1.1 基本公式
- v = v0 + at (速度方程)
- s = v0t + (1/2)at² (位移方程)
- v² = v0² + 2as (速度-位移方程)
其中:
v0: 初始速度
v: 当前速度
a: 加速度
t: 时间
s: 位移
2. 实现代码
2.1 运动参数类
public class MotionParameters
{
public double InitialVelocity { get; set; } // 初始速度
public double Acceleration { get; set; } // 加速度
public double MaxVelocity { get; set; } // 最大速度
public double Distance { get; set; } // 总距离
public Point StartPoint { get; set; } // 起点
public Point EndPoint { get; set; } // 终点
public MotionParameters()
{
InitialVelocity = 0;
Acceleration = 100; // 像素/秒²
MaxVelocity = 300; // 像素/秒
StartPoint = new Point(0, 0);
EndPoint = new Point(0, 0);
}
}
2.2 运动控制类
public class MotionControl
{
// 私有成员变量
private readonly MotionParameters _parameters; // 运动参数
private double _currentTime; // 当前运动时间
private double _currentVelocity; // 当前速度
private Point _currentPosition; // 当前位置
private bool _isAccelerating; // 是否处于加速阶段
private double _totalDistance; // 总运动距离
private double _currentDistance; // 当前已运动距离
// 添加公共属性访问
public double CurrentVelocity => _currentVelocity;
public bool IsCompleted => _currentDistance >= _totalDistance;
public Point StartPoint => _parameters.StartPoint;
public Point EndPoint => _parameters.EndPoint;
public MotionControl(MotionParameters parameters)
{
_parameters = parameters;
Initialize();
}
private void Initialize()
{
_currentTime = 0;
_currentVelocity = _parameters.InitialVelocity;
_currentPosition = _parameters.StartPoint;
_isAccelerating = true;
_currentDistance = 0;
// 计算总距离
_totalDistance = Math.Sqrt(
Math.Pow(_parameters.EndPoint.X - _parameters.StartPoint.X, 2) +
Math.Pow(_parameters.EndPoint.Y - _parameters.StartPoint.Y, 2));
}
public Point CalculatePosition(double deltaTime)
{
if (IsCompleted) return _currentPosition;
_currentTime += deltaTime;
// 更新速度
if (_isAccelerating)
{
_currentVelocity += _parameters.Acceleration * deltaTime;
if (_currentVelocity >= _parameters.MaxVelocity)
{
_currentVelocity = _parameters.MaxVelocity;
_isAccelerating = false;
}
}
// 计算这一帧移动的距离
double frameDistance = _currentVelocity * deltaTime;
_currentDistance += frameDistance;
// 确保不超过总距离
if (_currentDistance >= _totalDistance)
{
_currentDistance = _totalDistance;
_currentPosition = _parameters.EndPoint;
return _currentPosition;
}
// 计算当前位置
double ratio = _currentDistance / _totalDistance;
_currentPosition.X = (int)(_parameters.StartPoint.X +
(_parameters.EndPoint.X - _parameters.StartPoint.X) * ratio);
_currentPosition.Y = (int)(_parameters.StartPoint.Y +
(_parameters.EndPoint.Y - _parameters.StartPoint.Y) * ratio);
return _currentPosition;
}
public void Reset()
{
Initialize();
}
}
3. GDI+实现示例
3.1 主窗体类
public partial class Form1 : Form
{
private MotionControl _motionControl;
private Timer _animationTimer;
private Point _objectPosition;
private bool _isMoving;
private List _trajectoryPoints;
public Form1()
{
InitializeComponent();
this.DoubleBuffered = true;
_trajectoryPoints = new List();
InitializeComponents();
SetupMotionControl();
}
private void InitializeComponents()
{
_animationTimer = new Timer();
_animationTimer.Interval = 16; // ~60fps
_animationTimer.Tick += AnimationTimer_Tick;
this.Paint += MotionSimulationForm_Paint;
this.MouseClick += MotionSimulationForm_MouseClick;
}
private void SetupMotionControl()
{
var parameters = new MotionParameters
{
InitialVelocity = 0,
Acceleration = 200,
MaxVelocity = 400,
StartPoint = new Point(100, 300),
};
_motionControl = new MotionControl(parameters);
_objectPosition = parameters.StartPoint;
}
private void MotionSimulationForm_Paint(object sender, PaintEventArgs e)
{
Graphics g = e.Graphics;
g.SmoothingMode = SmoothingMode.AntiAlias;
// 绘制轨迹
if (_trajectoryPoints.Count > 1)
{
using (Pen pen = new Pen(Color.LightBlue, 2))
{
for (int i = 1; i < _trajectoryPoints.Count; i++)
{
g.DrawLine(pen, _trajectoryPoints[i - 1], _trajectoryPoints[i]);
}
}
}
// 绘制起点和终点
if (_isMoving)
{
using (Pen pen = new Pen(Color.Gray, 1))
{
g.DrawLine(pen, _motionControl.StartPoint, _motionControl.EndPoint);
}
}
// 绘制运动物体
using (SolidBrush brush = new SolidBrush(Color.Blue))
{
g.FillEllipse(brush,
_objectPosition.X - 15,
_objectPosition.Y - 15,
30, 30);
}
// 绘制信息
using (Font font = new Font("Arial", 10))
using (SolidBrush brush = new SolidBrush(Color.Black))
{
string info = $"速度: {_motionControl.CurrentVelocity:F2} 像素/秒";
g.DrawString(info, font, brush, 10, 10);
}
}
private void AnimationTimer_Tick(object sender, EventArgs e)
{
if (_isMoving)
{
_objectPosition = _motionControl.CalculatePosition(0.016);
_trajectoryPoints.Add(_objectPosition);
if (_motionControl.IsCompleted)
{
_isMoving = false;
_animationTimer.Stop();
}
Invalidate();
}
}
private void MotionSimulationForm_MouseClick(object sender, MouseEventArgs e)
{
if (!_isMoving)
{
var parameters = new MotionParameters
{
InitialVelocity = 0,
Acceleration = 200,
MaxVelocity = 400,
StartPoint = _objectPosition,
EndPoint = e.Location
};
_motionControl = new MotionControl(parameters);
_trajectoryPoints.Clear();
_trajectoryPoints.Add(_objectPosition);
_isMoving = true;
_animationTimer.Start();
}
}
}
4. 总结
在本文中,我们展示了如何通过使用GDI+提供的优秀绘图支持、清晰的代码结构,实现了基础的加速运动模式。这个基础实现可以作为更复杂运动控制系统的基础,使得后续的开发更加简单、稳定和流畅。