Initial Commit

Assets/Scripts/UnitSelection.cs

@@ -0,0 +1,103 @@
+using UnityEngine;
+using System.Collections.Generic;
+using System;
+
+public class UnitSelection : MonoBehaviour
+{
+    public LayerMask unitLayerMask;
+    private List<Unit> selectedUnits = new List<Unit>();
+    public RectTransform selectionBox;
+    private Vector2 startPos;
+
+    //components
+    private Camera cam;
+    private Player player;
+
+    void Awake()
+    {
+        //get the components
+        cam = Camera.main;
+        player = GetComponent<Player>();
+    }
+    // Start is called once before the first execution of Update after the MonoBehaviour is created
+    void Start()
+    {
+        
+    }
+
+    // Update is called once per frame
+    void Update()
+    {
+        //mouse up
+        if(Input.GetMouseButtonUp(0))
+        {
+            ReleaseSelectionBox();
+        }
+        //mouse held down
+        if(Input.GetMouseButton(0))
+        {
+            UpdateSelectionBox(Input.mousePosition);
+        }
+        //mouse down
+        if(Input.GetMouseButtonDown(0))
+        {
+            startPos = Input.mousePosition;
+            ToggleSelectionVisual(false);
+            selectedUnits = new List<Unit>();
+            TrySelect(Input.mousePosition);
+        }
+    }
+
+    //called when we release the selection box
+    void ReleaseSelectionBox()
+    {
+        selectionBox.gameObject.SetActive(false);
+        Vector2 min = selectionBox.anchoredPosition - (selectionBox.sizeDelta / 2);
+        Vector2 max = selectionBox.anchoredPosition + (selectionBox.sizeDelta / 2);
+        foreach(Unit unit in player.units)
+        {
+            Vector3 screenPos = cam.WorldToScreenPoint(unit.transform.position);
+            if(screenPos.x > min.x && screenPos.x < max.x && screenPos.y > min.y && screenPos.y < max.y)
+            {
+                selectedUnits.Add(unit);
+                unit.ToggleSelectionVisual(true);
+            }   
+        }    
+    }
+
+    //called when we are creating a selection box
+    void UpdateSelectionBox(Vector2 curMousePos)
+    {
+        if(!selectionBox.gameObject.activeInHierarchy)
+            selectionBox.gameObject.SetActive(true);
+        float width = curMousePos.x - startPos.x;
+        float height = curMousePos.y - startPos.y;
+        selectionBox.sizeDelta = new Vector2(MathF.Abs(width), Mathf.Abs(height));
+        selectionBox.anchoredPosition = startPos + new Vector2(width / 2, height / 2);
+    }
+
+    //called when we click on a unit
+    private void TrySelect(Vector2 screenPos)
+    {
+        Ray ray = cam.ScreenPointToRay(screenPos);
+        RaycastHit hit;
+        if(Physics.Raycast(ray, out hit, 100, unitLayerMask))
+        {
+            Unit unit = hit.collider.GetComponent<Unit>();
+            if(player.IsMyUnit(unit))
+            {
+                selectedUnits.Add(unit);
+                unit.ToggleSelectionVisual(true);
+            }
+
+        }
+    }
+
+    void ToggleSelectionVisual(bool selected)
+    {
+        foreach(Unit unit in selectedUnits)
+        {
+            unit.ToggleSelectionVisual(selected);
+        }
+    }
+}