New Engine: Pure Data

Finally, the long-time-awaited Pure Data zynthian’s engine is here!

The new engine will allow to run any standard patch for “pd vanilla”. No “pd extended” support as it’s completely deprecated.

If you already have a zynthian box with the last SD image (Gorgona Omega), you simply update from the Admin Menu or from the command line:

/zynthian/zynthian-sys/scripts/update_zynthian.sh

Although any “vanilla” patch should work out-the-box, you would like to have your MIDI controllers correctly mapped and labeled. Don’t worry!! … integrating patches for working nicely with Zynthian is pretty easy. The trick is done by a simple YAML config file called “zynconfig.yml” that should be present in the patch folder. If no config file is found, the engine will try to detect the patch’s main file and some default controllers will be created.

You can use the example patches as reference for “patch integration”. This is an example:

main_file: "threeosc1.pd"

midi_controllers:
 volume:
  midi_cc: 7
  value: 64
 program:
  midi_cc: 2
  value: '1'
  labels: ['1', '2', '3', '4', '5', '6', '7', '8', '9', '10', '11', '12', '13', '14', '15', '16']
 vibrato_depth:
  midi_cc: 1
  value: 64
 cutoff_mod:
  midi_cc: 63
  value: 64
 filter_env_mod:
  midi_cc: 65
  value: 64
 osc3_mod_env_amt:
  midi_cc: 66
  value: 0
 pitch_mod_amt:
  midi_cc: 67
  value: 0

As you can see, there is little to explain. You can specify more options for the controllers, “ticks” values for the “labels”, etc… Take a look to “zyngine/zynthian_controller.py” for more details. Currently only MIDI integration is implemented, although OSC wont be too difficult to implement.

Of course, you have to customize a little bit your patches for getting a good integration, specially if you want “selector” controllers, like the “program” selector in the example above.

Finally, my experience with PD is really small, so i would appreciate any feedback, suggestion or help for improving the new engine.