VocalEasel/mma/MMA/patArpeggio.py

# patArpeggio.py

"""
This module is an integeral part of the program
MMA - Musical Midi Accompaniment.

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.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

Bob van der Poel <bvdp@xplornet.com>

"""

import random

import gbl
from   MMA.notelen import getNoteLen
from   MMA.common import *
from   MMA.harmony import harmonize
from   MMA.pat import PC



class Arpeggio(PC):
	""" Pattern class for an arpeggio track. """

	vtype = 'ARPEGGIO'
	arpOffset = -1
	arpDirection = 1

	def getPgroup(self, ev):
		""" Get group for apreggio pattern.

		    Fields - start, length, volume
		"""

		a = struct()
		if len(ev) != 3:
			error("There must be exactly 3 items in each group "
				  "for apreggio define, not <%s>." % ' '.join(ev) )

		a.offset    = self.setBarOffset(ev[0])
		a.duration  = getNoteLen(ev[1])
		a.vol       = stoi(ev[2], "Type error in Arpeggio definition.")

		return a


	def restart(self):
		self.ssvoice = -1
		self.arpOffset=-1
		self.arpDirection=1

	def trackBar(self, pattern, ctable):
		""" Do a arpeggio bar.

		Called from self.bar()

		"""

		sc = self.seq
		direct = self.direction[sc]

		for p in pattern:
			tb = self.getChordInPos(p.offset, ctable)

			if tb.arpeggioZ:
				continue

			if direct == 'DOWN':
				self.arpDirection = -1

			if self.chordLimit:
				tb.chord.limit(self.chordLimit)

			if self.compress[sc]:
				tb.chord.compress()

			if self.invert[sc]:
				tb.chord.invert(self.invert[sc])

			# This should be optimized, it recreates the chord for every pattern.
			# Problem is that one would need to check all the LIMIT, COMPRESS, etc
			# settings each for each bar as well, so it's probably just as easy to
			# leave it as is. Besides, this works.

			ln = self.chordRange[sc]
			o = 0
			ourChord = []
			while ln >= 1:
				for a in tb.chord.noteList:
					ourChord.append(a+o)
				ln -= 1
				o += 12

			if ln > 0 and ln < 1: 	 # for fractional  lengths
				ln = int(tb.chord.noteListLen * ln)
				if ln < 2:   # important, min of 2 notes in arp.
					ln=2
				for a in tb.chord.noteList[:ln]:
					ourChord.append(a+o)

			if direct == 'BOTH':
				if self.arpOffset < 0:
					self.arpOffset = 1
					self.arpDirection = 1
				elif self.arpOffset >= len(ourChord):
					self.arpOffset = len(ourChord)-2
					self.arpDirection = -1

			elif direct == 'UP':
				if self.arpOffset >= len(ourChord) or self.arpOffset < 0:
					self.arpOffset = 0
					self.arpDirection = 1

			elif direct == 'DOWN':
				if self.arpOffset < 0 or self.arpOffset >= len(ourChord):
					self.arpOffset = len(ourChord)-1
					self.arpDirection = -1

			if direct == 'RANDOM':
				note  = random.choice(ourChord)
			else:
				note = ourChord[self.arpOffset]

			self.arpOffset += self.arpDirection


			if not self.harmonyOnly[sc]:
				self.sendNote(
					p.offset,
					self.getDur(p.duration),
					self.adjustNote(note),
					self.adjustVolume(p.vol, p.offset) )


			if self.harmony[sc]:
				h = harmonize(self.harmony[sc], note, ourChord)
				for n in h:
					self.sendNote(
						p.offset,
						self.getDur(p.duration),
						self.adjustNote(n),
						self.adjustVolume(p.vol * self.harmonyVolume[sc], -1) )


			tb.chord.reset()	# important, other tracks chord object