Function reflect_index

src/framework/audio/chunking.cpp:21–34

        throw std::runtime_error(std::string("Audio chunker requires positive ") + name);
    }
}

int64_t reflect_index(int64_t index, int64_t length) {
    require_positive(length, "reflect length");
    if (length == 1) {
        return 0;
    }
    while (index < 0 || index >= length) {
        if (index < 0) {
            index = -index;
        } else {
            index = 2 * length - index - 2;
        }
    }
    return index;
}