Initial Commit

3 files changed, 131 insertions, 0 deletions

diff --git a/Cargo.toml b/Cargo.toml
new file mode 100644
index 0000000..511f890
--- /dev/null
+++ b/Cargo.toml
@@ -0,0 +1,8 @@
+[package]
+name = "bevy_blacklight_material"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies.bevy]
+version = "0.14"
+features = ["bevy_render", "bevy_asset"]
diff --git a/assets/shaders/blacklight_material.wgsl b/assets/shaders/blacklight_material.wgsl
new file mode 100644
index 0000000..8807404
--- /dev/null
+++ b/assets/shaders/blacklight_material.wgsl
@@ -0,0 +1,45 @@
+#import bevy_pbr::forward_io::VertexOutput;
+
+struct BlackLight {
+	position: vec3<f32>,
+	direction: vec3<f32>,
+	color: vec4<f32>,
+	range: f32,
+	radius: f32,
+}
+
+@group(2) @binding(0) var<storage> lights: array<BlackLight>;
+@group(2) @binding(1) var base_texture: texture_2d<f32>;
+@group(2) @binding(2) var base_sampler: sampler;
+
+@fragment
+fn fragment(
+	in: VertexOutput,
+) -> @location(0) vec4<f32> {
+	let base_color = textureSample(base_texture, base_sampler, in.uv);
+	var final_color = vec4f(0.0, 0.0, 0.0, 0.0);
+	for (var i = u32(0); i < arrayLength(&lights); i = i+1) {
+		let light = lights[i];
+		let light_distance_squared = distance_squared(in.world_position.xyz, light.position);
+		let light_arccosine = abs(acos(dot(normalize(light.direction), normalize(in.world_position.xyz - light.position)))) * radians(180.0);
+		final_color = saturate(final_color + base_color * (inverse_falloff_radius(light_distance_squared / (light.range * light.range), 0.5) * inverse_falloff_radius(light_arccosine, 0.9)));
+	}
+	return final_color;
+}
+
+fn distance_squared(a: vec3f, b: vec3f) -> f32 {
+	return pow(a.x - b.x, 2.0) + pow(a.y - b.y, 2.0) + pow(a.z - b.z, 2.0);
+}
+
+fn inverse_falloff(factor: f32) -> f32 {
+	let squared = factor * factor;
+	return (1.0 - squared) / (10 * squared + 1.0);
+}
+
+fn inverse_falloff_radius(factor: f32, radius: f32) -> f32 {
+	if factor < radius {
+		return 1.0;
+	} else {
+		return inverse_falloff((factor - radius) / (1.0 - radius));
+	}
+}
diff --git a/src/lib.rs b/src/lib.rs
new file mode 100644
index 0000000..65dfc80
--- /dev/null
+++ b/src/lib.rs
@@ -0,0 +1,78 @@
+use bevy::{
+    asset::embedded_asset,
+    prelude::*,
+    render::render_resource::{AsBindGroup, ShaderType},
+};
+
+pub struct BlacklightPlugin;
+
+impl Plugin for BlacklightPlugin {
+    fn build(&self, app: &mut App) {
+        embedded_asset!(app, "../assets/shaders/blacklight_material.wgsl");
+        app.add_plugins(MaterialPlugin::<BlacklightMaterial>::default()).add_systems(Update, update_shader_blacklight_data);
+    }
+}
+
+#[derive(Component, Debug)]
+pub struct Blacklight;
+
+#[derive(Clone, Debug, ShaderType)]
+pub struct BlacklightData {
+    pub position: Vec3,
+    pub direction: Vec3,
+    pub color: Vec4,
+    pub range: f32,
+    pub radius: f32,
+}
+
+#[derive(Asset, TypePath, AsBindGroup, Debug, Clone)]
+pub struct BlacklightMaterial {
+    #[storage(0, read_only)]
+    pub lights: Vec<BlacklightData>,
+    #[texture(1)]
+    #[sampler(2)]
+    pub base_texture: Option<Handle<Image>>,
+    pub alpha_mode: AlphaMode,
+}
+
+impl Default for BlacklightMaterial {
+    fn default() -> Self {
+        Self {
+            lights: vec![],
+            base_texture: None,
+            alpha_mode: AlphaMode::Blend,
+        }
+    }
+}
+
+impl Material for BlacklightMaterial {
+    fn fragment_shader() -> bevy::render::render_resource::ShaderRef {
+        "embedded://bevy_blacklight_material/../assets/shaders/blacklight_material.wgsl".into()
+    }
+
+    fn alpha_mode(&self) -> AlphaMode {
+        self.alpha_mode
+    }
+}
+
+fn update_shader_blacklight_data(
+    blacklight_query: Query<(&ViewVisibility, &GlobalTransform, &Transform, &SpotLight), With<Blacklight>>,
+    blacklight_material_query: Query<&Handle<BlacklightMaterial>>,
+    mut blacklight_materials: ResMut<Assets<BlacklightMaterial>>,
+) {
+    let light_data = blacklight_query
+        .iter()
+        .filter(|(visibility, _, _, _)| visibility.get())
+        .map(|(_, global_transform, transform, light)| BlacklightData {
+            position: global_transform.translation(),
+            direction: *global_transform.forward(),
+            color: light.color.to_srgba().to_vec4(),
+            range: light.range,
+            radius: light.radius,
+        })
+        .collect::<Vec<_>>();
+    for handle in blacklight_material_query.iter() {
+        let material = blacklight_materials.get_mut(handle).unwrap();
+        material.lights = light_data.clone();
+    }
+}