%!
%%BoundingBox: 124.38 124.38 487.61 487.61
% Cookbook Example Program from First Printing, Revised 7 Jan 1985
% Program: Repeated Shapes Number: 6
%-----------------------------------------------------------------------------
%
% This program prints a rosette
% design by defining a section of
% that design and printing that
% section repeatedly. This program
% illustrates the ``for'' and
% "arc" operators, and it shows
% how coordinate transformations
% can be nested so as to use the
% most convenient coordinate
% system for each part of a
% design.
/inch {72 mul} def
/wedge % Define an ``ice cream cone''
{ newpath % shape by means of the ``arc''
0 0 moveto % operator. This shape will have a
1 0 translate % 30 degree angle topped off with
15 rotate % a semicircle. Set the path's
0 15 sin translate % first point at the current
0 0 15 sin -90 90 arc % origin. Next, move the origin to
closepath % the center of the semicircle by
} def % translating to the right 1 unit,
% rotating counter-clockwise by 15
% degrees, and translating ``up''
% in the rotated system by the
% radius of the semicircle. The
% ``arc'' operator includes a
% straight line to the initial
% point of the arc and a curved
% section to the end of the arc.
% Note that the semicircle goes
% from -90 degrees to 90 degrees
% in the rotated coordinate
% system.
gsave
4.25 inch 4.25 inch translate % Move into position for the
% rosette.
1.75 inch 1.75 inch scale % Make the edges of the rosette 1
% 3/4 inches long.
0.02 setlinewidth % Use a 7/200 inch thick line.
2 1 13 % Set up the ``for'' operator to
% iterate 12 times, pushing 2 onto
% the stack the first time, 3 the
% next time, ... , and 13 the last
% time.
{ % The last argument for ``for'' is
% the sequence of operations to be
% repeated. This sequence must be
% enclosed by braces.
13 div setgray % Divide the loop index by 13 to
% set a gray value.
gsave % Enclose the ``wedge'' operation
wedge % in a ``gsave''-``grestore''
% pair, as it will mess up the
% coordinate system.
gsave % Save the wedge path for use
% after the ``fill''.
fill
grestore
0 setgray stroke % Draw a black border around the
% wedge.
grestore % Get out of the coordinate system
% left by wedge.
30 rotate % Set up for the next section.
} for % Close the last argument and
% execute the ``for'' operator.
grestore
showpage
