Mathf.Sin

参数

返回

float 介于 -1 与 +1 之间的返回值。

描述

返回角度 f 的正弦。

Note: If using very large numbers with this function, there is an acceptable range for input angle values for this method, beyond which the calculation will fail. On windows, the acceptable range is approximately between -9223372036854775295 to 9223372036854775295. This range may differ on other platforms. For values outside of the acceptable range, the Sin method returns the input value, rather than throwing an exception.

using UnityEngine;
using System.Collections;


public class PolyDrawExample : MonoBehaviour
{
    public int numberOfSides;
    public float polygonRadius;
    public Vector2 polygonCenter;


    void Update()
    {
        DebugDrawPolygon(polygonCenter, polygonRadius, numberOfSides);
    }

    // Draw a polygon in the XY plane with a specfied position, number of sides
    // and radius.
    void DebugDrawPolygon(Vector2 center, float radius, int numSides)
    {
        // The corner that is used to start the polygon (parallel to the X axis).
        Vector2 startCorner = new Vector2(radius, 0) + polygonCenter;

        // The "previous" corner point, initialised to the starting corner.
        Vector2 previousCorner = startCorner;

        // For each corner after the starting corner...
        for (int i = 1; i < numSides; i++)
        {
            // Calculate the angle of the corner in radians.
            float cornerAngle = 2f * Mathf.PI / (float)numSides * i;

            // Get the X and Y coordinates of the corner point.
            Vector2 currentCorner = new Vector2(Mathf.Cos(cornerAngle) * radius, Mathf.Sin(cornerAngle) * radius) + polygonCenter;

            // Draw a side of the polygon by connecting the current corner to the previous one.
            Debug.DrawLine(currentCorner, previousCorner);

            // Having used the current corner, it now becomes the previous corner.
            previousCorner = currentCorner;
        }

        // Draw the final side by connecting the last corner to the starting corner.
        Debug.DrawLine(startCorner, previousCorner);
    }
}