游戲人生Silverlight:星際競技場
介紹
使用 Silverlight 2.0(c#, Farseer Physics Engine) 開發一個射擊游戲:星際競技場
玩法
W 或者 ↑ = 前進;S 或者 ↓ = 后退:A 或者 ← = 左轉;D 或者 → = 右轉;J 或者 Ctrl = 開火
思路
1、使用一個開源的 Silverlight 物理引擎:Farseer Physics Engine
2、將 Farseer Physics Engine 中的物理運算器 PhysicsSimulator 放到一個全局變量中,對 Body 和 Geom 做即時運算,
3、寫個 IPhysicsControl 接口,用于描述物理對象的各個屬性,需要運動和碰撞的對象,要實現該接口抽象出來的各個屬性
4、寫個抽象類(Sprite),在其內封裝好物理引擎。各種類型的物理對象的模擬器,都需要重寫該抽象類的兩個方法GetForce()和GetTorque()即可,其分別要返回對象在當前時刻所受到的牽引力和力矩
5、寫個 IFire 接口,所有可開火的對象都要實現該接口
6、寫個控件 PhysicsBox,用于包裝 IPhysicsControl,從而將模擬器計算出的運動和碰撞結果呈現到界面上
關鍵代碼Sprite.cs(Sprite 模擬器的基類)
- using System;
- using System.Net;
- using System.Windows;
- using System.Windows.Controls;
- using System.Windows.Documents;
- using System.Windows.Ink;
- using System.Windows.Input;
- using System.Windows.Media;
- using System.Windows.Media.Animation;
- using System.Windows.Shapes;
- using FarseerGames.FarseerPhysics;
- using FarseerGames.FarseerPhysics.Mathematics;
- using FarseerGames.FarseerPhysics.Dynamics;
- using FarseerGames.FarseerPhysics.Collisions;
- namespace YYArena.Core
- {
- /**//// <summary>
- /// Sprite 基類
- /// </summary>
- public abstract class Sprite
- {
- private PhysicsSimulator _physicsSimulator;
- protected PhysicsBox playerBox;
- protected Geom playerGeometry;
- /**//// <summary>
- /// 構造函數
- /// </summary>
- /// <param name="physicsSimulator">PhysicsSimulator</param>
- /// <param name="physicsControl">IPhysicsControl</param>
- /// <param name="position">初始位置</param>
- /// <param name="angle">初始轉角</param>
- /// <param name="originalVelocity">初始速度</param>
- public Sprite(PhysicsSimulator physicsSimulator,
- IPhysicsControl physicsControl, Vector2 position, float angle, float originalVelocity)
- {
- _physicsSimulator = physicsSimulator;
- playerBox = new PhysicsBox(physicsControl);
- playerBox.Body.Position = position;
- playerBox.Body.Rotation = (float)Helper.Angle2Radian(angle);
- playerBox.Body.LinearVelocity = Helper.Convert2Vector(originalVelocity, (float)Helper.Angle2Radian(angle));
- // Body 和 Geom 的 Tag 保存為 Sprite,方便引用
- playerBox.Body.Tag = this;
- playerBox.Geom.Tag = this;
- playerBox.Update();
- }
- /**//// <summary>
- /// 即時計算力和力矩
- /// </summary>
- void CompositionTarget_Rendering(object sender, EventArgs e)
- {
- if (Enabled)
- {
- var force = GetForce();
- var torque = GetTorque();
- playerBox.Body.ApplyForce(force);
- playerBox.Body.ApplyTorque(torque);
- playerBox.Update();
- }
- }
- /**//// <summary>
- /// 返回 Sprite 當前受的力
- /// </summary>
- protected abstract Vector2 GetForce();
- /**//// <summary>
- /// 返回 Sprite 當前受的力矩
- /// </summary>
- protected abstract float GetTorque();
- public PhysicsBox PhysicsBox
- {
- get { return playerBox; }
- }
- private bool _enabled = false;
- /**//// <summary>
- /// 是否啟用此 Sprite
- /// </summary>
- public bool Enabled
- {
- get { return _enabled; }
- set
- {
- _enabled = value;
- if (value)
- {
- CompositionTarget.Rendering += new EventHandler(CompositionTarget_Rendering);
- _physicsSimulator.Add(playerBox.Body);
- _physicsSimulator.Add(playerBox.Geom);
- }
- else
- {
- CompositionTarget.Rendering -= new EventHandler(CompositionTarget_Rendering);
- GC.SuppressFinalize(this);
- _physicsSimulator.Remove(playerBox.Body);
- _physicsSimulator.Remove(playerBox.Geom);
- }
- }
- }
- }
- }
#p#
PlayerSprite.cs(玩家 Sprite 模擬器)
- using System;
- using System.Net;
- using System.Windows;
- using System.Windows.Controls;
- using System.Windows.Documents;
- using System.Windows.Ink;
- using System.Windows.Input;
- using System.Windows.Media;
- using System.Windows.Media.Animation;
- using System.Windows.Shapes;
- using System.Collections.Generic;
- using FarseerGames.FarseerPhysics.Mathematics;
- using FarseerGames.FarseerPhysics;
- using FarseerGames.FarseerPhysics.Collisions;
- namespace YYArena.Core
- {
- /**//// <summary>
- /// 玩家 Sprite
- /// </summary>
- public class PlayerSprite : Sprite, IFire
- {
- private List<Key> _upKeys { get; set; }
- private List<Key> _downKeys { get; set; }
- private List<Key> _leftKeys { get; set; }
- private List<Key> _rightKeys { get; set; }
- private List<Key> _fireKeys { get; set; }
- private KeyboardHandler _keyHandler;
- private IPhysicsControl _physicsControl;
- /**//// <summary>
- /// 構造函數
- /// </summary>
- /// <param name="physicsSimulator">PhysicsSimulator</param>
- /// <param name="physicsControl">IPhysicsControl</param>
- /// <param name="position">初始位置</param>
- /// <param name="angle">初始轉角</param>
- /// <param name="originalVelocity">初始速度</param>
- /// <param name="keyboardHandler">KeyboardHandler</param>
- /// <param name="up">操作玩家向前移動的按鍵集合</param>
- /// <param name="down">操作玩家向后移動的按鍵集合</param>
- /// <param name="left">操作玩家向左轉動的按鍵集合</param>
- /// <param name="right">操作玩家向右轉動的按鍵集合</param>
- /// <param name="fire">操作玩家開火的按鍵集合</param>
- public PlayerSprite(PhysicsSimulator physicsSimulator,
- IPhysicsControl physicsControl, Vector2 position, float angle, float originalVelocity,
- KeyboardHandler keyboardHandler,
- List<Key> up, List<Key> down, List<Key> left, List<Key> right, List<Key> fire)
- : base(physicsSimulator, physicsControl, position, angle, originalVelocity)
- {
- PrevFireDateTime = DateTime.MinValue;
- MinFireInterval = 500d;
- _upKeys = up;
- _downKeys = down;
- _leftKeys = left;
- _rightKeys = right;
- _fireKeys = fire;
- _keyHandler = keyboardHandler;
- _physicsControl = physicsControl;
- CompositionTarget.Rendering += new EventHandler(CompositionTarget_Rendering);
- }
- void CompositionTarget_Rendering(object sender, EventArgs e)
- {
- if (Enabled)
- {
- // 如果按了開火鍵,是否可開火
- if (_keyHandler.AnyKeyPressed(_fireKeys) && (DateTime.Now - PrevFireDateTime).TotalMilliseconds > MinFireInterval)
- {
- PrevFireDateTime = DateTime.Now;
- if (Fire != null)
- Fire(this, EventArgs.Empty);
- }
- }
- }
- public DateTime PrevFireDateTime { get; set; }
- public double MinFireInterval { get; set; }
- public event EventHandler<EventArgs> Fire;
- protected override Vector2 GetForce()
- {
- Vector2 force = Vector2.Zero;
- if (_keyHandler.AnyKeyPressed(_upKeys))
- force += Helper.Convert2Vector(_physicsControl.ForceAmount, playerBox.Body.Rotation);
- if (_keyHandler.AnyKeyPressed(_downKeys))
- force += Helper.Convert2Vector(_physicsControl.ForceAmount, playerBox.Body.Rotation - Helper.Angle2Radian(180));
- // 最大線性速度限制
- if (playerBox.Body.LinearVelocity.Length() > _physicsControl.MaxLinearVelocity)
- force = Vector2.Zero;
- return force;
- }
- protected override float GetTorque()
- {
- float torque = 0;
- if (_keyHandler.AnyKeyPressed(_leftKeys))
- torque -= _physicsControl.TorqueAmount;
- if (_keyHandler.AnyKeyPressed(_rightKeys))
- torque += _physicsControl.TorqueAmount;
- // 用于修正 RotationalDragCoefficient (在沒有任何 Torque 的情況下,如果轉速小于 1.3 則設其為 0)
- // 如果不做此修正的話,轉速小于 1.3 后還會轉好長時間
- if (!_keyHandler.AnyKeyPressed(_leftKeys) && !_keyHandler.AnyKeyPressed(_rightKeys) && Math.Abs(playerBox.Body.AngularVelocity) < 1.3)
- playerBox.Body.AngularVelocity = 0;
- // 最大轉速限制
- if (Math.Abs(playerBox.Body.AngularVelocity) > _physicsControl.MaxAngularVelocity)
- torque = 0;
- return torque;
- }
- }
- }
#p#
AISprite.cs(敵軍 Sprite 模擬器)
- using System;
- using System.Net;
- using System.Windows;
- using System.Windows.Controls;
- using System.Windows.Documents;
- using System.Windows.Ink;
- using System.Windows.Input;
- using System.Windows.Media;
- using System.Windows.Media.Animation;
- using System.Windows.Shapes;
- using System.Collections.Generic;
- using FarseerGames.FarseerPhysics.Mathematics;
- using FarseerGames.FarseerPhysics;
- using FarseerGames.FarseerPhysics.Collisions;
- using FarseerGames.FarseerPhysics.Dynamics;
- namespace YYArena.Core
- {
- /**//// <summary>
- /// 敵軍 Sprite
- /// </summary>
- public class AISprite : Sprite, IFire
- {
- private Sprite _attackTarget;
- private int _aiLevel;
- private IPhysicsControl _physicsControl;
- /**//// <summary>
- /// 構造函數
- /// </summary>
- /// <param name="physicsSimulator">PhysicsSimulator</param>
- /// <param name="physicsControl">IPhysicsControl</param>
- /// <param name="position">初始位置</param>
- /// <param name="angle">初始轉角</param>
- /// <param name="originalVelocity">初始速度</param>
- /// <param name="attackTarget">攻擊目標</param>
- /// <param name="aiLevel">ai等級</param>
- public AISprite(PhysicsSimulator physicsSimulator,
- IPhysicsControl physicsControl, Vector2 position, float angle, float originalVelocity, Sprite attackTarget, int aiLevel)
- : base(physicsSimulator, physicsControl, position, angle, originalVelocity)
- {
- // 上次開火時間
- PrevFireDateTime = DateTime.Now.AddSeconds(3);
- // 最小開火間隔
- MinFireInterval = 3000d;
- _attackTarget = attackTarget;
- _aiLevel = aiLevel;
- _physicsControl = physicsControl;
- InitAI();
- CompositionTarget.Rendering += new EventHandler(CompositionTarget_Rendering);
- }
- private void InitAI()
- {
- // 根據 ai 等級設置最小開火間隔
- double fireCoefficient = 1 + 30 / _aiLevel;
- MinFireInterval = Helper.GenerateRandom((int)MinFireInterval, (int)(fireCoefficient * MinFireInterval));
- }
- void CompositionTarget_Rendering(object sender, EventArgs e)
- {
- if (Enabled && AttackTarget.Enabled)
- {
- // 是否開火
- if ((DateTime.Now - PrevFireDateTime).TotalMilliseconds > MinFireInterval)
- {
- PrevFireDateTime = DateTime.Now;
- if (Fire != null)
- Fire(this, EventArgs.Empty);
- }
- }
- }
- public DateTime PrevFireDateTime { get; set; }
- public double MinFireInterval { get; set; }
- public event EventHandler<EventArgs> Fire;
- public Sprite AttackTarget
- {
- get { return _attackTarget; }
- set { _attackTarget = value; }
- }
- protected override Vector2 GetForce()
- {
- Vector2 force = Vector2.Zero;
- if (!_attackTarget.Enabled)
- return force;
- force += Helper.Convert2Vector(_physicsControl.ForceAmount, playerBox.Body.Rotation);
- // 根據 ai 等級做最大線性速度限制
- if (playerBox.Body.LinearVelocity.Length() > _physicsControl.MaxLinearVelocity * Helper.GenerateRandom(50, 200) / 1000)
- force = Vector2.Zero;
- return force;
- }
- protected override float GetTorque()
- {
- float torque = 0f;
- if (!_attackTarget.Enabled)
- return torque;
- // 按某個方向旋轉,原則是以最小的旋轉角度對準目標
- Vector2 relativePosition = _attackTarget.PhysicsBox.Body.Position - playerBox.Body.Position;
- double targetRotation = Helper.Convert2Rotation(relativePosition);
- double currentRotation = playerBox.Body.Rotation;
- double relativeAngle = Helper.Radian2Angle(targetRotation - currentRotation);
- if (relativeAngle < 0)
- relativeAngle += 360;
- if (relativeAngle > 1)
- {
- if (relativeAngle < 180 && relativeAngle > 0)
- torque += _physicsControl.TorqueAmount;
- else if (relativeAngle > 180 && relativeAngle < 360)
- torque -= _physicsControl.TorqueAmount;
- }
- else
- {
- playerBox.Body.AngularVelocity = 0;
- }
- // 最大轉速限制
- if (Math.Abs(playerBox.Body.AngularVelocity) > _physicsControl.MaxAngularVelocity)
- torque = 0;
- return torque;
- }
- }
- }
原文鏈接:http://www.cnblogs.com/webabcd/archive/2009/06/22/1508042.html