Function sin_reduce_

src/fl/math/math.cpp.hpp:184–199

template <typename F>
inline F sin_reduce_(F x) FL_NOEXCEPT {
    const F kPi      = F(3.14159265358979323846);
    const F kTwoPi   = F(6.28318530717958647692);
    const F kPiHalf  = F(1.57079632679489661923);
    // Reduce to [-π, π]: subtract floor(x / 2π) * 2π.
    // For the FastLED use cases we expect |x| < ~100, so this loop runs a
    // bounded number of times. For pathological inputs we cap iterations.
    int guard = 32;
    while (x > kPi && guard > 0) { x -= kTwoPi; --guard; }
    while (x < -kPi && guard > 0) { x += kTwoPi; --guard; }
    // Map to [-π/2, π/2] using sin(π - x) = sin(x).
    if (x > kPiHalf)  x = kPi - x;
    if (x < -kPiHalf) x = -kPi - x;
    // [-π/2, π/2] -- the polynomial works fine here (max |x| ≈ 1.57).
    return sin_poly_quarterturn_(x);
}

template <typename F>
inline F cos_reduce_(F x) FL_NOEXCEPT {