#include "twiddle_builder.hpp"
#include <cmath>
#include <cstring>

namespace twiddle {

double* build_twiddle(uint32_t log2N, double* dst) {
    uint32_t N = 1U << log2N;
    uint32_t N_quarter = N / 4;
    
    if (log2N < 11) {
        uint32_t stride = 1U << (10 - log2N);
        for (uint32_t k = 0; k < N_quarter; k++) {
            dst[k] = phase_table[k * stride];
        }
    } else {
        double angle_step = (2.0 * M_PI) / N;
        for (uint32_t k = 0; k < N_quarter; k++) {
            dst[k] = k * angle_step;
        }
    }
    
    dst[N_quarter] = 1.0;
    
    uint8_t* p = reinterpret_cast<uint8_t*>(dst);
    uintptr_t aligned = (reinterpret_cast<uintptr_t>(p + N * 8 + 0x3f) & ~0x3f);
    return reinterpret_cast<double*>(aligned);
}

}