
* Circuit_macros Version 10.0, copyright (c) 2022 J. D. Aplevich under     *
* the LaTeX Project Public Licence in file Licence.txt. The files of       *
* this distribution may be redistributed or modified provided that this    *
* copyright notice is included and provided that modifications are clearly *
* marked to distinguish them from this distribution.  There is no warranty *
* whatsoever for these files.                                              *

  This is a set of macros for drawing high-quality line diagrams to
  include in LaTeX, web, or similar documents, with support for SVG
  (including Inkscape) and other formats.  Fundamental electric circuit
  elements and basic logic gates based on IEEE and European standards are
  included with several tools and examples of other types of diagrams.
  Elements can be scaled or drawn in any orientation and are easy
  to modify.  The advantages and disadvantages of such a system in its
  basic form are similar to those of TeX itself, which is macro-based
  and non-WYSIWYG. Graphical interfaces are available for specific
  operating systems.

  The macros are to be processed by an m4 macro processor, and evaluate to
  drawing commands in the pic "little language," which is easy to read and
  learn. The diagram is then automatically translated into TiKZ, PSTricks,
  or other formats for processing by LaTeX or other applications. Pic
  is well suited to line drawings requiring parametric or conditional
  components, fine adjustment, geometric calculations, repetition, or
  recursion.  Arbitrary text for formatting by LaTeX can be included.
  Free interpreters for m4 and pic are readily available.

Sources are available as a git repository at
   https://gitlab.com/aplevich/Circuit_macros

REQUIRED SOFTWARE:
Preferred setup:
  m4, dpic, LaTeX or PDFLaTeX, TikZ-PGF
  or
  GNU m4, dpic, LaTeX, PSTricks, dvips

  The GNU m4 macro processor is assumed, and a small number of macros
  require GNU m4 features. Other versions of m4 will work with most macros.

  The dpic interpreter can translate pic input into several forms,
  typically a .tex file for processing by latex with pgf/Tikz or PSTicks.

Alternative:
  m4, GNU pic (gpic), TeX or LaTeX, and a driver recognizing tpic specials
   (eg dvips)

  The GNU pic interpreter with option -t produces tpic special commands.

Also possible for some diagrams:
  m4 and dpic with output in the following formats:
    LaTeX graphics or LaTeX eepic (for simple diagrams), mfpic, xfig,
    MetaPost, SVG, PDF, or Postscript.

USAGE
  First-time users should read the Quick Start section of Circuit_macros.pdf.

  The following describes the most common basic usage to produce tikz
  or pstricks graphics for LaTeX; see below for integration with other
  tools and production of other formats. You probably should try out
  the basic usage before integrating the macros with sophisticated
  system-dependent tools. When developing your own diagrams, refer to the
  macro descriptions in the List of Macros section of Circuit_macros.pdf.

  Suppose that  a source file, cct.m4 say, has been created and the top
  two lines are
  .PS
  cct_init
  ...

  The file is processed by feeding a configuration file followed by the
  diagram source to m4, and routing the output to dpic.  If you have set
  the M4PATH environment variable as described in the INSTAllATION
  instructions, the command for Tikz processing is

    m4 pgf.m4 cct.m4 | dpic -g > cct.tex

  NOTE: The order in which the files are given to m4 is important.
  A configuration file (pgf.m4 in this example) must ALWAYS appear first.

  If you have not set the M4PATH environmental variable then the command is

    m4 -I <path> pgf.m4 cct.m4 | dpic -g > cct.tex

  where <path> is the absolute path to the directory containing the library
  macros.

  If the first line of cct.m4 is
  include(pgf.m4)
  and M4PATH is defined, then this command can be simplified to

    m4 cct.m4 | dpic -g > cct.tex

  In each case, the resulting file cct.tex is normally inserted into
  a document to be processed by LaTeX.  The -g option of dpic produces
  Tikz-pgf graphics commands in cct.tex so the LaTeX document must have
  \usepackage{tikz} in the preamble.

  To produce postscript output, the LaTeX preamble must contain
  \usepackage{pstricks}, pstricks.m4 is read instead of pgf.m4, and the dpic
  option is -p, so the command is

    m4 pstricks.m4 cct.m4 | dpic -p > cct.tex or m4 cct.m4 | dpic -p > cct.tex

  Read Section 2 of the manual to see how to process the diagram source
  from within the main .tex source file.

  To use the GNU gpic processor (called pic on some systems) instead of dpic,
  the command is

    m4 gpic.m4 cct.m4 | gpic -t > cct.tex

  The basic commands given above suffice for documents of moderate
  size and complexity; otherwise, a "make" facility or equivalent should
  be used or, for modest documents, diagram processing can be controlled
  from within the tex document source as described in the manual. For
  near-immediate viewing of the basic process, three windows can be kept
  open: one in which to edit the source, one to process the source and
  produce postscript or pdf, and a viewer such as GSview 5.0, which updates
  when clicked.

INSTALLATION AND TESTING: See the INSTALL file.

SOURCES AND MANUALS:
  View or print Circuit_macros.pdf in the doc directory.

  M4 is widely available on Unix systems.  PC source and executables are
  also available: http://gnuwin32.sourceforge.net/packages/m4.htm
  A large set of Unix-like Windows tools, including m4, is available via
  http://www.cygwin.com/
  DJGPP versions are available as m4-NNb.zip (where NN is the current
  release number) on web archives and at
  http://www.delorie.com/djgpp/dl/ofc/dlfiles.cgi/current/v2gnu/

  There are several sources of hints on m4 usage; some places to look are
  http://gnuwin32.sourceforge.net/packages/m4.htm  (m4 for Windows)
  http://www.gnu.org/software/m4/manual/   (GNU m4 manual)
  https://mbreen.com/m4.html    (m4 by example)
  The m4 (computer language) article in Wikipedia gives a concise overview.
  An academic discussion of the language can be found in
  http://www.cs.stir.ac.uk/~kjt/research/pdf/expl-m4.pdf.
  The GNU Autoconf manual contains a chapter on M4 programming:
  http://www.gnu.org/software/autoconf/manual/index.html
  (Do not read this manual first). Autoconf uses quote characters [ and ]
  instead of the default ` and ' which work well with the pic language.

DPIC:
  Several Linux distributions will install dpic by command but the version
  may not be the latest.  A git repository containing complete source is at
  https://gitlab.com/aplevich/dpic
  and source plus a Windows executable can be obtaied from
  http://ece.uwaterloo.ca/~aplevich/dpic/
  The best advice is to obtain the newest version.

  The dpic distribution includes dpic-doc.pdf, a manual containing a summary
  of the pic language and a detailed description of features unique to dpic.

GPIC:
  Gpic is part of the GNU groff distribution, for which the source
  and documentation is available from http://ftp.gnu.org/gnu/groff/
  but there are mirror sites as well.  A more extensive manual is found
  in the documentation that comes with GNU pic, which is typically
  installed as gpic. A pdf copy is included with the dpic distribution.
  The original AT&T pic manual can be found at
  http://doc.cat-v.org/unix/v10/10thEdMan/pic.pdf

SVG output, Inkscape:
  Dpic -v produces svg output.  If the result is to be directly
  inserted into html, then as for Postscript output, the diagram
  source file has to be adapted to remove any LaTeX formatting. The
  configuration file svg.m4 contains macros that can assist.  To avoid
  this problem at the expense of an extra postprocessing step,
  sophisticated text formatting and font selection can be retained
  by first producing pdf output and then converting to SVG using,
  say, pdf2svg (https://github.com/dawbarton/pdf2svg) or dvisvgm
  (https://www.ctan.org/pkg/dvisvgm).

  SVG is the native file format for the Inkscape graphics editor.
  Therefore, elements defined by these macros can be output by dpic -v in
  svg format for later manipulation by Inkscape.  A very basic palette of
  circuit elements for Inkscape is found in examples/svg/paletteSVG.m4.
  In the svg subdirectory, type "make paletteSVG.svg", read the resulting
  file into Inkscape, and then ungroup the elements as desired. You would
  probably wish to add to or customize these elements for extensive use.

EXAMPLES
  A set of examples is included in this distribution, showing electric
  circuits, block diagrams, flow charts, signal-flow graphs, basic
  use of colour and fill, and other applications.  Some of the examples
  test the boundaries of the domain of application of dpic with m4
  macros. Read the manual Circuit_macros.pdf and view examples.pdf
  in the examples directory or make and view the html file in the
  examples/svg directory. For the curious, There are additional source
  files in the examples directory that are not shown in examples.pdf.
  For the possibly unstable development version of these macros, try
  http://ece.uwaterloo.ca/~aplevich/Circuit_macros/

  The examples directory Makefile automates the generation of .ps, .eps,
  .png, and .pdf files for individual diagrams.  Subdirectories of the
  examples directory are for testing metafont, metapost, pgf, psfrag,
  and xfig examples.

WORKFLOW:
  Installation and usage of the macros have evolved somewhat since the
  beginning, so archived instructions on the net may be slightly more
  complicated than currently necessary.

  I use a very simple workflow most of the time: three open windows;
  one to edit the diagram source, one to run LaTeX and produce pdf or
  postscript, and a document viewer window. The lines
   :set mps+=`:'
   :set mps+=<:>
  were added to my default .vimrc file to highlight matched pairs of
  brackets, braces, parentheses, and, expecially for m4 programming,
  single quotes.

INTEGRATION WITH OTHER TOOLS:
  To automate document production, I simply added commands to
  the appropriate Makefiles. However, others have developed tools
  that simplify workflow for their circumstances.  The following are
  representative but keep in mind that systems and installations evolve
  over time:

  A Python-based GUI called PyCirkuit is
  at https://pypi.org/project/pycirkuit/ and
  https://github.com/orestesmas/pycirkuit.  For an
  introduction, look at the FOSDEM video by Orestes Mas:
  https://archive.fosdem.org/2020/schedule/event/pycirkuit/

  A python build-automation tool, m4cm, by Peter Jan Randewijk is at
  https://m4cmpy.wordpress.com/ and very clear instructions about getting
  started with Circuit_macros are at
  https://m4cmpy.wordpress.com/2020/02/23/getting-started-with-m4-circuit-macros/

  Fabrice Salvaire has a blog and a useful bash script at
  https://www.fabrice-salvaire.fr/en/blog/electronic-circuit-diagrams/

  A set of examples and hints intended for his colleagues has been
  produced by Alan Robert Clark at http://ytdp.ee.wits.ac.za/cct.html

  A video "Drawing Circuit Diagrams with Circuits Macros" by James Green
  showing how to use Circuit_macros with his setup is at 
  https://www.youtube.com/watch?time_continue=53&v=pFRIBvUJHS4

  A git repository of a KDE interface by Andrew G. for Linux is at
  https://github.com/ag-ckt/cirkuit/tree/V0.5.0.

  Another recent introduction is at
  https://www.root.cz/clanky/publikovanie-elektrickych-schem-a-diagramov-pomocou-circuit-macros/
  It is in Czech but Google translate works well.

  LaTeX automation tools are discussed at, for example, 
  http://tex.stackexchange.com/questions/64/tools-for-automating-document-compilation

  A Windows batch file for Circuit_macros is found at
  http://someonehasdonethis.blogspot.ca/2012/12/a-solution-for-drawing-circuit-diagrams.html

  Mac users:
  A nice description of a Mac installation is at
  https://www.hamish.science/2020/06/24/circuitmacros

VARIATIONS
  Macros such as these will be modified inevitably to suit individual
  needs and taste.  They continue to evolve in my own library as I use
  them and as others send comments.  No such collection can hope to
  include all possible circuit-related symbols, so you will probably
  find yourself writing your own macros or adapting some of these.
  Be careful to rename modified macros to avoid confusion.  The learning
  curve compares well to other packages, but there is no trivially
  easy way to produce high-quality graphics.  (If "a picture is worth
  a thousand words," ask yourself how long it would take to write, revise,
  and perfect a thousand words.)

  See eschpic on Github for IEC-style electrical drawings.

  The pic language dates from the 1980s and was first developed
  as a preprocessor for the *roff family of Unix wordprocessors.
  Some additional libraries such as chem (for chemical structures)
  and dformat (for data structures) are still viable.

  Pic macros for drawing graphs are described at
  http://www.math.uiuc.edu/~west/gpic.html
  After minor adaptation to dpic syntax, many of them can be simplified.

  A collection of traditional pic resources and related material is
  available at http://www.kohala.com/start/troff/troff.html In particular,
  W. Richard Stevens illustrated his books on Unix and TCP/IP using
  pic macros. Some of the sources found there need minor tuning to work
  under dpic.

MetaPost examples:  Go to the examples/mpost directory.  Check the
  Makefile as described in the README file, type "make", and stand well back.

Postscript with embedded psfrag strings:
  Type "make" in the examples/psfrag directory to process examples
  using dpic -f for creating .eps files with embedded psfrag strings.

Postscript, CorelDraw, Adobe Illustrator:
  Circuits and other diagrams not requiring LaTeX-formatted text can be
  processed through m4 and dpic -r to produce encapsulated Postscript
  output. This output can also be imported into CorelDraw or Adobe
  Illustrator.  However, Postscript is not a word processor, so any
  LaTeX formatting instructions in the source are not obeyed. These programs
  also import svg output produced by dpic -v.

Metafont:
  The file examples/mf/cct.mf is a Metafont source for a few variants of
  the basic elements, produced using the mfpic output of dpic.  It may
  be of interest to persons who cannot otherwise implement the macros.
  To see the elements (assuming a typical installation), type "make"
  in the mf directory.

Xfig:
  The file examples/xfig/xfiglib.fig contains circuit elements in xfig
  3.2 format produced by dpic.  The file is a prototype because many
  more elements could be included.  Logic gates often have many labels,
  and xfig is not a word processor, so some fine tuning of labels is in
  order.  Translation between languages always involves a loss of
  information and idiom, but Xfig can store diagrams in pic format, so
  it is possible to alternate between xfig and dpic.

LIBRARIES:
  The file libgen.m4 contains general-purpose macros and is read
  automatically by other libraries.  The file libcct.m4 defines basic
  circuit elements.  Binary logic-circuit elements are in liblog.m4 and
  additional single-line elements are in libSLD.m4. Macros for drawing 3D
  projections are in lib3D.m4, and some macros for drawing double-line
  arrows are in darrow.m4. The file dpictools.pic contains pic macros
  and is read automatically by some of the examples.

Feel free to contact me with comments or questions.  I have retired
from full-time work but continue the hobby of maintaining these files.
I may now be able to spend more time on individual requests but I may
not reply instantly to email.


Dwight Aplevich
aplevich (AT) uwaterloo (DOT) ca
