delta_clipped, 0.0);
+    let luma = (0.2126 * screen_color.r + 0.7152 * screen_color.g + 0.0722 * screen_color.b);
+    if settings.adaptive != 0 && luma < 0.5 {
+        outline = outline * -1;
+    }
 
     return screen_color - outline;
 }

src/components.rs

@@ -5,11 +5,34 @@ use bevy::{
 
 /// Component which, when inserted into an entity with a camera and normal prepass, enables an outline effect for that
 /// camera.
-#[derive(Component, ShaderType, ExtractComponent, PartialEq, Clone, Default)]
+#[derive(Component, ShaderType, ExtractComponent, PartialEq, Clone)]
 pub struct OutlinePostProcessSettings {
     /// Weight of outlines in pixels.
-    pub weight: f32,
+    weight: f32,
     /// A threshold for normal differences, values below this threshold will not become outlines.
     /// Higher values will result in more outlines which may look better on smooth surfaces.
-    pub threshold: f32,
+    threshold: f32,
+    /// Whether to use adaptive outlines. White outlines will be drawn around darker objects, while black ones will be drawn around lighter ones.
+    adaptive: u32,
 }
+
+impl OutlinePostProcessSettings {
+    /// Create a new instance with the given settings
+    pub fn new(weight: f32, threshold: f32, adaptive: bool) -> Self {
+        Self {
+            weight,
+            threshold,
+            adaptive: adaptive as u32,
+        }
+    }    
+}
+
+impl Default for OutlinePostProcessSettings {
+    fn default() -> Self {
+        Self { 
+            weight: 1.0,
+            threshold: 0.0,
+            adaptive: 0
+        }
+    }
+}