Rename Light => PointLight and remove unused properties (#1778)

After an inquiry on Reddit about support for Directional Lights and the unused properties on Light, I wanted to clean it up, to hopefully make it ever so slightly more clear for anyone wanting to add additional light types.

Co-authored-by: Carter Anderson <mcanders1@gmail.com>

crates/bevy_pbr/src/entity.rs

@@ -1,4 +1,4 @@
-use crate::{light::Light, material::StandardMaterial, render_graph::PBR_PIPELINE_HANDLE};
+use crate::{light::PointLight, material::StandardMaterial, render_graph::PBR_PIPELINE_HANDLE};
 use bevy_asset::Handle;
 use bevy_ecs::bundle::Bundle;
 use bevy_render::{
@@ -42,8 +42,8 @@ impl Default for PbrBundle {
 
 /// A component bundle for "light" entities
 #[derive(Debug, Bundle, Default)]
-pub struct LightBundle {
-    pub light: Light,
+pub struct PointLightBundle {
+    pub point_light: PointLight,
     pub transform: Transform,
     pub global_transform: GlobalTransform,
 }

crates/bevy_pbr/src/lib.rs

@@ -9,7 +9,7 @@ pub use light::*;
 pub use material::*;
 
 pub mod prelude {
-    pub use crate::{entity::*, light::Light, material::StandardMaterial};
+    pub use crate::{entity::*, light::PointLight, material::StandardMaterial};
 }
 
 use bevy_app::prelude::*;
@@ -26,7 +26,7 @@ pub struct PbrPlugin;
 impl Plugin for PbrPlugin {
     fn build(&self, app: &mut AppBuilder) {
         app.add_asset::<StandardMaterial>()
-            .register_type::<Light>()
+            .register_type::<PointLight>()
             .add_system_to_stage(
                 CoreStage::PostUpdate,
                 shader::asset_shader_defs_system::<StandardMaterial>.system(),

crates/bevy_pbr/src/light.rs

@@ -1,30 +1,22 @@
 use bevy_core::Byteable;
 use bevy_ecs::reflect::ReflectComponent;
 use bevy_reflect::Reflect;
-use bevy_render::{
-    camera::{CameraProjection, PerspectiveProjection},
-    color::Color,
-};
+use bevy_render::color::Color;
 use bevy_transform::components::GlobalTransform;
-use std::ops::Range;
 
 /// A point light
 #[derive(Debug, Reflect)]
 #[reflect(Component)]
-pub struct Light {
+pub struct PointLight {
     pub color: Color,
-    pub fov: f32,
-    pub depth: Range<f32>,
     pub intensity: f32,
     pub range: f32,
 }
 
-impl Default for Light {
+impl Default for PointLight {
     fn default() -> Self {
-        Light {
+        PointLight {
             color: Color::rgb(1.0, 1.0, 1.0),
-            depth: 0.1..50.0,
-            fov: f32::to_radians(60.0),
             intensity: 200.0,
             range: 20.0,
         }
@@ -33,33 +25,25 @@ impl Default for Light {
 
 #[repr(C)]
 #[derive(Debug, Clone, Copy)]
-pub(crate) struct LightRaw {
-    pub proj: [[f32; 4]; 4],
+pub(crate) struct PointLightUniform {
     pub pos: [f32; 4],
     pub color: [f32; 4],
+    pub inverse_range_squared: f32,
 }
 
-unsafe impl Byteable for LightRaw {}
+unsafe impl Byteable for PointLightUniform {}
 
-impl LightRaw {
-    pub fn from(light: &Light, global_transform: &GlobalTransform) -> LightRaw {
-        let perspective = PerspectiveProjection {
-            fov: light.fov,
-            aspect_ratio: 1.0,
-            near: light.depth.start,
-            far: light.depth.end,
-        };
-
-        let proj = perspective.get_projection_matrix() * global_transform.compute_matrix();
+impl PointLightUniform {
+    pub fn from(light: &PointLight, global_transform: &GlobalTransform) -> PointLightUniform {
         let (x, y, z) = global_transform.translation.into();
 
         // premultiply color by intensity
         // we don't use the alpha at all, so no reason to multiply only [0..3]
         let color: [f32; 4] = (light.color * light.intensity).into();
-        LightRaw {
-            proj: proj.to_cols_array_2d(),
-            pos: [x, y, z, 1.0 / (light.range * light.range)], // pos.w is the attenuation.
+        PointLightUniform {
+            pos: [x, y, z, 1.0],
             color,
+            inverse_range_squared: 1.0 / (light.range * light.range),
         }
     }
 }

crates/bevy_pbr/src/render_graph/lights_node.rs

@@ -1,5 +1,5 @@
 use crate::{
-    light::{AmbientLight, Light, LightRaw},
+    light::{AmbientLight, PointLight, PointLightUniform},
     render_graph::uniform,
 };
 use bevy_core::{AsBytes, Byteable};
@@ -20,13 +20,13 @@ use bevy_transform::prelude::*;
 #[derive(Debug, Default)]
 pub struct LightsNode {
     command_queue: CommandQueue,
-    max_lights: usize,
+    max_point_lights: usize,
 }
 
 impl LightsNode {
     pub fn new(max_lights: usize) -> Self {
         LightsNode {
-            max_lights,
+            max_point_lights: max_lights,
             command_queue: CommandQueue::default(),
         }
     }
@@ -57,7 +57,7 @@ impl SystemNode for LightsNode {
         let system = lights_node_system.system().config(|config| {
             config.0 = Some(LightsNodeSystemState {
                 command_queue: self.command_queue.clone(),
-                max_lights: self.max_lights,
+                max_point_lights: self.max_point_lights,
                 light_buffer: None,
                 staging_buffer: None,
             })
@@ -72,7 +72,7 @@ pub struct LightsNodeSystemState {
     light_buffer: Option<BufferId>,
     staging_buffer: Option<BufferId>,
     command_queue: CommandQueue,
-    max_lights: usize,
+    max_point_lights: usize,
 }
 
 pub fn lights_node_system(
@@ -82,7 +82,7 @@ pub fn lights_node_system(
     // TODO: this write on RenderResourceBindings will prevent this system from running in parallel
     // with other systems that do the same
     mut render_resource_bindings: ResMut<RenderResourceBindings>,
-    query: Query<(&Light, &GlobalTransform)>,
+    query: Query<(&PointLight, &GlobalTransform)>,
 ) {
     let state = &mut state;
     let render_resource_context = &**render_resource_context;
@@ -91,16 +91,16 @@ pub fn lights_node_system(
     let ambient_light: [f32; 4] =
         (ambient_light_resource.color * ambient_light_resource.brightness).into();
     let ambient_light_size = std::mem::size_of::<[f32; 4]>();
-    let light_count = query.iter().count();
-    let size = std::mem::size_of::<LightRaw>();
+    let point_light_count = query.iter().count();
+    let size = std::mem::size_of::<PointLightUniform>();
     let light_count_size = ambient_light_size + std::mem::size_of::<LightCount>();
-    let light_array_size = size * light_count;
-    let light_array_max_size = size * state.max_lights;
-    let current_light_uniform_size = light_count_size + light_array_size;
-    let max_light_uniform_size = light_count_size + light_array_max_size;
+    let point_light_array_size = size * point_light_count;
+    let point_light_array_max_size = size * state.max_point_lights;
+    let current_point_light_uniform_size = light_count_size + point_light_array_size;
+    let max_light_uniform_size = light_count_size + point_light_array_max_size;
 
     if let Some(staging_buffer) = state.staging_buffer {
-        if light_count == 0 {
+        if point_light_count == 0 {
             return;
         }
 
@@ -132,21 +132,22 @@ pub fn lights_node_system(
     let staging_buffer = state.staging_buffer.unwrap();
     render_resource_context.write_mapped_buffer(
         staging_buffer,
-        0..current_light_uniform_size as u64,
+        0..current_point_light_uniform_size as u64,
         &mut |data, _renderer| {
             // ambient light
             data[0..ambient_light_size].copy_from_slice(ambient_light.as_bytes());
 
             // light count
             data[ambient_light_size..light_count_size]
-                .copy_from_slice([light_count as u32, 0, 0, 0].as_bytes());
+                .copy_from_slice([point_light_count as u32, 0, 0, 0].as_bytes());
 
             // light array
-            for ((light, global_transform), slot) in query
-                .iter()
-                .zip(data[light_count_size..current_light_uniform_size].chunks_exact_mut(size))
-            {
-                slot.copy_from_slice(LightRaw::from(&light, &global_transform).as_bytes());
+            for ((point_light, global_transform), slot) in query.iter().zip(
+                data[light_count_size..current_point_light_uniform_size].chunks_exact_mut(size),
+            ) {
+                slot.copy_from_slice(
+                    PointLightUniform::from(&point_light, &global_transform).as_bytes(),
+                );
             }
         },
     );

crates/bevy_pbr/src/render_graph/mod.rs

@@ -26,6 +26,7 @@ use bevy_render::{
 };
 use bevy_transform::prelude::GlobalTransform;
 
+pub const MAX_POINT_LIGHTS: usize = 10;
 pub(crate) fn add_pbr_graph(world: &mut World) {
     {
         let mut graph = world.get_resource_mut::<RenderGraph>().unwrap();
@@ -37,7 +38,8 @@ pub(crate) fn add_pbr_graph(world: &mut World) {
             node::STANDARD_MATERIAL,
             AssetRenderResourcesNode::<StandardMaterial>::new(true),
         );
-        graph.add_system_node(node::LIGHTS, LightsNode::new(10));
+
+        graph.add_system_node(node::LIGHTS, LightsNode::new(MAX_POINT_LIGHTS));
 
         // TODO: replace these with "autowire" groups
         graph

crates/bevy_pbr/src/render_graph/pbr_pipeline/pbr.frag

@@ -36,10 +36,10 @@
 
 const int MAX_LIGHTS = 10;
 
-struct Light {
-    mat4 proj;
+struct PointLight {
     vec4 pos;
     vec4 color;
+    float inverseRangeSquared;
 };
 
 layout(location = 0) in vec3 v_WorldPosition;
@@ -62,7 +62,7 @@ layout(std140, set = 0, binding = 1) uniform CameraPosition {
 layout(std140, set = 1, binding = 0) uniform Lights {
     vec4 AmbientColor;
     uvec4 NumLights;
-    Light SceneLights[MAX_LIGHTS];
+    PointLight PointLights[MAX_LIGHTS];
 };
 
 layout(set = 3, binding = 0) uniform StandardMaterial_base_color {
@@ -130,9 +130,8 @@ float pow5(float x) {
 //
 // light radius is a non-physical construct for efficiency purposes,
 // because otherwise every light affects every fragment in the scene
-float getDistanceAttenuation(const vec3 posToLight, float inverseRadiusSquared) {
-    float distanceSquare = dot(posToLight, posToLight);
-    float factor = distanceSquare * inverseRadiusSquared;
+float getDistanceAttenuation(float distanceSquare, float inverseRangeSquared) {
+    float factor = distanceSquare * inverseRangeSquared;
     float smoothFactor = saturate(1.0 - factor * factor);
     float attenuation = smoothFactor * smoothFactor;
     return attenuation * 1.0 / max(distanceSquare, 1e-4);
@@ -343,13 +342,14 @@ void main() {
     // accumulate color
     vec3 light_accum = vec3(0.0);
     for (int i = 0; i < int(NumLights.x) && i < MAX_LIGHTS; ++i) {
-        Light light = SceneLights[i];
+        PointLight light = PointLights[i];
 
-        vec3 lightDir = light.pos.xyz - v_WorldPosition.xyz;
-        vec3 L = normalize(lightDir);
+        vec3 light_to_frag = light.pos.xyz - v_WorldPosition.xyz;
+        vec3 L = normalize(light_to_frag);
+        float distance_square = dot(light_to_frag, light_to_frag);
 
         float rangeAttenuation =
-            getDistanceAttenuation(lightDir, light.pos.w);
+            getDistanceAttenuation(distance_square, light.inverseRangeSquared);
 
         vec3 H = normalize(L + V);
         float NoL = saturate(dot(N, L));

examples/3d/3d_scene.rs

@@ -28,7 +28,7 @@ fn setup(
         ..Default::default()
     });
     // light
-    commands.spawn_bundle(LightBundle {
+    commands.spawn_bundle(PointLightBundle {
         transform: Transform::from_xyz(4.0, 8.0, 4.0),
         ..Default::default()
     });

examples/3d/load_gltf.rs

@@ -20,7 +20,7 @@ fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
         ..Default::default()
     });
     commands
-        .spawn_bundle(LightBundle {
+        .spawn_bundle(PointLightBundle {
             transform: Transform::from_xyz(3.0, 5.0, 3.0),
             ..Default::default()
         })

examples/3d/msaa.rs

@@ -25,7 +25,7 @@ fn setup(
         ..Default::default()
     });
     // light
-    commands.spawn_bundle(LightBundle {
+    commands.spawn_bundle(PointLightBundle {
         transform: Transform::from_xyz(4.0, 8.0, 4.0),
         ..Default::default()
     });

examples/3d/orthographic.rs

@@ -54,7 +54,7 @@ fn setup(
         ..Default::default()
     });
     // light
-    commands.spawn_bundle(LightBundle {
+    commands.spawn_bundle(PointLightBundle {
         transform: Transform::from_xyz(3.0, 8.0, 5.0),
         ..Default::default()
     });

examples/3d/parenting.rs

@@ -52,7 +52,7 @@ fn setup(
             });
         });
     // light
-    commands.spawn_bundle(LightBundle {
+    commands.spawn_bundle(PointLightBundle {
         transform: Transform::from_xyz(4.0, 5.0, -4.0),
         ..Default::default()
     });

examples/3d/pbr.rs

@@ -39,7 +39,7 @@ fn setup(
         }
     }
     // light
-    commands.spawn_bundle(LightBundle {
+    commands.spawn_bundle(PointLightBundle {
         transform: Transform::from_translation(Vec3::new(0.0, 5.0, 5.0)),
         ..Default::default()
     });

examples/3d/spawner.rs

@@ -41,7 +41,7 @@ fn setup(
     mut materials: ResMut<Assets<StandardMaterial>>,
 ) {
     // light
-    commands.spawn_bundle(LightBundle {
+    commands.spawn_bundle(PointLightBundle {
         transform: Transform::from_xyz(4.0, -4.0, 5.0),
         ..Default::default()
     });

examples/3d/update_gltf_scene.rs

@@ -24,7 +24,7 @@ fn setup(
     mut scene_spawner: ResMut<SceneSpawner>,
     mut scene_instance: ResMut<SceneInstance>,
 ) {
-    commands.spawn_bundle(LightBundle {
+    commands.spawn_bundle(PointLightBundle {
         transform: Transform::from_xyz(4.0, 5.0, 4.0),
         ..Default::default()
     });

examples/3d/wireframe.rs

@@ -46,7 +46,7 @@ fn setup(
         // This enables wireframe drawing on this entity
         .insert(Wireframe);
     // light
-    commands.spawn_bundle(LightBundle {
+    commands.spawn_bundle(PointLightBundle {
         transform: Transform::from_xyz(4.0, 8.0, 4.0),
         ..Default::default()
     });

examples/android/android.rs

@@ -30,7 +30,7 @@ fn setup(
         ..Default::default()
     });
     // light
-    commands.spawn_bundle(LightBundle {
+    commands.spawn_bundle(PointLightBundle {
         transform: Transform::from_xyz(4.0, 8.0, 4.0),
         ..Default::default()
     });

examples/asset/asset_loading.rs

@@ -65,7 +65,7 @@ fn setup(
         ..Default::default()
     });
     // light
-    commands.spawn_bundle(LightBundle {
+    commands.spawn_bundle(PointLightBundle {
         transform: Transform::from_xyz(4.0, 5.0, 4.0),
         ..Default::default()
     });

examples/asset/hot_asset_reloading.rs

@@ -23,7 +23,7 @@ fn setup(mut commands: Commands, asset_server: Res<AssetServer>) {
     // mesh
     commands.spawn_scene(scene_handle);
     // light
-    commands.spawn_bundle(LightBundle {
+    commands.spawn_bundle(PointLightBundle {
         transform: Transform::from_xyz(4.0, 5.0, 4.0),
         ..Default::default()
     });

examples/game/alien_cake_addict.rs

@@ -104,7 +104,7 @@ fn setup(mut commands: Commands, asset_server: Res<AssetServer>, mut game: ResMu
     game.player.i = BOARD_SIZE_I / 2;
     game.player.j = BOARD_SIZE_J / 2;
 
-    commands.spawn_bundle(LightBundle {
+    commands.spawn_bundle(PointLightBundle {
         transform: Transform::from_xyz(4.0, 5.0, 4.0),
         ..Default::default()
     });

examples/ios/src/lib.rs

@@ -45,7 +45,7 @@ fn setup(
         ..Default::default()
     });
     // light
-    commands.spawn_bundle(LightBundle {
+    commands.spawn_bundle(PointLightBundle {
         transform: Transform::from_xyz(4.0, 8.0, 4.0),
         ..Default::default()
     });

examples/window/multiple_windows.rs

@@ -187,7 +187,7 @@ fn setup_pipeline(
     // add entities to the world
     commands.spawn_scene(asset_server.load("models/monkey/Monkey.gltf#Scene0"));
     // light
-    commands.spawn_bundle(LightBundle {
+    commands.spawn_bundle(PointLightBundle {
         transform: Transform::from_xyz(4.0, 5.0, 4.0),
         ..Default::default()
     });