Unity小功能记录（一）------ 色环与拾取颜色

最近有个需求，一个圆环图片要移动拾取色环上的颜色，具体效果如：

                                        

主要代码如下：

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;

public class PointMove : MonoBehaviour {
    public RectTransform rect;

    public Texture2D heatMapImage;
    public Color32 outputColor;
    public Text text;
    // Use this for initialization
    void Start () {
        rect = GetComponent<RectTransform>();
    }
	
	// Update is called once per frame
	void Update () {
		
	}
    public void SetPos(Vector2 pos)
    {
        float Y =1;
        float X = 1;
        if(pos.x >180 && pos.x < 550)
        {
            X = pos.x - 375;
            if (pos.y > 667)
            {
                //上半部分
                Y = 1;
            }
            else
            {
                //下半部分
                Y = -1;
            }
            if (X >= 220)
            {
                X = 220;
            }
            if (X <= -220)
            {
                X = -220;
            }
            Y = Y * Mathf.Sqrt(220 * 220 - X * X);
            if (float.IsNaN(Y))
            {
                Y = pos.y - 667f;
            }
        }
        else
        {
            if (pos.x > 375)
            {
                //上半部分
                X = 1;
            }
            else
            {
                //下半部分
                X = -1;
            }
            Y = pos.y - 667f;
            X = X * Mathf.Sqrt(220 * 220 - Y * Y);
            if (float.IsNaN(X))
            {
                X = pos.x - 375;
            }
        }
        rect.anchoredPosition = new Vector2(X, Y);
        outputColor = GetHeatMapColor((int)(X+220),(int)(Y+220));
        text.text ="Color:" + outputColor.ToString();
        Debug.Log(outputColor.ToString());
    }
    public Color32 GetHeatMapColor(int x, int y)
    {
        outputColor = heatMapImage.GetPixel(x, y);
        Color32 outColor = new Color32((byte)(outputColor.r * 255), (byte)(outputColor.g * 255), (byte)(outputColor.b * 255), 
            255);

        return outColor;
    }
}

Demo下载地址：https://download.csdn.net/download/dengshunhao/10427987