-- final model: Railway_and_SteamMachine
-- author Anatoly Ossipov, MePHI, Moscow, Russia

BOX(x[3], a[6])
{
-- a[1] - center of the box on the x[1] axis
-- a[2] - center of the box on the x[2] axis
-- a[3] - center of the box on the x[3] axis
-- a[4] - size of side on the x[1] axis
-- a[5] - size of side on the x[2] axis
-- a[6] - size of side on the x[3] axis
   array C[3];

   C[1]       = x[1] - a[1];
   C[2]       = x[2] - a[2];
   C[3]       = x[3] - a[3];

   H_1 = a[4]/2;
   H_2 = a[5]/2;
   H_3 = a[6]/2;

   box = (C[1]+H_1) & (H_1-C[1]) &
         (C[2]+H_2) & (H_2-C[2]) &
         (C[3]+H_3) & (H_3-C[3]) ;
}

CYL_x(x[3], a[5])
{
-- a[1] - center of the wheel on the x[1] axis
-- a[2] - center of the wheel on the x[2] axis
-- a[3] - center of the wheel on the x[3] axis
-- a[4] - radius of the wheel
-- a[5] - width of the wheel
   Cx       = x[1] - a[1];
   Cy       = x[2] - a[2];
   Cz       = x[3] - a[3];

   Radius   = a[4];
   H_Width  = a[5]/2;

   CYL_x = (Radius - sqrt(Cy*Cy + Cz*Cz)) & (H_Width+Cx) & (H_Width-Cx);
}

CYL_y(x[3], a[5])
{
-- a[1] - center of the wheel on the x[1] axis
-- a[2] - center of the wheel on the x[2] axis
-- a[3] - center of the wheel on the x[3] axis
-- a[4] - radius of the wheel
-- a[5] - width of the wheel
   Cx       = x[1] - a[1];
   Cy       = x[2] - a[2];
   Cz       = x[3] - a[3];

   Radius   = a[4];
   H_Width  = a[5]/2;

   CYL_y = (Radius - sqrt(Cx*Cx + Cz*Cz)) & (H_Width+Cy) & (H_Width-Cy);
}

CYL_z(x[3], a[5])
{
-- a[1] - center of the wheel on the x[1] axis
-- a[2] - center of the wheel on the x[2] axis
-- a[3] - center of the wheel on the x[3] axis
-- a[4] - radius of the wheel
-- a[5] - width of the wheel
   Cx       = x[1] - a[1];
   Cy       = x[2] - a[2];
   Cz       = x[3] - a[3];

   Radius   = a[4];
   H_Width  = a[5]/2;

   CYL_z = (Radius - sqrt(Cy*Cy + Cx*Cx)) & (H_Width+Cz) & (H_Width-Cz);
}

railway_xz(x[3], a[9])
{
-- a[1] - center of the railway on the x[1] axis
-- a[2] - center of the railway on the x[2] axis
-- a[3] - center of the railway on the x[3] axis
-- a[4] - railway length
-- a[5] - railway width
-- a[6] - rut width
-- a[7] - amount of sleeper
-- a[8] - radius of sleeper
-- a[9] - radius of rail
   array rail_array[5];
   array ruts_array[5];
   array C[3];

   C[1]       = x[1] - a[1];
   C[2]       = x[2] - a[2];
   C[3]       = x[3] - a[3];

-- Construct two rails:
-- The first:
   rail_array [1] = a[1];        --
   rail_array [2] = a[8];        -- (2*a[8] + 2*a[9])/2 - a[9]
   rail_array [3] = a[6]/2;      --
   rail_array [4] = a[9];        -- Cylinder radius
   rail_array [5] = a[4];        --

   Rail1 = Cyl_x(C, rail_array);
-- The first:
-- Second:
   rail_array [3] = -a[6]/2;      --
   Rail2 = Cyl_x(C, rail_array);

-- Construct the ruts:
   L_Between      = a[4] / a[7]; -- Distance beetween two sleepers
   C_X            = (-a[4] + L_Between)/2;
   Upper_Boundary = a[4]/2+a[8];

   ruts_array [1] = C_X;
   ruts_array [2] = -a[9];
   ruts_array [3] = 0;
   ruts_array [4] = a[8];
   ruts_array [5] = a[5];

   Ruts           = Cyl_z(C, ruts_array);
   C_X            = C_X + L_Between;

   while(C_X < Upper_Boundary) loop
      ruts_array [1] = C_X;
      Ruts           = Ruts | Cyl_z(C, ruts_array);
      C_X            = C_X + L_Between;
   endloop;

   railway_xz = Rail1 | Rail2 | Ruts;
}



Steam_Machine_X(x[3], a[6])
{
-- a[1] - center of the machine on the x[1] axis
-- a[2] - center of the machine on the x[2] axis
-- a[3] - center of the machine on the x[3] axis
-- a[4] - length of the machine
-- a[5] - width  of the machine
-- a[6] - height of the machine
   array C[3];
   array Wheel_Array[5];
   array Wheel[3];

   Cabin_D   = 0.3;

   Window_Up   = 0.9;
   Window_Down = 0.6;
   Window_P    = 0.1;
   Window_H    = 0.1;

   C[1]       = x[1] - a[1];
   C[2]       = x[2] - a[2];
   C[3]       = x[3] - a[3];

   H_Length = a[4]/2;
   H_Width  = a[5]/2;
   H_Height = a[6]/2;

   Window_1    = (C[1]-(-H_Length+a[4]*Cabin_D*Window_P)) & (-H_Length + a[4]*Cabin_D*(1-Window_P) - C[1]) &
                 (C[2]-(-H_Height+a[6]*Window_Down)) & (-H_Height+a[6]*Window_Up - C[2]);

   Window_2    = (C[3]-(-H_Width + a[5]*Window_H)) & (-a[5]*Window_H-C[3]) &
                 (C[2]-(-H_Height+a[6]*Window_Down)) & (-H_Height+a[6]*Window_Up - C[2]) & 
                 (C[1]+H_Length) & (-H_Length + a[4]*Cabin_D - C[1]);

   Window_3    = (C[3]-a[5]*Window_H) & (H_Width - a[5]*Window_H-C[3]) &
                 (C[2]-(-H_Height+a[6]*Window_Down)) & (-H_Height+a[6]*Window_Up - C[2]) &
                 (C[1]+H_Length) & (-H_Length + a[4]*Cabin_D - C[1]);

   Cabin   = (C[1]+H_Length) & (-H_Length + a[4]*Cabin_D - C[1]) &
             (C[2]+H_Height) & (H_Height-C[2]) &
             (C[3]+H_Width) & (H_Width-C[3]);

   Body    = (C[1]+H_Length) & (H_Length-C[1]) &
             ((C[3]-(-H_Width+Window_P*a[5])) & (H_Width-Window_P*a[5]-C[3]) &
              (C[2]-(-H_Height)) & (-H_Height + a[6]*Window_P-C[2]) |

             (1 - sqrt( ((C[2] + (H_Height-a[6]*Window_P)/2)/((H_Height-a[6]*Window_P)/2))^2+(C[3]/(H_Width-Window_P*a[5]))^2 )));

   Pipe    = (H_Height-H_Height*Cabin_D/2-C[2]) & ((C[2]+H_Height)/4 - sqrt((C[1]-(H_Length-a[4]*Cabin_D/2))^2 + C[3]^2));

   Radius = a[4]/10;
   i = 1;
   while(i<4) loop
      Wheel_Array[1] = -H_Length + Radius*2 + (a[4]*0.3)*(i-1);
      Wheel_Array[2] = -H_Height - Radius*1.5;
      Wheel_Array[3] = -H_Width;
      Wheel_Array[4] = Radius; -- Radius
      Wheel_Array[5] = a[5]/5;

      Wheel[i]       = Cyl_z(C, Wheel_Array);
      Wheel_Array[3] = H_Width;
      Wheel[i]       = Wheel[i] | Cyl_z(C, Wheel_Array);

      i = i + 1;
   endloop;

   Steam_Machine_x = (Cabin | Body | Pipe | Wheel[1] | Wheel[2] | Wheel[3]) \ Window_1 \ Window_2 \ Window_3;
}

Railway_and_SteamMachine(X[3], A[1])
{
   array For_SM[6];
   array For_RW[9];

   For_SM[1] = 0;
   For_SM[2] = 0;
   For_SM[3] = 0;
   For_SM[4] = 12.0;
   For_SM[5] =  6.0;
   For_SM[6] =  8.0;

   For_RW[1] =  0.0;
   For_RW[2] = -8.2;
   For_RW[3] =  0.0;
   For_RW[4] = 14.0;
   For_RW[5] =  8.0;
   For_RW[6] =  6.0;
   For_RW[7] =  5;
   For_RW[8] =  0.5;
   For_RW[9] =  0.3;

-- a[4] - railway length
-- a[5] - railway width
-- a[6] - rut width
-- a[7] - amount of sleeper
-- a[8] - radius of sleeper
-- a[9] - radius of rail

   Railway_and_SteamMachine = Steam_Machine_x(x, For_SM) | railway_xz(x, For_RW);
}