RenderGraph2: Lights node

bevy_render/src/lib.rs

@@ -39,8 +39,7 @@ use self::{
     },
     render_graph::RenderGraph,
     render_resource::{
-        entity_render_resource_assignments_system,
-        resource_providers::{LightResourceProvider, UniformResourceProvider},
+        entity_render_resource_assignments_system, resource_providers::UniformResourceProvider,
         AssetBatchers, EntityRenderResourceAssignments, RenderResourceAssignments,
     },
     shader::{uniforms::StandardMaterial, Shader},
@@ -54,7 +53,10 @@ use bevy_window::{WindowCreated, WindowReference, WindowResized};
 use pass::PassDescriptor;
 use pipeline::pipelines::build_forward_pipeline;
 use render_graph_2::{
-    nodes::{Camera2dNode, CameraNode, PassNode, WindowSwapChainNode, WindowTextureNode, UniformNode},
+    nodes::{
+        Camera2dNode, CameraNode, LightsNode, PassNode, UniformNode, WindowSwapChainNode,
+        WindowTextureNode,
+    },
     RenderGraph2,
 };
 use render_resource::resource_providers::mesh_resource_provider_system;
@@ -77,7 +79,6 @@ impl RenderPlugin {
         let mut render_graph = resources.get_mut::<RenderGraph>().unwrap();
         render_graph
             .build(&mut pipelines, &mut shaders)
-            .add_resource_provider(LightResourceProvider::new(10))
             .add_resource_provider(UniformResourceProvider::<LocalToWorld>::new(true));
     }
 }
@@ -123,7 +124,12 @@ impl AppPlugin for RenderPlugin {
             let resources = app.resources_mut();
             render_graph.add_system_node_named("camera", CameraNode::default(), resources);
             render_graph.add_system_node_named("camera2d", Camera2dNode::default(), resources);
-            render_graph.add_system_node_named("standard_material", UniformNode::<StandardMaterial>::new(true), resources);
+            render_graph.add_system_node_named(
+                "standard_material",
+                UniformNode::<StandardMaterial>::new(true),
+                resources,
+            );
+            render_graph.add_system_node_named("lights", LightsNode::new(10), resources);
             render_graph.add_node_named(
                 "swapchain",
                 WindowSwapChainNode::new(
@@ -185,7 +191,10 @@ impl AppPlugin for RenderPlugin {
             // TODO: replace these with "autowire" groups
             render_graph.add_node_edge("camera", "main_pass").unwrap();
             render_graph.add_node_edge("camera2d", "main_pass").unwrap();
-            render_graph.add_node_edge("standard_material", "main_pass").unwrap();
+            render_graph
+                .add_node_edge("standard_material", "main_pass")
+                .unwrap();
+            render_graph.add_node_edge("lights", "main_pass").unwrap();
             render_graph
                 .add_slot_edge(
                     "swapchain",

bevy_render/src/render_graph_2/nodes.rs

@@ -4,10 +4,12 @@ mod window_texture_node;
 mod window_swapchain_node;
 mod pass_node;
 mod uniform_node;
+mod lights_node;
 
 pub use camera_node::*;
 pub use camera2d_node::*;
 pub use window_texture_node::*;
 pub use window_swapchain_node::*;
 pub use pass_node::*;
-pub use uniform_node::*;
+pub use uniform_node::*;
+pub use lights_node::*;

bevy_render/src/render_graph_2/nodes/lights_node.rs

@@ -0,0 +1,150 @@
+use crate::{
+    render_graph_2::{CommandQueue, Node, ResourceSlots, SystemNode},
+    render_resource::{resource_name, BufferInfo, BufferUsage, RenderResourceAssignments},
+    renderer_2::{GlobalRenderResourceContext, RenderContext},
+    Light, LightRaw,
+};
+
+use bevy_transform::prelude::*;
+use legion::prelude::*;
+use zerocopy::AsBytes;
+
+#[derive(Default)]
+pub struct LightsNode {
+    command_queue: CommandQueue,
+    max_lights: usize,
+}
+
+impl LightsNode {
+    pub fn new(max_lights: usize) -> Self {
+        LightsNode {
+            max_lights,
+            command_queue: CommandQueue::default(),
+        }
+    }
+}
+
+impl Node for LightsNode {
+    fn update(
+        &mut self,
+        _world: &World,
+        _resources: &Resources,
+        render_context: &mut dyn RenderContext,
+        _input: &ResourceSlots,
+        _output: &mut ResourceSlots,
+    ) {
+        self.command_queue.execute(render_context);
+    }
+}
+
+#[repr(C)]
+#[derive(Clone, Copy, AsBytes)]
+pub struct LightCount {
+    pub num_lights: [u32; 4],
+}
+
+impl SystemNode for LightsNode {
+    fn get_system(&self, resources: &mut Resources) -> Box<dyn Schedulable> {
+        let mut light_buffer = None;
+        let mut lights_are_dirty = true;
+        // TODO: merge these
+        let mut tmp_count_buffer = None;
+        let mut tmp_light_buffer = None;
+        let mut command_queue = self.command_queue.clone();
+        let max_lights = self.max_lights;
+        SystemBuilder::new("light_node")
+            .read_resource::<GlobalRenderResourceContext>()
+            // TODO: this write on RenderResourceAssignments will prevent this system from running in parallel with other systems that do the same
+            .write_resource::<RenderResourceAssignments>()
+            .with_query(<(Read<Light>, Read<LocalToWorld>, Read<Translation>)>::query())
+            .build(
+                move |_,
+                      world,
+                      (render_resource_context, ref mut render_resource_assignments),
+                      query| {
+                    if !lights_are_dirty {
+                        return;
+                    }
+
+                    let render_resources = &render_resource_context.context;
+                    if light_buffer.is_none() {
+                        let light_uniform_size = std::mem::size_of::<LightCount>()
+                            + max_lights * std::mem::size_of::<LightRaw>();
+
+                        let buffer = render_resources.create_buffer(BufferInfo {
+                            size: light_uniform_size,
+                            buffer_usage: BufferUsage::UNIFORM
+                                | BufferUsage::COPY_SRC
+                                | BufferUsage::COPY_DST,
+                            ..Default::default()
+                        });
+                        render_resource_assignments.set(resource_name::uniform::LIGHTS, buffer);
+                        light_buffer = Some(buffer);
+                    }
+
+                    let light_count = query.iter(world).count();
+
+                    if light_count == 0 {
+                        return;
+                    }
+
+                    lights_are_dirty = false;
+                    let size = std::mem::size_of::<LightRaw>();
+                    let total_size = size * light_count;
+                    let light_count_size = std::mem::size_of::<LightCount>();
+
+                    if let Some(old_tmp_light_buffer) = tmp_light_buffer {
+                        render_resources.remove_buffer(old_tmp_light_buffer);
+                    }
+
+                    if let Some(old_tmp_count_buffer) = tmp_count_buffer {
+                        render_resources.remove_buffer(old_tmp_count_buffer);
+                    }
+
+                    tmp_light_buffer = Some(render_resources.create_buffer_mapped(
+                        BufferInfo {
+                            size: total_size,
+                            buffer_usage: BufferUsage::COPY_SRC,
+                            ..Default::default()
+                        },
+                        &mut |data, _renderer| {
+                            for ((light, local_to_world, translation), slot) in
+                                query.iter(world).zip(data.chunks_exact_mut(size))
+                            {
+                                slot.copy_from_slice(
+                                    LightRaw::from(&light, &local_to_world.0, &translation)
+                                        .as_bytes(),
+                                );
+                            }
+                        },
+                    ));
+                    tmp_count_buffer = Some(render_resources.create_buffer_mapped(
+                        BufferInfo {
+                            size: light_count_size,
+                            buffer_usage: BufferUsage::COPY_SRC,
+                            ..Default::default()
+                        },
+                        &mut |data, _renderer| {
+                            data.copy_from_slice([light_count as u32, 0, 0, 0].as_bytes());
+                        },
+                    ));
+
+                    command_queue.copy_buffer_to_buffer(
+                        tmp_count_buffer.unwrap(),
+                        0,
+                        light_buffer.unwrap(),
+                        0,
+                        light_count_size as u64,
+                    );
+
+                    command_queue.copy_buffer_to_buffer(
+                        tmp_light_buffer.unwrap(),
+                        0,
+                        light_buffer.unwrap(),
+                        light_count_size as u64,
+                        total_size as u64,
+                    );
+                },
+            )
+    }
+}