BuildProcess/FlowChartModule/绘制模块/BezierCurveModel.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Prism.Mvvm;
using System.Windows;
using System.Collections;
using MathNet.Numerics.LinearAlgebra.Factorization;



namespace FlowChartModule.绘制模块
{
    public class BezierCurveModel : BindableBase
    {

        private  Point _StartPoint;

        private  Point _ControlPoint1 ;
        private  Point _ControlPoint2;
        private  Point _EndPoint;
        public Point StartPoint
        {
            get
            {
                return _StartPoint;
            }
            set
            {
                ControlPoint1 = CalculateMiddlePointWithSimpleControlPoints(StartPoint, EndPoint, 0.3f);
                ControlPoint2 = CalculateMiddlePointWithSimpleControlPoints(StartPoint, EndPoint, 0.75f);
                SetProperty(ref _StartPoint, value);
            }
        }
        public Point ControlPoint1
        {
            get
            {
              
                return _ControlPoint1;
            }
            set
            {
                SetProperty(ref _ControlPoint1, value);
            }
        }
        public Point ControlPoint2
        {
            get
            {
                return _ControlPoint2;
            }
            set
            {
                SetProperty(ref _ControlPoint2, value);
            }
        }
        public Point EndPoint
        {
            get
            {
                return _EndPoint;
            }
            set
            {
                ControlPoint1 = CalculateMiddlePointWithSimpleControlPoints(StartPoint,EndPoint,0.3f);
                ControlPoint2 = CalculateMiddlePointWithSimpleControlPoints(StartPoint, EndPoint, 0.75f);
                SetProperty(ref _EndPoint, value);
               
            }
        }


        // 计算三阶贝塞尔曲线上指定 t 值的点
        public static Point CalculateCubicBezierPoint(Point p0, Point p1, Point p2, Point p3, double t)
        {
            double u = 1 - t;
            double tt = t * t;
            double uu = u * u;
            double uuu = uu * u;
            double ttt = tt * t;

            double x = uuu * p0.X + 3 * uu * t * p1.X + 3 * u * tt * p2.X + ttt * p3.X;
            double y = uuu * p0.Y + 3 * uu * t * p1.Y + 3 * u * tt * p2.Y + ttt * p3.Y;

            return new Point(x, y);
        }

        // 根据起点和终点简单生成控制点并计算中间点
        public static Point CalculateMiddlePointWithSimpleControlPoints(Point start, Point end, double t)
        {
            // 简单线性插值确定控制点
            Point p1 = new Point(start.X + (end.X - start.X) * 0.25f, start.Y + (end.Y - start.Y) * 0.25f);
            Point p2 = new Point(start.X + (end.X - start.X) * 0.75f, start.Y + (end.Y - start.Y) * 0.75f);

            return CalculateCubicBezierPoint(start, p1, p2, end, t);
        }
    }
}