Move egui/math into new crate emath

emath/src/vec2.rs

@@ -0,0 +1,237 @@
+use std::ops::{Add, AddAssign, Div, Mul, MulAssign, Neg, RangeInclusive, Sub, SubAssign};
+
+use crate::*;
+
+/// A vector has a direction and length.
+/// A [`Vec2`] is often used to represent a size.
+///
+/// Egui represents positions using [`Pos2`].
+///
+/// Normally the units are points (logical pixels).
+#[derive(Clone, Copy, Default)]
+#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
+pub struct Vec2 {
+    pub x: f32,
+    pub y: f32,
+}
+
+/// `vec2(x,y) == Vec2::new(x, y)`
+#[inline(always)]
+pub const fn vec2(x: f32, y: f32) -> Vec2 {
+    Vec2 { x, y }
+}
+
+impl From<[f32; 2]> for Vec2 {
+    fn from(v: [f32; 2]) -> Self {
+        Self { x: v[0], y: v[1] }
+    }
+}
+
+impl From<&[f32; 2]> for Vec2 {
+    fn from(v: &[f32; 2]) -> Self {
+        Self { x: v[0], y: v[1] }
+    }
+}
+
+impl Vec2 {
+    pub const X: Vec2 = Vec2 { x: 1.0, y: 0.0 };
+    pub const Y: Vec2 = Vec2 { x: 0.0, y: 1.0 };
+
+    pub fn zero() -> Self {
+        Self { x: 0.0, y: 0.0 }
+    }
+
+    pub fn infinity() -> Self {
+        Self {
+            x: f32::INFINITY,
+            y: f32::INFINITY,
+        }
+    }
+
+    pub fn new(x: f32, y: f32) -> Self {
+        Self { x, y }
+    }
+
+    pub fn splat(v: impl Into<f32>) -> Self {
+        let v: f32 = v.into();
+        Self { x: v, y: v }
+    }
+
+    #[must_use]
+    pub fn normalized(self) -> Self {
+        let len = self.length();
+        if len <= 0.0 {
+            self
+        } else {
+            self / len
+        }
+    }
+
+    /// Rotates the vector by 90°, i.e positive X to positive Y
+    /// (clockwise in Egui coordinates).
+    #[inline(always)]
+    pub fn rot90(self) -> Self {
+        vec2(self.y, -self.x)
+    }
+
+    pub fn length(self) -> f32 {
+        self.x.hypot(self.y)
+    }
+
+    pub fn length_sq(self) -> f32 {
+        self.x * self.x + self.y * self.y
+    }
+
+    /// Create a unit vector with the given angle (in radians).
+    /// * An angle of zero gives the unit X axis.
+    /// * An angle of 𝞃/4 = 90° gives the unit Y axis.
+    pub fn angled(angle: f32) -> Self {
+        vec2(angle.cos(), angle.sin())
+    }
+
+    #[must_use]
+    pub fn floor(self) -> Self {
+        vec2(self.x.floor(), self.y.floor())
+    }
+
+    #[must_use]
+    pub fn round(self) -> Self {
+        vec2(self.x.round(), self.y.round())
+    }
+
+    #[must_use]
+    pub fn ceil(self) -> Self {
+        vec2(self.x.ceil(), self.y.ceil())
+    }
+
+    /// True if all members are also finite.
+    pub fn is_finite(self) -> bool {
+        self.x.is_finite() && self.y.is_finite()
+    }
+
+    #[must_use]
+    pub fn min(self, other: Self) -> Self {
+        vec2(self.x.min(other.x), self.y.min(other.y))
+    }
+
+    #[must_use]
+    pub fn max(self, other: Self) -> Self {
+        vec2(self.x.max(other.x), self.y.max(other.y))
+    }
+
+    /// Returns the minimum of `self.x` and `self.y`.
+    #[must_use]
+    pub fn min_elem(self) -> f32 {
+        self.x.min(self.y)
+    }
+
+    /// Returns the maximum of `self.x` and `self.y`.
+    #[must_use]
+    pub fn max_elem(self) -> f32 {
+        self.x.max(self.y)
+    }
+
+    #[must_use]
+    pub fn clamp(self, range: RangeInclusive<Self>) -> Self {
+        Self {
+            x: clamp(self.x, range.start().x..=range.end().x),
+            y: clamp(self.y, range.start().y..=range.end().y),
+        }
+    }
+}
+
+impl PartialEq for Vec2 {
+    fn eq(&self, other: &Self) -> bool {
+        self.x == other.x && self.y == other.y
+    }
+}
+impl Eq for Vec2 {}
+
+impl Neg for Vec2 {
+    type Output = Vec2;
+
+    fn neg(self) -> Vec2 {
+        vec2(-self.x, -self.y)
+    }
+}
+
+impl AddAssign for Vec2 {
+    fn add_assign(&mut self, rhs: Vec2) {
+        *self = Vec2 {
+            x: self.x + rhs.x,
+            y: self.y + rhs.y,
+        };
+    }
+}
+
+impl SubAssign for Vec2 {
+    fn sub_assign(&mut self, rhs: Vec2) {
+        *self = Vec2 {
+            x: self.x - rhs.x,
+            y: self.y - rhs.y,
+        };
+    }
+}
+
+impl Add for Vec2 {
+    type Output = Vec2;
+    fn add(self, rhs: Vec2) -> Vec2 {
+        Vec2 {
+            x: self.x + rhs.x,
+            y: self.y + rhs.y,
+        }
+    }
+}
+
+impl Sub for Vec2 {
+    type Output = Vec2;
+    fn sub(self, rhs: Vec2) -> Vec2 {
+        Vec2 {
+            x: self.x - rhs.x,
+            y: self.y - rhs.y,
+        }
+    }
+}
+
+impl MulAssign<f32> for Vec2 {
+    fn mul_assign(&mut self, rhs: f32) {
+        self.x *= rhs;
+        self.y *= rhs;
+    }
+}
+
+impl Mul<f32> for Vec2 {
+    type Output = Vec2;
+    fn mul(self, factor: f32) -> Vec2 {
+        Vec2 {
+            x: self.x * factor,
+            y: self.y * factor,
+        }
+    }
+}
+
+impl Mul<Vec2> for f32 {
+    type Output = Vec2;
+    fn mul(self, vec: Vec2) -> Vec2 {
+        Vec2 {
+            x: self * vec.x,
+            y: self * vec.y,
+        }
+    }
+}
+
+impl Div<f32> for Vec2 {
+    type Output = Vec2;
+    fn div(self, factor: f32) -> Vec2 {
+        Vec2 {
+            x: self.x / factor,
+            y: self.y / factor,
+        }
+    }
+}
+
+impl std::fmt::Debug for Vec2 {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "[{:.1} {:.1}]", self.x, self.y)
+    }
+}