旋轉的飛機

using System;
using System.Collections.Generic;
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.Net;
using Microsoft.Xna.Framework.Storage;
namespace GoingBeyond1_Tutorial
{
    /// <summary>
    /// This is the main type for your game
    /// </summary>
    public class Game1 : Microsoft.Xna.Framework.Game
    {
        GraphicsDeviceManager graphics;
        SpriteBatch spriteBatch;
        GameObject terrain = new GameObject();
        GameObject missileLauncherBase = new GameObject();
        GameObject missileLauncherHead = new GameObject();
        const int numMissiles = 20;
        GameObject[] missiles;
        GamePadState previousState;
        KeyboardState previousKeyboardState;
        const float launcherHeadMuzzleOffset = 20.0f;
        const float missilePower = 20.0f;
        Vector3 cameraLookAt = new Vector3(0.0f, 50.0f, 0.0f);
        Matrix cameraProjectionMatrix;
        Matrix cameraViewMatrix;
        public Game1()
        {
            graphics = new GraphicsDeviceManager(this);
            Content.RootDirectory = "Content";
        }
        protected override void Initialize()
        {
            base.Initialize();
        }
        // Set the 3D model to draw.
        Model myModel;
        // The aspect ratio determines how to scale 3d to 2d projection.
        float aspectRatio;
        protected override void LoadContent()
        {
            // Create a new SpriteBatch, which can be used to draw textures.
            spriteBatch = new SpriteBatch(GraphicsDevice);
            cameraViewMatrix = Matrix.CreateLookAt(
                cameraPosition,
                cameraLookAt,
                Vector3.Up);
            cameraProjectionMatrix = Matrix.CreatePerspectiveFieldOfView(
                MathHelper.ToRadians(45.0f),
                graphics.GraphicsDevice.Viewport.AspectRatio,
                1.0f,
                10000.0f);
            missiles = new GameObject[numMissiles];
            for (int i = 0; i < numMissiles; i++)
            {
                missiles[i] = new GameObject();
                missiles[i].model =
                    Content.Load<Model>("Models\\missile");
                missiles[i].scale = 3.0f;
            }
           

            myModel = Content.Load<Model>("Models\\p1_wedge");
            aspectRatio = (float)graphics.GraphicsDevice.Viewport.Width /
            (float)graphics.GraphicsDevice.Viewport.Height;
        }
        protected override void UnloadContent()
        {
        }
      
        protected override void Update(GameTime gameTime)
        {
            // Allows the game to exit
            if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed)
                this.Exit();
            GamePadState gamePadState = GamePad.GetState(PlayerIndex.One);
            missileLauncherHead.rotation.Y -=
                gamePadState.ThumbSticks.Left.X * 0.1f;
            missileLauncherHead.rotation.X +=
                gamePadState.ThumbSticks.Left.Y * 0.1f;
          
            KeyboardState keyboardState = Keyboard.GetState();
            if (keyboardState.IsKeyDown(Keys.Left))
            {
                missileLauncherHead.rotation.Y += 0.05f;
            }
            if (keyboardState.IsKeyDown(Keys.Right))
            {
                missileLauncherHead.rotation.Y -= 0.05f;
            }
            if (keyboardState.IsKeyDown(Keys.Up))
            {
                missileLauncherHead.rotation.X += 0.05f;
            }
            if (keyboardState.IsKeyDown(Keys.Down))
            {
                missileLauncherHead.rotation.X -= 0.05f;
            }
 
            if (keyboardState.IsKeyDown(Keys.Space) &&
                previousKeyboardState.IsKeyUp(Keys.Space))
            {
                FireMissile();
                modelRotation += (float)gameTime.ElapsedGameTime.TotalMilliseconds * MathHelper.ToRadians(0.1f);
            }
            previousKeyboardState = keyboardState;

           
            base.Update(gameTime);
        }
        void FireMissile()
        {
            foreach (GameObject missile in missiles)
            {
                if (!missile.alive)
                {
                    //soundBank.PlayCue("missilelaunch");
                    missile.velocity = GetMissileMuzzleVelocity();
                    missile.position = GetMissileMuzzlePosition();
                    missile.rotation = missileLauncherHead.rotation;
                    missile.alive = true;
                    break;
                }
            }
        }
        Vector3 GetMissileMuzzleVelocity()
        {
            Matrix rotationMatrix =
                Matrix.CreateFromYawPitchRoll(
                missileLauncherHead.rotation.Y,
                missileLauncherHead.rotation.X,
                0);
            return Vector3.Normalize(
                Vector3.Transform(Vector3.Forward,
                rotationMatrix)) * missilePower;
        }
        Vector3 GetMissileMuzzlePosition()
        {
            return missileLauncherHead.position +
                (Vector3.Normalize(
                GetMissileMuzzleVelocity()) *
                launcherHeadMuzzleOffset);
        }
       
       
        // Set the position of the model in world space, and set the rotation.
        Vector3 modelPosition = Vector3.Zero;
        float modelRotation = 0.0f;
        // Set the position of the camera in world space, for our view matrix.
        Vector3 cameraPosition = new Vector3(0.0f, 50.0f, 1500.0f);
        protected override void Draw(GameTime gameTime)
        {
            graphics.GraphicsDevice.Clear(Color.CornflowerBlue);

            // Copy any parent transforms.
            Matrix[] transforms = new Matrix[myModel.Bones.Count];
            myModel.CopyAbsoluteBoneTransformsTo(transforms);
            // Draw the model. A model can have multiple meshes, so loop.
            foreach (ModelMesh mesh in myModel.Meshes)
            {
                // This is where the mesh orientation is set, as well as our camera and projection.
                foreach (BasicEffect effect in mesh.Effects)
                {
                    effect.EnableDefaultLighting();
                    effect.World = transforms[mesh.ParentBone.Index] * Matrix.CreateRotationY(modelRotation)
                        * Matrix.CreateTranslation(modelPosition);
                    effect.View = Matrix.CreateLookAt(cameraPosition, Vector3.Zero, Vector3.Up);
                    effect.Projection = Matrix.CreatePerspectiveFieldOfView(MathHelper.ToRadians(45.0f),
                        aspectRatio, 1.0f, 10000.0f);
                }
                // Draw the mesh, using the effects set above.
                mesh.Draw();
            }
                base.Draw(gameTime);
        }
          
       
    }
}