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use crate::NearlyEqual;
#[derive(Copy, Clone, Debug, PartialEq)]
#[repr(C)]
pub struct Vector2 {
pub x: f32,
pub y: f32,
}
#[derive(Copy, Clone, Debug, PartialEq)]
#[repr(C)]
pub struct Vector3 {
pub x: f32,
pub y: f32,
pub z: f32,
}
#[derive(Copy, Clone, Debug, PartialEq)]
#[repr(C)]
pub struct Point {
pub x: f32,
pub y: f32,
pub z: f32,
}
#[derive(Copy, Clone, Debug, PartialEq)]
#[repr(C)]
pub struct Vector4 {
pub x: f32,
pub y: f32,
pub z: f32,
pub w: f32,
}
macro_rules! implement_operator {
(impl $Op:ident<$S:ident> for $T:ident {
fn $op:ident($x:ident, $s:ident) -> $Output:ty $body:block
}) => {
impl std::ops::$Op<$S> for $T {
type Output = $Output;
fn $op($x, $s: $S) -> Self::Output $body
}
};
(impl $Op:ident<$S:ident> for $T:ident {
fn $op:ident(&mut $x:ident, $s:ident) $body:block
}) => {
impl std::ops::$Op<$S> for $T {
fn $op(&mut $x, $s: $S) $body
}
};
}
macro_rules! implement_vector {
($VectorT:ident { $($field:ident),+ }) => {
impl $VectorT {
pub const fn new($($field: f32),+) -> Self {
Self { $($field),+ }
}
pub const fn from_scalar(s: f32) -> Self {
Self { $($field: s),+ }
}
pub const fn zero() -> Self {
Self { $($field: 0.0),+ }
}
pub const fn one() -> Self {
Self { $($field: 1.0),+ }
}
pub fn dot(&self, rhs: Self) -> f32 {
[$(self.$field * rhs.$field),+].iter().sum()
}
pub fn lerp(&self, rhs: Self, factor: f32) -> Self {
let t = factor.min(1.0).max(0.0);
Self::new($(self.$field * (1.0 - t) + rhs.$field * t),+)
}
pub fn min(&self, rhs: Self) -> Self {
Self::new($(self.$field.min(rhs.$field)),+)
}
pub fn max(&self, rhs: Self) -> Self {
Self::new($(self.$field.max(rhs.$field)),+)
}
pub fn magnitude_squared(&self) -> f32 {
self.dot(*self)
}
pub fn magnitude(&self) -> f32 {
self.magnitude_squared().sqrt()
}
pub fn normalized(&self) -> Self {
let d = self.magnitude();
if d > 0.0 {
let d = 1.0 / d;
*self * d
} else {
*self
}
}
pub fn as_slice(&self) -> &[f32] {
unsafe { std::slice::from_raw_parts(&self.x, std::mem::size_of::<Self>() / std::mem::size_of::<f32>()) }
}
}
impl std::ops::Neg for $VectorT {
type Output = $VectorT;
fn neg(self) -> $VectorT { $VectorT::new($(-self.$field),+) }
}
implement_operator!(impl Add<f32> for $VectorT {
fn add(self, t) -> $VectorT { $VectorT::new($(self.$field + t),+) }
});
implement_operator!(impl Sub<f32> for $VectorT {
fn sub(self, t) -> $VectorT { $VectorT::new($(self.$field - t),+) }
});
implement_operator!(impl Mul<f32> for $VectorT {
fn mul(self, t) -> $VectorT { $VectorT::new($(self.$field * t),+) }
});
implement_operator!(impl Div<f32> for $VectorT {
fn div(self, t) -> $VectorT { $VectorT::new($(self.$field / t),+) }
});
implement_operator!(impl AddAssign<f32> for $VectorT {
fn add_assign(&mut self, t) { $(self.$field += t);+ }
});
implement_operator!(impl SubAssign<f32> for $VectorT {
fn sub_assign(&mut self, t) { $(self.$field -= t);+ }
});
implement_operator!(impl MulAssign<f32> for $VectorT {
fn mul_assign(&mut self, t) { $(self.$field *= t);+ }
});
implement_operator!(impl DivAssign<f32> for $VectorT {
fn div_assign(&mut self, t) { $(self.$field /= t);+ }
});
implement_operator!(impl Mul<$VectorT> for f32 {
fn mul(self, t) -> $VectorT { $VectorT::new($(self * t.$field),+) }
});
implement_operator!(impl Div<$VectorT> for f32 {
fn div(self, t) -> $VectorT { $VectorT::new($(self / t.$field),+) }
});
impl std::ops::Index<usize> for $VectorT {
type Output = f32;
fn index(&self, i: usize) -> &f32 {
[$(&self.$field),+][i]
}
}
impl std::ops::IndexMut<usize> for $VectorT {
fn index_mut(&mut self, i: usize) -> &mut f32 {
[$(&mut self.$field),+][i]
}
}
impl NearlyEqual for &$VectorT {
fn nearly_equals(self, rhs: Self) -> bool {
$(self.$field.nearly_equals(rhs.$field))&&+
}
}
}
}
implement_vector!(Vector2 { x, y });
implement_vector!(Vector3 { x, y, z });
implement_vector!(Point { x, y, z });
implement_vector!(Vector4 { x, y, z, w });
impl Vector2 {
pub fn cross(&self, rhs: Self) -> f32 {
self.x * rhs.y - self.y * rhs.x
}
}
impl Vector3 {
pub fn cross(&self, rhs: Self) -> Self {
Self {
x: self.y * rhs.z - self.z * rhs.y,
y: self.z * rhs.x - self.x * rhs.z,
z: self.x * rhs.y - self.y * rhs.x,
}
}
}
impl From<Point> for Vector3 {
fn from(p: Point) -> Self {
Vector3 {
x: p.x,
y: p.y,
z: p.z,
}
}
}
impl From<Vector4> for Vector3 {
fn from(v: Vector4) -> Self {
Vector3 {
x: v.x,
y: v.y,
z: v.z,
}
}
}
impl From<Vector3> for Point {
fn from(v: Vector3) -> Self {
Point {
x: v.x,
y: v.y,
z: v.z,
}
}
}
impl From<Vector4> for Point {
fn from(v: Vector4) -> Self {
Point {
x: v.x,
y: v.y,
z: v.z,
}
}
}
impl From<Vector3> for Vector4 {
fn from(v: Vector3) -> Self {
Vector4 {
x: v.x,
y: v.y,
z: v.z,
w: 0.0,
}
}
}
impl From<Point> for Vector4 {
fn from(p: Point) -> Self {
Vector4 {
x: p.x,
y: p.y,
z: p.z,
w: 1.0,
}
}
}
#[cfg(test)]
mod tests {
use crate::*;
#[test]
fn products() {
let a = Vector3::new(3.0, -5.0, 4.0);
let b = Vector3::new(2.0, 6.0, 5.0);
assert!(a.dot(b).nearly_equals(-4.0));
assert_eq!(a.cross(b), Vector3::new(-49.0, -7.0, 28.0));
}
#[test]
fn lerp() {
let a = Vector3::new(1.0, 0.0, 0.0);
let b = Vector3::new(0.0, 1.0, 0.0);
assert_eq!(a.lerp(b, 0.75), Vector3::new(0.25, 0.75, 0.0));
}
#[test]
fn slice() {
let a = Vector3::new(1.0, 2.0, 3.0);
assert_eq!(a.as_slice(), &[1.0, 2.0, 3.0]);
}
}