问题
I'm trying to get unity to recognize that I am swiping left to right, I have solved that but my issue is that it doesn't understand this till I lift my finger off the screen.
My question is how would i make it so that it knows i went right and then left and then right again all without ever taking my finger of the screen
Here is the code I have so far
using UnityEngine;
using System.Collections;
public class Gestures : MonoBehaviour {
private Vector2 fingerStart;
private Vector2 fingerEnd;
public int leftRight = 0;
public int upDown = 0;
void Update () {
foreach(Touch touch in Input.touches)
{
if (touch.phase == TouchPhase.Began)
{
fingerStart = touch.position;
fingerEnd = touch.position;
}
if (touch.phase == TouchPhase.Moved )
{
fingerEnd = touch.position;
}
if(touch.phase == TouchPhase.Ended)
{
if((fingerStart.x - fingerEnd.x) > 80 || (fingerStart.x - fingerEnd.x) < -80) // Side to side Swipe
{
leftRight ++;
}
else if((fingerStart.y - fingerEnd.y) < -80 || (fingerStart.y - fingerEnd.y) > 80) // top to bottom swipe
{
upDown ++;
}
if(leftRight >= 3){
leftRight = 0;
}
if(upDown >= 4){
upDown = 0;
}
}
}
}
}
回答1:
The issue you're facing is because you've done your checks in the TouchPhase.Ended. What you want to do is perform your checks in TouchPhase.Moved, with a smaller change in value (you're using 80 in Ended, try something like 10 if you the code doesn't work)
Unity's documentation on TouchPhase http://docs.unity3d.com/ScriptReference/TouchPhase.html
foreach(Touch touch in Input.touches)
{
if (touch.phase == TouchPhase.Began)
{
fingerStart = touch.position;
fingerEnd = touch.position;
}
if (touch.phase == TouchPhase.Moved )
{
fingerEnd = touch.position;
if((fingerStart.x - fingerEnd.x) > 80 ||
(fingerStart.x - fingerEnd.x) < -80) // Side to side Swipe
{
leftRight ++;
}
else if((fingerStart.y - fingerEnd.y) < -80 ||
(fingerStart.y - fingerEnd.y) > 80) // top to bottom swipe
{
upDown ++;
}
if(leftRight >= 3){
leftRight = 0;
}
if(upDown >= 4){
upDown = 0;
}
//After the checks are performed, set the fingerStart & fingerEnd to be the same
fingerStart = touch.position;
}
if(touch.phase == TouchPhase.Ended)
{
leftRight = 0;
upDown = 0;
fingerStart = Vector2.zero;
fingerEnd = Vector2.zero;
}
If you want to explicitly check for a pattern (i.e. left -> right -> left), rather than just checking if it's some lateral / vertical movement as the code you have will do, try the below code. Just remember to include System.Collentions.Generic & System.Linq namespaces
private Vector2 fingerStart;
private Vector2 fingerEnd;
public enum Movement
{
Left,
Right,
Up,
Down
};
public List<Movement> movements = new List<Movement>();
void Update () {
foreach(Touch touch in Input.touches)
{
if (touch.phase == TouchPhase.Began) {
fingerStart = touch.position;
fingerEnd = touch.position;
}
if(touch.phase == TouchPhase.Moved) {
fingerEnd = touch.position;
//There is more movement on the X axis than the Y axis
if(Mathf.Abs(fingerStart.x - fingerEnd.x) > Mathf.Abs(fingerStart.y - fingerEnd.y)) {
//Right Swipe
if((fingerEnd.x - fingerStart.x) > 0)
movements.Add(Movement.Right);
//Left Swipe
else
movements.Add(Movement.Left);
}
//More movement along the Y axis than the X axis
else {
//Upward Swipe
if((fingerEnd.y - fingerStart.y) > 0)
movements.Add(Movement.Up);
//Downward Swipe
else
movements.Add(Movement.Down);
}
//After the checks are performed, set the fingerStart & fingerEnd to be the same
fingerStart = touch.position;
//Now let's check if the Movement pattern is what we want
//In this example, I'm checking whether the pattern is Left, then Right, then Left again
Debug.Log (CheckForPatternMove(0, 3, new List<Movement>() { Movement.Left, Movement.Right, Movement.Left } ));
}
if(touch.phase == TouchPhase.Ended)
{
fingerStart = Vector2.zero;
fingerEnd = Vector2.zero;
movements.Clear();
}
}
}
private bool CheckForPatternMove (int startIndex, int lengthOfPattern, List<Movement> movementToCheck) {
//If the currently stored movements are fewer than the length of the pattern to be detected
//it can never match the pattern. So, let's get out
if(lengthOfPattern > movements.Count)
return false;
//In case the start index for the check plus the length of the pattern
//exceeds the movement list's count, it'll throw an exception, so lets get out
if(startIndex + lengthOfPattern > movements.Count)
return false;
//Populate a temporary list with the respective elements
//from the movement list
List<Movement> tMovements = new List<Movement>();
for(int i = startIndex; i < startIndex + lengthOfPattern; i++)
tMovements.Add(movements[i]);
//Now check whether the sequence of movements is the same as the pattern you want to check for
//The SequenceEqual method is in the System.Linq namespace
return tMovements.SequenceEqual(movementToCheck);
}
EDIT Added some more code as a sample
//The idea of a pattern match is to check for the exact same set of swipe gesture.
//This requires the following conditions to be met
// (a) The List of movements that need to be checked must be at least as long as the List of movements to check against.
// (b) The correct indices should be used for the startIndex. In this case I'm just using 0 as the startIndex.
// (c) Remember to clear the List right after you get a true return from the method, otherwise the next return will most likely be a false.
//Example - Training set is Left -> Right -> Left (This is what we want to check)
// Step 1 - User swipes LEFT, method returns false because there are too few Movements to check
// Step 2 - User swipes RIGHT, method returns false (same reason as above)
// Step 3a - User swipes RIGHT (L, R, R now) - false, incorrect pattern (L, R, R instead of L, R, L)
// Step 3b - User swipes LEFT (L, R, L now) - TRUE, Correct pattern!
//Immediately clear if Step 3b happens otherwise Step 4 will occur
// Step 4 - User swipes L or R (direction is immaterial right now), and method will return FALSE
// if you use the last three indexes!
//Pre-populating the movements List with L, R, L
movements = new List<Movement>()
{
Movement.Left,
Movement.Right,
Movement.Left
};
//Checking a match against an L, R, L training set
//This prints true to the console
Debug.Log (CheckForPatternMove(0, 3, new List<Movement>() { Movement.Left, Movement.Right, Movement.Left } ));
Here's how my Update function looks like. Note the usage of GetMouseButton over Input.touch
void Update () {
//Example usage in Update. Note how I use Input.GetMouseButton instead of Input.touch
//GetMouseButtonDown(0) instead of TouchPhase.Began
if (Input.GetMouseButtonDown(0)) {
fingerStart = Input.mousePosition;
fingerEnd = Input.mousePosition;
}
//GetMouseButton instead of TouchPhase.Moved
//This returns true if the LMB is held down in standalone OR
//there is a single finger touch on a mobile device
if(Input.GetMouseButton(0)) {
fingerEnd = Input.mousePosition;
//There was some movement! The tolerance variable is to detect some useful movement
//i.e. an actual swipe rather than some jitter. This is the same as the value of 80
//you used in your original code.
if(Mathf.Abs(fingerEnd.x - fingerStart.x) > tolerance ||
Mathf.Abs(fingerEnd.y - fingerStart.y) > tolerance) {
//There is more movement on the X axis than the Y axis
if(Mathf.Abs(fingerStart.x - fingerEnd.x) > Mathf.Abs(fingerStart.y - fingerEnd.y)) {
//Right Swipe
if((fingerEnd.x - fingerStart.x) > 0)
movements.Add(Movement.Right);
//Left Swipe
else
movements.Add(Movement.Left);
}
//More movement along the Y axis than the X axis
else {
//Upward Swipe
if((fingerEnd.y - fingerStart.y) > 0)
movements.Add(Movement.Up);
//Downward Swipe
else
movements.Add(Movement.Down);
}
//After the checks are performed, set the fingerStart & fingerEnd to be the same
fingerStart = fingerEnd;
//Now let's check if the Movement pattern is what we want
//In this example, I'm checking whether the pattern is Left, then Right, then Left again
Debug.Log (CheckForPatternMove(0, 3, new List<Movement>() { Movement.Left, Movement.Right, Movement.Left } ));
}
}
//GetMouseButtonUp(0) instead of TouchPhase.Ended
if(Input.GetMouseButtonUp(0)) {
fingerStart = Vector2.zero;
fingerEnd = Vector2.zero;
movements.Clear();
}
}
来源：https://stackoverflow.com/questions/27712233/swipe-gestures-on-android-in-unity