二维平面中,据坐标值判断点在三角形内

public class Pvector {
    public double L=0,z=0;
    public double a=0,x=0;
    public double b=0,y=0;
    
    public double GetL(){return L;}
    public double GetZ(){return L;}
    public void SetL(double l){
        this.L=l;
        this.z=l;
    }
    public void SetZ(double z){
        this.L=z;
        this.z=z;
    }
    
    public double GetA(){return a;}
    public double GetX(){return a;}
    public void SetA(double a){
        this.a=a;
        this.x=a;
    }
    public void SetX(double x){
        this.a=x;
        this.x=x;
    }
    
    public double GetB(){return b;}
    public double GetY(){return b;}
    public void SetB(double b){
        this.b=b;
        this.y=b;
    }
    public void SetY(double y){
        this.b=y;
        this.y=y;
    }
}

///二维平面中,据坐标值判断点在三角形内
    public boolean isInTrigon(Pvector[] trigABC,Pvector trigS) {
        Pvector a = trigABC[0];
        Pvector b = trigABC[1];
        Pvector c = trigABC[2];

        double signOfTrig = (b.x - a.x)*(c.y - a.y) - (b.y - a.y)*(c.x - a.x);
        double signOfAB = (b.x - a.x)*(trigS.y - a.y) - (b.y - a.y)*(trigS.x - a.x);
        double signOfCA = (a.x - c.x)*(trigS.y - c.y) - (a.y - c.y)*(trigS.x - c.x);
        double signOfBC = (c.x - b.x)*(trigS.y - c.y) - (c.y - b.y)*(trigS.x - c.x);

        boolean d1 = (signOfAB * signOfTrig > 0);
        boolean d2 = (signOfCA * signOfTrig > 0);
        boolean d3 = (signOfBC * signOfTrig > 0);

        return d1 && d2 && d3;
    }