lib.rs

//! # Useful Environment Variables
//!
//! Both `bevy_render` and `wgpu` have a number of environment variable options for changing the runtime behavior
//! of both crates. Many of these may be useful in development or release environments.
//!
//! - `WGPU_DEBUG=1` enables debug labels, which can be useful in release builds.
//! - `WGPU_VALIDATION=0` disables validation layers. This can help with particularly spammy errors.
//! - `WGPU_FORCE_FALLBACK_ADAPTER=1` attempts to force software rendering. This typically matches what is used in CI.
//! - `WGPU_ADAPTER_NAME` allows selecting a specific adapter by name.
//! - `WGPU_SETTINGS_PRIO=webgl2` uses webgl2 limits.
//! - `WGPU_SETTINGS_PRIO=compatibility` uses webgpu limits.
//! - `VERBOSE_SHADER_ERROR=1` prints more detailed information about WGSL compilation errors, such as shader defs and shader entrypoint.

#![expect(missing_docs, reason = "Not all docs are written yet, see #3492.")]
#![expect(unsafe_code, reason = "Unsafe code is used to improve performance.")]
#![cfg_attr(
    any(docsrs, docsrs_dep),
    expect(
        internal_features,
        reason = "rustdoc_internals is needed for fake_variadic"
    )
)]
#![cfg_attr(any(docsrs, docsrs_dep), feature(doc_cfg, rustdoc_internals))]
#![doc(
    html_logo_url = "https://bevy.org/assets/icon.png",
    html_favicon_url = "https://bevy.org/assets/icon.png"
)]

#[cfg(target_pointer_width = "16")]
compile_error!("bevy_render cannot compile for a 16-bit platform.");

extern crate alloc;
extern crate core;

// Required to make proc macros work in bevy itself.
extern crate self as bevy_render;

pub mod alpha;
pub mod batching;
pub mod camera;
pub mod diagnostic;
pub mod erased_render_asset;
pub mod experimental;
pub mod extract_component;
pub mod extract_instances;
mod extract_param;
pub mod extract_resource;
pub mod globals;
pub mod gpu_component_array_buffer;
pub mod gpu_readback;
pub mod mesh;
#[cfg(not(target_arch = "wasm32"))]
pub mod pipelined_rendering;
pub mod render_asset;
pub mod render_graph;
pub mod render_phase;
pub mod render_resource;
pub mod renderer;
pub mod settings;
pub mod storage;
pub mod sync_component;
pub mod sync_world;
pub mod texture;
pub mod view;

/// The render prelude.
///
/// This includes the most common types in this crate, re-exported for your convenience.
pub mod prelude {
    #[doc(hidden)]
    pub use crate::{
        alpha::AlphaMode, camera::NormalizedRenderTargetExt as _, texture::ManualTextureViews,
        view::Msaa, ExtractSchedule,
    };
}

pub use extract_param::Extract;

use crate::{
    camera::CameraPlugin,
    gpu_readback::GpuReadbackPlugin,
    mesh::{MeshRenderAssetPlugin, RenderMesh},
    render_asset::prepare_assets,
    render_resource::PipelineCache,
    renderer::{render_system, RenderAdapterInfo},
    settings::RenderCreation,
    storage::StoragePlugin,
    texture::TexturePlugin,
    view::{ViewPlugin, WindowRenderPlugin},
};
use alloc::sync::Arc;
use batching::gpu_preprocessing::BatchingPlugin;
use bevy_app::{App, AppLabel, Plugin, SubApp};
use bevy_asset::{AssetApp, AssetServer};
use bevy_ecs::{
    prelude::*,
    schedule::{ScheduleBuildSettings, ScheduleLabel},
};
use bevy_image::{CompressedImageFormatSupport, CompressedImageFormats};
use bevy_shader::{load_shader_library, Shader, ShaderLoader};
use bevy_utils::prelude::default;
use bevy_window::{PrimaryWindow, RawHandleWrapperHolder};
use bitflags::bitflags;
use core::ops::{Deref, DerefMut};
use experimental::occlusion_culling::OcclusionCullingPlugin;
use globals::GlobalsPlugin;
use render_asset::{
    extract_render_asset_bytes_per_frame, reset_render_asset_bytes_per_frame,
    RenderAssetBytesPerFrame, RenderAssetBytesPerFrameLimiter,
};
use settings::RenderResources;
use std::sync::Mutex;
use sync_world::{despawn_temporary_render_entities, entity_sync_system, SyncWorldPlugin};

/// Contains the default Bevy rendering backend based on wgpu.
///
/// Rendering is done in a [`SubApp`], which exchanges data with the main app
/// between main schedule iterations.
///
/// Rendering can be executed between iterations of the main schedule,
/// or it can be executed in parallel with main schedule when
/// [`PipelinedRenderingPlugin`](pipelined_rendering::PipelinedRenderingPlugin) is enabled.
#[derive(Default)]
pub struct RenderPlugin {
    pub render_creation: RenderCreation,
    /// If `true`, disables asynchronous pipeline compilation.
    /// This has no effect on macOS, Wasm, iOS, or without the `multi_threaded` feature.
    pub synchronous_pipeline_compilation: bool,
    /// Debugging flags that can optionally be set when constructing the renderer.
    pub debug_flags: RenderDebugFlags,
}

bitflags! {
    /// Debugging flags that can optionally be set when constructing the renderer.
    #[derive(Clone, Copy, PartialEq, Default, Debug)]
    pub struct RenderDebugFlags: u8 {
        /// If true, this sets the `COPY_SRC` flag on indirect draw parameters
        /// so that they can be read back to CPU.
        ///
        /// This is a debugging feature that may reduce performance. It
        /// primarily exists for the `occlusion_culling` example.
        const ALLOW_COPIES_FROM_INDIRECT_PARAMETERS = 1;
    }
}

/// The systems sets of the default [`App`] rendering schedule.
///
/// These can be useful for ordering, but you almost never want to add your systems to these sets.
#[derive(Debug, Hash, PartialEq, Eq, Clone, SystemSet)]
pub enum RenderSystems {
    /// This is used for applying the commands from the [`ExtractSchedule`]
    ExtractCommands,
    /// Prepare assets that have been created/modified/removed this frame.
    PrepareAssets,
    /// Prepares extracted meshes.
    PrepareMeshes,
    /// Create any additional views such as those used for shadow mapping.
    ManageViews,
    /// Queue drawable entities as phase items in render phases ready for
    /// sorting (if necessary)
    Queue,
    /// A sub-set within [`Queue`](RenderSystems::Queue) where mesh entity queue systems are executed. Ensures `prepare_assets::<RenderMesh>` is completed.
    QueueMeshes,
    /// A sub-set within [`Queue`](RenderSystems::Queue) where meshes that have
    /// become invisible or changed phases are removed from the bins.
    QueueSweep,
    // TODO: This could probably be moved in favor of a system ordering
    // abstraction in `Render` or `Queue`
    /// Sort the [`SortedRenderPhase`](render_phase::SortedRenderPhase)s and
    /// [`BinKey`](render_phase::BinnedPhaseItem::BinKey)s here.
    PhaseSort,
    /// Prepare render resources from extracted data for the GPU based on their sorted order.
    /// Create [`BindGroups`](render_resource::BindGroup) that depend on those data.
    Prepare,
    /// A sub-set within [`Prepare`](RenderSystems::Prepare) for initializing buffers, textures and uniforms for use in bind groups.
    PrepareResources,
    /// Collect phase buffers after
    /// [`PrepareResources`](RenderSystems::PrepareResources) has run.
    PrepareResourcesCollectPhaseBuffers,
    /// Flush buffers after [`PrepareResources`](RenderSystems::PrepareResources), but before [`PrepareBindGroups`](RenderSystems::PrepareBindGroups).
    PrepareResourcesFlush,
    /// A sub-set within [`Prepare`](RenderSystems::Prepare) for constructing bind groups, or other data that relies on render resources prepared in [`PrepareResources`](RenderSystems::PrepareResources).
    PrepareBindGroups,
    /// Actual rendering happens here.
    /// In most cases, only the render backend should insert resources here.
    Render,
    /// Cleanup render resources here.
    Cleanup,
    /// Final cleanup occurs: any entities with
    /// [`TemporaryRenderEntity`](sync_world::TemporaryRenderEntity) will be despawned.
    ///
    /// Runs after [`Cleanup`](RenderSystems::Cleanup).
    PostCleanup,
}

/// The startup schedule of the [`RenderApp`]
#[derive(ScheduleLabel, Debug, Hash, PartialEq, Eq, Clone, Default)]
pub struct RenderStartup;

/// The main render schedule.
#[derive(ScheduleLabel, Debug, Hash, PartialEq, Eq, Clone, Default)]
pub struct Render;

impl Render {
    /// Sets up the base structure of the rendering [`Schedule`].
    ///
    /// The sets defined in this enum are configured to run in order.
    pub fn base_schedule() -> Schedule {
        use RenderSystems::*;

        let mut schedule = Schedule::new(Self);

        schedule.configure_sets(
            (
                ExtractCommands,
                PrepareMeshes,
                ManageViews,
                Queue,
                PhaseSort,
                Prepare,
                Render,
                Cleanup,
                PostCleanup,
            )
                .chain(),
        );

        schedule.configure_sets((ExtractCommands, PrepareAssets, PrepareMeshes, Prepare).chain());
        schedule.configure_sets(
            (QueueMeshes, QueueSweep)
                .chain()
                .in_set(Queue)
                .after(prepare_assets::<RenderMesh>),
        );
        schedule.configure_sets(
            (
                PrepareResources,
                PrepareResourcesCollectPhaseBuffers,
                PrepareResourcesFlush,
                PrepareBindGroups,
            )
                .chain()
                .in_set(Prepare),
        );

        schedule
    }
}

/// Schedule in which data from the main world is 'extracted' into the render world.
///
/// This step should be kept as short as possible to increase the "pipelining potential" for
/// running the next frame while rendering the current frame.
///
/// This schedule is run on the render world, but it also has access to the main world.
/// See [`MainWorld`] and [`Extract`] for details on how to access main world data from this schedule.
#[derive(ScheduleLabel, PartialEq, Eq, Debug, Clone, Hash, Default)]
pub struct ExtractSchedule;

/// The simulation [`World`] of the application, stored as a resource.
///
/// This resource is only available during [`ExtractSchedule`] and not
/// during command application of that schedule.
/// See [`Extract`] for more details.
#[derive(Resource, Default)]
pub struct MainWorld(World);

impl Deref for MainWorld {
    type Target = World;

    fn deref(&self) -> &Self::Target {
        &self.0
    }
}

impl DerefMut for MainWorld {
    fn deref_mut(&mut self) -> &mut Self::Target {
        &mut self.0
    }
}

pub mod graph {
    use crate::render_graph::RenderLabel;

    #[derive(Debug, Hash, PartialEq, Eq, Clone, RenderLabel)]
    pub struct CameraDriverLabel;
}

#[derive(Resource)]
struct FutureRenderResources(Arc<Mutex<Option<RenderResources>>>);

/// A label for the rendering sub-app.
#[derive(Debug, Clone, Copy, Hash, PartialEq, Eq, AppLabel)]
pub struct RenderApp;

impl Plugin for RenderPlugin {
    /// Initializes the renderer, sets up the [`RenderSystems`] and creates the rendering sub-app.
    fn build(&self, app: &mut App) {
        app.init_asset::<Shader>()
            .init_asset_loader::<ShaderLoader>();

        match &self.render_creation {
            RenderCreation::Manual(resources) => {
                let future_render_resources_wrapper = Arc::new(Mutex::new(Some(resources.clone())));
                app.insert_resource(FutureRenderResources(
                    future_render_resources_wrapper.clone(),
                ));
                // SAFETY: Plugins should be set up on the main thread.
                unsafe { initialize_render_app(app) };
            }
            RenderCreation::Automatic(render_creation) => {
                if let Some(backends) = render_creation.backends {
                    let future_render_resources_wrapper = Arc::new(Mutex::new(None));
                    app.insert_resource(FutureRenderResources(
                        future_render_resources_wrapper.clone(),
                    ));

                    let primary_window = app
                        .world_mut()
                        .query_filtered::<&RawHandleWrapperHolder, With<PrimaryWindow>>()
                        .single(app.world())
                        .ok()
                        .cloned();

                    let settings = render_creation.clone();

                    #[cfg(feature = "raw_vulkan_init")]
                    let raw_vulkan_init_settings = app
                        .world_mut()
                        .get_resource::<renderer::raw_vulkan_init::RawVulkanInitSettings>()
                        .cloned()
                        .unwrap_or_default();

                    let async_renderer = async move {
                        let render_resources = renderer::initialize_renderer(
                            backends,
                            primary_window,
                            &settings,
                            #[cfg(feature = "raw_vulkan_init")]
                            raw_vulkan_init_settings,
                        )
                        .await;

                        *future_render_resources_wrapper.lock().unwrap() = Some(render_resources);
                    };

                    // In wasm, spawn a task and detach it for execution
                    #[cfg(target_arch = "wasm32")]
                    bevy_tasks::IoTaskPool::get()
                        .spawn_local(async_renderer)
                        .detach();
                    // Otherwise, just block for it to complete
                    #[cfg(not(target_arch = "wasm32"))]
                    bevy_tasks::block_on(async_renderer);

                    // SAFETY: Plugins should be set up on the main thread.
                    unsafe { initialize_render_app(app) };
                }
            }
        };

        app.add_plugins((
            WindowRenderPlugin,
            CameraPlugin,
            ViewPlugin,
            MeshRenderAssetPlugin,
            GlobalsPlugin,
            #[cfg(feature = "morph")]
            mesh::MorphPlugin,
            TexturePlugin,
            BatchingPlugin {
                debug_flags: self.debug_flags,
            },
            SyncWorldPlugin,
            StoragePlugin,
            GpuReadbackPlugin::default(),
            OcclusionCullingPlugin,
            #[cfg(feature = "tracing-tracy")]
            diagnostic::RenderDiagnosticsPlugin,
        ));

        app.init_resource::<RenderAssetBytesPerFrame>();
        if let Some(render_app) = app.get_sub_app_mut(RenderApp) {
            render_app.init_resource::<RenderAssetBytesPerFrameLimiter>();
            render_app
                .add_systems(ExtractSchedule, extract_render_asset_bytes_per_frame)
                .add_systems(
                    Render,
                    reset_render_asset_bytes_per_frame.in_set(RenderSystems::Cleanup),
                );
        }
    }

    fn ready(&self, app: &App) -> bool {
        app.world()
            .get_resource::<FutureRenderResources>()
            .and_then(|frr| frr.0.try_lock().map(|locked| locked.is_some()).ok())
            .unwrap_or(true)
    }

    fn finish(&self, app: &mut App) {
        load_shader_library!(app, "maths.wgsl");
        load_shader_library!(app, "color_operations.wgsl");
        load_shader_library!(app, "bindless.wgsl");
        if let Some(future_render_resources) =
            app.world_mut().remove_resource::<FutureRenderResources>()
        {
            let render_resources = future_render_resources.0.lock().unwrap().take().unwrap();
            let RenderResources(device, queue, adapter_info, render_adapter, instance, ..) =
                render_resources;

            let compressed_image_format_support = CompressedImageFormatSupport(
                CompressedImageFormats::from_features(device.features()),
            );

            app.insert_resource(device.clone())
                .insert_resource(queue.clone())
                .insert_resource(adapter_info.clone())
                .insert_resource(render_adapter.clone())
                .insert_resource(compressed_image_format_support);

            let render_app = app.sub_app_mut(RenderApp);

            #[cfg(feature = "raw_vulkan_init")]
            {
                let additional_vulkan_features: renderer::raw_vulkan_init::AdditionalVulkanFeatures =
                    render_resources.5;
                render_app.insert_resource(additional_vulkan_features);
            }

            render_app
                .insert_resource(instance)
                .insert_resource(PipelineCache::new(
                    device.clone(),
                    render_adapter.clone(),
                    self.synchronous_pipeline_compilation,
                ))
                .insert_resource(device)
                .insert_resource(queue)
                .insert_resource(render_adapter)
                .insert_resource(adapter_info);
        }
    }
}

/// A "scratch" world used to avoid allocating new worlds every frame when
/// swapping out the [`MainWorld`] for [`ExtractSchedule`].
#[derive(Resource, Default)]
struct ScratchMainWorld(World);

/// Executes the [`ExtractSchedule`] step of the renderer.
/// This updates the render world with the extracted ECS data of the current frame.
fn extract(main_world: &mut World, render_world: &mut World) {
    // temporarily add the app world to the render world as a resource
    let scratch_world = main_world.remove_resource::<ScratchMainWorld>().unwrap();
    let inserted_world = core::mem::replace(main_world, scratch_world.0);
    render_world.insert_resource(MainWorld(inserted_world));
    render_world.run_schedule(ExtractSchedule);

    // move the app world back, as if nothing happened.
    let inserted_world = render_world.remove_resource::<MainWorld>().unwrap();
    let scratch_world = core::mem::replace(main_world, inserted_world.0);
    main_world.insert_resource(ScratchMainWorld(scratch_world));
}

/// # Safety
/// This function must be called from the main thread.
unsafe fn initialize_render_app(app: &mut App) {
    app.init_resource::<ScratchMainWorld>();

    let mut render_app = SubApp::new();
    render_app.update_schedule = Some(Render.intern());

    let mut extract_schedule = Schedule::new(ExtractSchedule);
    // We skip applying any commands during the ExtractSchedule
    // so commands can be applied on the render thread.
    extract_schedule.set_build_settings(ScheduleBuildSettings {
        auto_insert_apply_deferred: false,
        ..default()
    });
    extract_schedule.set_apply_final_deferred(false);

    render_app
        .add_schedule(extract_schedule)
        .add_schedule(Render::base_schedule())
        .init_resource::<render_graph::RenderGraph>()
        .insert_resource(app.world().resource::<AssetServer>().clone())
        .add_systems(ExtractSchedule, PipelineCache::extract_shaders)
        .add_systems(
            Render,
            (
                // This set applies the commands from the extract schedule while the render schedule
                // is running in parallel with the main app.
                apply_extract_commands.in_set(RenderSystems::ExtractCommands),
                (PipelineCache::process_pipeline_queue_system, render_system)
                    .chain()
                    .in_set(RenderSystems::Render),
                despawn_temporary_render_entities.in_set(RenderSystems::PostCleanup),
            ),
        );

    // We want the closure to have a flag to only run the RenderStartup schedule once, but the only
    // way to have the closure store this flag is by capturing it. This variable is otherwise
    // unused.
    let mut should_run_startup = true;
    render_app.set_extract(move |main_world, render_world| {
        if should_run_startup {
            // Run the `RenderStartup` if it hasn't run yet. This does mean `RenderStartup` blocks
            // the rest of the app extraction, but this is necessary since extraction itself can
            // depend on resources initialized in `RenderStartup`.
            render_world.run_schedule(RenderStartup);
            should_run_startup = false;
        }

        {
            #[cfg(feature = "trace")]
            let _stage_span = tracing::info_span!("entity_sync").entered();
            entity_sync_system(main_world, render_world);
        }

        // run extract schedule
        extract(main_world, render_world);
    });

    let (sender, receiver) = bevy_time::create_time_channels();
    render_app.insert_resource(sender);
    app.insert_resource(receiver);
    app.insert_sub_app(RenderApp, render_app);
}

/// Applies the commands from the extract schedule. This happens during
/// the render schedule rather than during extraction to allow the commands to run in parallel with the
/// main app when pipelined rendering is enabled.
fn apply_extract_commands(render_world: &mut World) {
    render_world.resource_scope(|render_world, mut schedules: Mut<Schedules>| {
        schedules
            .get_mut(ExtractSchedule)
            .unwrap()
            .apply_deferred(render_world);
    });
}

/// If the [`RenderAdapterInfo`] is a Qualcomm Adreno, returns its model number.
///
/// This lets us work around hardware bugs.
pub fn get_adreno_model(adapter_info: &RenderAdapterInfo) -> Option<u32> {
    if !cfg!(target_os = "android") {
        return None;
    }

    let adreno_model = adapter_info.name.strip_prefix("Adreno (TM) ")?;

    // Take suffixes into account (like Adreno 642L).
    Some(
        adreno_model
            .chars()
            .map_while(|c| c.to_digit(10))
            .fold(0, |acc, digit| acc * 10 + digit),
    )
}

/// Get the Mali driver version if the adapter is a Mali GPU.
pub fn get_mali_driver_version(adapter_info: &RenderAdapterInfo) -> Option<u32> {
    if !cfg!(target_os = "android") {
        return None;
    }

    if !adapter_info.name.contains("Mali") {
        return None;
    }
    let driver_info = &adapter_info.driver_info;
    if let Some(start_pos) = driver_info.find("v1.r")
        && let Some(end_pos) = driver_info[start_pos..].find('p')
    {
        let start_idx = start_pos + 4; // Skip "v1.r"
        let end_idx = start_pos + end_pos;

        return driver_info[start_idx..end_idx].parse::<u32>().ok();
    }

    None
}