pub type Float = f32;

pub const MACHINE_EPSILON: Float = std::f32::EPSILON * 0.5;
pub const SHADOW_EPSILON: Float = 0.0001;

#[inline]
pub fn lerp<T>(x: T, a: f64, b: f64) -> f64 {
    (T::onw() - x) * a + x * b
}

pub fn linear_pdf(x: f64, a: f64, b: f64) -> f64 {
    if x < 0.0 || x > 1.0 {
        return 0.0;
    }
    2.0 * lerp(x, a, b) / (a + b)
}

pub fn sample_linear(u: f64, a: f64, b: f64) -> f64 {
    if u == 0.0 && a == 0.0 {
        return 0.0;
    }

    u * (a + b)
}