c++ - 如何通过在 for 循环中旋转方向来获取采样点？

Question

我需要遍历给定数量的采样点。这些采样点是表示方向的归一化向量。它们应该在代码中计算出来。从正向向量开始1, 0，我想围绕原点旋转，以便得出给定数量的方向。

for(int i = 0; i < number_of_sampling_points; ++i)
{
    // get direction vector based on i and number_of_sampling_points
    // ...
}

例如， with number_of_sampling_pointsis4在循环内，我想获取值对1, 0, 0, 1, -1, 0, 0, -1。顺序无关紧要。

Answer 1

尝试这个：

const double PI = 3.14159265358979323846;
const int number_of_sampling_points = 4;
for (int i = 0; i < number_of_sampling_points; ++i)
{
    const double a = PI * 2 * (1.0 - i) / number_of_sampling_points;

    double x = sin(a);
    double y = cos(a);

    cout << "(" << x << " , " << y << ")" << endl;
}

输出（四舍五入）：

(1 , 0)
(0 , 1)
(-1 , 0)
(0 , -1)

Answer 2

使用触发：

double x = std::cos(pi * 2 * (double)i / (double)number_of_sampling_points);
double y = std::sin(pi * 2 * (double)i / (double)number_of_sampling_points);