Added basic physics lib

src/physics/body.rs

@@ -0,0 +1,48 @@
+use crate::physics::PhysVec;
+use std::f64::consts::{PI, TAU};
+
+pub struct PhysBody {
+	pub pos: PhysVec,
+	pub vel: PhysVec,
+	pub mass: f64,
+	pub angle: f64, // In radians
+}
+
+impl PhysBody {
+	pub fn new() -> Self {
+		return PhysBody {
+			pos: PhysVec { x: 200.0, y: 200.0 },
+			vel: PhysVec::zero(),
+			mass: 1.0,
+			angle: 0.0,
+		};
+	}
+
+	/// Calculate the state of this body after t seconds.
+	pub fn tick(&mut self, t: f64) {
+		self.pos += self.vel * t;
+	}
+
+	/// Apply an instantaneous force to this object
+	pub fn force(&mut self, v: PhysVec) {
+		self.vel += v / self.mass;
+	}
+
+	/// Apply force in the direction this object is pointing.
+	pub fn thrust(&mut self, f: f64) {
+		self.force(
+			PhysVec {
+				x: self.angle.sin(),
+				y: -self.angle.cos(),
+			} * f,
+		);
+	}
+
+	// Rotate this object by `a` radians.
+	pub fn rot(&mut self, a: f64) {
+		self.angle -= a;
+		if self.angle.abs() > PI {
+			self.angle -= self.angle.signum() * TAU;
+		}
+	}
+}

src/physics/mod.rs

@@ -0,0 +1,5 @@
+mod body;
+mod physvec;
+
+pub use body::PhysBody;
+pub use physvec::PhysVec;

src/physics/physvec.rs

@@ -0,0 +1,92 @@
+use std::ops::{Add, AddAssign, Div, DivAssign, Mul, MulAssign, Sub, SubAssign};
+
+#[derive(Debug, Clone, Copy)]
+pub struct PhysVec {
+	pub x: f64,
+	pub y: f64,
+}
+
+impl PhysVec {
+	pub fn zero() -> Self {
+		return PhysVec { x: 0f64, y: 0f64 };
+	}
+}
+
+impl From<(u32, u32)> for PhysVec {
+	fn from(value: (u32, u32)) -> Self {
+		PhysVec {
+			x: value.0 as f64,
+			y: value.1 as f64,
+		}
+	}
+}
+
+impl Add for PhysVec {
+	type Output = Self;
+
+	fn add(self, other: Self) -> Self {
+		Self {
+			x: self.x + other.x,
+			y: self.y + other.y,
+		}
+	}
+}
+
+impl AddAssign for PhysVec {
+	fn add_assign(&mut self, rhs: Self) {
+		self.x += rhs.x;
+		self.y += rhs.y;
+	}
+}
+
+impl Sub for PhysVec {
+	type Output = Self;
+
+	fn sub(self, other: Self) -> Self {
+		Self {
+			x: self.x - other.x,
+			y: self.y - other.y,
+		}
+	}
+}
+
+impl SubAssign for PhysVec {
+	fn sub_assign(&mut self, rhs: Self) {
+		self.x += rhs.x;
+		self.y += rhs.y;
+	}
+}
+
+impl Mul<f64> for PhysVec {
+	type Output = PhysVec;
+	fn mul(self, rhs: f64) -> Self::Output {
+		Self {
+			x: self.x * rhs,
+			y: self.y * rhs,
+		}
+	}
+}
+
+impl MulAssign<f64> for PhysVec {
+	fn mul_assign(&mut self, rhs: f64) {
+		self.x *= rhs;
+		self.y *= rhs;
+	}
+}
+
+impl Div<f64> for PhysVec {
+	type Output = PhysVec;
+	fn div(self, rhs: f64) -> Self::Output {
+		Self {
+			x: self.x / rhs,
+			y: self.y / rhs,
+		}
+	}
+}
+
+impl DivAssign<f64> for PhysVec {
+	fn div_assign(&mut self, rhs: f64) {
+		self.x /= rhs;
+		self.y /= rhs;
+	}
+}