我在这里尝试实现的目标是，当白球（精灵）在一定距离内朝向黑球（AI）时，黑球将跟随白球。
我已经做到了，所以人工智能会自动转向精灵，但我不知道只有精灵在一定距离内时该怎么做。
这是主要的游戏类
using System;
using System.Collections.Generic;
using System.Linq;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Audio;
using Microsoft.Xna.Framework.Content;
using Microsoft.Xna.Framework.GamerServices;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;
using Microsoft.Xna.Framework.Media;
using System.IO;
namespace PickUpTheCrewGame
{
/// <summary>
/// This is the main type for your game
/// </summary>
public class PickUpTheCrewGame : Microsoft.Xna.Framework.Game
{
GraphicsDeviceManager graphics;
SpriteBatch spriteBatch;
SpriteFont messageFont;
Texture2D backgroundTexture;
Rectangle backgroundRectangle;
Sprite BlueBall;
Sprite GreenBall;
Sprite OrangeBall;
Sprite PinkBall;
Sprite RedBall;
Sprite c;
Sprite YellowBall;
//---player scores
int playerScore = 0;
//List<Sprite> sprite = new List<Sprite>();
List<sharks> sharks = new List<sharks>();
List<Sprite> crew = new List<Sprite>();
//Sprite Background;
public PickUpTheCrewGame()
{
graphics = new GraphicsDeviceManager(this);
Content.RootDirectory = "Content";
//sreen size
graphics.PreferredBackBufferWidth = 1280;
graphics.PreferredBackBufferHeight = 720;
}
/// <summary>
/// Allows the game to perform any initialization it needs to before starting to run.
/// This is where it can query for any required services and load any non-graphic
/// related content. Calling base.Initialize will enumerate through any components
/// and initialize them as well.
/// </summary>
protected override void Initialize()
{
// TODO: Add your initialization logic here
//enable the mousepointer
IsMouseVisible = true;
base.Initialize();
}
public void Save(string filename)
{
System.IO.TextWriter textOut = null;
try
{
textOut = new System.IO.StreamWriter(filename);
Save(textOut);
}
catch (Exception e)
{
throw e;
}
finally
{
if (textOut != null) textOut.Close();
}
}
private void Save(TextWriter textOut)
{
try
{
foreach (Sprite crew1 in crew)
{
textOut.WriteLine(crew1.location.X);
textOut.WriteLine(crew1.location.Y);
}
foreach (sharks enemySprite in sharks)
{
textOut.WriteLine("Shark");
textOut.WriteLine(enemySprite.location.X);
textOut.WriteLine(enemySprite.location.Y);
}
}
catch
{
}
}
public void Load(string filename)
{
System.IO.TextReader textIn = null;
//try
//{
textIn = new System.IO.StreamReader(filename);
Load(textIn);
//}
//catch (Exception e)
//{
// throw e;
//}
//finally
//{
if (textIn != null) textIn.Close();
//}
}
private void Load(TextReader textIn)
{
foreach (Sprite crew1 in crew)
{
crew1.location.X = int.Parse(textIn.ReadLine());
crew1.location.Y = int.Parse(textIn.ReadLine());
}
foreach (sharks enemySprite in sharks)
{
enemySprite.location.X = int.Parse(textIn.ReadLine());
enemySprite.location.Y = int.Parse(textIn.ReadLine());
}
throw new NotImplementedException();
}
/// <summary>
/// LoadContent will be called once per game and is the place to load
/// all of your content.
/// </summary>
protected override void LoadContent()
{
// Create a new SpriteBatch, which can be used to draw textures.
spriteBatch = new SpriteBatch(GraphicsDevice);
backgroundTexture = Content.Load<Texture2D>("Background");
backgroundRectangle = new Rectangle(
0, 0, // top left hand corner
Window.ClientBounds.Width,
Window.ClientBounds.Height); // size of screen display
//-------Captains crew-------
c = new Sprite(new Vector2(0, 0), new Vector2(0, 0),
Content.Load<Texture2D>("WhiteBall"), Color.White);
BlueBall = new Sprite(new Vector2(640, 450),
Content.Load<Texture2D>("BlueBall"));
crew.Add(BlueBall);
GreenBall = new Sprite(new Vector2(250, 600),
Content.Load<Texture2D>("GreenBall"));
crew.Add(GreenBall);
OrangeBall = new Sprite(new Vector2(115, 400),
Content.Load<Texture2D>("OrangeBall"));
crew.Add(OrangeBall);
RedBall = new Sprite(new Vector2(500, 600),
Content.Load<Texture2D>("RedBall"));
crew.Add(RedBall);
YellowBall = new Sprite(new Vector2(800, 400),
Content.Load<Texture2D>("YellowBall"));
crew.Add(YellowBall);
PinkBall = new Sprite(new Vector2(25, 175),
Content.Load<Texture2D>("PinkBall"));
crew.Add(PinkBall);
//--------Sharks------
sharks s = new sharks(new Vector2(1000, 200),
Content.Load<Texture2D>("BlackBall"));
sharks.Add(s);
s = new sharks(new Vector2(900, 200),
Content.Load<Texture2D>("BlackBall"));
sharks.Add(s);
s = new sharks(new Vector2(800, 200),
Content.Load<Texture2D>("BlackBall"));
sharks.Add(s);
messageFont = Content.Load<SpriteFont>("messageFont");
// TODO: use this.Content to load your game content here
}
/// <summary>
/// UnloadContent will be called once per game and is the place to `enter code here`unload
/// all content.
/// </summary>
protected override void UnloadContent()
{
// TODO: Unload any non ContentManager content here
}
/// <summary>
/// Allows the game to run logic such as updating the world,
/// checking for collisions, gathering input, and playing audio.
/// </summary>
/// <param name="gameTime">Provides a snapshot of timing values.</param>
protected override void Update(GameTime gameTime)
{
//----------This gets the time value---------
float elapsed = (float)gameTime.ElapsedGameTime.TotalSeconds;
//--------------keyboard input---------------
//Exit
if (Keyboard.GetState().IsKeyDown(Keys.Back))
this.Exit();
//Save
if (Keyboard.GetState().IsKeyDown(Keys.S))
Save("test.txt");
//Load
if (Keyboard.GetState().IsKeyDown(Keys.L))
Load("test.txt");
//Directional Movement
if (Keyboard.GetState().IsKeyDown(Keys.Left))
c.velocity.X = -350;
if (Keyboard.GetState().IsKeyDown(Keys.Right))
c.velocity.X = 350;
if (Keyboard.GetState().IsKeyDown(Keys.Down))
c.velocity.Y = 350;
if (Keyboard.GetState().IsKeyDown(Keys.Up))
c.velocity.Y = -350;
c.Update(elapsed);
foreach (Sprite cr in crew)
{
cr.Update(elapsed);
}
c.col = Color.White;
//----sharks intersects with whiteball----
foreach (sharks s in sharks)
{
if (c.bounds.Intersects(s.bounds))
{
c.col = Color.Red;
break;
}
}
foreach (sharks s in sharks)
{
s.Update(elapsed, c.location);
}
//----sprites intersect with whiteball----
foreach (Sprite crew1 in crew)
{
if (c.bounds.Intersects(crew1.bounds))
{
c.col = Color.Red;
playerScore += 1;
crew1.bounds.X = 10000;
crew1.bounds.Y = 10000;
crew1.location.Y = 10000;
crew1.location.X = 10000;
break;
}
}
base.Update(gameTime);
}
/// <summary>
/// This is called when the game should draw itself.
/// </summary>
/// <param name="gameTime">Provides a snapshot of timing values.</param>
protected override void Draw(GameTime gameTime)
{
GraphicsDevice.Clear(Color.CornflowerBlue);
spriteBatch.Begin();
spriteBatch.Draw(backgroundTexture, backgroundRectangle,
Color.White);
//Background.Draw(spriteBatch);
c.Draw(spriteBatch);
foreach (Sprite cr in crew)
{
cr.Draw(spriteBatch);
}
foreach (sharks s in sharks)
{
s.Draw(spriteBatch);
}
//---------messsage font succussfully saved----------
spriteBatch.DrawString(messageFont, playerScore.ToString(),
new Vector2(145, 0),
Color.White);
spriteBatch.DrawString(messageFont, " Player Scores",
new Vector2(0, 0), Color.White);
spriteBatch.End();
base.Draw(gameTime);
}
}
}
Sprite类保存动作，界定一切
using System;
using System.Collections.Generic;
using System.Linq;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Audio;
using Microsoft.Xna.Framework.Content;
using Microsoft.Xna.Framework.GamerServices;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;
using Microsoft.Xna.Framework.Media;
namespace PickUpTheCrewGame
{
class Sprite
{
public Vector2 location;
public Vector2 velocity;//this hold the sprite movement
public Texture2D image;
public Rectangle bounds;//inventing the boundaries using rectange variable
public Color col = Color.White;
int maxVel = 600;
public Sprite(Vector2 location, Texture2D image, Color clr)
{
this.location = location;
this.image = image;
this.col = clr;
//----setting the boundaries of the screen to match the window-----
bounds = new Rectangle((int)location.X, (int)location.Y, 64, 64);
}
public Sprite(Vector2 location, Texture2D image)
{
this.location = location;
this.image = image;
//----setting the boundaries of the screen to match the window-----
bounds = new Rectangle((int)location.X, (int)location.Y, 64, 64);
}
public Sprite(Vector2 location,Vector2 vel, Texture2D image, Color clr)
{
this.location = location;
this.velocity = vel;
this.image = image;
this.col = clr;
//----setting the boundaries of the screen to match the window-----
bounds = new Rectangle((int)location.X, (int)location.Y, 64, 64);
}
public void Draw(SpriteBatch spriteBatch)
{
spriteBatch.Draw(image, location, col);
}
public void Update(float elapsed)
{
//----sets the speed for the players----
location += velocity * elapsed;
//-------initialising the boundaries for the screen-----
bounds.X = (int)location.X;
bounds.Y = (int)location.Y;
//--------Posotive velocity---------
if (velocity.X > maxVel)
velocity.X = maxVel;
if (velocity.Y > maxVel)
velocity.Y = maxVel;
//----Negative velocity-------
if (velocity.X < -maxVel)
velocity.X = -maxVel;
if (velocity.Y < -maxVel)
velocity.Y = -maxVel;
//------adding friction to the AI------
velocity = velocity * 0.9f;
//-------Assigning the boundaries-----
if (bounds.Left < 0)
location.X = 0;
if (bounds.Top < 0)
location.Y = 0;
if (bounds.Right > 1280)
location.X = 1280 - bounds.Width;
if (bounds.Bottom > 720)
location.Y = 720 - bounds.Height;
}
public void Accelerate(Vector2 direction)
{
//-----normalises is to get a unit vector (40 is force), normal is direction
velocity += 15 * Vector2.Normalize(direction);
}
}
}
简单的敌人精灵（AI）类
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Content;
using Microsoft.Xna.Framework.Graphics;
namespace PickUpTheCrewGame
{
class sharks:Sprite
{
public sharks(Vector2 location, Texture2D image)
:base(location,image)
{
}
public void Update(float elapsed, Vector2 playerLoc)
{
Accelerate(playerLoc - location);//should make the ai go towards the player all the time
base.Update(elapsed);
}
}
}