Struct DynamicUniformIndex 

pub struct DynamicUniformIndex<C>
where
    C: Component,
{ /* private fields */ }

Stores the index of a uniform inside of ComponentUniforms.

Implementations

impl<C> DynamicUniformIndex<C>

where C: Component,

pub fn index(&self) -> u32

Examples found in repository

examples/shader_advanced/custom_post_processing.rs (line 162)

fn post_process_system(
    view: ViewQuery<(
        &ViewTarget,
        &PostProcessSettings,
        &DynamicUniformIndex<PostProcessSettings>,
    )>,
    post_process_pipeline: Option<Res<PostProcessPipeline>>,
    pipeline_cache: Res<PipelineCache>,
    settings_uniforms: Res<ComponentUniforms<PostProcessSettings>>,
    mut cache: Local<PostProcessBindGroupCache>,
    mut ctx: RenderContext,
) {
    let Some(post_process_pipeline) = post_process_pipeline else {
        return;
    };

    let (view_target, _post_process_settings, settings_index) = view.into_inner();

    let Some(pipeline) = pipeline_cache.get_render_pipeline(post_process_pipeline.pipeline_id)
    else {
        return;
    };

    let Some(settings_binding) = settings_uniforms.uniforms().binding() else {
        return;
    };

    // This will start a new "post process write", obtaining two texture
    // views from the view target - a `source` and a `destination`.
    // `source` is the "current" main texture and you _must_ write into
    // `destination` because calling `post_process_write()` on the
    // [`ViewTarget`] will internally flip the [`ViewTarget`]'s main
    // texture to the `destination` texture. Failing to do so will cause
    // the current main texture information to be lost.
    let post_process = view_target.post_process_write();

    let bind_group = match &mut cache.cached {
        Some((texture_id, bind_group)) if post_process.source.id() == *texture_id => bind_group,
        cached => {
            // The bind_group gets created each frame.
            //
            // Normally, you would create a bind_group in the Queue set,
            // but this doesn't work with the post_process_write().
            // The reason it doesn't work is because each post_process_write will alternate the source/destination.
            // The only way to have the correct source/destination for the bind_group
            // is to make sure you get it during the node execution.
            let bind_group = ctx.render_device().create_bind_group(
                "post_process_bind_group",
                &pipeline_cache.get_bind_group_layout(&post_process_pipeline.layout),
                // It's important for this to match the BindGroupLayout defined in the PostProcessPipeline
                &BindGroupEntries::sequential((
                    // Make sure to use the source view
                    post_process.source,
                    // Use the sampler created for the pipeline
                    &post_process_pipeline.sampler,
                    // Set the settings binding
                    settings_binding.clone(),
                )),
            );

            let (_, bind_group) = cached.insert((post_process.source.id(), bind_group));
            bind_group
        }
    };

    let mut render_pass = ctx
        .command_encoder()
        .begin_render_pass(&RenderPassDescriptor {
            label: Some("post_process_pass"),
            color_attachments: &[Some(RenderPassColorAttachment {
                // We need to specify the post process destination view here
                // to make sure we write to the appropriate texture.
                view: post_process.destination,
                depth_slice: None,
                resolve_target: None,
                ops: Operations::default(),
            })],
            depth_stencil_attachment: None,
            timestamp_writes: None,
            occlusion_query_set: None,
            multiview_mask: None,
        });

    render_pass.set_pipeline(pipeline);
    // By passing in the index of the post process settings on this view, we ensure
    // that in the event that multiple settings were sent to the GPU (as would be the
    // case with multiple cameras), we use the correct one.
    render_pass.set_bind_group(0, bind_group, &[settings_index.index()]);
    render_pass.draw(0..3, 0..1);
}

Trait Implementations

impl<C> Component for DynamicUniformIndex<C>

where C: Component, DynamicUniformIndex<C>: Send + Sync + 'static,

const STORAGE_TYPE: StorageType = bevy_ecs::component::StorageType::Table

A constant indicating the storage type used for this component.

type Mutability = Mutable

A marker type to assist Bevy with determining if this component is mutable, or immutable. Mutable components will have Component<Mutability = Mutable>, while immutable components will instead have Component<Mutability = Immutable>.

fn register_required_components( _requiree: ComponentId, required_components: &mut RequiredComponentsRegistrator<'_, '_>, )

Registers required components.

fn clone_behavior() -> ComponentCloneBehavior

Called when registering this component, allowing to override clone function (or disable cloning altogether) for this component.

fn relationship_accessor() -> Option<ComponentRelationshipAccessor<DynamicUniformIndex<C>>>

Returns ComponentRelationshipAccessor required for working with relationships in dynamic contexts.

fn on_add() -> Option<for<'w> fn(DeferredWorld<'w>, HookContext)>

Gets the on_add ComponentHook for this Component if one is defined.

fn on_insert() -> Option<for<'w> fn(DeferredWorld<'w>, HookContext)>

Gets the on_insert ComponentHook for this Component if one is defined.

fn on_discard() -> Option<for<'w> fn(DeferredWorld<'w>, HookContext)>

Gets the on_discard ComponentHook for this Component if one is defined.

fn on_remove() -> Option<for<'w> fn(DeferredWorld<'w>, HookContext)>

Gets the on_remove ComponentHook for this Component if one is defined.

fn on_despawn() -> Option<for<'w> fn(DeferredWorld<'w>, HookContext)>

Gets the on_despawn ComponentHook for this Component if one is defined.

fn map_entities<E>(_this: &mut Self, _mapper: &mut E)

where E: EntityMapper,

Maps the entities on this component using the given EntityMapper. This is used to remap entities in contexts like scenes and entity cloning. When deriving Component, this is populated by annotating fields containing entities with #[entities]