You could do it directly in postscript, and then convert it to whatever graphic format you wanted.

%!
%% Example of simple line drawing

/inch {72 mul} def      % Define an inch->point conversion function

newpath                 % Start a new path

1 inch 1 inch moveto    % Set the current point an inch in and up

2 inch 1 inch lineto    % Create an inch long line segment to the righ
+t

stroke                  % Draw the line

showpage                % Paint and eject the page
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