MonoGame.Samples/BookSourceCode/XNAGameDevelopmentbyExampleCode/RobotRampage/ComputerTerminal.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;

namespace Robot_Rampage
{
    class ComputerTerminal
    {
        #region Declarations
        private Sprite activeSprite;
        private Sprite inactiveSprite;
        public Vector2 MapLocation;
        public bool Active = true;
        public float LastSpawnCounter = 0;
        public float minSpawnTime = 6.0f;
        #endregion

        #region Constructor
        public ComputerTerminal(
            Sprite activeSprite,
            Sprite inactiveSprite,
            Vector2 mapLocation)
        {
            MapLocation = mapLocation;
            this.activeSprite = activeSprite;
            this.inactiveSprite = inactiveSprite;
        }
        #endregion

        #region Public Methods
        public bool IsCircleColliding(Vector2 otherCenter, float radius)
        {
            if (!Active)
            {
                return false;
            }

            return activeSprite.IsCircleColliding(otherCenter, radius);
        }

        public void Deactivate()
        {
            Active = false;
        }

        public void Update(GameTime gameTime)
        {
            if (Active)
            {
                float elapsed = (float)gameTime.ElapsedGameTime.TotalSeconds;

                LastSpawnCounter += elapsed;
                if (LastSpawnCounter > minSpawnTime)
                {
                    if (Vector2.Distance(activeSprite.WorldCenter,
                        Player.BaseSprite.WorldCenter) > 128)
                    {
                        if (EnemyManager.Enemies.Count <
                            EnemyManager.MaxActiveEnemies)
                        {
                            EnemyManager.AddEnemy(MapLocation);
                            LastSpawnCounter = 0;
                        }
                    }
                }

                activeSprite.Update(gameTime);
            }
            else
            {
                inactiveSprite.Update(gameTime);
            }
        }

        public void Draw(SpriteBatch spriteBatch)
        {
            if (Active)
            {
                activeSprite.Draw(spriteBatch);
            }
            else
            {
                inactiveSprite.Draw(spriteBatch);
            }
        }
        #endregion

    }
}