eeshow - Eeschema schematics renderer and viewer
================================================

Eeshow renders schematics made by KiCad Eeschema to FIG, PDF, or PNG,
and generates graphical differences between different versions of
schematics sheets. It can work in plain files but it can also
retrieve design files directly from a git repository. Furthermore,
eeshow has an interactive mode for viewing schematics and differences.

This work is distributed under the terms of the GNU GENERAL PUBLIC
LICENSE, Version 2:

  This program is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 2 of the License, or
  (at your option) any later version.

For your convenience, a copy of the complete license has been included
in the file COPYING.GPLv2.


Prerequisites
-------------

libcairo2-dev
libgit2-dev
libgtk-3-dev
ibwebkit2gtk-4.0-dev


Development status
------------------

Eeshow is still incomplete. It should generally be usable, but still has
many limitations, especially in the following areas:

- not all details are rendered, e.g., pin attributes such as "clock input"

- rendering isn't always exactly the same as in KiCad, e.g., text size may
  differ significantly

- interactive use is not streamlined yet, e.g., revision selection

- there may be bugs

More details on pending items can be found in the file TODO.


Non-interactive rendering
=========================

Eeshow can be invoked from the command line to render KiCad schematics
to FIG, PDF, and PNG.


Invocation
----------

The general form of invocation for rendering is as follows:

eeshow [-r] file.lib ... file.sch -- format [options]

Common if using PDF, the option -r can be used (after "eeshow") to
recursively process sub-sheets. For PDF and PNG, the options -s scale
and -o output-file can be used to control the size of the output and
the output file. By default, eeshow writes to standard output.

Examples:

eeshow test.lib test.sch -- png -s 2 -o test.png

eeshow -r neo900.lib kicad-libs/components/powered.lib neo900.sch \
  -- pdf -o neo900.pdf

More details on the above example can be found in the file DEMO.


Revision access
---------------

If the files are stored in a git repository, a revisions can be selected
by prefixing file names with the commit ID, e.g.,

eeshow neo900.lib kicad-libs/components/powered.lib 6a9f71:neo900_SS_5.sch \
  -- png -s 2 -o old.png

Revision selection propagates to dependent files, unless explicitly
overridden. E.g., the above example selects also revision 6a9f71 of
neo900.lib.


Non-interactive differences
===========================

Eeshow can render two versions of a sheet to a bitmap and then compare them
pixel by pixel, highlighting areas where differences are found. The output
is written to a PNG file.


Invocation
----------

The general form of invocation for rendering is as follows:

eeshow file.lib ... file.sch -- diff [options] file.lib ... file.sch

The usual options and revision selection can be used here as well.

Example:

LIBS="neo900.lib kicad-libs/components/powered.lib"
eeshow $LIBS  6a9f71:neo900_SS_5.sch \
  -- diff -s 2 -o diff.png $LIBS neo900_SS_5.sch


GUI mode
========

GUI mode allows exploration of schematics and the comparison of different
git revisions. Compared to eeschema, eeshow currently offers the following
additional features:

- access to the git revision history with visual differences between
  versions.

- on hover, global labels show on which other sheets the label is used.
  Clicking on a name jumps to that sheet.

- fast sheet change with PgUp/PgDn


Invocation
----------

The basic invocation of GUI mode is as follows:

eeshow file.lib ... file.sch

Add the option -r to recursively load sub-sheets of file.sch

If file.sch is in a git repository, eeshow automatically loads the
revision history. The depth of the history can be limited with the
option -N number-of-commits

Examples:

eeshow -N 30 -r neo900.lib kicad-libs/components/powered.lib neo900.sch

eeshow `sed -n '/pcbnew/q;/^LibName[0-9]*=/{s///;s/$/.lib/p;};d' anelok.pro` \
  anelok.sch


Mouse function in GUI mode
--------------------------

Eeshow uses only the left mouse button and the scroll wheel.

Hover			show additional details on revisions, sheets, global
			labels
Click			jump to sheet (on sub-sheet, sheet stack, global
			label hover box), open history, select revision
Click and drag		pan sheet, scroll history
Scroll wheel		zoom in or out


Key functions in GUI mode
-------------------------

+ or =			zoom in
-			zoom out
*			zoom to extents
Home			go to the top sheet
Delete or Backspace	go to the next higher sheet in hierarchy
PgUp			go to the previous sheet in sequence
PgDn			go to the next sheet in sequence
Up or Down		invoke the revision history (WIP)
Tab			toggle between old and new revision
? or H			show/hide help window
D			when comparing revisions, show difference (default)
N			show newer sheet
O			show older sheet
Q			quit the viewer