MetaFun - Pragma ADE

2 A few more details
In this chapter we will see how to define a METAPOST graphic, and how to include it in a document. Since
the exact dimensions of graphics play an important role in the placement of a graphic, we will explore the
way a bounding box is constructed.
We will also pay attention to the usage of units and the side effects of scaling and shifting, since they can
contradict our expectations in unexpected ways. Furthermore we will explore a few obscure areas.
2.1 Making graphics
In this manual we will use METAPOST in a rather straightforward way, and we will try to avoid
complicated math as much as possible. We will do a bit of drawing, clipping, and moving around.
Occasionally we will see some more complicated manipulations.
When defined as stand--alone graphic, a METAPOST file looks like this:
% Let's draw a circle.
beginfig (7) ;
draw fullcircle scaled 3cm withpen pencircle scaled 1cm ;
endfig ;
end .
The main structuring components in such a file are the beginfig and endfig macros. Like in
a big story, the file has many sub--sentences, where each sub--sentence ends with a semi--colon.
Although the end command at the end of the file concludes the story, putting a period there is
a finishing touch. Actually, after the end command you can put whatever text you wish, your
comments, your grocery list, whatever. Comments in METAPOST, prefixed by a percent sign, as in %
Let's draw a circle, are ignored by the interpreter, but useful reminders for the programmer.
If the file is saved as yourfile.mp, then the file is processed by METAPOST by issuing the following
command:
mpost yourfile
after which you will have a graphic called yourfile.7, which contains a series of POSTSCRIPT commands.
Because METAPOST does all the work, this file is efficient and compact. The number of
distinct POSTSCRIPT operators used is limited, which has the advantage that we can postprocess
this file rather easily. Alternatively METAPOST can generate SVG output. It does when you say
outputformat := "svg" ;
Here we will not go into details about this format. Even POSTSCRIPT is not covered in detail as we
use METAPOST mostly in embedded form.
Making graphics A few more details
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