Creating and using pics
In LaTeX, we can write macros containing code that can be used repeatedly. How about using TikZ picture code repeatedly in a drawing? We cannot simply put one tikzpicture environment into another one. These pictures and their elements would interfere with each other’s styles and settings.
To solve this, TikZ provides a syntax for creating small pictures that can be used as building blocks in a TikZ drawing. The feature name is pic; let’s also call these short pictures pics.
A pic is a TikZ drawing code sequence, defined in a similar way to setting a style. To get practical, we will define a smiley pic based on the code for our self-made smiley in Chapter 2, Creating the First TikZ Images. The basic syntax is as follows:
\tikzset{smiley/.pic={ ... drawing commands ... }}
Like .style, .pic is also an example of a key handler.
We take our code for Figure 2.11 and put this code into the \tikzset command in the following way:
\tikzset...