lines.ps

实现并行算法

%!
% ** Copyright (C) 1989, 1990, 1992, 1994, 1996 by Aladdin Enterprises. **
% ** All rights reserved. **

% Test line rendering (stroke).

% Exercise the miter limit.  The left column of lines should bevel at
% 90 degrees, the right column at 60 degrees.

gsave
1.8 setlinewidth
0 setgray
15 15 scale
-5 5 translate
[1.415 2.0]
 { setmiterlimit 12 0 translate 0 0 moveto
   10 30 360
    { gsave 5 0 rlineto rotate 2.5 0 rlineto
      gsave 0 setlinewidth 1 0 0 setrgbcolor stroke grestore
      strokepath 0 setlinewidth stroke
      grestore
      0 4 rmoveto
    } for
 } forall

showpage
grestore

% Exercise all the combinations of cap and join styles
% for one-line, two-line, and closed paths.

gsave

/drawlines {
gsave
2.0 setmiterlimit
2.0 setlinewidth
6 6 scale
5 20 translate
{0 1 2}				% line cap
 { setlinecap gsave
   {0 1 2}			% line join
    { setlinejoin gsave
      { {currentpoint lineto}
	{3 7 lineto}
	{3 7 lineto 5 1 lineto}
	{3 7 lineto 6 3 lineto closepath}
      }
       { gsave 0 0 moveto exec
         gsave stroke grestore
	 0.5 setlinewidth 1 0 0 setrgbcolor stroke
	 grestore 8 0 translate
       } forall
      grestore 35 0 translate
    } forall
   grestore 0 20 translate
 } forall
grestore
} def
/xflip
 { 8.5 72 mul 0 translate -1 1 scale
 } def
/rot90
 { 90 rotate 0 -9.75 72 mul translate
 } def
/rot180
 { rot90 rot90
 } def
/rot270
 { rot180 rot90
 } def

drawlines showpage
gsave xflip drawlines grestore showpage
gsave rot90 drawlines grestore showpage
gsave rot90 xflip drawlines grestore showpage
gsave drawlines rot180 showpage
gsave rot180 xflip drawlines grestore showpage
gsave rot270 drawlines grestore showpage
gsave rot270 xflip drawlines grestore showpage
grestore

% Here are some boundary conditions, contributed by Mark Rawling.

gsave
1 setlinecap
2.6 setmiterlimit
3.0 setlinewidth

5 5 scale
10 20 translate

% [ 0.5 sqrt dup dup dup neg exch 0 0 ] concat	% 45 rotate

{0 1 2}                        % line join
{
    setlinejoin gsave
    0 0 moveto 0 10 lineto 10 0 lineto gsave stroke grestore
    15 0 translate
    0 0 moveto 0 10 lineto 10 20 lineto gsave stroke grestore
    15 0 translate
    10 0 moveto 10 10 lineto 0 20 lineto gsave stroke grestore
    15 0 translate
    10 0 moveto 10 10 lineto 0 0 lineto gsave stroke grestore
    grestore
    gsave
    0 20 translate
    0 20 moveto 0 10 lineto 10 20 lineto gsave stroke grestore
    15 0 translate
    0 20 moveto 0 10 lineto 10 0 lineto gsave stroke grestore
    15 0 translate
    10 20 moveto 10 10 lineto 0 0 lineto gsave stroke grestore
    15 0 translate
    10 20 moveto 10 10 lineto 0 20 lineto gsave stroke grestore
    grestore 60 0 translate
} forall

showpage
grestore

% Test narrow lines at a variety of angles.

gsave

/rad 120 def
/ray { gsave rotate 0 0 moveto rad 0 rlineto stroke grestore } def
/star
 { newpath gsave
   gsave 0.5 setgray 0 0 rad 0 360 arc stroke grestore
   0 90 359
    { rotate 
      0 3 14 { ray } for
      15 15 89 { ray } for
    } for
   grestore
 } def

0 setgray
150 150 translate
[ [ 0 0.5 1 ] [ 1.5 2 2.5 ] [ 3 3.5 4 ] ]
 { gsave
    { setlinewidth star
      250 0 translate
    } forall
   grestore 0 250 translate
 } forall

grestore showpage

% End

quit