计算圆中点的位置

Question

目前我对此有一点空白.我有一个问题,我需要计算中心点周围点的位置,假设它们距离中心和彼此都是等距的.

点的数量是可变的,所以DrawCirclePoints(int x) 我确信这是一个简单的解决方案,但对于我的生活,我只是看不到它:)

Answer 1

给定半径长度r和弧度角度t以及圆心(h,k),您可以如下计算圆周上点的坐标(这是伪代码,您必须将其调整为您的语言):

float x = r*cos(t) + h;
float y = r*sin(t) + k;

Answer 2

圆心的角度θ为圆心,圆心(x0,y0)的半径r为(x0 + r cos theta, y0 + r sin theta).现在选择theta均匀分布在0到2pi之间的值.

Answer 3

这是使用C#的解决方案:

void DrawCirclePoints(int points, double radius, Point center)
{
    double slice = 2 * Math.PI / points;
    for (int i = 0; i < points; i++)
    {
        double angle = slice * i;
        int newX = (int)(center.X + radius * Math.Cos(angle));
        int newY = (int)(center.Y + radius * Math.Sin(angle));
        Point p = new Point(newX, newY);
        Console.WriteLine(p);
    }
}

样本输出来自DrawCirclePoints(8, 10, new Point(0,0));:

{X=10,Y=0}
{X=7,Y=7}
{X=0,Y=10}
{X=-7,Y=7}
{X=-10,Y=0}
{X=-7,Y=-7}
{X=0,Y=-10}
{X=7,Y=-7}

祝好运!

Answer 4

使用上述答案之一作为基础,这是Java/Android示例:

protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);

    RectF bounds = new RectF(canvas.getClipBounds());
    float centerX = bounds.centerX();
    float centerY = bounds.centerY();

    float angleDeg = 90f;
    float radius = 20f

    float xPos = radius * (float)Math.cos(Math.toRadians(angleDeg)) + centerX;
    float yPos = radius * (float)Math.sin(Math.toRadians(angleDeg)) + centerY;

    //draw my point at xPos/yPos
}

Answer 5

在圆形路径中放置一个数字

// variable

let number = 12; // how many number to be placed
let size = 260; // size of circle i.e. w = h = 260
let cx= size/2; // center of x(in a circle)
let cy = size/2; // center of y(in a circle)
let r = size/2; // radius of a circle

for(let i=1; i<=number; i++) {
  let ang = i*(Math.PI/(number/2));
  let left = cx + (r*Math.cos(ang));
  let top = cy + (r*Math.sin(ang));
  console.log("top: ", top, ", left: ", left);
}