Trait Curve

Source

pub trait Curve {
    type Value;
    type Velocity;

    // Required methods
    fn approximate(
        &self,
        time: f32,
    ) -> Approximation<Self::Value, Self::Velocity>;
    fn target(&self) -> Self::Value;
}

Expand description

Curves provide the mathematical foundation for animation.

Within Yoyo, we restrict curves to those with a closed-form approximation / analytical solution and similarly, a closed-form derivative that we can use to compute velocity. Typically, especially for springs, animation frameworks use numerical integrations, like RK4. We want closed-form solutions because they let us pause and resume animations at arbitrary time steps.