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use core::ops::{AddAssign, Mul, MulAssign, Sub}; use cast_trait::Cast; use num_traits::{One, Zero}; use vec2; #[inline] pub fn linear<'out, T, F>( out: &'out mut [T; 2], p0: &[T; 2], p1: &[T; 2], t: &F, ) -> &'out mut [T; 2] where T: Clone + Cast<F>, for<'a> T: AddAssign<&'a T>, for<'a, 'b> &'a T: Sub<&'b T, Output = T>, F: Clone + One + Zero + PartialOrd + Cast<T> + Sub<F, Output = F> + Mul<F, Output = F>, for<'a> F: MulAssign<&'a F>, for<'a, 'b> &'a F: Sub<&'b F, Output = F> + Mul<&'b F, Output = F>, { if t <= &F::zero() { *out = p0.clone(); out } else if t >= &F::one() { *out = p1.clone(); out } else { vec2::lerp::<T, F>(out, p0, p1, t) } } #[test] fn test_linear() { assert_eq!(linear(&mut [0, 0], &[0, 0], &[200, 0], &0.25), &[50, 0]); assert_eq!(linear(&mut [0, 0], &[0, 0], &[200, 0], &0.5), &[100, 0]); assert_eq!(linear(&mut [0, 0], &[0, 0], &[200, 0], &0.75), &[150, 0]); }