在游戏中,有各种各样特效,其中有一种特效是通过计算随机产生,而不是一张又一张的图片更换,通过模拟现实中的粒子物理规律得到有趣真实的效果,这种叫作粒子特效,它能大量的降低资源大小,咱们一起实现一个简单的跟随鼠标的粒子特效。
- public class GlobalValue
- {
- /// <summary>
- /// 全局随机函数,从时间取得种子,保证每次都不一样
- /// </summary>
- public static Random random = new Random((int)DateTime.Now.Ticks);
- /// <summary>
- /// 起始透明度
- /// </summary>
- public const double OPACITY = 1;
- /// <summary>
- /// 每次添加多少个粒子
- /// </summary>
- public const double FIREWORK_NUM = 2;
- /// <summary>
- /// 重力
- /// </summary>
- public const double GRAVITY = 0.1;
- /// <summary>
- /// 偏移X
- /// </summary>
- public const double X_VELOCITY = 5;
- /// <summary>
- /// 偏移Y
- /// </summary>
- public const double Y_VELOCITY = 5;
- /// <summary>
- /// 最小的半径
- /// </summary>
- public const int SIZE_MIN = 1;
- /// <summary>
- /// 最大的半径
- /// </summary>
- public const int SIZE_MAX = 10;
- /// <summary>
- /// 透明度衰减值
- /// </summary>
- public const double OpacityInc = -0.02;
- }
- public class Dot: Canvas
- {
- public double XVelocity = 1;
- public double YVelocity = 1;
- public double Gravity = 1;
- public Dot(byte red, byte green, byte blue, double size)
- {
- double opac = GlobalValue.OPACITY;
- size = GlobalValue.random.Next(GlobalValue.SIZE_MIN,GlobalValue.SIZE_MAX);
- //生成圆圈粒子
- {
- Ellipse ellipse = new Ellipse();
- ellipse.Width = size;
- ellipse.Height = size;
- ellipse.Fill = new SolidColorBrush(Color.FromArgb(255, red, green, blue));
- ellipse.Opacity = opac;
- ellipse.SetValue(Canvas.LeftProperty, -ellipse.Width / 2);
- ellipse.SetValue(Canvas.TopProperty, -ellipse.Height / 2);
- this.Children.Add(ellipse);
- }
- }
- public void RunFirework()
- {
- XX = X + XVelocity;
- YY = Y + YVelocity;
- this.Opacity += GlobalValue.OpacityInc;
- YVelocity += Gravity;
- }
- //制作一个绑定属性
- public double X
- {
- get { return (double)(GetValue(Canvas.LeftProperty)); }
- set { SetValue(Canvas.LeftProperty, value); }
- }
- public double Y
- {
- get { return (double)(GetValue(Canvas.TopProperty)); }
- set { SetValue(Canvas.TopProperty, value); }
- }
- }
- public class Colorful : Canvas
- {
- private List<Dot> _dotGroup = new List<Dot>();
- private DispatcherTimer _timer;
- private static int IntervalTime = 20;
- public Colorful()
- {
- this.Background = new SolidColorBrush(Colors.Gray);
- List<Object> array = new List<Object>();
- Object abc = new Object();
- Start();
- }
- void loop_timer_Tick(object sender, EventArgs e)
- {
- moveDots();
- }
- void moveDots()
- {
- for (int i = _dotGroup.Count - 1; i >= 0; i--)
- {
- Dot dot = _dotGroup[i];
- dot.RunFirework();
- if (dot.Opacity <= 0.1)
- {
- this.Children.Remove(dot);
- _dotGroup.Remove(dot);
- }
- }
- }
- public virtual void addDotToGroup(double x, double y)
- {
- int seed = (int)DateTime.Now.Ticks;
- for (int i = 0; i < GlobalValue.FIREWORK_NUM; i++)
- {
- double size = GlobalValue.SIZE_MIN + (GlobalValue.SIZE_MAX - GlobalValue.SIZE_MIN) * GlobalValue.random.NextDouble();
- byte red = (byte)(128 + (128 * GlobalValue.random.NextDouble()));
- byte green = (byte)(128 + (128 * GlobalValue.random.NextDouble()));
- byte blue = (byte)(128 + (128 * GlobalValue.random.NextDouble()));
- double xVelocity = GlobalValue.X_VELOCITY - 2 * GlobalValue.X_VELOCITY * GlobalValue.random.NextDouble();
- double yVelocity = -GlobalValue.Y_VELOCITY * GlobalValue.random.NextDouble();
- Dot dot = new Dot(red, green, blue, size);
- dot.X = x;
- dot.Y = y;
- dot.XVelocity = xVelocity;
- dot.YVelocity = yVelocity;
- dot.Gravity = GlobalValue.GRAVITY;
- dot.RunFirework();
- _dotGroup.Add(dot);
- this.Children.Add(dot);
- }
- }
- public virtual void Start()
- {
- _timer = new DispatcherTimer();
- _timer.Interval = TimeSpan.FromMilliseconds(IntervalTime);
- _timer.Tick += new EventHandler(loop_timer_Tick);
- _timer.Start();
- }
- }
- 这是一个只有执行逻辑的容器,addDot用来增加粒子,moveDots是移动粒子并且检测是否消失,如果消失则从List和父结构中移除掉。
- 生成逻辑通过面向对象的方式实现,建立一个Colorful_FollowMouse类:
- public class Colorful_FollowMouse : Colorful
- {
- public Colorful_FollowMouse()
- {
- MouseMove += new MouseEventHandler(Colorful_FollowMouse_MouseMove);
- }
- void Colorful_FollowMouse_MouseMove(object sender, MouseEventArgs e)
- {
- addDotToGroup(e.GetPosition(this).X, e.GetPosition(this).Y);
- }
- }