Merge pull request #2537 from iced-rs/feature/canvas-image-support

`image` and `svg` support for `canvas`

core/src/image.rs

@@ -7,6 +7,73 @@ use rustc_hash::FxHasher;
 use std::hash::{Hash, Hasher};
 use std::path::{Path, PathBuf};
 
+/// A raster image that can be drawn.
+#[derive(Debug, Clone, PartialEq)]
+pub struct Image<H = Handle> {
+    /// The handle of the image.
+    pub handle: H,
+
+    /// The filter method of the image.
+    pub filter_method: FilterMethod,
+
+    /// The rotation to be applied to the image; on its center.
+    pub rotation: Radians,
+
+    /// The opacity of the image.
+    ///
+    /// 0 means transparent. 1 means opaque.
+    pub opacity: f32,
+
+    /// If set to `true`, the image will be snapped to the pixel grid.
+    ///
+    /// This can avoid graphical glitches, specially when using
+    /// [`FilterMethod::Nearest`].
+    pub snap: bool,
+}
+
+impl Image<Handle> {
+    /// Creates a new [`Image`] with the given handle.
+    pub fn new(handle: impl Into<Handle>) -> Self {
+        Self {
+            handle: handle.into(),
+            filter_method: FilterMethod::default(),
+            rotation: Radians(0.0),
+            opacity: 1.0,
+            snap: false,
+        }
+    }
+
+    /// Sets the filter method of the [`Image`].
+    pub fn filter_method(mut self, filter_method: FilterMethod) -> Self {
+        self.filter_method = filter_method;
+        self
+    }
+
+    /// Sets the rotation of the [`Image`].
+    pub fn rotation(mut self, rotation: impl Into<Radians>) -> Self {
+        self.rotation = rotation.into();
+        self
+    }
+
+    /// Sets the opacity of the [`Image`].
+    pub fn opacity(mut self, opacity: impl Into<f32>) -> Self {
+        self.opacity = opacity.into();
+        self
+    }
+
+    /// Sets whether the [`Image`] should be snapped to the pixel grid.
+    pub fn snap(mut self, snap: bool) -> Self {
+        self.snap = snap;
+        self
+    }
+}
+
+impl From<&Handle> for Image {
+    fn from(handle: &Handle) -> Self {
+        Image::new(handle.clone())
+    }
+}
+
 /// A handle of some image data.
 #[derive(Clone, PartialEq, Eq)]
 pub enum Handle {
@@ -101,6 +168,12 @@ where
     }
 }
 
+impl From<&Handle> for Handle {
+    fn from(value: &Handle) -> Self {
+        value.clone()
+    }
+}
+
 impl std::fmt::Debug for Handle {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {
@@ -166,14 +239,6 @@ pub trait Renderer: crate::Renderer {
     /// Returns the dimensions of an image for the given [`Handle`].
     fn measure_image(&self, handle: &Self::Handle) -> Size<u32>;
 
-    /// Draws an image with the given [`Handle`] and inside the provided
-    /// `bounds`.
-    fn draw_image(
-        &mut self,
-        handle: Self::Handle,
-        filter_method: FilterMethod,
-        bounds: Rectangle,
-        rotation: Radians,
-        opacity: f32,
-    );
+    /// Draws an [`Image`] inside the provided `bounds`.
+    fn draw_image(&mut self, image: Image<Self::Handle>, bounds: Rectangle);
 }

core/src/lib.rs

@@ -57,6 +57,7 @@ pub use element::Element;
 pub use event::Event;
 pub use font::Font;
 pub use gradient::Gradient;
+pub use image::Image;
 pub use layout::Layout;
 pub use length::Length;
 pub use overlay::Overlay;
@@ -69,6 +70,7 @@ pub use rotation::Rotation;
 pub use shadow::Shadow;
 pub use shell::Shell;
 pub use size::Size;
+pub use svg::Svg;
 pub use text::Text;
 pub use theme::Theme;
 pub use transformation::Transformation;

core/src/rectangle.rs

@@ -47,6 +47,62 @@ impl Rectangle<f32> {
         }
     }
 
+    /// Creates a new square [`Rectangle`] with the center at the origin and
+    /// with the given radius.
+    pub fn with_radius(radius: f32) -> Self {
+        Self {
+            x: -radius,
+            y: -radius,
+            width: radius * 2.0,
+            height: radius * 2.0,
+        }
+    }
+
+    /// Creates a new axis-aligned [`Rectangle`] from the given vertices; returning the
+    /// rotation in [`Radians`] that must be applied to the axis-aligned [`Rectangle`]
+    /// to obtain the desired result.
+    pub fn with_vertices(
+        top_left: Point,
+        top_right: Point,
+        bottom_left: Point,
+    ) -> (Rectangle, Radians) {
+        let width = (top_right.x - top_left.x).hypot(top_right.y - top_left.y);
+
+        let height =
+            (bottom_left.x - top_left.x).hypot(bottom_left.y - top_left.y);
+
+        let rotation =
+            (top_right.y - top_left.y).atan2(top_right.x - top_left.x);
+
+        let rotation = if rotation < 0.0 {
+            2.0 * std::f32::consts::PI + rotation
+        } else {
+            rotation
+        };
+
+        let position = {
+            let center = Point::new(
+                (top_right.x + bottom_left.x) / 2.0,
+                (top_right.y + bottom_left.y) / 2.0,
+            );
+
+            let rotation = -rotation - std::f32::consts::PI * 2.0;
+
+            Point::new(
+                center.x + (top_left.x - center.x) * rotation.cos()
+                    - (top_left.y - center.y) * rotation.sin(),
+                center.y
+                    + (top_left.x - center.x) * rotation.sin()
+                    + (top_left.y - center.y) * rotation.cos(),
+            )
+        };
+
+        (
+            Rectangle::new(position, Size::new(width, height)),
+            Radians(rotation),
+        )
+    }
+
     /// Returns the [`Point`] at the center of the [`Rectangle`].
     pub fn center(&self) -> Point {
         Point::new(self.center_x(), self.center_y())

core/src/renderer/null.rs

@@ -1,11 +1,10 @@
 use crate::alignment;
-use crate::image;
+use crate::image::{self, Image};
 use crate::renderer::{self, Renderer};
 use crate::svg;
 use crate::text::{self, Text};
 use crate::{
-    Background, Color, Font, Pixels, Point, Radians, Rectangle, Size,
-    Transformation,
+    Background, Color, Font, Pixels, Point, Rectangle, Size, Transformation,
 };
 
 impl Renderer for () {
@@ -178,35 +177,19 @@ impl text::Editor for () {
 }
 
 impl image::Renderer for () {
-    type Handle = ();
+    type Handle = image::Handle;
 
     fn measure_image(&self, _handle: &Self::Handle) -> Size<u32> {
         Size::default()
     }
 
-    fn draw_image(
-        &mut self,
-        _handle: Self::Handle,
-        _filter_method: image::FilterMethod,
-        _bounds: Rectangle,
-        _rotation: Radians,
-        _opacity: f32,
-    ) {
-    }
+    fn draw_image(&mut self, _image: Image, _bounds: Rectangle) {}
 }
 
 impl svg::Renderer for () {
     fn measure_svg(&self, _handle: &svg::Handle) -> Size<u32> {
         Size::default()
     }
 
-    fn draw_svg(
-        &mut self,
-        _handle: svg::Handle,
-        _color: Option<Color>,
-        _bounds: Rectangle,
-        _rotation: Radians,
-        _opacity: f32,
-    ) {
-    }
+    fn draw_svg(&mut self, _svg: svg::Svg, _bounds: Rectangle) {}
 }

core/src/svg.rs

@@ -7,6 +7,66 @@ use std::hash::{Hash, Hasher as _};
 use std::path::PathBuf;
 use std::sync::Arc;
 
+/// A raster image that can be drawn.
+#[derive(Debug, Clone, PartialEq)]
+pub struct Svg<H = Handle> {
+    /// The handle of the [`Svg`].
+    pub handle: H,
+
+    /// The [`Color`] filter to be applied to the [`Svg`].
+    ///
+    /// If some [`Color`] is set, the whole [`Svg`] will be
+    /// painted with it—ignoring any intrinsic colors.
+    ///
+    /// This can be useful for coloring icons programmatically
+    /// (e.g. with a theme).
+    pub color: Option<Color>,
+
+    /// The rotation to be applied to the image; on its center.
+    pub rotation: Radians,
+
+    /// The opacity of the [`Svg`].
+    ///
+    /// 0 means transparent. 1 means opaque.
+    pub opacity: f32,
+}
+
+impl Svg<Handle> {
+    /// Creates a new [`Svg`] with the given handle.
+    pub fn new(handle: impl Into<Handle>) -> Self {
+        Self {
+            handle: handle.into(),
+            color: None,
+            rotation: Radians(0.0),
+            opacity: 1.0,
+        }
+    }
+
+    /// Sets the [`Color`] filter of the [`Svg`].
+    pub fn color(mut self, color: impl Into<Color>) -> Self {
+        self.color = Some(color.into());
+        self
+    }
+
+    /// Sets the rotation of the [`Svg`].
+    pub fn rotation(mut self, rotation: impl Into<Radians>) -> Self {
+        self.rotation = rotation.into();
+        self
+    }
+
+    /// Sets the opacity of the [`Svg`].
+    pub fn opacity(mut self, opacity: impl Into<f32>) -> Self {
+        self.opacity = opacity.into();
+        self
+    }
+}
+
+impl From<&Handle> for Svg {
+    fn from(handle: &Handle) -> Self {
+        Svg::new(handle.clone())
+    }
+}
+
 /// A handle of Svg data.
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct Handle {
@@ -95,12 +155,5 @@ pub trait Renderer: crate::Renderer {
     fn measure_svg(&self, handle: &Handle) -> Size<u32>;
 
     /// Draws an SVG with the given [`Handle`], an optional [`Color`] filter, and inside the provided `bounds`.
-    fn draw_svg(
-        &mut self,
-        handle: Handle,
-        color: Option<Color>,
-        bounds: Rectangle,
-        rotation: Radians,
-        opacity: f32,
-    );
+    fn draw_svg(&mut self, svg: Svg, bounds: Rectangle);
 }