Draft new iced_graphics crate 🎉

wgpu/src/widget/canvas/cache.rs

@@ -1,108 +0,0 @@
-use crate::{
-    canvas::{Frame, Geometry},
-    Primitive,
-};
-
-use iced_native::Size;
-use std::{cell::RefCell, sync::Arc};
-
-enum State {
-    Empty,
-    Filled {
-        bounds: Size,
-        primitive: Arc<Primitive>,
-    },
-}
-
-impl Default for State {
-    fn default() -> Self {
-        State::Empty
-    }
-}
-/// 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.
-///
-/// [`Layer`]: ../trait.Layer.html
-/// [`Cache`]: struct.Cache.html
-/// [`Geometry`]: struct.Geometry.html
-#[derive(Debug, Default)]
-pub struct Cache {
-    state: RefCell<State>,
-}
-
-impl Cache {
-    /// Creates a new empty [`Cache`].
-    ///
-    /// [`Cache`]: struct.Cache.html
-    pub fn new() -> Self {
-        Cache {
-            state: Default::default(),
-        }
-    }
-
-    /// Clears the [`Cache`], forcing a redraw the next time it is used.
-    ///
-    /// [`Cache`]: struct.Cache.html
-    pub fn clear(&mut self) {
-        *self.state.borrow_mut() = State::Empty;
-    }
-
-    /// 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.
-    ///
-    /// [`Cache`]: struct.Cache.html
-    pub fn draw(&self, bounds: Size, draw_fn: impl Fn(&mut Frame)) -> Geometry {
-        use std::ops::Deref;
-
-        if let State::Filled {
-            bounds: cached_bounds,
-            primitive,
-        } = self.state.borrow().deref()
-        {
-            if *cached_bounds == bounds {
-                return Geometry::from_primitive(Primitive::Cached {
-                    cache: primitive.clone(),
-                });
-            }
-        }
-
-        let mut frame = Frame::new(bounds);
-        draw_fn(&mut frame);
-
-        let primitive = {
-            let geometry = frame.into_geometry();
-
-            Arc::new(geometry.into_primitive())
-        };
-
-        *self.state.borrow_mut() = State::Filled {
-            bounds,
-            primitive: primitive.clone(),
-        };
-
-        Geometry::from_primitive(Primitive::Cached { cache: primitive })
-    }
-}
-
-impl std::fmt::Debug for State {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        match self {
-            State::Empty => write!(f, "Empty"),
-            State::Filled { primitive, bounds } => f
-                .debug_struct("Filled")
-                .field("primitive", primitive)
-                .field("bounds", bounds)
-                .finish(),
-        }
-    }
-}