Adding feature: Image rotation

core/src/angle.rs

@@ -1,12 +1,17 @@
 use crate::{Point, Rectangle, Vector};
 
 use std::f32::consts::{FRAC_PI_2, PI};
-use std::ops::{Add, AddAssign, Div, Mul, RangeInclusive, Sub, SubAssign};
+use std::ops::{Add, AddAssign, Div, Mul, RangeInclusive, Rem, Sub, SubAssign};
 
 /// Degrees
 #[derive(Debug, Copy, Clone, PartialEq, PartialOrd)]
 pub struct Degrees(pub f32);
 
+impl Degrees {
+    /// The range of degrees of a circle.
+    pub const RANGE: RangeInclusive<Self> = Self(0.0)..=Self(360.0);
+}
+
 impl PartialEq<f32> for Degrees {
     fn eq(&self, other: &f32) -> bool {
         self.0.eq(other)
@@ -19,6 +24,52 @@ impl PartialOrd<f32> for Degrees {
     }
 }
 
+impl From<f32> for Degrees {
+    fn from(degrees: f32) -> Self {
+        Self(degrees)
+    }
+}
+
+impl From<u8> for Degrees {
+    fn from(degrees: u8) -> Self {
+        Self(f32::from(degrees))
+    }
+}
+
+impl From<Degrees> for f32 {
+    fn from(degrees: Degrees) -> Self {
+        degrees.0
+    }
+}
+
+impl From<Degrees> for f64 {
+    fn from(degrees: Degrees) -> Self {
+        Self::from(degrees.0)
+    }
+}
+
+impl Mul<f32> for Degrees {
+    type Output = Degrees;
+
+    fn mul(self, rhs: f32) -> Self::Output {
+        Self(self.0 * rhs)
+    }
+}
+
+impl num_traits::FromPrimitive for Degrees {
+    fn from_i64(n: i64) -> Option<Self> {
+        Some(Self(n as f32))
+    }
+
+    fn from_u64(n: u64) -> Option<Self> {
+        Some(Self(n as f32))
+    }
+
+    fn from_f64(n: f64) -> Option<Self> {
+        Some(Self(n as f32))
+    }
+}
+
 /// Radians
 #[derive(Debug, Copy, Clone, PartialEq, PartialOrd)]
 pub struct Radians(pub f32);
@@ -65,6 +116,12 @@ impl From<u8> for Radians {
     }
 }
 
+impl From<Radians> for f32 {
+    fn from(radians: Radians) -> Self {
+        radians.0
+    }
+}
+
 impl From<Radians> for f64 {
     fn from(radians: Radians) -> Self {
         Self::from(radians.0)
@@ -107,6 +164,14 @@ impl Add for Radians {
     }
 }
 
+impl Add<Degrees> for Radians {
+    type Output = Self;
+
+    fn add(self, rhs: Degrees) -> Self::Output {
+        Self(self.0 + rhs.0.to_radians())
+    }
+}
+
 impl AddAssign for Radians {
     fn add_assign(&mut self, rhs: Radians) {
         self.0 = self.0 + rhs.0;
@@ -153,6 +218,14 @@ impl Div for Radians {
     }
 }
 
+impl Rem for Radians {
+    type Output = Self;
+
+    fn rem(self, rhs: Self) -> Self::Output {
+        Self(self.0 % rhs.0)
+    }
+}
+
 impl PartialEq<f32> for Radians {
     fn eq(&self, other: &f32) -> bool {
         self.0.eq(other)

core/src/content_fit.rs

@@ -1,6 +1,8 @@
 //! Control the fit of some content (like an image) within a space.
 use crate::Size;
 
+use std::fmt;
+
 /// The strategy used to fit the contents of a widget to its bounding box.
 ///
 /// Each variant of this enum is a strategy that can be applied for resolving
@@ -11,7 +13,7 @@ use crate::Size;
 /// in CSS, see [Mozilla's docs][1], or run the `tour` example
 ///
 /// [1]: https://developer.mozilla.org/en-US/docs/Web/CSS/object-fit
-#[derive(Debug, Hash, Clone, Copy, PartialEq, Eq)]
+#[derive(Debug, Hash, Clone, Copy, PartialEq, Eq, Default)]
 pub enum ContentFit {
     /// Scale as big as it can be without needing to crop or hide parts.
     ///
@@ -23,6 +25,7 @@ pub enum ContentFit {
     /// This is a great fit for when you need to display an image without losing
     /// any part of it, particularly when the image itself is the focus of the
     /// screen.
+    #[default]
     Contain,
 
     /// Scale the image to cover all of the bounding box, cropping if needed.
@@ -117,3 +120,15 @@ impl ContentFit {
         }
     }
 }
+
+impl fmt::Display for ContentFit {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.write_str(match self {
+            ContentFit::Contain => "Contain",
+            ContentFit::Cover => "Cover",
+            ContentFit::Fill => "Fill",
+            ContentFit::None => "None",
+            ContentFit::ScaleDown => "Scale Down",
+        })
+    }
+}

core/src/image.rs

@@ -1,7 +1,7 @@
 //! Load and draw raster graphics.
 pub use bytes::Bytes;
 
-use crate::{Rectangle, Size};
+use crate::{Radians, Rectangle, Size};
 
 use rustc_hash::FxHasher;
 use std::hash::{Hash, Hasher};
@@ -173,5 +173,6 @@ pub trait Renderer: crate::Renderer {
         handle: Self::Handle,
         filter_method: FilterMethod,
         bounds: Rectangle,
+        rotation: Radians,
     );
 }

core/src/lib.rs

@@ -39,6 +39,7 @@ mod padding;
 mod pixels;
 mod point;
 mod rectangle;
+mod rotation;
 mod shadow;
 mod shell;
 mod size;
@@ -64,6 +65,7 @@ pub use pixels::Pixels;
 pub use point::Point;
 pub use rectangle::Rectangle;
 pub use renderer::Renderer;
+pub use rotation::Rotation;
 pub use shadow::Shadow;
 pub use shell::Shell;
 pub use size::Size;

core/src/rectangle.rs

@@ -1,6 +1,6 @@
-use crate::{Point, Size, Vector};
+use crate::{Point, Radians, Size, Vector};
 
-/// A rectangle.
+/// An axis-aligned rectangle.
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
 pub struct Rectangle<T = f32> {
     /// X coordinate of the top-left corner.
@@ -172,6 +172,18 @@ impl Rectangle<f32> {
             height: self.height + amount * 2.0,
         }
     }
+
+    /// Rotates the [`Rectangle`] and returns the smallest [`Rectangle`]
+    /// containing it.
+    pub fn rotate(self, rotation: Radians) -> Self {
+        let size = self.size().rotate(rotation);
+        let position = Point::new(
+            self.center_x() - size.width / 2.0,
+            self.center_y() - size.height / 2.0,
+        );
+
+        Self::new(position, size)
+    }
 }
 
 impl std::ops::Mul<f32> for Rectangle<f32> {
@@ -227,3 +239,19 @@ where
         }
     }
 }
+
+impl<T> std::ops::Mul<Vector<T>> for Rectangle<T>
+where
+    T: std::ops::Mul<Output = T> + Copy,
+{
+    type Output = Rectangle<T>;
+
+    fn mul(self, scale: Vector<T>) -> Self {
+        Rectangle {
+            x: self.x * scale.x,
+            y: self.y * scale.y,
+            width: self.width * scale.x,
+            height: self.height * scale.y,
+        }
+    }
+}

core/src/renderer/null.rs

@@ -4,7 +4,8 @@ use crate::renderer::{self, Renderer};
 use crate::svg;
 use crate::text::{self, Text};
 use crate::{
-    Background, Color, Font, Pixels, Point, Rectangle, Size, Transformation,
+    Background, Color, Font, Pixels, Point, Radians, Rectangle, Size,
+    Transformation,
 };
 
 impl Renderer for () {
@@ -171,6 +172,7 @@ impl image::Renderer for () {
         _handle: Self::Handle,
         _filter_method: image::FilterMethod,
         _bounds: Rectangle,
+        _rotation: Radians,
     ) {
     }
 }
@@ -185,6 +187,7 @@ impl svg::Renderer for () {
         _handle: svg::Handle,
         _color: Option<Color>,
         _bounds: Rectangle,
+        _rotation: Radians,
     ) {
     }
 }

core/src/rotation.rs

@@ -0,0 +1,72 @@
+//! Control the rotation of some content (like an image) within a space.
+use crate::{Degrees, Radians, Size};
+
+/// The strategy used to rotate the content.
+///
+/// This is used to control the behavior of the layout when the content is rotated
+/// by a certain angle.
+#[derive(Debug, Clone, Copy, PartialEq)]
+pub enum Rotation {
+    /// The element will float while rotating. The layout will be kept exactly as it was
+    /// before the rotation.
+    ///
+    /// This is especially useful when used for animations, as it will avoid the
+    /// layout being shifted or resized when smoothly i.e. an icon.
+    ///
+    /// This is the default.
+    Floating(Radians),
+    /// The element will be solid while rotating. The layout will be adjusted to fit
+    /// the rotated content.
+    ///
+    /// This allows you to rotate an image and have the layout adjust to fit the new
+    /// size of the image.
+    Solid(Radians),
+}
+
+impl Rotation {
+    /// Returns the angle of the [`Rotation`] in [`Radians`].
+    pub fn radians(self) -> Radians {
+        match self {
+            Rotation::Floating(radians) | Rotation::Solid(radians) => radians,
+        }
+    }
+
+    /// Returns a mutable reference to the angle of the [`Rotation`] in [`Radians`].
+    pub fn radians_mut(&mut self) -> &mut Radians {
+        match self {
+            Rotation::Floating(radians) | Rotation::Solid(radians) => radians,
+        }
+    }
+
+    /// Returns the angle of the [`Rotation`] in [`Degrees`].
+    pub fn degrees(self) -> Degrees {
+        Degrees(self.radians().0.to_degrees())
+    }
+
+    /// Applies the [`Rotation`] to the given [`Size`], returning
+    /// the minimum [`Size`] containing the rotated one.
+    pub fn apply(self, size: Size) -> Size {
+        match self {
+            Self::Floating(_) => size,
+            Self::Solid(rotation) => size.rotate(rotation),
+        }
+    }
+}
+
+impl Default for Rotation {
+    fn default() -> Self {
+        Self::Floating(Radians(0.0))
+    }
+}
+
+impl From<Radians> for Rotation {
+    fn from(radians: Radians) -> Self {
+        Self::Floating(radians)
+    }
+}
+
+impl From<f32> for Rotation {
+    fn from(radians: f32) -> Self {
+        Self::Floating(Radians(radians))
+    }
+}

core/src/size.rs

@@ -1,4 +1,4 @@
-use crate::Vector;
+use crate::{Radians, Vector};
 
 /// An amount of space in 2 dimensions.
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Default)]
@@ -51,6 +51,19 @@ impl Size {
             height: self.height + other.height,
         }
     }
+
+    /// Rotates the given [`Size`] and returns the minimum [`Size`]
+    /// containing it.
+    pub fn rotate(self, rotation: Radians) -> Size {
+        let radians = f32::from(rotation);
+
+        Size {
+            width: (self.width * radians.cos()).abs()
+                + (self.height * radians.sin()).abs(),
+            height: (self.width * radians.sin()).abs()
+                + (self.height * radians.cos()).abs(),
+        }
+    }
 }
 
 impl<T> From<[T; 2]> for Size<T> {
@@ -113,3 +126,17 @@ where
         }
     }
 }
+
+impl<T> std::ops::Mul<Vector<T>> for Size<T>
+where
+    T: std::ops::Mul<Output = T> + Copy,
+{
+    type Output = Size<T>;
+
+    fn mul(self, scale: Vector<T>) -> Self::Output {
+        Size {
+            width: self.width * scale.x,
+            height: self.height * scale.y,
+        }
+    }
+}

core/src/svg.rs

@@ -1,5 +1,5 @@
 //! Load and draw vector graphics.
-use crate::{Color, Rectangle, Size};
+use crate::{Color, Radians, Rectangle, Size};
 
 use rustc_hash::FxHasher;
 use std::borrow::Cow;
@@ -100,5 +100,6 @@ pub trait Renderer: crate::Renderer {
         handle: Handle,
         color: Option<Color>,
         bounds: Rectangle,
+        rotation: Radians,
     );
 }