sphere.py 文件源码

 复制代码def advance_wrap(self, steps):
        assert self.is_valid()
        if steps == 0:
            return self

        step_shift = 2 * (self.__class__.MAX_LEVEL - self.level()) + 1
        if steps < 0:
            min_steps = -(self.id() >> step_shift)
            if steps < min_steps:
                step_wrap = self.__class__.WRAP_OFFSET >> step_shift
                # cannot use steps %= step_wrap as Python % different to C++
                steps = int(math.fmod(steps, step_wrap))
                if steps < min_steps:
                    steps += step_wrap
        else:
            max_steps = (self.__class__.WRAP_OFFSET - self.id()) >> step_shift
            if steps > max_steps:
                step_wrap = self.__class__.WRAP_OFFSET >> step_shift
                # cannot use steps %= step_wrap as Python % different to C++
                steps = int(math.fmod(steps, step_wrap))
                if steps > max_steps:
                    steps -= step_wrap

        return self.__class__(self.id() + (steps << step_shift))