RTS - Unit Selection System

Overview

This system allows you to select, deselect, drag-select units, and interact with them, making it perfect for real-time strategy (RTS) games.

RTS-Unit-Selection-Gitgub-README.mp4

Features

• Single Click Selection: Select individual units with a simple click.
• Shift Click Selection: Add or remove units from the selection with shift-click.
• Drag Selection: Select multiple units by dragging a selection box.
• Unit Interaction: Execute actions on selected units.

Class Responsibilities

Selection System

SelectionManager

File: Assets/Script/Selection System/SelectionManager.cs

Description: This singleton class handles all selection actions (ClickSelect, ShiftSelect, DragClick, DeselectAll) and maintains lists of all selectable GameObjects and currently selected GameObjects.

SelectionClick

File: Assets/Script/Selection System/SelectionClick.cs

Description: Detects player clicks on selectable units and determines the type of selection action (click, shift-click).

SelectionDrag

File: Assets/Script/Selection System/SelectionDrag.cs

Description: Creates the visual representation of the drag selection box and tracks which units are selected within the dragged area.

Unit System

ISelectable

File: Assets/Script/Interface/ISelectable.cs

Description: An interface with the OnClick() method, serving as a template for classes that need to respond to selection actions.

Unit

File: Assets/Script/Unit/Unit.cs

Description: Implements the ISelectable interface. Contains logic for unit interaction when selected. In the provided example, it uses NavMeshAgent to move the unit to the clicked position.

Input Management

InputManager

File: Assets/Script/InputManager.cs

Description: Handles user input and executes the OnClick() method on selected units.

Setup and Usage

Setup

1. Layer Configuration:

   • Ensure all units are on a layer named "Selectable".
   • Attach the SelectionManager, SelectionClick, SelectionDrag, and InputManager scripts to appropriate GameObjects in your scene.

2. Implementing Units:

   • Implement the ISelectable interface in any class that should be selectable.
   • Define the logic for the OnClick() method in your unit class.

Example Usage

Here's a simple example of a unit class implementing ISelectable:

using UnityEngine;
using UnityEngine.AI;

public class Unit : MonoBehaviour, ISelectable
{
    [SerializeField] private LayerMask groundLayer;
    private NavMeshAgent agent;
    private Camera cam;

    private void Start()
    {
        agent = GetComponent<NavMeshAgent>();
        cam = Camera.main;
    }

    public void OnClick()
    {
        MoveToDestination();
    }

    private void MoveToDestination()
    {
        Ray ray = cam.ScreenPointToRay(Input.mousePosition);
        if (Physics.Raycast(ray, out RaycastHit hit, Mathf.Infinity, groundLayer))
        {
            agent.SetDestination(hit.point);
        }
    }
}