Point and the distance of the space plane line

1, the linear distance between the point of the plane:

 

 Code:

struct Point{
    double x;
    double y;
}

struct PlaneEquation{
    double A;
    double B;
    double C;
}


//计算点到面距离
double dist(Point &pt, PlaneEquation &pe) //Distance between point and plane
{
    double dt = 0.0;
    double mA, mB, mC, mX, mY;

    mA = pe.A;
    mB = pe.B;
    mC = pe.C;

    mX = pt.X;
    mY = Pt.Y; 


    IF (mA + mA * * mB of mB of mC * + mC) // If mA * mA + mB * mB + mC * mC == 0 shrunk point described straight 
    { 
        dt = ABS (mX + mA * mC * + mY mB of) / sqrt (mA + mA * * mB of mB of); 
    } 
    the else 
    { 
        STD :: COUT << " equation :: input error coefficients are all zero !!!! " ; 
        dt = pt.mod () ; 
    } // of The IS reduced to Plane The Origin Point (Pt) to Point (ZERO) Distance.. 
    return dt; 
}

 

2, the straight line distance between the point of space:

 

 

 

 

 

 

// use of space linear two-point (X0 Y0 Z0) for the straight outer point 

Xc = (X2-X1) * T + X1; 
YC = (Y2-Y1) * T + Y1; 
Zc = (Z2-Z1) * T + Z1;    // pedal 

T = ((the X1-an X2) * (the X1-X0) + (Yl-Y2) * (Y0-Yl) + (Zl-Z2 of) * (Z0 of-Zl)) / ((X2- the X1) * (the X1-an X2) + (Yl-Y2) * (Yl-Y2) + (Zl-Z2 of) * (Z2- Zl)) 

D = sqrt ((X0-Xc) * (X0-Xc) + ( Yc-Y0) * (Y0-Yc) + (Z0 of-Zc) * (Z0 of-Zc))   // solving two-norm