好的，所以我正在使用 xna studio 在 Visual Studio 2010 c# 中制作太空入侵者类型的游戏，目前卡在子弹类上，它会生成子弹，但不会朝精灵指向的方向发射。项目符号类表示 Public Vector2 来源；没有被分配给任何东西并保持其默认值，但我不知道是什么原因造成的。
子弹代码
class Bullets
{
public Texture2D texture;
public Vector2 position;
public Vector2 velocity;
public Vector2 origin;
public bool isVisible;
public Bullets(Texture2D newTexture)
{
texture = newTexture;
isVisible = false;
}
public void Draw(SpriteBatch spriteBatch)
{
spriteBatch.Draw(texture, position, null, Color.White, 0f, origin, 1f, SpriteEffects.None, 1);
}
}
游戏代码如下：
namespace Rotationgame
{
/// <summary>
/// This is the main type for your game
/// </summary>
public class Game1 : Microsoft.Xna.Framework.Game
{
GraphicsDeviceManager graphics;
SpriteBatch spriteBatch;
Vector2 spriteVelocity;
const float tangentialVelocity = 0f;
float friction = 1f;
Texture2D spriteTexture;
Rectangle spriteRectangle;
Rectangle screenRectangle;
// The centre of the image
Vector2 spriteOrigin;
Vector2 spritePosition;
float rotation;
// Background
Texture2D backgroundTexture;
Rectangle backgroundRectangle;
// Shield
Texture2D shieldTexture;
Rectangle shieldRectangle;
// Bullets
List<Bullets> bullets = new List<Bullets>();
KeyboardState pastKey;
public Game1()
{
graphics = new GraphicsDeviceManager(this);
Content.RootDirectory = "Content";
graphics.PreferredBackBufferWidth = 1250;
graphics.PreferredBackBufferHeight = 930;
screenRectangle = new Rectangle(
0,
0,
graphics.PreferredBackBufferWidth,
graphics.PreferredBackBufferHeight);
}
/// <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
base.Initialize();
}
/// <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);
shieldTexture = Content.Load<Texture2D>("Shield");
shieldRectangle = new Rectangle(517, 345, 250, 220);
spriteTexture = Content.Load<Texture2D>("PlayerShipup");
spritePosition = new Vector2(640, 450);
backgroundTexture = Content.Load<Texture2D>("Background");
backgroundRectangle = new Rectangle(0, 0, 1250, 930);
// TODO: use this.Content to load your game content here
}
/// <summary>
/// UnloadContent will be called once per game and is the place to 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)
{
// Allows the game to exit
if (Keyboard.GetState().IsKeyDown(Keys.Escape))
this.Exit();
// TODO: Add your update logic here
if (Keyboard.GetState().IsKeyDown(Keys.Space) && pastKey.IsKeyUp(Keys.Space))
Shoot();
pastKey = Keyboard.GetState();
spritePosition = spriteVelocity + spritePosition;
spriteRectangle = new Rectangle((int)spritePosition.X, (int)spritePosition.Y,
spriteTexture.Width, spriteTexture.Height);
spriteOrigin = new Vector2(spriteRectangle.Width / 2, spriteRectangle.Height / 2);
if (Keyboard.GetState().IsKeyDown(Keys.Right)) rotation += 0.025f;
if (Keyboard.GetState().IsKeyDown(Keys.Left)) rotation -= 0.025f;
if (Keyboard.GetState().IsKeyDown(Keys.Up))
{
spriteVelocity.X = (float)Math.Cos(rotation) * tangentialVelocity;
spriteVelocity.Y = (float)Math.Sin(rotation) * tangentialVelocity;
}
else if (Vector2.Zero != spriteVelocity)
{
float i = spriteVelocity.X;
float j = spriteVelocity.Y;
spriteVelocity.X = i -= friction * i;
spriteVelocity.Y = j -= friction * j;
base.Update(gameTime);
}
}
public void UpdateBullets()
{
foreach (Bullets bullet in bullets)
{
bullet.position += bullet.velocity;
if (Vector2.Distance(bullet.position, spritePosition) > 100)
bullet.isVisible = false;
}
for (int i = 0; i < bullets.Count; i++)
{
if(!bullets[i].isVisible)
{
bullets.RemoveAt(i);
i--;
}
}
}
public void Shoot()
{
Bullets newBullet = new Bullets(Content.Load<Texture2D>("ball"));
newBullet.velocity = new Vector2((float)Math.Cos(rotation),(float)Math.Sin(rotation)) * 5f + spriteVelocity;
newBullet.position = spritePosition + newBullet.velocity * 5;
newBullet.isVisible = true;
if(bullets.Count() < 20)
bullets.Add(newBullet);
}
/// <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);
spriteBatch.Draw(shieldTexture, shieldRectangle, Color.White);
foreach (Bullets bullet in bullets)
bullet.Draw(spriteBatch);
spriteBatch.Draw(spriteTexture, spritePosition, null, Color.White, rotation, spriteOrigin, 1f, SpriteEffects.None, 0);
spriteBatch.End();
// TODO: Add your drawing code here
base.Draw(gameTime);
}
}
我哪里错了？