Struct bevy::render::view::ViewTarget

pub struct ViewTarget { /* private fields */ }

Implementations

impl ViewTarget

pub const TEXTURE_FORMAT_HDR: TextureFormat = TextureFormat::Rgba16Float

pub fn get_color_attachment(&self) -> RenderPassColorAttachment<'_>

Retrieve this target’s main texture’s color attachment.

pub fn get_unsampled_color_attachment(&self) -> RenderPassColorAttachment<'_>

Retrieve this target’s “unsampled” main texture’s color attachment.

pub fn main_texture(&self) -> &Texture

The “main” unsampled texture.

pub fn main_texture_other(&self) -> &Texture

The other “main” unsampled texture. In most cases you should use Self::main_texture instead and never this. The textures will naturally be swapped when Self::post_process_write is called.

A use case for this is to be able to prepare a bind group for all main textures ahead of time.

pub fn main_texture_view(&self) -> &TextureView

The “main” unsampled texture.

pub fn main_texture_other_view(&self) -> &TextureView

The other “main” unsampled texture view. In most cases you should use Self::main_texture_view instead and never this. The textures will naturally be swapped when Self::post_process_write is called.

A use case for this is to be able to prepare a bind group for all main textures ahead of time.

pub fn sampled_main_texture(&self) -> Option<&Texture>

The “main” sampled texture.

pub fn sampled_main_texture_view(&self) -> Option<&TextureView>

The “main” sampled texture view.

pub fn main_texture_format(&self) -> TextureFormat

pub fn is_hdr(&self) -> bool

Returns true if and only if the main texture is Self::TEXTURE_FORMAT_HDR

pub fn out_texture(&self) -> &TextureView

The final texture this view will render to.

pub fn out_texture_format(&self) -> TextureFormat

The format of the final texture this view will render to

pub fn post_process_write(&self) -> PostProcessWrite<'_>

This will start a new “post process write”, which assumes that the caller will write the PostProcessWrite’s source to the destination.

source is the “current” main texture. This will internally flip this ViewTarget’s main texture to the destination texture, so the caller must ensure source is copied to destination, with or without modifications. Failing to do so will cause the current main texture information to be lost.

Examples found in repository

examples/shader/post_processing.rs (line 171)

    fn run(
        &self,
        _graph: &mut RenderGraphContext,
        render_context: &mut RenderContext,
        (view_target, _post_process_settings): QueryItem<Self::ViewQuery>,
        world: &World,
    ) -> Result<(), NodeRunError> {
        // Get the pipeline resource that contains the global data we need
        // to create the render pipeline
        let post_process_pipeline = world.resource::<PostProcessPipeline>();

        // The pipeline cache is a cache of all previously created pipelines.
        // It is required to avoid creating a new pipeline each frame,
        // which is expensive due to shader compilation.
        let pipeline_cache = world.resource::<PipelineCache>();

        // Get the pipeline from the cache
        let Some(pipeline) = pipeline_cache.get_render_pipeline(post_process_pipeline.pipeline_id)
        else {
            return Ok(());
        };

        // Get the settings uniform binding
        let settings_uniforms = world.resource::<ComponentUniforms<PostProcessSettings>>();
        let Some(settings_binding) = settings_uniforms.uniforms().binding() else {
            return Ok(());
        };

        // 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();

        // 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 = render_context.render_device().create_bind_group(
            "post_process_bind_group",
            &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(),
            )),
        );

        // Begin the render pass
        let mut render_pass = render_context.begin_tracked_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,
                resolve_target: None,
                ops: Operations::default(),
            })],
            depth_stencil_attachment: None,
            timestamp_writes: None,
            occlusion_query_set: None,
        });

        // This is mostly just wgpu boilerplate for drawing a fullscreen triangle,
        // using the pipeline/bind_group created above
        render_pass.set_render_pipeline(pipeline);
        render_pass.set_bind_group(0, &bind_group, &[]);
        render_pass.draw(0..3, 0..1);

        Ok(())
    }

Trait Implementations

impl Component for ViewTarget

where ViewTarget: Send + Sync + 'static,

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

A constant indicating the storage type used for this component.

fn register_component_hooks(_hooks: &mut ComponentHooks)

Called when registering this component, allowing mutable access to its ComponentHooks.