Drag and drop in unity 2d - drag-and-drop

Question

I am trying to implement drag and drop functionality for my game in unity 2d. I have multiple copies of same object in my screen and they differ only by collider name. I attached the same script to them. Here is a piece of my code
function Start () {
playerTouches = [-1, -1];
}
function resetPlayer(touchNumber: int) {
for(var i = 0; i < playerTouches.length; ++i) {
if(touchNumber == playerTouches[i]) {
playerTouches[i] = -1;
}
}
}
function getCollider(vec: Vector2) {
var ray : Ray = Camera.main.ScreenPointToRay(vec);
var hit : RaycastHit2D = Physics2D.Raycast(ray.origin, ray.direction);
if (hit) {
if (hit.collider != null) {
Debug.Log(hit.collider.name);
return hit.collider.name;
} else {
Debug.Log("is null");
return "null";
}
} else {
Debug.Log("empty");
return "";
}
return "";
}
function processTouch(touch: Touch, touchNumber: int) {
if(touch.phase == TouchPhase.Began) {
var colliderName: String = getCollider(touch.position);
if(colliderName == "Object01" && playerTouches[0] == -1) {
playerTouches[0] = touchNumber;
} else if(colliderName == "Object02" && playerTouches[1] == -1) {
playerTouches[1] = touchNumber;
}
} else if(touch.phase == TouchPhase.Moved) {
// get object and change coords
} else if(touch.phase == TouchPhase.Ended || touch.phase == TouchPhase.Canceled) {
resetPlayer(touchNumber);
}
}
function Update() {
if(Input.touchCount > 0) {
//Debug.Log("count = " + Input.touchCount);
for(var i = 0; i < Input.touchCount; i++)
{
processTouch(Input.GetTouch(i), i);
//Debug.Log("touch : " + i + " " + Input.GetTouch(i).position);
}
}
}
For now I'm detecting on which object user touch. I need to be able to get that object and change it's position.
I also found this code snippet which allows to move rigidbody
var touchDeltaPosition: Vector2 = touch.deltaPosition;
var touchPosition: Vector2;
touchPosition.Set(touchDeltaPosition.x, touchDeltaPosition.y);
rigidbody2D.transform.position = Vector2.Lerp(transform.position, touchPosition, Time.deltaTime * spd);
but it moves all objects regardless of what object I select.

Answer 1

Well, you can do like this. If you have 12 copies of same object and want to move the object which selected by user. So when user Touches the object Change that GameObject tag or Name to another tag. Afterward you can use the some Conditional Statement to work with your code.
Example :
if(Input.GetMouseButtonDown(0)) {
Debug.Log("Mouse is down");
Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
RaycastHit hitInfo = new RaycastHit();
//bool hit = Physics.Raycast (Camera.main.ScreenPointToRay (Input.mousePosition), out hitInfo);
if(Physics.Raycast(ray, out hitInfo, 30)) {
Debug.Log("Hit " + hitInfo.transform.gameObject.name);
if(hitInfo.transform.gameObject.tag == "Deselected") {
//Debug.Log ("It's working! Attaching MoveCube Script to game :" + hitInfo.transform.gameObject.tag);
findObject = GameObject.FindGameObjectsWithTag("Deselected");
foreach(GameObject go in findObject) {
//go.gameObject.renderer.material.color = Color.white;
go.GetComponent<MoveCube>().enabled = false;
if(hitInfo.transform.gameObject.name.Equals(go.gameObject.name)) {
//hitInfo.transform.renderer.material.color = Color.white;
hitInfo.transform.gameObject.GetComponent<MoveCube>().enabled = true;
changeTAG = true;
} else {
hitInfo.transform.gameObject.tag = "Deselected"
}
}
playerObject = GameObject.FindGameObjectsWithTag("Player");
foreach(GameObject game in playerObject) {
count++;
if(count == 1) {
hitInfo.transform.gameObject.tag = "Player";
}
if(count >= 1) {
game.gameObject.tag = "Deselected";
game.gameObject.GetComponent<MoveCube>().enabled = false;
//game.gameObject.renderer.material.color = Color.white;
}
}
if(changeTAG) {
hitInfo.transform.gameObject.tag = "Player";
/*if (hitInfo.transform.gameObject.GetComponent<Rigidbody> ()) {
Debug.Log ("RigidBody is already added Can't add another RigidBody");
hitInfo.transform.rigidbody.WakeUp ();
} else {
hitInfo.transform.gameObject.AddComponent<Rigidbody> ().useGravity = false;
// hitInfo.transform.gameObject.GetComponent<Rigidbody> ().WakeUp ();
}*/
changeTAG = false;
} else if(!changeTAG) {
hitInfo.transform.gameObject.tag = "Deselected";
}
} else {
Debug.Log("Not Working");
}
} else {
Debug.Log("No hit");
}
Debug.Log("Mouse is down");
}
The above code is for Change the tag for selected and deselected cube. After that you can easily identify the Selected gameObject and can move it where ever you want.
You can use this code in the Update function.