[C#] Check position of multiple GameObjects with mouse click position

Questions & Answers
1

Hey guys,

I’m really new to programming and I’ve been bashing my head against the wall with this. I’ve searched for existing questions/answers but seeing as I don’t fully understand this, they’re of very little help as I get errors I have no idea how to fix.

The goal: (Imagine a Plants vs Zombies style game) When placing a defender, first check to see if there’s already a defender in that square. If not, place a defender. If so, communicate that it’s not allowed.

My question: How do I store the positions of the objects in the placedDefenders array and then check them against the position of the mouse click (roundedPos)?

I have the GameObject array working properly, but then figuring out how to get the positions of those objects is where I come undone (let alone checking them against the mouse click position).

Here’s my script, I’ve deleted all the crud where I was trying to store the positions in another array because it was getting very sloppy. I hope it makes sense.

I appreciate any help.

using UnityEngine;
using System.Collections;

public class DefenderSpawner : MonoBehaviour {

	Camera myCamera;
	GameObject defenderParent;

	void Start () {
		myCamera = Camera.main;
		defenderParent = GameObject.Find ("Defenders");
		
		if (defenderParent == null) {
			defenderParent = new GameObject ("Defenders");
		}
	}

	void OnMouseDown () {
		// Coordinate stuff
		Vector2 rawPos = CalculateWorldPointOfMouseClick ();
		Vector2 roundedPos = SnapToGrid (rawPos);

		// Arrays for placement checking
		Vector3[] placedDefenderPositions;
		GameObject[] placedDefenders;

		placedDefenders = GameObject.FindGameObjectsWithTag ("Defender");

		// Instantiate Defender and parent it in hierarchy
		GameObject defender = Instantiate (Button.selectedDefender, roundedPos, Quaternion.identity) as GameObject;
		defender.transform.parent = defenderParent.transform;
	}

	Vector2 SnapToGrid (Vector2 rawWorldPos) {
		float newX = Mathf.RoundToInt (rawWorldPos.x);
		float newY = Mathf.RoundToInt (rawWorldPos.y);

		return new Vector2 (newX, newY);
	}

	Vector2 CalculateWorldPointOfMouseClick () {
		float mouseX = Input.mousePosition.x;
		float mouseY = Input.mousePosition.y;
		float distanceFromCamera = 10f;

		Vector3 cameraPoints = new Vector3 (mouseX, mouseY, distanceFromCamera);
		Vector2 worldPos = myCamera.ScreenToWorldPoint (cameraPoints);

		return worldPos;
	}
}
2

You can get the position of any gameObject in Unity by calling theGameObject.transform.position. This gives you the world-space position of the object. You could check them against the mouse position by doing a for loop like so:

for (int i=0;i<placedDefenders.Length;i++)
{
     Vector3 objectPosition = placedDefenders*.transform.position;*

Vector2 objectPosition2D = new Vector2(objectPosition.x, objectPosition.y);

if (SnapToGrid(objectPosition2D) == roundedPos)
{
//One of the defenders is in this spot!
NotifyPlayerFunction();
break;
}
}