#include <Precision.hxx>
#include <Standard_Failure.hxx>

void Compute(const Standard_Real P1,
	     const Standard_Real P2,
	     const Standard_Real Ra,
	     const Standard_Real Rb,
	     const Coord& Xd,
	     const Coord& Yd,
	     const Coord& O,
	     Bound& B) {

  Standard_Real Teta1;
  Standard_Real Teta2;
  if (P2<P1) { 
    Teta1 = P2;
    Teta2 = P1;
  }
  else {
    Teta1 = P1;
    Teta2 = P2;
  }
  Standard_Real Delta =Abs(Teta2-Teta1); 

  if (Delta > 2. * PI) {
    Teta1 = 0.;
    Teta2 = 2. * PI;
  }
  else {
 
    if (Teta1 < 0.) {
      do { Teta1+=2.*PI;} while (Teta1< 0.);
    }
    else if (Teta1> 2.*PI) {
      do { Teta1-=2.*PI;} while (Teta1> 2.*PI);
    }
    Teta2 = Teta1 + Delta;

  }

// One places already both ends
  Standard_Real Cn1,Sn1,Cn2,Sn2;
  Cn1 = Cos(Teta1); Sn1 = Sin(Teta1);
  Cn2 = Cos(Teta2); Sn2 = Sin(Teta2);
  B.Add(Point(O +Ra*Cn1*Xd +Rb*Sn1*Yd));  
  B.Add(Point(O +Ra*Cn2*Xd +Rb*Sn2*Yd));  
  
  Standard_Real Ram,Rbm;
  if (Delta > PI/8.) {
    // Main radiuses to take into account only 8 points (/cos(Pi/8.))
    Ram=Ra/0.92387953251128674;
    Rbm=Rb/0.92387953251128674;
  }
  else {
    // Main radiuses to take into account the arrow
    Standard_Real tc=cos(Delta/2);
    Ram=Ra/tc;
    Rbm=Rb/tc;
  }
  B.Add(Point(O +Ram*Cn1*Xd +Rbm*Sn1*Yd));  
  B.Add(Point(O +Ram*Cn2*Xd +Rbm*Sn2*Yd));  
  

// cos or sin PI/4.
#define PI4 0.70710678118654746

// 8 points of the polygon
#define addP0 B.Add(Point(O +Ram*Xd ))
#define addP1 B.Add(Point(O +Ram*PI4*Xd +Rbm*PI4*Yd))
#define addP2 B.Add(Point(O +Rbm*Yd))
#define addP3 B.Add(Point(O -Ram*PI4*Xd +Rbm*PI4*Yd))
#define addP4 B.Add(Point(O -Ram*Xd ))
#define addP5 B.Add(Point(O -Ram*PI4*Xd -Rbm*PI4*Yd))
#define addP6 B.Add(Point(O -Rbm*Yd)); 
#define addP7 B.Add(Point(O +Ram*PI4*Xd -Rbm*PI4*Yd))

  Standard_Integer deb = (Standard_Integer )( Teta1/(PI/4.));
  Standard_Integer fin = (Standard_Integer )( Teta2/(PI/4.));
  deb++;

  if (deb>fin) return;

  switch (deb) {
  case 1 : 
    {
      addP1;
      if (fin <= 1) break;
    }
  case 2 :  
    {
      addP2;
      if (fin <= 2) break;
    }
  case 3 :  
    {
      addP3;
      if (fin <= 3) break;
    }
  case 4 :  
    {
      addP4;
      if (fin <= 4) break;
    }
  case 5 :  
    {
      addP5;
      if (fin <= 5) break;
    }
  case 6 :  
    {
      addP6;
      if (fin <= 6) break;
    }
  case 7 :  
    {
      addP7;
      if (fin <= 7) break;
    }
  case 8 :  
    {
      addP0;
      if (fin <= 8) break;
    }
  case 9 :  
    {
      addP1;
      if (fin <= 9) break;
    }  
  case 10 :  
    {
      addP2;
      if (fin <= 10) break;
    }
  case 11:  
    {
      addP3;
      if (fin <= 11) break;
    }  
  case 12:  
    {
      addP4;
      if (fin <= 12) break;
    }  
  case 13:  
    {
      addP5;
      if (fin <= 13) break;
    }
  case 14:  
    {
      addP6;
      if (fin <= 14) break;
    }
  case 15:  
    {
      addP7;
      if (fin <= 15) break;
    }
  }
}