3D打飛機

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 missileLauncherBase = new GameObject();
        GameObject missileLauncherHead = new GameObject();
        const int numMissiles = 20;
        GameObject[] missiles;
        Vector3 cameraPosition = new Vector3(0.0f, 60.0f,160.0f);
        Vector3 cameraLookAt = new Vector3(0.0f, 50.0f, 0.0f);
        Matrix cameraProjectionMatrix;
        Matrix cameraViewMatrix;
        GamePadState previousState;
        KeyboardState previousKeyboardState;
        const float launcherHeadMuzzleOffset = 20.0f;
        const float missilePower = 20.0f;
        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);
            myModel = Content.Load<Model>("Models\\p1_wedge");
            aspectRatio = (float)graphics.GraphicsDevice.Viewport.Width /
            (float)graphics.GraphicsDevice.Viewport.Height;
            cameraViewMatrix = Matrix.CreateLookAt(
                cameraPosition,
                cameraLookAt,
                Vector3.Up);
            cameraProjectionMatrix = Matrix.CreatePerspectiveFieldOfView(
                MathHelper.ToRadians(45.0f),
                graphics.GraphicsDevice.Viewport.AspectRatio,
                1.0f,
                10000.0f);
            missileLauncherBase.scale = 0.2f;

            missileLauncherHead.scale = 0.2f;
            missileLauncherHead.position = missileLauncherBase.position +
                new Vector3(0.0f, 20.0f, 0.0f);
            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;
            }
        }
        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();
            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;
            missileLauncherHead.rotation.Y = MathHelper.Clamp(
                missileLauncherHead.rotation.Y,
                -MathHelper.PiOver4, MathHelper.PiOver4);
            missileLauncherHead.rotation.X = MathHelper.Clamp(
                missileLauncherHead.rotation.X,
                0, MathHelper.PiOver4);
            if (gamePadState.Buttons.A == ButtonState.Pressed &&
                previousState.Buttons.A == ButtonState.Released)
            {
                FireMissile();
            }
           

            //modelRotation += (float)gameTime.ElapsedGameTime.TotalMilliseconds * MathHelper.ToRadians(0.1f);
            KeyboardState keyboardState = Keyboard.GetState();
            if (keyboardState.IsKeyDown(Keys.Space) &&
                previousKeyboardState.IsKeyUp(Keys.Space))
            {
                FireMissile();
    
            }
            UpdateMissiles();
            previousState = gamePadState;
            previousKeyboardState = keyboardState;
            base.Update(gameTime);
        }

        // 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.
        void FireMissile()
        {
            foreach (GameObject missile in missiles)
            {
                if (!missile.alive)
                {

                    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);
        }
        void UpdateMissiles()
        {
            foreach (GameObject missile in missiles)
            {
                if (missile.alive)
                {
                    missile.position += missile.velocity;
                    if (missile.position.Z < -6000.0f)
                    {
                        missile.alive = false;
                    }
                    else
                    {
                        TestCollision(missile);
                    }
                }
            }
        }
        void TestCollision(GameObject missile)
        {
            BoundingSphere missilesphere =
                missile.model.Meshes[0].BoundingSphere;
            missilesphere.Center = missile.position;
            missilesphere.Radius *= missile.scale;

        }
        protected override void Draw(GameTime gameTime)
        {
            graphics.GraphicsDevice.Clear(Color.CornflowerBlue);

           

            foreach (GameObject missile in missiles)
            {
                if (missile.alive)
                {
                    DrawGameObject(missile);
                }
            }
            // 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);
        }
      void DrawGameObject(GameObject gameobject)
        {
            foreach (ModelMesh mesh in gameobject.model.Meshes)
            {
                foreach (BasicEffect effect in mesh.Effects)
                {
                    effect.EnableDefaultLighting();
                    effect.PreferPerPixelLighting = true;

                    effect.World =
                        Matrix.CreateFromYawPitchRoll(
                        gameobject.rotation.Y,
                        gameobject.rotation.X,
                        gameobject.rotation.Z) *

                        Matrix.CreateScale(gameobject.scale) *
                        Matrix.CreateTranslation(gameobject.position);
                    effect.Projection = cameraProjectionMatrix;
                    effect.View = cameraViewMatrix;
                }
                mesh.Draw();
            }
        }
    }
    }