:orphan:

Indispensability
================

*Example script* (scamp_extensions): `examples/Composition & form/Algorithmic approaches/indispensibility_example.py <https://github.com/MarcTheSpark/scamp_extensions/blob/main/examples/Composition%20%26%20form/Algorithmic%20approaches/indispensibility_example.py>`__

*Download:* :download:`indispensibility_example.py <downloads/composition_form_algorithmic_approaches_indispensibility_example/indispensibility_example.py>`

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

Mouse position controls a rhythmic texture based on Barlow's beat indispensability (barlicity extension).

*Topics:* :doc:`Interactivity & visualization › Mouse input <interactivity_visualization>`, :doc:`Composition & form › Algorithmic approaches <composition_form>`

.. raw:: html

   <iframe src="https://www.youtube-nocookie.com/embed/436LmCJ5BmY" style="width:100%;max-width:640px;aspect-ratio:16/9;border:0;display:block;margin:0.6em 0" allowfullscreen></iframe>

.. code-block:: python

   from scamp import *
   from scamp_extensions.composers.barlicity import *
   import random


   threshold = 0
   syncopation_chance = 0


   def mouse_move(x, y):
       global threshold, syncopation_chance
       syncopation_chance = x
       threshold = y


   s = Session()

   s.register_mouse_listener(on_move=mouse_move, relative_coordinates=True)

   drum = s.new_part("taiko", (0, 116), num_channels=150)
   violin = s.new_part("violin")

   indispensibilities = get_indispensability_array(((2, 3), 2, 3, (2, 3), (2, 3, 2), (3, 2, 3, 3)), True)  # (5, 7), (7, 11)

   handle = None
   pitch = None

   while True:
       for indispensibility in indispensibilities:
           if indispensibility > 0.9:
               if handle is None:
                   pitch = 65 + (1 - threshold) * 25
                   handle = violin.start_note(pitch, 0.8)
               elif random.random() < 0.6:
                   handle.end()
                   handle = None
           elif handle is not None:
               handle.change_pitch(pitch + (1 - indispensibility) * random.uniform(-syncopation_chance * 15, syncopation_chance * 15), 0.15)

           if random.random() < syncopation_chance:
               indispensibility = 1 - indispensibility
           if indispensibility > threshold:
               drum.play_note(40 + int(80 * (1 - indispensibility)),
                              0.5 + 0.5 * (indispensibility - threshold) / (1 - threshold), 0.1)
           else:
               wait(0.1)