Move egui/math into new crate emath

emath/src/pos2.rs

@@ -0,0 +1,153 @@
+use std::ops::{Add, AddAssign, RangeInclusive, Sub, SubAssign};
+
+use crate::*;
+
+/// A position on screen.
+///
+/// Normally given in points (logical pixels).
+///
+/// Mathematically this is known as a "point", but the term position was chosen so not to
+/// conflict with the unit (one point = X physical pixels).
+#[derive(Clone, Copy, Default)]
+#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
+pub struct Pos2 {
+    pub x: f32,
+    pub y: f32,
+    // implicit w = 1
+}
+
+/// `pos2(x,y) == Pos2::new(x, y)`
+#[inline(always)]
+pub const fn pos2(x: f32, y: f32) -> Pos2 {
+    Pos2 { x, y }
+}
+
+impl From<[f32; 2]> for Pos2 {
+    fn from(v: [f32; 2]) -> Self {
+        Self { x: v[0], y: v[1] }
+    }
+}
+
+impl From<&[f32; 2]> for Pos2 {
+    fn from(v: &[f32; 2]) -> Self {
+        Self { x: v[0], y: v[1] }
+    }
+}
+
+impl Pos2 {
+    pub const fn new(x: f32, y: f32) -> Self {
+        Self { x, y }
+    }
+
+    /// The vector from origin to this position.
+    /// `p.to_vec2()` is equivalent to `p - Pos2::default()`.
+    pub fn to_vec2(self) -> Vec2 {
+        Vec2 {
+            x: self.x,
+            y: self.y,
+        }
+    }
+
+    pub fn distance(self, other: Self) -> f32 {
+        (self - other).length()
+    }
+
+    pub fn distance_sq(self, other: Self) -> f32 {
+        (self - other).length_sq()
+    }
+
+    pub fn floor(self) -> Self {
+        pos2(self.x.floor(), self.y.floor())
+    }
+
+    pub fn round(self) -> Self {
+        pos2(self.x.round(), self.y.round())
+    }
+
+    pub fn ceil(self) -> Self {
+        pos2(self.x.ceil(), self.y.ceil())
+    }
+
+    pub fn is_finite(self) -> bool {
+        self.x.is_finite() && self.y.is_finite()
+    }
+
+    #[must_use]
+    pub fn min(self, other: Self) -> Self {
+        pos2(self.x.min(other.x), self.y.min(other.y))
+    }
+
+    #[must_use]
+    pub fn max(self, other: Self) -> Self {
+        pos2(self.x.max(other.x), self.y.max(other.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 Pos2 {
+    fn eq(&self, other: &Self) -> bool {
+        self.x == other.x && self.y == other.y
+    }
+}
+impl Eq for Pos2 {}
+
+impl AddAssign<Vec2> for Pos2 {
+    fn add_assign(&mut self, rhs: Vec2) {
+        *self = Pos2 {
+            x: self.x + rhs.x,
+            y: self.y + rhs.y,
+        };
+    }
+}
+
+impl SubAssign<Vec2> for Pos2 {
+    fn sub_assign(&mut self, rhs: Vec2) {
+        *self = Pos2 {
+            x: self.x - rhs.x,
+            y: self.y - rhs.y,
+        };
+    }
+}
+
+impl Add<Vec2> for Pos2 {
+    type Output = Pos2;
+    fn add(self, rhs: Vec2) -> Pos2 {
+        Pos2 {
+            x: self.x + rhs.x,
+            y: self.y + rhs.y,
+        }
+    }
+}
+
+impl Sub for Pos2 {
+    type Output = Vec2;
+    fn sub(self, rhs: Pos2) -> Vec2 {
+        Vec2 {
+            x: self.x - rhs.x,
+            y: self.y - rhs.y,
+        }
+    }
+}
+
+impl Sub<Vec2> for Pos2 {
+    type Output = Pos2;
+    fn sub(self, rhs: Vec2) -> Pos2 {
+        Pos2 {
+            x: self.x - rhs.x,
+            y: self.y - rhs.y,
+        }
+    }
+}
+
+impl std::fmt::Debug for Pos2 {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "[{:.1} {:.1}]", self.x, self.y)
+    }
+}