unity实现方向盘转动效果

本文实例为大家分享了unity实现方向盘转动效果的具体代码，供大家参考，具体内容如下

效果

手指或鼠标拖动方向盘旋转，有角度限制，松手后自动回转。

代码

将代码添加到方向盘image上。

注意需要赋值canvas。

using unityengine;
using unityengine.eventsystems;

public class steeringwheel : monobehaviour,idraghandler,ienddraghandler
{
    public canvas canvasroot;//需要指定画布 
    private recttransform m_recttransform;//坐标

    private bool m_isfirst = true;           //用于记录第一帧按下鼠标时鼠标的位置，便于计算
    private vector3 m_currentpos;            //记录当前帧鼠标所在位置
    private bool m_isclockwise;              //是否顺时针
    private float m_roundvalue = 0;          //记录总的旋转角度 用这个数值来控制一圈半
    private bool m_isturingsteeringwheel;    //是否在转方向盘 用这个判断复位

    public void ondrag(pointereventdata eventdata)
    {
        m_isturingsteeringwheel = true;
        vector2 pos;
        if (recttransformutility.screenpointtolocalpointinrectangle(m_recttransform, input.mouseposition, canvasroot.worldcamera, out pos))    //获取鼠标点击位置
        {

            pos.x = pos.x + (screen.width / 2) - getcomponent<recttransform>().position.x;
            pos.y = pos.y + (screen.height / 2) - getcomponent<recttransform>().position.y;

            vector3 pos3 = new vector3(pos.x, pos.y, 0);   //计算后鼠标以方向盘圆心为坐标原点的坐标位置

            if (m_isfirst)
            {
                m_currentpos = pos3;
                m_isfirst = false;
            }

            vector3 currentpos = vector3.cross(pos3, m_currentpos);      //计算当前帧和上一帧手指位置 用于判断旋转方向
            if (currentpos.z > 0)
            {
                m_isclockwise = true;
            }
            else if (currentpos.z < 0)
            {
                m_isclockwise = false;
            }

            if (m_currentpos != pos3)     //范围内让方向盘随着手指转动
            {
                if (m_isclockwise)
                {
                    if (m_roundvalue <= 180)
                    {
                        m_roundvalue += vector3.angle(m_currentpos, pos3);

                        transform.rotate(new vector3(0, 0, -vector3.angle(m_currentpos, pos3)));
                    }
                }

                else
                {
                    if (m_roundvalue >= -180)
                    {
                        m_roundvalue -= vector3.angle(m_currentpos, pos3);

                        transform.rotate(new vector3(0, 0, vector3.angle(m_currentpos, pos3)));
                    }
                }

            }
            m_currentpos = pos3;
        }
    }

    public void onenddrag(pointereventdata eventdata)
    {
        m_isfirst = true;
        m_isturingsteeringwheel = false;
    }

    void start()
    {
        canvasroot = gameobject.find("canvas").getcomponent<canvas>();
        m_recttransform = canvasroot.transform as recttransform;
    }


    void update()
    {
        if (!m_isturingsteeringwheel && m_roundvalue != 0)   //复位
        {
            if (m_roundvalue >= 0)
            {
                m_roundvalue -= 8f;               //复位速度
                if (m_roundvalue < 0)
                    m_roundvalue = 0;
                transform.rotation = quaternion.euler(new vector3(0, 0, -m_roundvalue));
            }
            else
            {
                m_roundvalue += 8f;
                if (m_roundvalue > 0)
                    m_roundvalue = 0;
                transform.rotation = quaternion.euler(new vector3(0, 0, -m_roundvalue));
            }
        }
    }
}

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。