thus

Curiously, in modern PostScript, the point in a polygon problem can
be solved even more easily.  To wit:

%!
%%Title: Point in Polygon
%%Creator: Allen B (ab@cc.purdue.edu)
%%For: the amusement of comp.graphics regulars
%%LanguageLevel: 2
%%DocumentNeededResource: humor sense thereof
%%EndComments

% This program will test whether a point is inside a given polygon.
% Currently it uses the even-odd rule, but that can be changed by
% replacing ineofill with infill.  These are Level 2 operators,
% so if you've only got Level 1 you're out of luck.
%
% The result will be printed on the output stream.
%
% Caution: only accurate to device pixels!
% Put a huge scale in first if you aren't sure.

% Point to test
% PUT X AND Y COORDINATES HERE

50 75

% Vertices of polygon in counter-clockwise order
% PUT ARRAY OF PAIRS OF COORDINATES HERE
[
[   0   0 ]
[ 100   0 ]
[ 100 100 ]
[  67 100 ]
[  67  50 ]
[  33  50 ]
[  33 100 ]
[   0 100 ]
]