Simplify image rotation API and its internals

Author: hecrj

core/src/angle.rs

@@ -65,6 +65,12 @@ 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)

core/src/content_fit.rs

@@ -11,7 +11,7 @@ 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 +23,7 @@ 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.

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};
@@ -173,7 +173,6 @@ pub trait Renderer: crate::Renderer {
         handle: Self::Handle,
         filter_method: FilterMethod,
         bounds: Rectangle,
-        rotation: f32,
-        scale: Size,
+        rotation: Radians,
     );
 }

core/src/lib.rs

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

core/src/rectangle.rs

@@ -227,3 +227,19 @@ 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 () {
@@ -171,8 +172,7 @@ impl image::Renderer for () {
         _handle: Self::Handle,
         _filter_method: image::FilterMethod,
         _bounds: Rectangle,
-        _rotation: f32,
-        _scale: Size,
+        _rotation: Radians,
     ) {
     }
 }
@@ -187,8 +187,7 @@ impl svg::Renderer for () {
         _handle: svg::Handle,
         _color: Option<Color>,
         _bounds: Rectangle,
-        _rotation: f32,
-        _scale: Size,
+        _rotation: Radians,
     ) {
     }
 }

core/src/rotation.rs

@@ -1,37 +1,68 @@
-//! Control the rotation of some content (like an image) with the `RotationLayout` within a
-//! space.
-use crate::Size;
+//! Control the rotation of some content (like an image) within a space.
+use crate::{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, Hash, Clone, Copy, PartialEq, Eq)]
-pub enum RotationLayout {
-    /// The layout is kept exactly as it was before the rotation.
+#[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.
-    Keep,
-    /// The layout is adjusted to fit the rotated content.
+    ///
+    /// 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.
-    Change,
+    Solid(Radians),
 }
 
-impl RotationLayout {
-    /// Applies the rotation to the layout while respecting the [`RotationLayout`] strategy.
-    /// The rotation is given in radians.
-    pub fn apply_to_size(&self, size: Size, rotation: f32) -> Size {
+impl Rotation {
+    /// Returns the angle of the [`Rotation`] in [`Radians`].
+    pub fn radians(self) -> Radians {
+        match self {
+            Rotation::Floating(radians) | Rotation::Solid(radians) => radians,
+        }
+    }
+
+    /// Rotates the given [`Size`].
+    pub fn apply(self, size: Size) -> Size {
         match self {
-            Self::Keep => size,
-            Self::Change => Size {
-                width: (size.width * rotation.cos()).abs()
-                    + (size.height * rotation.sin()).abs(),
-                height: (size.width * rotation.sin()).abs()
-                    + (size.height * rotation.cos()).abs(),
-            },
+            Self::Floating(_) => size,
+            Self::Solid(rotation) => {
+                let radians = f32::from(rotation);
+
+                Size {
+                    width: (size.width * radians.cos()).abs()
+                        + (size.height * radians.sin()).abs(),
+                    height: (size.width * radians.sin()).abs()
+                        + (size.height * radians.cos()).abs(),
+                }
+            }
         }
     }
 }
+
+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

@@ -113,3 +113,17 @@ 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;
@@ -100,7 +100,6 @@ pub trait Renderer: crate::Renderer {
         handle: Handle,
         color: Option<Color>,
         bounds: Rectangle,
-        rotation: f32,
-        scale: Size,
+        rotation: Radians,
     );
 }

core/src/vector.rs

@@ -18,6 +18,9 @@ impl<T> Vector<T> {
 impl Vector {
     /// The zero [`Vector`].
     pub const ZERO: Self = Self::new(0.0, 0.0);
+
+    /// The unit [`Vector`].
+    pub const UNIT: Self = Self::new(0.0, 0.0);
 }
 
 impl<T> std::ops::Add for Vector<T>