[unity notes] screen coordinates to ugui coordinates

API :

RectTransformUtility Static functions under class ScreenPointToLocalPointInRectangle

You need to pass in four parameters ,

---

① RectTransform：

This parameter is equivalent to indicating A canvas , The screen coordinate point is the position of the canvas . Under the canvas UI Coordinate changes are shown in the figure ：

---

② Vector2

Screen coordinates , From bottom left to top right , Use " Input.mousePosition " Can be judged

---

③ Camera

Canvas The rendering mode is Camera Of , The camera needs to be filled in this parameter ;Overlay Can be filled directly null

---

④ out Vector2

Output conversion completed UGUI coordinate

---

The following implementation UI As the mouse moves ：

Implementation code ：

    public RectTransform rect;// Based on which Rect Transform
    public RectTransform targetRect;// Following the movement of the mouse UI

    void Update()
    {
    
        RectTransformUtility.ScreenPointToLocalPointInRectangle(rect, Input.mousePosition, null, out Vector2 v2);
        targetRect.localPosition = v2;
    }

What we use here is Recttransform.localPosition instead of anchoredPosition,anchoredPosition Is based on the current UI Anchor point to get the coordinate position , If the anchor point is in the center, it is and localPosition equal , Make a note of ~