# Example 9 - More efficient Channel Communications

# Author: Steven Yi <stevenyi@gmail.com>

# 2013.10.28

#

# This example continues on from Example 9 and just refactors the

# creation and setup of CsoundMYFLTArray's into a createChannel()

# function. This example illustrates some natural progression that

# might occur in your own API-based projects, and how you might

# simplify your own code.

import csnd6

from random import randint, random

class RandomLine(object):

def __init__(self, base, range):

self.curVal = 0.0

self.reset()

self.base = base

self.range = range

def reset(self):

self.dur = randint(256,512)

self.end = random()

self.slope = (self.end - self.curVal) / self.dur

def getValue(self):

self.dur -= 1

if(self.dur < 0):

self.reset()

retVal = self.curVal

self.curVal += self.slope

return self.base + (self.range * retVal)

def createChannel(csound, channelName):

"Creates a Csound Channel and returns a CsoundMYFLTArray wrapper object"

chn = csnd6.CsoundMYFLTArray(1)

csound.GetChannelPtr(chn.GetPtr(), channelName,

csnd6.CSOUND_CONTROL_CHANNEL | csnd6.CSOUND_INPUT_CHANNEL)

return chn

###############################

# Our Orchestra for our project

orc = """

sr=44100

ksmps=32

nchnls=2

0dbfs=1

instr 1

kamp chnget "amp"

kfreq chnget "freq"

printk 0.5, kamp

printk 0.5, kfreq

aout vco2 kamp, kfreq

aout moogladder aout, 2000, 0.25

outs aout, aout

endin"""

c = csnd6.Csound() # create an instance of Csound

c.SetOption("-odac") # Set option for Csound

c.SetOption("-m7") # Set option for Csound

c.CompileOrc(orc) # Compile Orchestra from String

sco = "i1 0 60\n"

c.ReadScore(sco) # Read in Score generated from notes

c.Start() # When compiling from strings, this call is necessary before doing any performing

ampChannel = createChannel(c, "amp") # uses utility method to create a channel and get a CsoundMYFLTArray

freqChannel = createChannel(c, "freq")

amp = RandomLine(.4, .2)

freq = RandomLine(400, 80)

ampChannel.SetValue(0, amp.getValue())

freqChannel.SetValue(0, freq.getValue())

while (c.PerformKsmps() == 0):

ampChannel.SetValue(0, amp.getValue())

freqChannel.SetValue(0, freq.getValue())

c.Stop()