Method atan

src/fl/math/fixed_point.h:405–407

    // Arctangent: atan(1.0) ≈ π/4 ≈ 0.785
    static FASTLED_FORCE_INLINE fixed_point atan(fixed_point x) FL_NOEXCEPT {
        return from_raw(Base::atan(x).raw());
    }

    // Two-argument arctangent: atan2(y, x) returns angle in [-π, π].
    //   FP::atan2(FP(1.0f), FP(1.0f))  // ≈ π/4 ≈ 0.785