:orphan:

L-System
========

*Example script* (scamp_extensions): `examples/Composition & form/Algorithmic approaches/l_system_example.py <https://github.com/MarcTheSpark/scamp_extensions/blob/main/examples/Composition & form/Algorithmic approaches/l_system_example.py>`__

*Download:* :download:`l_system_example.py <downloads/composition_form_algorithmic_approaches_l_system_example/l_system_example.py>`

**Requires the** ``scamp_extensions`` **package** (``pip install scamp_extensions``).

Example usage of the from :class:`~scamp_extensions.process.l_system.LSystem` class, which allows you to set a vocabulary of symbols, set their rewrite rules and meanings, and evolve and play the resulting L-System.

*Topics:* :doc:`Composition & form › Algorithmic approaches <composition_form>`

.. raw:: html

   <div style="margin:0.6em 0"><audio controls preload="none" src="../_static/media/Composition%20%26%20form/Algorithmic%20approaches/l_system_example.mp3" style="width:100%;max-width:520px"></audio></div>

.. code-block:: python

   from scamp import *
   from scamp_extensions.process import LSystem

   s = Session()
   s.tempo = 100


   perc1 = s.new_part("Perc. 1", preset="power")
   perc2 = s.new_part("Perc. 2", preset="power")
   perc3 = s.new_part("Perc. 3", preset="power")


   l_syst1 = LSystem(
       "a",
       {
           "a": "c b",
           "b": "bac",
           "c": " aa"
       },
       {
           " ": None,
           "a": 56,
           "b": 60,
           "c": 81,
       }
   )

   l_syst2 = LSystem(
       "b",
       {
           "a": "c b",
           "b": "bac",
           "c": " aa"
       },
       {
           " ": None,
           "a": 50,
           "b": 67,
           "c": 63,
       }
   )

   l_syst3 = LSystem(
       "c",
       {
           "a": "c b",
           "b": "bac",
           "c": " aa"
       },
       {
           " ": None,
           "a": 70,
           "b": 75,
           "c": 82,
       }
   )


   def play_notes(instrument, pitches, volume, duration):
       for pitch in pitches:
           instrument.play_note(pitch, volume, duration)


   for generation in range(6):
       print(f"Generation {generation}:")
       print(f"  Part 1: {l_syst1.get_generation(generation)}")
       print(f"  Part 2: {l_syst2.get_generation(generation)}")
       print(f"  Part 3: {l_syst3.get_generation(generation)}")
       fork(play_notes, args=(perc1, l_syst1.get_generation_meanings(generation), 0.8, 0.25))
       fork(play_notes, args=(perc2, l_syst2.get_generation_meanings(generation), 0.8, 0.25))
       fork(play_notes, args=(perc3, l_syst3.get_generation_meanings(generation), 0.8, 0.25))
       wait_for_children_to_finish()
       wait(2)