/// <summary>
/// 计算p3处的斜率
/// </summary>
/// <param name="p1"></param>
/// <param name="p2"></param>
/// <param name="p3"></param>
/// <param name="p4"></param>
/// <param name="p5"></param>
/// <returns></returns>
public static void calCosSin(MyPoint p1, MyPoint p2, MyPoint p3, MyPoint p4, MyPoint p5,
ref double cos, ref double sin)
{
MyCurve mycurve = new MyCurve();
double a0, a1, a2, a3, a4, b0, b1, b2, b3, b4;
double w2, w3;
a1 = p2.x - p1.x;
a2 = p3.x - p2.x;
a3 = p4.x - p3.x;
a4 = p5.x - p4.x;
b1 = p2.y - p1.y;
b2 = p3.y - p2.y;
b3 = p4.y - p3.y;
b4 = p5.y - p4.y;
w2 = Math.Abs(a3 * b4 - a4 * b3);
w3 = Math.Abs(a1 * b2 - a2 * b1);
a0 = w2 * a2 + w3 * a3;
b0 = w2 * b2 + w3 * b3;
cos = a0 / (Math.Sqrt(a0 * a0 + b0 * b0));
sin = b0 / (Math.Sqrt(a0 * a0 + b0 * b0));
}
/// <summary>
/// 通过点集构建曲线
/// </summary>
/// <param name="mypoint_list"></param>
/// <param name="is_close">是否闭合</param>
public static List <MyCurve> builtCurve(List <MyPoint> mypoint_list, bool is_close)
{
List <MyCurve> mycurve_list = new List <MyCurve>();
List <MyPoint> mypoint_list_supply = supplyPoints(mypoint_list, is_close);
for (int i = 0; i < mypoint_list_supply.Count - 5; i++)
{
//计算点i + 2到点i + 3之间的曲线
double cos0 = 0, cos1 = 0, sin0 = 0, sin1 = 0, r = 0;
r = mypoint_list_supply[i + 3].distance(mypoint_list_supply[i + 2]);
calCosSin(mypoint_list_supply[i + 1], mypoint_list_supply[i + 2], mypoint_list_supply[i + 3], mypoint_list_supply[i + 4], mypoint_list_supply[i + 5],
ref cos1, ref sin1);
calCosSin(mypoint_list_supply[i], mypoint_list_supply[i + 1], mypoint_list_supply[i + 2], mypoint_list_supply[i + 3], mypoint_list_supply[i + 4],
ref cos0, ref sin0);
MyCurve mycurve = new MyCurve();
mycurve.p0 = mypoint_list_supply[i + 2].x;
mycurve.p1 = r * cos0;
mycurve.p2 = 3 * (mypoint_list_supply[i + 3].x - mypoint_list_supply[i + 2].x) - r * (cos1 + 2 * cos0);
mycurve.p3 = -2 * (mypoint_list_supply[i + 3].x - mypoint_list_supply[i + 2].x) + r * (cos1 + cos0);
mycurve.q0 = mypoint_list_supply[i + 2].y;
mycurve.q1 = r * sin0;
mycurve.q2 = 3 * (mypoint_list_supply[i + 3].y - mypoint_list_supply[i + 2].y) - r * (sin1 + 2 * sin0);
mycurve.q3 = -2 * (mypoint_list_supply[i + 3].y - mypoint_list_supply[i + 2].y) + r * (sin1 + sin0);
mycurve.mypoint_start = mypoint_list_supply[i + 2];
mycurve.mypoint_end = mypoint_list_supply[i + 3];
mycurve_list.Add(mycurve);
}
return(mycurve_list);
}