DetectTouchMovement

Author: Caue Rego (cawas)

Description

Simple script to detect pinch and/or turning with 2 fingers.

Usage

Easier to explain by example. Attach this to the camera:

<csharp> void LateUpdate() { float pinchAmount = 0; Quaternion desiredRotation = transform.rotation;

DetectTouchMovement.Calculate();

if (Mathf.Abs(DetectTouchMovement.pinchDistanceDelta) > 0) { // zoom pinchAmount = DetectTouchMovement.pinchDistanceDelta; }

if (Mathf.Abs(DetectTouchMovement.turnAngleDelta) > 0) { // rotate Vector3 rotationDeg = Vector3.zero; rotationDeg.z = -DetectTouchMovement.turnAngleDelta; desiredRotation *= Quaternion.Euler(rotationDeg); }

// not so sure those will work: transform.rotation = desiredRotation; transform.position += Vector3.forward * pinchAmount; } </csharp>

DetectTouchMovement.cs

<csharp> using UnityEngine; using System.Collections;

public class DetectTouchMovement : MonoBehaviour { const float pinchTurnRatio = Mathf.PI / 2; const float minTurnAngle = 0;

const float pinchRatio = 1; const float minPinchDistance = 0;

const float panRatio = 1; const float minPanDistance = 0;

/// <summary> /// The delta of the angle between two touch points /// </summary> static public float turnAngleDelta; /// <summary> /// The angle between two touch points /// </summary> static public float turnAngle;

/// <summary> /// The delta of the distance between two touch points that were distancing from each other /// </summary> static public float pinchDistanceDelta; /// <summary> /// The distance between two touch points that were distancing from each other /// </summary> static public float pinchDistance;

/// <summary> /// Calculates Pinch and Turn - This should be used inside LateUpdate /// </summary> static public void Calculate () { pinchDistance = pinchDistanceDelta = 0; turnAngle = turnAngleDelta = 0;

// if two fingers are touching the screen at the same time ... if (Input.touchCount == 2) { Touch touch1 = Input.touches[0]; Touch touch2 = Input.touches[1];

// ... if at least one of them moved ... if (touch1.phase == TouchPhase.Moved || touch2.phase == TouchPhase.Moved) { // ... check the delta distance between them ... pinchDistance = Vector2.Distance(touch1.position, touch2.position); float prevDistance = Vector2.Distance(touch1.position - touch1.deltaPosition, touch2.position - touch2.deltaPosition); pinchDistanceDelta = pinchDistance - prevDistance;

// ... if it's greater than a minimum threshold, it's a pinch! if (Mathf.Abs(pinchDistanceDelta) > minPinchDistance) { pinchDistanceDelta *= pinchRatio; } else { pinchDistance = pinchDistanceDelta = 0; }

// ... or check the delta angle between them ... turnAngle = Angle(touch1.position, touch2.position); float prevTurn = Angle(touch1.position - touch1.deltaPosition, touch2.position - touch2.deltaPosition); turnAngleDelta = Mathf.DeltaAngle(prevTurn, turnAngle);

// ... if it's greater than a minimum threshold, it's a turn! if (Mathf.Abs(turnAngleDelta) > minTurnAngle) { turnAngleDelta *= pinchTurnRatio; } else { turnAngle = turnAngleDelta = 0; } } } }

static private float Angle (Vector2 pos1, Vector2 pos2) { Vector2 from = pos2 - pos1; Vector2 to = new Vector2(1, 0);

float result = Vector2.Angle( from, to ); Vector3 cross = Vector3.Cross( from, to );

if (cross.z > 0) { result = 360f - result; }

return result; } } </csharp>