pcb-rnd modularization

Why bother...

I believe good software should be modular. This is especially important in the context of large software, such as CAD applications. There should be a thin core that can model the world and provide the basic operations defined on it but anything else should go in separate modules.

Fortunately PCB already had a strong infrastructure supporting this idea. It has dynamic loadable plugins and the GUI and exporters are in separate HID modules. While working on pcb-gpmi and later pcb-rnd, I added the gpmi module as a separate plugin.

In version 1.0.8 to 1.1.0 a considerable chunk of core code has been moved into core plugins. A core plugin is just a plugin that is maintained together with the core, in the same repository, still the code is somewhat detached from the core. More importantly, the user can choose, for each plugin, separately:

I believe such modularization has benefits on multiple levels:

Progress in charts


All numbers are in SLOC and are acquired running sloccount on the given directory. While lines of code alone is not a true measure of complexity, it's a good estimation. The slices of pie charts are the major components of the pcb-rnd executable.
Before modularization: pcb-rnd version 1.0.7
Note: gpmi was already a plugin
After modularization: current pcb-rnd
Note: gpmi is part of the "plugins" slice

Zooming on to the plugins

total size per class
IO plugins
feature plugins
export plugins
HID plugins
import plugins
library plugins
footprint plugins

(Red means the plugin doesn't really work).

Progress in numbers

Below is a table with the summary of core plugins.
module size [sloc] status configure
class description
acompnet304 WIP disable feature Auto-complete the current network. A very limited autorouter/assistant.
act_draw565 works buildin feature Expose drawing related API as actions
act_read306 works buildin feature Data access related API as actions
ar_cpcb318 WIP buildin feature Autoroute using external tool c-pcb
asm559 WIP buildin feature hand assembly assistant GUI
autocrop51 works buildin feature Reduce the board dimensions to just enclose the objects on the board.
autoplace646 works buildin feature Automatically place subcircuits.
autoroute4385 works buildin feature Automatically route selected or all rats. This is the original autorouter.
cam1574 works buildin export Configurable output job based batch exporting
ddraft2129 WIP buildin export Actions and a command interpreter for supporting advanced/precise 2 dimensional drafting
diag795 works disable feature Actions for pcb-rnd core diagnostics, intended for developers. These are not in core because end users normally don't need these. As a plugin, due to dynamic loading, it can be dropped on an existing pcb-rnd installation with minimal risk of scaring away a reproducible bug.
dialogs8710 works disable feature Interactive core functionality: HID-independent GUI dialogs (enabled by GUI HIDs)
distalign439 works buildin feature Introducing Align() and Distribute(), which work much like the similarly named functions in Visio. Given that PCB does not have the concept of "first selected object" to draw on, the reference points can be selected by arguments.
distaligntext475 works buildin feature Same as distalign, operates on text objects.
djopt2251 works buildin feature Various board optimization algorithms.
draw_csect787 works disable feature Draw cross section and layer map.
draw_fab291 works buildin feature Draw the fab layer (for various exporters).
draw_fontsel143 works disable feature Draw the font selector GUI
drc_orig352 buildin feature A few simple, hardwired Design Rule Checks.
expfeat31 works disable feature Staging plugin for experimenting with new actions and dialogs before getting them into core or other plugins
export_bom240 works buildin export Export bom (Bill of Materials)
export_dsn445 works buildin export Export specctra .dsn files
export_dxf2332 works buildin export Export dxf
export_excellon563 works buildin export Export to excellon drill/cnc files
export_fidocadj274 WIP buildin export Export to FidoCadJ format (.fcd)
export_gcode2501 works buildin export Export to gcode
export_gerber1142 works buildin export Export to gerber
export_ipcd356383 works buildin export IPC-D-356 Netlist export.
export_lpr104 works buildin export Export to lpr (using export_ps to generate postscript)
export_oldconn241 works buildin export Export subc/terminal connection map in an old, custom file format
export_openems2180 WIP buildin export Export copper to OpenEMS simulation
export_openscad725 WIP buildin export Export openscad
export_png1448 works buildin export Export to png, gif and jpeg
export_ps1552 works buildin export Export postscript or embedded postscript.
export_stat320 works buildin export Export various board statistics in lihata format
export_stl26 WIP disable export Export stl (triangulated surface)
export_svg703 works buildin export Scalable Vector Graphics (SVG) exporter
export_test90 WIP disable export A thin layer of code to dump exporter calls for testing the HID exporter API.
export_vfs_fuse311 WIP disable export Export all data and config of a board to a FUSE mountable filesystem
export_vfs_mc149 WIP disable export Export all data and config of a board to GNU mc
export_xy988 works buildin export Template based export of XY centroid subcircuit data e.g. for pick & place.
extedit352 works buildin feature invoke external program to edit parts of the current board
fontmode257 works buildin feature Font editing actions.
fp_board120 WIP buildin fp Footprint: load a board and expose all the unique subcircuits on that board as a footprint library
fp_fs440 works buildin fp Footprint: file system based implementation. Used to be called Newlib: load footprints from directories. Run external processes for the parametric footprints.
fp_wget654 works buildin fp Footprint: get static (file) footprints from the web, e.g. from http://gedasymbols.org
hid_batch325 works buildin hid HID without GUI: read actions from stdin.
hid_gtk2_gdk1286 works buildin hid GUI: GTK2 HID with GDK software rendering.
hid_gtk2_gl830 works buildin hid GUI: GTK2 with opengl rendering
hid_lesstif9162 works buildin hid GUI: the lesstif HID.
hid_remote1100 WIP disable-all hid Remote access HID: implement a protocol and use it to relay between a core and a remote HID implementation.
import_calay175 works buildin import Import the netlist and footprints from a calay netlist.
import_dsn268 works buildin import Import specctra .dsn files
import_edif3620 works buildin import Import plugin for netlists in the EDIF format.
import_fpcb_nl151 works buildin import Import the netlist and footprints from freepcb format (exported by e.g. easyeda)
import_hpgl131 works buildin import Emulate a plotter and import the plot as lines, arcs and polygons.
import_ipcd356381 works buildin import IPC-D-356 Netlist and pad centroid import
import_ltspice502 works buildin import Import the netlist and footprints from an ltspice .asc and .net pair of files
import_mentor_sch494 works buildin import Import Mentor Graphics Design Capture from flattened .edf netlist, using a parts conversion table.
import_mucs122 works buildin import Import lines and vias from MUCS unixplot .pl files
import_netlist133 works buildin import Import plugin for netlists in the classic pcb netlist format.
import_pxm_gd103 works buildin import Import png, gif and jpeg using libgd
import_pxm_pnm119 works buildin import Import pnm P4, P5 and P6 into pcb-rnd pixmaps
import_sch333 works buildin import Imports footprints and netlist data from the schematics (or some other source).
import_tinycad149 works buildin import Import the netlist and footprints from a tinycad netlist.
import_ttf163 WIP buildin import Import outline ttf glyphs into the current font, either as polygons or lines
io_autotrax1585 works buildin io Import and export autotrax layouts and footprints.
io_dsn1673 works disable io Load and save specctra DSN files
io_eagle4044 works buildin io Load the design from eagle's xml and binary formats.
io_hyp4096 works buildin io Import plugin for hyperlynx geometry (no polygons yet).
io_kicad3546 works buildin io Load and save the design and footprints in Kicad's s-expression format - this is the new, currently preferred format in Kicad.
io_kicad_legacy902 works buildin io Export the design and footprints in Kicad's legacy format.
io_lihata4341 works buildin io Load and save the design and footprints in the lihata board format.
io_mentor_cell401 WIP disable io Load Mentor Graphics cell footprint library and make footprints available (e.g. for fp_board)
io_pcb2950 works buildin io Load and save the design and footprints in the original gEDA/PCB text format.
io_tedax2518 works buildin io Import and export tEDAx netlists and footprints.
jostle420 works buildin feature Pushes lines out of the way.
lib_compat_help1249 works buildin lib a library of functions providing a simplified API compatibility layer, mainly for I/O plugins
lib_gensexpr13 works disable-all lib S-expression parser lib
lib_gtk_common5639 works disable-all lib hid_gtk* common code (regardless of rendering mechanism: for both gdk sw rendering and gl)
lib_hid_common2044 works disable-all lib hidlib common helper functions for non-PCB GUI
lib_hid_gl1014 works disable-all lib generic openGL renderer shared among GUI HIDs
lib_hid_pcbui2419 works disable-all lib PCB related helper functions for GUI HIDs
lib_netmap216 works disable-all lib create disposable cross-reference maps between all objects and all nets
lib_polyhelp740 works buildin lib functions to help plugins processing polygons and PolyHatch() action
lib_vfs456 works disable-all lib Retrieve, sort and query data under VFS export plugins
lib_wget67 works disable-all lib retrieve files from the web using wget(1)
loghid295 WIP disable feature Sits between a HID (or exporter) and the core and logs all core->plugin calls made through the HID structure.
millpath402 WIP disable feature Calculate and simulate toolpath for milling away opper
mincut882 works buildin feature Use the minimal cut algorithm to indicate shorts: instead of highlighting two random pins/pads, try to highlight the least number of objects that connect the two networks.
oldactions268 works disable feature Random collection of old/obsolete actions. Bell(): audible feedback, DumpLibrary(): print footprint library on stdout, a set of debug actions useful for writing pcb scripts: Debug(), DebugXY(), Return(). Old plugin actions to toggle or set settings that are now accessible via the unified config system (vendordrill, djopt)
order309 WIP disable feature order boards through the Internet
order_pcbway612 WIP disable feature order from PCBWay through the Internet
polycombine207 works buildin feature The selected polygons are combined together according to the ordering of their points.
polystitch96 works buildin feature The polygon under the cursor (based on closest-corner) is stitched together with the polygon surrounding it on the same layer. Use with pstoedit conversions where there's a "hole" in the shape - select the hole.
propedit1913 works buildin feature List and edit properties of a group of objects.
puller1747 works buildin feature Pull traces to minimize their length.
query2276 works buildin feature pcb-rnd query language: execute expressions on objects and rules for the programmed drc.
renumber322 works buildin feature Renumber subcircuits (renaming them) and generate a text file for back annotation.
report910 works buildin feature Report() and ReportObject() actions - print a report about design objects.
rubberband_orig1219 works buildin feature The original rubberband code.
script1498 works buildin feature Load and execute scripts written in any language supported by fungw
serpentine369 WIP disable-all feature Create serpentines on existing lines.
shand_cmd165 works buildin feature vi-like command shorthands (1..3 character long commands)
shape828 works buildin feature Generate objects of regular shape (regular polygons, circle, round rect)
sketch_route2701 WIP disable feature TODO
smartdisperse164 works buildin feature Improve the initial dispersion of subcircuits by choosing an order based on the netlist, rather than the arbitrary subcircuit order. This isn't the same as a global autoplace, it's more of a linear autoplace. It might make some useful local groupings. For example, you should not have to chase all over the board to find the resistor that goes with a given LED.
stroke288 works buildin feature Configurable gesture recognition with libstroke.
teardrops215 works buildin feature Draw teardrops on pins.
vendordrill515 works buildin feature Vendor drill mapping.


Each plugin implements a class (rarely a set of classes). Classes are:
name description
feature random features directly accessible for the user, usually actions
lib support code library for other plugins (core doesn't depend on these); functionality not directly accessible for the user but other plugins may depend on it
hid Human Interface Device: interactive user interface, usually GUI
import load alien formats into the design space
export save (parts of) the design space in alien formats
fp footprint (element) library implementation
io native file format (save & load) implementation


Common status column values mean:
name description
works production quality code - configures, compiles, tested
WIP work in progress: the plugin may be avaialble for testing but is not yet production quality
abandoned unmaintained plugin; may be in working condition but there is no developer supporting it
deprecated legacy plugin scheduled for removal; may still work but will soon be removed; if your workflow depends on it, please report ASAP

Plugin dependency map

pcb-rnd plugin dependency graph