Struct Cache

pub struct Cache<Renderer>
where
    Renderer: Renderer,
{ /* private fields */ }

Available on crate feature geometry only.

A simple cache that stores generated geometry to avoid recomputation.

A Cache will not redraw its geometry unless the dimensions of its layer change or it is explicitly cleared.

Implementations

impl<Renderer> Cache<Renderer>

where Renderer: Renderer,

pub fn new() -> Self

Creates a new empty Cache.

pub fn with_group(group: Group) -> Self

Creates a new empty Cache with the given Group.

Caches within the same group may reuse internal rendering storage.

You should generally group caches that are likely to change together.

pub fn clear(&self)

Clears the Cache, forcing a redraw the next time it is used.

pub fn draw( &self, renderer: &Renderer, bounds: Size, draw_fn: impl FnOnce(&mut Frame<Renderer>), ) -> Renderer::Geometry

Draws geometry using the provided closure and stores it in the Cache.

The closure will only be called when

• the bounds have changed since the previous draw call.
• the Cache is empty or has been explicitly cleared.

Otherwise, the previously stored geometry will be returned. The Cache is not cleared in this case. In other words, it will keep returning the stored geometry if needed.

Trait Implementations

impl<Renderer> Debug for Cache<Renderer>

where Renderer: Renderer, <Renderer::Geometry as Cached>::Cache: Debug,

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<Renderer> Default for Cache<Renderer>

where Renderer: Renderer,

fn default() -> Self

Returns the “default value” for a type.