!This file is part of VEL_demo, copyright David Keyes, 2007. 
    !
    !This source file is free software: you can redistribute it and/or modify
    !it under the terms of the GNU General Public License as published by
    !the Free Software Foundation, either version 3 of the License, or
    !(at your option) any later version.
    !
    !This code is distributed in the hope that it will be useful,
    !but WITHOUT ANY WARRANTY; without even the implied warranty of
    !MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    !GNU General Public License for more details.
    !
    !For terms of the GNU General Public license see <http://www.gnu.org/licenses/>.

GLOBAL DRAWING MODULE dim_hline(
VECTOR p1 > "start pos";
VECTOR p2 > "end pos";
FLOAT offset:=10.0 > "offset";
INT arr_slash:=0 > "0=slash, 1=arrow";
VAR FLOAT d_inch);

FLOAT pos;
FLOAT t_off, t_sizeA, t_sizeB, t_width, slash_len, dim_ext, dim_off;
INT scale, pen_col;

BEGINMODULE

  part(#1, dim_vars(scale, pen_col, t_off, t_sizeA, t_sizeB, t_width, slash_len, dim_ext, dim_off));
  set(PEN=pen_col);

pos:=p1.y - offset;
  lin_free(#10,p1, p2:BLANK=1);

  IF p1.y > pos THEN 
   dim_off:=-dim_off;
   dim_ext:=-dim_ext;
  ENDIF;

  lin_free(#11,vec(p1.x, p1.y + dim_off), vec(p1.x,  pos + dim_ext));
  dim_ext:=abs(dim_ext);
  dim_off:=abs(dim_off);

  IF p2.y > pos THEN 
    dim_off:=-dim_off;
    dim_ext:=-dim_ext;
  ENDIF;

  lin_free(#12,vec(p2.x, p2.y + dim_off), vec(p2.x, pos + dim_ext));
  lin_free(#13,vec(p1.x, pos), vec(p2.x, pos));
  csys_1p(#15,"a", intersect(#13, #11, -1), 0.0, 0.0, 0.0:BLANK=1);
  csys_1p(#16,"b", intersect(#13, #12, -1), 0.0, 0.0, 180.0:BLANK=1);

IF arr_slash = 0 THEN
  part(#17, slash(slash_len),#15);
  part(#18, slash(slash_len),#16);
ELSE
  part(#19, arrow(slash_len*0.5),#15);
  part(#20, arrow(slash_len*0.5),#16);
ENDIF;

  d_inch:=p2.x - p1.x;

ENDMODULE