!**********************************************

  BASIC GEOMETRY MODULE sline(
   FLOAT x:=500  >"Distance from bow !");

!*   Generates a single section line.
!*
!*   (C)Microform AB, J.Kjellander
!*
!**********************************************

 VECTOR p1;
 REF    hull_id,l_id,r_id;
 STRING s*132;

BEGINMODULE

!*
!***Check distance from bow.
!*
   if x < 1 then
     exit("Bow distance too small !");
   endif;
!*
!***Global ID of hull.
!*
   set_root_gm();
   hull_id:=get_next_gm(1,16384,"hull");
!*
!***ID for left and right hull surfaces.
!*
   s:=rstr(hull_id);
   l_id:=rval(s+"#30#30");  
   r_id:=rval(s+"#30#33");  
!*
!***Where does hull begin.
!*
   p1:=on(l_id,vec(0,0));
!*
!***Local system in bow.
!*
   csys_1p(#1,"Bow",p1,0,0,0:BLANK=1);
   mode_local(#1);
!*
!***Local system at section.
!*
   csys_1p(#2,"Section",vec(x,0,0),0,90,0:BLANK=1);
!*
!***Create section curve.
!*
   cur_int(#3,l_id,#2,1:BLANK=0,LEVEL=2,PEN=2);
   cur_int(#4,r_id,#2,1:BLANK=0,LEVEL=2,PEN=2);
!   cur_comp(#5,#3,#4:LEVEL=2,PEN=2);

ENDMODULE

!*****************************************************