PGF/TikZ Manual

The TikZ and PGF Packages
Manual for version 3.1.9a

Libraries

77 Views Library

TikZ Library views

\usetikzlibrary{views} % and plain
\usetikzlibrary[views] % Cont

This library is used for creating views, which are transformations of a part of a picture so that this part “fits” into a “viewbox”. Mostly, views are useful in conjunction with animations.

A view is essentially a “window” through which you see a graphic. To establish a view, you specify a rectangle – which is the window – and another rectangle surrounding the to-be-viewed graphic. The graphic will then be rescaled and shifted in such a way that the to-be-viewed rectangle matches the view’s rectangle as well as possible. Note that establishing a view causes a canvas transformation to be installed, not a coordinate transformation.

View boxes are only seldom needed in normal graphics; you may prefer to use coordinate transformations or the spy library. Their main application is with animations since you can animate the to-be-viewed rectangle. This makes it easy to create animations in which you zoom in, zoom out, and pan a graphic.

/tikz/meet=⟨to-be-viewed corner⟩ rectangle ⟨to-be-viewed corner⟩ at ⟨window corner⟩ rectangle ⟨window corner⟩(no default)

Use this key with a scope to establish a view for the scope. In the argument to the meet key, both rectangle texts are optional. Also, everything following at is optional; when it is missing, the ⟨window corner⟩s are assumed to be the same as the ⟨to-be-viewed corner⟩s. The latter are two corners of a rectangle that should be transformed in such a way that it fits inside the rectangle described by the two window corners.

More precisely, at the beginning of the scope a canvas transformation is installed that scales and translates the canvas is such a way that

1. the center of the to-be-viewed rectangle lies at the center of the window rectangle and

2. the to-be-viewed rectangle has maximum size that it still fits inside the window rectangle.

(-tikz- diagram)

\usetikzlibrary {views}
\tikz {
  \draw [red, very thick] (0,0) rectangle (20mm,20mm);
  \begin{scope}[meet = {(0.5,0.5) (2.5,1.5) at (0,0) (2,2)}]
    \draw [blue, very thick] (5mm,5mm) rectangle (25mm,15mm);
    \draw [thick] (1,1) circle [x radius=5mm, y radius=10mm] node {Hi};
  \end{scope} }

(-tikz- diagram)

\usetikzlibrary {views}
\tikz {
  \draw [red, very thick] (0,0) rectangle (20mm,20mm);
  \begin{scope}[slice = {(0.5,0.5) (2.5,1.5) at (0,0) (2,2)}]
    \draw [blue, very thick] (5mm,5mm) rectangle (25mm,15mm);
    \draw [thick] (1,1) circle [x radius=5mm, y radius=10mm] node {Hi};
  \end{scope} }

As mentioned earlier, the main use of views is in conjunction with animations. In order to animate a view, you specify the scope containing the meet command as the target object and then animate its :view attribute:


\tikz [animate = {
  my scope:view = {
    begin on = { click, of next = here },
    0s = "{(0.5,0.5) (2.5,1.5)}",
    2s = "{(0.5,0) (1.5,2)}", forever,
  }}] {
  \draw [red, fill=red!20, very thick, name=here]
    (0,0) rectangle (20mm,20mm);
  \begin{scope}[name = my scope,
                meet = {(0.5,0.5) (2.5,1.5) at (0,0) (2,2)}]
    \draw [blue, very thick] (5mm,5mm) rectangle (25mm,15mm);
    \draw [thick] (1,1) circle [x radius=5mm, y radius=10mm] node {Hi};
  \end{scope} }

You can, of course, also specify the animation using the animate myself: key when you specify the animation inside the scope:

(-tikz- diagram)

\usetikzlibrary {animations,views}
\tikz [animate = {
  my scope:view = {
  }}] {
  \draw [red, fill=red!20, very thick, name=here]
    (0,0) rectangle (20mm,20mm);
  \begin{scope}[animate = { myself: = { :view = {
                  begin on = { click, of = here },
                  0s = "{(0.5,0.5) (2.5,1.5)}",
                  2s = "{(0.5,0) (1.5,2)}", forever }}},
                slice = {(0.5,0.5) (2.5,1.5) at (0,0) (2,2)}]
    \draw [blue, very thick] (5mm,5mm) rectangle (25mm,15mm);
    \draw [thick] (1,1) circle [x radius=5mm, y radius=10mm] node {Hi};
  \end{scope} }

/tikz/view(no value)

This is an alias for /tikz/meet.

/tikz/slice=⟨to-be-viewed corner⟩ rectangle ⟨to-be-viewed corner⟩ at ⟨window corner⟩ rectangle ⟨window corner⟩(no default)

This key works exactly like meet, only the second rule is changed:

\(2'\). the to-be-viewed rectangle has minimal size that it encompasses all of the window rectangle.