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Forked from ditzel/ScrollAndPinch.cs
Created January 14, 2022 01:58
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Pinch and Scroll to Move and Zoom in Unity for Mobile Games
/*
Set this on an empty game object positioned at (0,0,0) and attach your active camera.
The script only runs on mobile devices or the remote app.
*/
using UnityEngine;
class ScrollAndPinch : MonoBehaviour
{
#if UNITY_IOS || UNITY_ANDROID
public Camera Camera;
public bool Rotate;
protected Plane Plane;
private void Awake()
{
if (Camera == null)
Camera = Camera.main;
}
private void Update()
{
//Update Plane
if (Input.touchCount >= 1)
Plane.SetNormalAndPosition(transform.up, transform.position);
var Delta1 = Vector3.zero;
var Delta2 = Vector3.zero;
//Scroll
if (Input.touchCount >= 1)
{
Delta1 = PlanePositionDelta(Input.GetTouch(0));
if (Input.GetTouch(0).phase == TouchPhase.Moved)
Camera.transform.Translate(Delta1, Space.World);
}
//Pinch
if (Input.touchCount >= 2)
{
var pos1 = PlanePosition(Input.GetTouch(0).position);
var pos2 = PlanePosition(Input.GetTouch(1).position);
var pos1b = PlanePosition(Input.GetTouch(0).position - Input.GetTouch(0).deltaPosition);
var pos2b = PlanePosition(Input.GetTouch(1).position - Input.GetTouch(1).deltaPosition);
//calc zoom
var zoom = Vector3.Distance(pos1, pos2) /
Vector3.Distance(pos1b, pos2b);
//edge case
if (zoom == 0 || zoom > 10)
return;
//Move cam amount the mid ray
Camera.transform.position = Vector3.LerpUnclamped(pos1, Camera.transform.position, 1 / zoom);
if (Rotate && pos2b != pos2)
Camera.transform.RotateAround(pos1, Plane.normal, Vector3.SignedAngle(pos2 - pos1, pos2b - pos1b, Plane.normal));
}
}
protected Vector3 PlanePositionDelta(Touch touch)
{
//not moved
if (touch.phase != TouchPhase.Moved)
return Vector3.zero;
//delta
var rayBefore = Camera.ScreenPointToRay(touch.position - touch.deltaPosition);
var rayNow = Camera.ScreenPointToRay(touch.position);
if (Plane.Raycast(rayBefore, out var enterBefore) && Plane.Raycast(rayNow, out var enterNow))
return rayBefore.GetPoint(enterBefore) - rayNow.GetPoint(enterNow);
//not on plane
return Vector3.zero;
}
protected Vector3 PlanePosition(Vector2 screenPos)
{
//position
var rayNow = Camera.ScreenPointToRay(screenPos);
if (Plane.Raycast(rayNow, out var enterNow))
return rayNow.GetPoint(enterNow);
return Vector3.zero;
}
private void OnDrawGizmos()
{
Gizmos.DrawLine(transform.position, transform.position + transform.up);
}
#endif
}
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