Guide to LaTeX (4th Edition) (Tools and Techniques

\frame{pic elem}
13.1. The picture environment 299
is used instead. The placement coordinate of the \put command then
refers to the lower left corner as usual.
W
\put(0.0,0.5){\frame{TEXT}}
TEXT
O
R
\put(1.5,0.0){\frame{\shortstack{W\\O\\R\\D}}}
D
The contents of the \frame command can be any of the previous
picture elements, and need not be merely text. However, in many cases
the output comes out wrong.
✛✘
\put(0,0){\frame{\vector(1,1){1.0}}}
\put(2,0){\frame{\circle{1.0}}} ✒
✚✙
The first example produces the correct result, while the second has
failed. In such cases, one can try putting the picture object inside a
\makebox of suitable size and positioning as argument for the \frame
command. However, it would then make more sense to use the \framebox
command itself in place of \frame{\makebox...}.
Curved lines
Curved lines may be drawn in the picture environment with the commands
\qbezier[num](x1,y1)(x2,y2)(x3,y3)
which draw a quadratic Bézier curve from point (x1, y1) to (x3, y3) with
(x2, y2) as the extra Bézier point. The curve is actually drawn as num + 1
dots. The number of points num is an optional argument; if it is omitted,
its value will be calculated to produce a solid-looking line.
The meaning of the extra point can
be illustrated with the example at
(20,20)
the right. The input is
\begin{picture}(40,20)
\qbezier(0,0)(20,20)(40,10)
\end{picture} ♣ ♣ ♣ ♣ ♣ ♣ ♣ ♣ ♣ ♣ ♣ ♣ ♣ ♣ ♣ ♣ ♣ ♣ ♣ ♣ ♣
♣ ♣ ♣ ♣ ♣ ♣ ♣ ♣ ♣ ♣ ♣ ♣ ♣ ♣ ♣ ♣ ♣ ♣ ♣
(40,10)
(0,0)
The curve is drawn from (0,0) to (40,10) such that the tangents at the
endpoints (the dotted lines) intersect at the extra Bézier point (20,20).
Another way of stating this is that, as one moves from the first to the
third point, one begins by heading directly towards the second point, and
on arrival at the destination, one is moving directly away from that second
point again. The dotted lines in the above example, which are not drawn
by the \bezier functions, illustrate this.
A dotted curve may be drawn by specifying the number of points num;
some experimentation may be required to get just the right effect.