Struct PathCaches 

pub struct PathCaches { /* private fields */ }

The PathCaches of a plot that is rebuilt on every render, kept in the window’s element state so they outlive the plot value.

Plots are plain values built by render and painted once, so a cache held by the plot would be empty every frame; this keeps them under the element id the plot paints in (plus key), for as long as the plot is painted on consecutive frames.

fn paint(&mut self, bounds: Bounds<Pixels>, window: &mut Window, cx: &mut App) {
    let caches = PathCaches::for_paint("lines", window, cx);
    caches.update(cx, |caches, _| {
        for (ix, line) in lines.iter().enumerate() {
            line.paint_cached(&bounds, caches.slot(ix), window);
        }
    });
}

Implementations

impl PathCaches

pub fn for_paint( key: impl Into<ElementId>, window: &mut Window, cx: &mut App, ) -> Entity<Self>

The caches for the plot painting under the window’s current element id; key tells apart several groups of shapes in one plot.

pub fn slot(&mut self, index: usize) -> &mut PathCache

The index-th cache, created on first use. Paint each shape through the same index every frame.

pub fn slot_pair(&mut self, index: usize) -> (&mut PathCache, &mut PathCache)

Two caches for a shape that keeps a fill and a stroke, such as Area::paint_cached, at 2 * index and 2 * index + 1.

Trait Implementations

impl Default for PathCaches

fn default() -> PathCaches

Returns the “default value” for a type.