NGUI研究院之在Unity中使用贝塞尔曲线（六）

using UnityEngine;

[System.Serializable]

public class Bezier : System.Object

{

    public Vector3 p0;

    public Vector3 p1;

    public Vector3 p2;

    public Vector3 p3;

    public float ti = 0f;

    private Vector3 b0 = Vector3.zero;

    private Vector3 b1 = Vector3.zero;

    private Vector3 b2 = Vector3.zero;

    private Vector3 b3 = Vector3.zero;

    private float Ax;

    private float Ay;

    private float Az;

    private float Bx;

    private float By;

    private float Bz;

    private float Cx;

    private float Cy;

    private float Cz;

    // Init function v0 = 1st point, v1 = handle of the 1st point , v2 = handle of the 2nd point, v3 = 2nd point

    // handle1 = v0 + v1

    // handle2 = v3 + v2

    public Bezier( Vector3 v0, Vector3 v1, Vector3 v2, Vector3 v3 )

    {

        this.p0 = v0;

        this.p1 = v1;

        this.p2 = v2;

        this.p3 = v3;

    }

    // 0.0 >= t <= 1.0

    public Vector3 GetPointAtTime( float t )

    {

        this.CheckConstant();

        float t2 = t * t;

        float t3 = t * t * t;

        float x = this.Ax * t3 + this.Bx * t2 + this.Cx * t + p0.x;

        float y = this.Ay * t3 + this.By * t2 + this.Cy * t + p0.y;

        float z = this.Az * t3 + this.Bz * t2 + this.Cz * t + p0.z;

        return new Vector3( x, y, z );

    }

    private void SetConstant()

    {

        this.Cx = 3f * ( ( this.p0.x + this.p1.x ) - this.p0.x );

        this.Bx = 3f * ( ( this.p3.x + this.p2.x ) - ( this.p0.x + this.p1.x ) ) - this.Cx;

        this.Ax = this.p3.x - this.p0.x - this.Cx - this.Bx;

        this.Cy = 3f * ( ( this.p0.y + this.p1.y ) - this.p0.y );

        this.By = 3f * ( ( this.p3.y + this.p2.y ) - ( this.p0.y + this.p1.y ) ) - this.Cy;

        this.Ay = this.p3.y - this.p0.y - this.Cy - this.By;

        this.Cz = 3f * ( ( this.p0.z + this.p1.z ) - this.p0.z );

        this.Bz = 3f * ( ( this.p3.z + this.p2.z ) - ( this.p0.z + this.p1.z ) ) - this.Cz;

        this.Az = this.p3.z - this.p0.z - this.Cz - this.Bz;

    }

    // Check if p0, p1, p2 or p3 have changed

    private void CheckConstant()

    {

        if( this.p0 != this.b0 || this.p1 != this.b1 || this.p2 != this.b2 || this.p3 != this.b3 )

        {

            this.SetConstant();

            this.b0 = this.p0;

            this.b1 = this.p1;

            this.b2 = this.p2;

            this.b3 = this.p3;

        }

    }

}

using UnityEngine;

public class MyBezier : MonoBehaviour

{

    //贝塞尔曲线算法类
    public Bezier myBezier;

	//曲线的对象
	public GameObject Yellowline;

	//曲线对象的曲线组件
	private LineRenderer YellowlineRenderer;

    //拖动条用来控制贝塞尔曲线的两个点
	public float hSliderValue0;
	public float hSliderValue1;

    void Start()
    {
    	//得到曲线组件
		YellowlineRenderer = Yellowline.GetComponent<LineRenderer>();
		//为了让曲线更加美观，设置曲线由100个点来组成
		YellowlineRenderer.SetVertexCount(100);
    }

	void OnGUI()
	{
		//拖动条得出 -5.0 - 5.0之间的一个数值
		hSliderValue0 = GUI.HorizontalSlider(new Rect(25, 25, 100, 30), hSliderValue0, -5.0F, 5.0F);
		hSliderValue1 = GUI.HorizontalSlider(new Rect(25, 70, 100, 30), hSliderValue1, -5.0F, 5.0F);
	}

    void Update()
    {
    	//在这里来计算贝塞尔曲线
    	//四个参数 表示当前贝塞尔曲线上的4个点 第一个点和第四个点
    	//我们是不需要移动的，中间的两个点是由拖动条来控制的。
        myBezier = new Bezier( new Vector3( -5f, 0f, 0f ),  new Vector3( hSliderValue1, hSliderValue0 , 0f ),  new Vector3( hSliderValue1, hSliderValue0, 0f ), new Vector3( 5f, 0f, 0f ) );

		//循环100遍来绘制贝塞尔曲线每个线段
		for(int i =1; i <= 100; i++)
		{
			//参数的取值范围 0 - 1 返回曲线没一点的位置
			//为了精确这里使用i * 0.01 得到当前点的坐标
			Vector3 vec = myBezier.GetPointAtTime( (float)(i *0.01) );
			//把每条线段绘制出来 完成白塞尔曲线的绘制
			YellowlineRenderer.SetPosition(i -1,vec);
		}

    }

}

using UnityEngine;
using System.Collections;

public class BallMove : MonoBehaviour
{

	void OnDrag (Vector2 delta)
	{

		float movex = transform.localPosition.x + (delta.x / 3);
		float movey = transform.localPosition.y + (delta.y / 3);
		 //避免越界操作，这里可以进行一些判断
		transform.localPosition = new Vector3(movex,movey ,transform.localPosition.z);
	}

}

using UnityEngine;
using System.Collections;

public class BallInit : MonoBehaviour {

	//黑色直角线段
	LineRenderer lineRenderer0;
	LineRenderer lineRenderer1;
	//贝塞尔曲线
	LineRenderer BezierRenderer;

	//三个小球触摸对象
	public GameObject mark0;
	public GameObject mark1;
	public GameObject mark2;

	//算法公式类
	private Bezier myBezier;

	void Start ()
	{
		//分别得到黑色直角线段 与黄色贝塞尔曲线的 线段组件
		lineRenderer0 = GameObject.Find("line0").GetComponent<LineRenderer>();
		lineRenderer1 = GameObject.Find("line1").GetComponent<LineRenderer>();
		BezierRenderer = GameObject.Find("Bezier").GetComponent<LineRenderer>();
		//黑色直角是有两个线段组成
		lineRenderer0.SetVertexCount(2);
		lineRenderer1.SetVertexCount(2);
		//为了让贝塞尔曲线细致一些 设置它有100个点组成
		BezierRenderer.SetVertexCount(100);

	}

	void Update ()
	{

		//mark0 表示中间的小球
		//mark1 表示右边的小球
		//mark2 表示左边的小球

		//中间的标志点分别减去左右两边的标志点，计算出曲线的X Y 的点
		float y = (mark0.transform.position.y  - mark2.transform.position.y)  ;
		float x = (mark0.transform.position.x  - mark2.transform.position.x) ; 

		//因为我们是通过3个点来确定贝塞尔曲线， 所以参数3 设置为0 即可。
		//这样参数1 表示起点 参数2表示中间点 参数3 忽略 参数4 表示结束点
		myBezier = new Bezier( mark2.transform.position,  new Vector3(x,y,0f),  new Vector3(0f,0f,0f), mark1.transform.position );

		//绘制贝塞尔曲线
		for(int i =1; i <= 100; i++)
		{
			Vector3 vec = myBezier.GetPointAtTime( (float)(i * 0.01) );
			BezierRenderer.SetPosition(i -1,vec);
		}

		//绘制直角黑色标志线段
		lineRenderer0.SetPosition(0,mark0.transform.position);
		lineRenderer0.SetPosition(1,mark2.transform.position);
		lineRenderer1.SetPosition(0,mark0.transform.position);
		lineRenderer1.SetPosition(1,mark1.transform.position);
	}
}