VocalEasel/mma/MMA/volume.py

# volume.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>
	
"""

from MMA.common import *


""" Volumes are specified in musical terms, but converted to
    midi velocities. This table has a list of percentage changes
	to apply to the current volume. Used in both track and global
	situations. Note that the volume for 'ffff' is 200%--this will
	most likely generate velocities outside the midi range of 0..127.
	But that's fine since mma will adjust volumes into the valid
	range. Using very high percentages will ensure that 'ffff' notes
	are (most likely) sounded with a maximum velocity.
"""

vols={ 'OFF': 0.00,  'PPPP': 0.05,  'PPP':  0.10,
       'PP':  0.25,  'P':    0.40,  'MP':   0.70,
	   'M':   1.00,  'MF':   1.10,  'F':    1.30,
	   'FF':  1.60,  'FFF':  1.80,  'FFFF': 2.00  }

volume = vols['M']		# default global volume
lastVolume = volume
futureVol = []
vTRatio = .6
vMRatio = 1-vTRatio


def adjvolume(ln):
	""" Adjust the ratio used in the volume table and track/global ratio. """

	global vols, vTRatio, vMRatio
	
	if not ln:
		error("Use: AdjustVolume DYN=RATIO [..].")

	for l in ln:

		try:
			v,r = l.split('=')
		except:
			error("AdjustVolume expecting DYN=RATIO pair, not '%s'." % l)
		
		v=v.upper()

		if v == 'RATIO':

			r=stof(r)

			if r<0 or r>100:
				error("VolumeRatio must be value 0 to 100.")

			vTRatio = r/100
			vMRatio = 1-vTRatio

		elif v in vols:
			vols[v] = calcVolume(r, vols[v])
			
		else:
			error("Dynamic '%s' for AdjustVolume is unknown." % v )
		


	if gbl.debug:
		print "Volume Ratio: %s%% Track / %s%% Master" % ( vTRatio * 100, vMRatio * 100)
		print "Volume table:",
		for a in vols:
			print "%s=%s" % (a, int(vols[a] * 100)),
		print

	

def calcVolume(new, old):
	""" Calculate a new volume "new" possibly adjusting from "old". """

	if new[0] == '-' or new[0] == '+':
		a = stoi(new, "Volume expecting value for %% adjustment, not %s." % new)
		v = old + (old * a/100.)

	elif new[0] in "0123456789":
		v = stoi(new, "Volume expecting value, not '%s'" % new) / 100.
		
	else:
		new = new.upper()
		
		adj = None
		
		if '+' in new:
			new,adj = new.split('+')
		elif '-' in new:
			new,adj = new.split('-')
			adj = '-' + adj

		if not new in vols:
			error("Unknown volume '%s'." % new)

		v=vols[new]

		if adj:
			a = stoi(adj, "Volume expecting adjustment value, not %s." % adj)
			v += (v * (a/100.))

	return v


def setVolume(ln):
	""" Set master volume. """

	global volume, lastVolume
	
	lastVolume = volume
	
	if len(ln) != 1:
		error ("Use: Volume DYNAMIC.")

	volume = calcVolume(ln[0], volume)
	
	if gbl.debug:
		print "Volume: %s%%" % volume


# The next 2 are called from the parser.

def setCresc(ln):
	setCrescendo(1, ln)

def setDecresc(ln):
	setCrescendo(-1, ln)
	

def setCrescendo(dir, ln):
	""" Combined (de)cresc() """
	
	global futureVol, volume, lastVolume

	lastVolume = volume

	if len(ln) == 3:
		setVolume([ln[0]])
		ln=ln[1:]

	
	futureVol = fvolume(dir, volume, ln)


# Used by both the 2 funcs above and from TRACK.setCresc()

def fvolume(dir, startvol, ln):
	""" Create a list of future vols. Called by (De)Cresc. """

	# Get destination volume
	
	destvol = calcVolume(ln[0], startvol)

	bcount = stoi(ln[1], "Type error in bar count for (De)Cresc, '%s'." % ln[1] )
	
	if bcount <= 0:
		error("Bar count for (De)Cresc must be postive.")
		
	if dir > 0 and destvol < startvol:
		warning("Cresc volume less than current setting. " )
			
	elif dir < 0 and destvol > startvol:
		warning("Decresc volume greater than current setting. " )
		
	elif destvol == startvol:
		warning("(De)Cresc volume equal to	current setting. " )

	bcount -= 1
	step = ( destvol-startvol ) / bcount

	volList=[startvol]
	
	for a in range(bcount-1):
		startvol += step
		volList.append( startvol)
		
	volList.append(destvol)

	return volList