VocalEasel/mma/MMA/patDrum.py

# patDrum.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 <bob@mellowood.ca>

"""

import gbl
from   MMA.common import *
from   MMA.notelen import getNoteLen
import MMA.translate
from   MMA.pat import PC, seqBump


class Drum(PC):
    """ Pattern class for a drum track. """

    vtype = 'DRUM'
    toneList = [38]

    def __init__(self, ln):
        """ init for drum track. """

        PC.__init__(self, ln)
        
        self.setChannel('10')
        if not gbl.mtrks[self.channel].trackname:
            gbl.mtrks[self.channel].addTrkName(0, 'Drum')

 
    def setTone(self, ln):
        """ Set a tone list. Only valid for DRUMs.
        ln[] is not nesc. the right length.
        """

        ln=self.lnExpand(ln, 'Tone')
        tmp = []

        for n in ln:
            tmp.append(MMA.translate.dtable.get(n))

        self.toneList = seqBump( tmp )


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


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

            Fields - start, length, volume
        """

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

        a = struct()

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

        return a



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

        Called from self.bar()

        """

        sc = self.seq

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

            if tb.drumZ:
                continue

            self.sendNote(
                p.offset,
                self.getDur(p.duration),
                self.toneList[sc],
                self.adjustVolume(p.vol, p.offset) )