f | 输入角度(以弧度为单位)。 |
float 介于 -1 与 1 之间的返回值。
返回角度 f
的余弦。
注意:如果此函数使用非常大的数字,此方法的输入角度值具有可接受范围,超出该范围,计算会失败。在 Windows 上,可接受范围大约是 -9223372036854775295 到 9223372036854775295 之间。此范围在其他平台上可能有所不同。对于可接受范围之外的值,Cos 方法返回输入值,而不是抛出异常。
另请参阅:Sin、Tan
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) + center;
// 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) + center;
// 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); } }
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