summaryrefslogtreecommitdiff
path: root/Master/texmf-dist/doc/generic/pgf/text-en/pgfmanual-en-library-spy.tex
diff options
context:
space:
mode:
authorKarl Berry <karl@freefriends.org>2010-10-29 00:31:31 +0000
committerKarl Berry <karl@freefriends.org>2010-10-29 00:31:31 +0000
commit6bc1f5497cfb2f56d65c80a4c36ea3bad6dc046c (patch)
treef7751da75030fb1e06653eeb44e579fcee09c65f /Master/texmf-dist/doc/generic/pgf/text-en/pgfmanual-en-library-spy.tex
parented0c7c756e441b2d2ba3633da233fc24361ac0d3 (diff)
pgf 2.10 (28oct10)
git-svn-id: svn://tug.org/texlive/trunk@20236 c570f23f-e606-0410-a88d-b1316a301751
Diffstat (limited to 'Master/texmf-dist/doc/generic/pgf/text-en/pgfmanual-en-library-spy.tex')
-rw-r--r--Master/texmf-dist/doc/generic/pgf/text-en/pgfmanual-en-library-spy.tex451
1 files changed, 451 insertions, 0 deletions
diff --git a/Master/texmf-dist/doc/generic/pgf/text-en/pgfmanual-en-library-spy.tex b/Master/texmf-dist/doc/generic/pgf/text-en/pgfmanual-en-library-spy.tex
new file mode 100644
index 00000000000..dc6f163929f
--- /dev/null
+++ b/Master/texmf-dist/doc/generic/pgf/text-en/pgfmanual-en-library-spy.tex
@@ -0,0 +1,451 @@
+% Copyright 2006 by Till Tantau
+%
+% This file may be distributed and/or modified
+%
+% 1. under the LaTeX Project Public License and/or
+% 2. under the GNU Free Documentation License.
+%
+% See the file doc/generic/pgf/licenses/LICENSE for more details.
+
+
+\section{Spy Library: Magnifying Parts of Pictures}
+\label{section-library-spy}
+
+\begin{tikzlibrary}{spy}
+ The package defines options for creating pictures in which some part
+ of the picture is repeated in another area in a magnified way (as if
+ you were looking through a spyglass, hence the name).
+\end{tikzlibrary}
+
+
+\subsection{Magnifying a Part of a Picture}
+
+The idea behind the |spy| library is to make is easy to create high-density
+pictures in which some important parts are repeated somewhere, but
+magnified as if you were looking through a spyglass:
+
+\begin{codeexample}[]
+\begin{tikzpicture}
+ [spy using outlines={circle, magnification=4, size=2cm, connect spies}]
+
+ \draw [help lines] (0,0) grid (3,2);
+
+ \draw [decoration=Koch curve type 1]
+ decorate { decorate{ decorate{ decorate{ (0,0) -- (2,0) }}}};
+
+ \spy [red] on (1.6,0.3)
+ in node [left] at (3.5,-1.25);
+
+ \spy [blue, size=1cm] on (1,1)
+ in node [right] at (0,-1.25);
+\end{tikzpicture}
+\end{codeexample}
+
+\begin{codeexample}[]
+\begin{tikzpicture}[spy using overlays={size=12mm}]
+ \draw [decoration=Koch snowflake]
+ decorate { decorate{ decorate{ decorate{ (0,0) -- (2,0) }}}};
+
+ \spy [green,magnification=3] on (0.6,0.1) in node at (-0.3,-1);
+ \spy [blue,magnification=5] on (1,0.5) in node at (1,-1);
+ \spy [red,magnification=10] on (1.6,0.1) in node at (2.3,-1);
+\end{tikzpicture}
+\end{codeexample}
+
+
+Note that this magnification uses what is called a \emph{canvas
+ transformation} in this manual: Everything is magnified, including
+line width and text.
+
+In order for ``spying'' to work, the picture obviously has to be drawn
+several times: Once at its normal size and then again for each
+``magnifying glass.'' Several keys and commands work in concert to
+make this possible:
+\begin{itemize}
+\item You need to make \tikzname\ aware of the fact that a picture (or
+ just a scope) is to be magnified. This is done by adding the special
+ key |spy scope| to a |{scope}| or |{tikzpicture}| (which is also
+ just a scope). Some special keys like |spy using outlines|
+ implicitly set the |spy scope|.
+
+\item Inside this scope you may then use the command |\spy|, which is
+ only available inside such scopes (so there is no danger of your
+ inadvertently using this command outside such a scope). This command
+ has a special syntax and will (at some point) create two nodes: One
+ node that shows the magnified picture (called the \emph{spy-in
+ node}) and another node showing which part of the original picture
+ is magnified (called the \emph{spy-on} node). The spy-in node is,
+ indeed, a normal node, so it can have any shape or border that you
+ like and you can apply all of \tikzname's advanced features to
+ it. The only difference compared to a normal node is that instead of
+ some ``text'' it contains a magnified version of the picture,
+ clipped to the size of the node.
+
+ The |\spy| command does not create the nodes immediately. Rather,
+ the creation of these nodes is postponed till the end of the
+ |spy scope| in which the |\spy| command is used. This is necessary
+ since in order to repeat the whole scope inside the node containing
+ the magnified version, the whole picture needs to be available when
+ this node is created.
+\end{itemize}
+
+A basic question any library for ``magnifying things'' has to address
+is how you specify which part of the picture is to be
+magnified (the spy-on node) and where this magnified part is to be
+shown (the spy-in node). There are two possible ways:
+\begin{enumerate}
+\item You specify the size and position of the spy-on node. Then the
+ size of the spy-in node is determined by the size of the spy-on node
+ and the magnification factor -- you can still decide where the
+ spy-in node should be placed, but not its size.
+\item Alternatively, you specify the size and position of the spy-in
+ node. Then, similarly to the first case, the size of the spy-on node
+ is determined implicitly and you can only decide where the
+ spy-on node should be placed, but not its size.
+\end{enumerate}
+
+The |spy| library uses the second method: You specify the size and
+position of the spy-in nodes, the sizes of the spy-on nodes are then
+computed automatically.
+
+
+
+\subsection{Spy Scopes}
+
+\begin{key}{/tikz/spy scope=\meta{options} (default \normalfont empty)}
+ This option may be used with a |{scope}| or any environment that
+ creates such a scope internally (like |{tikzpicture}|). It has the
+ following effects:
+ \begin{itemize}
+ \item It resets a number of graphic state parameters, including the
+ color, line style, and other. This is necessary for technical
+ reasons.
+ \item It tells \tikzname\ that the content of the scope should be saved
+ internally in a special box.
+ \item It defines the command |\spy| so that it can be used inside
+ the scope.
+ \item At the end of the scope, the nodes belonging to the |\spy|
+ commands used inside the scope are created.
+ \item The \meta{options} are saved in an internal style. Each time
+ |\spy| is used, these \meta{options} will be used.
+ \item Three keys are defined that provide useful shortcuts:
+ \begin{key}{/tikz/size=\meta{dimension}}
+ Inside a |spy scope|, |size| this is a shortcut for |minimum size|.
+ \end{key}
+ \begin{key}{/tikz/height=\meta{dimension}}
+ Inside a |spy scope|, |height| this is a shortcut for |minimum height|.
+ \end{key}
+ \begin{key}{/tikz/width=\meta{dimension}}
+ Inside a |spy scope|, |width| this is a shortcut for |minimum width|.
+ \end{key}
+ \end{itemize}
+ It is permissible to nest |spy scopes|. In this case, all |\spy|
+ commands inside the inner |spy scope| only have an effect on
+ material inside the scope, whereas |\spy| commands outside the inner
+ |spy scope| but inside the outer |spy scope| allow you to ``spy on
+ the spy.''
+
+\begin{codeexample}[]
+\begin{tikzpicture}
+ [spy using outlines={rectangle, red, magnification=5,
+ size=1.5cm, connect spies}]
+
+ \begin{scope}
+ [spy using outlines={circle, blue,
+ magnification=3, size=1.5cm, connect spies}]
+ \draw [help lines] (0,0) grid (3,2);
+
+ \draw [decoration=Koch curve type 1]
+ decorate{ decorate{ decorate{ (0,0) -- (2,0) }}};
+
+ \spy on (1.6,0.3) in node (zoom) [left] at (3.5,-1.25);
+ \end{scope}
+
+ \spy on (zoom.north west) in node [right] at (0,-1.25);
+\end{tikzpicture}
+\end{codeexample}
+
+\end{key}
+
+
+
+\subsection{The Spy Command}
+
+\begin{command}{\spy \opt{\oarg{options}} |on| \meta{coordinate}
+ |in node| \meta{node options}|;|}
+ This command can only be used inside a |spy scope|. Let us start with the syntax:
+ \begin{itemize}
+ \item The |\spy| command is not a special case of |\path|. Rather,
+ it has a small parser of its own.
+ \item Following the optional \meta{options}, you must write |on|,
+ followed by a coordinate. This coordinate will be the center of
+ the area that is to be magnified.
+ \item Following the \meta{coordinate}, you must write |in node|
+ followed by some \meta{node options}. The syntax for these options is the same
+ as for a normal |node| path command, such as |[left]| or
+ |(foo) [red] at (bar)|. \emph{However}, \meta{node options} are
+ \emph{not} followed by a curly brace. Rather, the \meta{node
+ options} must directly be followed by a semicolon.
+ \end{itemize}
+ The effect of this command is the following: The \meta{options},
+ \meta{coordinate}, and \meta{node options} are stored internally
+ till the end of the current
+ |spy scope|. This means that, in particular, you can reference any node
+ inside the |spy scope|, even if it is not yet defined when the
+ |\spy| command is given. At the end of the current |spy scope|, two
+ nodes are created, called the \emph{spy-in node} and the
+ \emph{spy-on node}.
+ \begin{itemize}
+ \item The \emph{spy-in node} is the node that contains a magnified
+ part of the picture (the node \emph{in} which we see on what we
+ spy). This node is, indeed, a normal \tikzname\
+ node, so you can use all standard options to style this node. In
+ particular, you can specify a shape or a border color or a drop
+ shadow or whatever. The only thing that is special about this node
+ is that instead of containing some normal text, its ``text'' is
+ the magnified picture.
+
+ To be precise, the picture of the |spy scope| is scaled by a
+ certain factor, specified by the |lens| or |magnification| options
+ discussed below, and the shifted in such a way that the
+ \meta{coordinate} lies at the center of the spy-on node.
+ \item The \emph{spy-on node} is a node that is centered on the
+ \meta{coordinate} and whose size reflects exactly the area shown
+ inside the spy-in node (the node containing \emph{on} what we
+ spy).
+ \end{itemize}
+
+ Let us now go over what happens in detail when the two nodes are
+ created:
+ \begin{enumerate}
+ \item A scope is started. Two sets of options are used with this
+ scope: First, the options passed to the enclosing |spy scope| and
+ then the \meta{options} (which will, thus, overrule the options of
+ the |spy scope|).
+ \item Then, the spy-on node is created. However, we will first
+ discuss the spy-in node.
+ \item The spy-in node is created after the spy-on node (and, hence,
+ will cover the spy-on node in case they overlap). When this node is
+ created, the \meta{node options} are used in addition to the
+ effect caused by the \meta{options} and the options of the
+ |{spy scope}|. Additionally, the following style is used:
+ \begin{stylekey}{/tikz/every spy in node}
+ This style is used with every spy in node.
+ \end{stylekey}
+ The position of the node (the |at| option) is set to the
+ \meta{coordinate} by default, so that it will cover the
+ to-be-magnified area. You can change this by providing the |at|
+ option yourself:
+\begin{codeexample}[]
+\begin{tikzpicture}
+ [spy using outlines={circle, magnification=3, size=1cm}]
+
+ \draw [decoration=Koch curve type 1]
+ decorate{ decorate{ decorate{ (0,0) -- (2,0) }}};
+
+ \spy [red] on (1.6,0.3) in node;
+ \spy [blue] on (1,1) in node at (1,-1);
+\end{tikzpicture}
+\end{codeexample}
+ No ``text'' can be specified for the node. Rather, the ``text''
+ shown inside this node is the picture of the current |spy scope|,
+ but canvas-transformed according to the following key:
+ \begin{key}{/tikz/lens=\meta{options}}
+ The \meta{options} should contain transformation commands like
+ |scale| or |rotate|. These transformations are applied to the
+ picture when it is shown inside the spy-on node.
+ \end{key}
+ Since the most common transformation is undoubtedly a simple
+ scaling, there is a special style for this:
+ \begin{key}{/tikz/magnification=\meta{number}}
+ This has the same effect as saying
+ |lens={scale=|\meta{number}|}|.
+ \end{key}
+ Now, usually the size of a node is determined in such a way that
+ it ``fits'' around the text of the node. For a spy-on node this is
+ not a good approach since the ``text'' of this node would contain
+ ``the whole picture.'' Because of this, \tikzname\ acts
+ as if the ``text'' of the node has zero size. You must then use
+ keys like |minimum size| to cause the node to have a certain
+ size. Note that the key |size| is an abbreviation for
+ |minimum size| inside a spy scope.
+
+ You can name the spy on node in the usual ways. Additionally, the
+ node is (also) always named |tikzspyinnode|. Following the spy
+ scope, you can use this node like any other node:
+\begin{codeexample}[]
+\begin{tikzpicture}
+ \begin{scope}
+ [spy using outlines={circle, magnification=3, size=2cm, connect spies}]
+
+ \draw [decoration=Koch curve type 1]
+ decorate{ decorate{ decorate{ (0,0) -- (2,0) }}};
+
+ \spy [red] on (1.6,0.3) in node (a) [left] at (3.5,-1.25);
+
+ \spy [blue, size=1cm] on (1,1) in node (b) [right] at (0,-1.25);
+ \end{scope}
+ \draw [ultra thick, green!50!black] (b) -- (a.north west);
+\end{tikzpicture}
+\end{codeexample}
+
+ \item Once both nodes have been created, the current value of the
+ following key is used to connect them:
+ \begin{key}{/tikz/spy connection path=\meta{code} (initially
+ \normalfont empty)}
+ The \meta{code} is executed after the spy-on and spy-in nodes
+ have just been created. Inside this \meta{code}, the two nodes
+ can be accessed as |tikzspyinnode| and |tikzspyonnode|.
+ For example, the key |connect spies| sets this command to
+\begin{codeexample}[code only]
+\draw[thin] (tikzspyonnode) -- (tikzspyinnode);
+\end{codeexample}
+ \end{key}
+ \end{enumerate}
+ Returning to the creation of the spy-in node: This node is centered on
+ \meta{coordinate} (more precisely, its anchor is set to |center| and
+ the |at| option is set to \meta{coordinate}). Its size and shape are
+ initially determined in the same way as the size and shape of the
+ spy-on node (unless, of course, you explicitly provide a different
+ shape for, say, the spy-on node locally, which is not really a good
+ idea). Then, additionally, the \emph{inverted} transformation done
+ by the |lens| option is applied, resulting in a node whose size and
+ shape exactly corresponds to the area in the picture that is shown
+ in the spy-on node.
+\begin{codeexample}[]
+\begin{tikzpicture}
+ [spy using outlines={lens={scale=3,rotate=20}, size=2cm, connect spies}]
+
+ \draw [decoration=Koch curve type 1]
+ decorate{ decorate{ decorate{ (0,0) -- (2,0) }}};
+
+ \spy [red] on (1.6,0.3) in node at (2.5,-1.25);
+\end{tikzpicture}
+\end{codeexample}
+
+ Like for the spy-in node, a style can be used to format the spy-on
+ node:
+ \begin{stylekey}{/tikz/every spy on node}
+ This style is used with every spy on node.
+ \end{stylekey}
+ The spy-on node is named |tikzspyonnode| (but, as always, this node
+ is only available after the spy scope). If you have multiple
+ spy-on nodes and you would like to access all of them, you need to
+ use the |name| key inside the |every spy on node| style.
+
+ The |inner sep| and |outer sep| of both spy-in and spy-on nodes are
+ set to |0pt|.
+\end{command}
+
+
+
+\subsection{Predefined Spy Styles}
+
+There are some predefined styles that make using the |spy| library
+easier. The following two styles can be used instead of |spy scope|,
+they pass their \meta{options} directly to |spy scope|. They
+additionally setup the graphic styles to be used for the spy-in nodes
+and the spy-on nodes in some special way.
+
+\begin{key}{/tikz/spy using outlines=\meta{options} (default
+ \normalfont empty)}
+ This key creates a |spy scope| in which the spy-in node is drawn,
+ but not filled, using a thick line; and the spy-on node is drawn,
+ but not filled, using a very thin line.
+
+\begin{codeexample}[]
+\begin{tikzpicture}
+ [spy using outlines={circle, magnification=3, size=1cm, connect spies}]
+
+ \draw [decoration=Koch curve type 1]
+ decorate{ decorate{ decorate{ (0,0) -- (2,0) }}};
+
+ \spy [red] on (1.6,0.3) in node at (3,1);
+\end{tikzpicture}
+\end{codeexample}
+\end{key}
+
+\begin{key}{/tikz/spy using overlays=\meta{options} (default
+ \normalfont empty)}
+ This key creates a |spy scope| in which both the spy-in and spy-on
+ nodes are filled, but with the fill opacity set to 20\%.
+
+\begin{codeexample}[]
+\begin{tikzpicture}
+ [spy using overlays={circle, magnification=3, size=1cm, connect spies}]
+
+ \draw [decoration=Koch curve type 1]
+ decorate{ decorate{ decorate{ (0,0) -- (2,0) }}};
+
+ \spy [green] on (1.6,0.3) in node at (3,1);
+\end{tikzpicture}
+\end{codeexample}
+\end{key}
+
+The following style is useful for connecting the spy-in and the spy-on
+nodes:
+
+\begin{key}{/tikz/connect spies}
+ Causes the spy-in and the spy-on nodes to be connected by a thin
+ line.
+
+\begin{codeexample}[]
+\begin{tikzpicture}
+ [spy using overlays={circle, magnification=3, size=1cm}]
+
+ \draw [decoration=Koch curve type 2]
+ decorate{ decorate{ decorate{ (0,0) -- (2,0) }}};
+
+ \spy [green] on (1.6,0.1) in node at (3,1);
+ \spy [red,connect spies] on (0.5,0.4) in node at (1,1.5);
+\end{tikzpicture}
+\end{codeexample}
+\end{key}
+
+
+\subsection{Examples}
+
+Usually, the spy-in node and the spy-on node should have the same
+shape. However, you might also wish to use the |circle| shape for the
+spy-on node and the |magnifying glass| shape for the spy-in node:
+
+\begin{codeexample}[]
+\tikzset{spy using mag glass/.style={
+ spy scope={
+ every spy on node/.style={
+ circle,
+ fill, fill opacity=0.2, text opacity=1},
+ every spy in node/.style={
+ magnifying glass, circular drop shadow,
+ fill=white, draw, ultra thick, cap=round},
+ #1
+ }}}
+\begin{tikzpicture}[spy using mag glass={magnification=3, size=1cm}]
+ \draw [decoration=Koch curve type 2]
+ decorate{ decorate{ decorate{ (0,0) -- (2,0) }}};
+
+ \spy [green!50!black] on (1.6,0.1) in node at (2.5,-0.5);
+\end{tikzpicture}
+\end{codeexample}
+
+With the magnifying glass, you can also put it ``on top'' of the
+picture itself:
+
+\begin{codeexample}[]
+\begin{tikzpicture}
+ [spy scope={magnification=4, size=1cm},
+ every spy in node/.style={
+ magnifying glass, circular drop shadow,
+ fill=white, draw, ultra thick, cap=round}]
+
+ \draw [decoration=Koch curve type 2]
+ decorate{ decorate{ decorate{ (0,0) -- (2,0) }}};
+
+ \spy on (1.6,0.1) in node;
+\end{tikzpicture}
+\end{codeexample}
+
+%%% Local Variables:
+%%% mode: latex
+%%% TeX-master: "pgfmanual-pdftex-version"
+%%% End: