/* Example 7 - Communicating continuous values with Csound's Channel System
*
* This example introduces using Csound's Channel System to communicate
* continuous control data (k-rate) from a host program to Csound. The
* first thing to note is the RandomLine class. It takes in a base value
* and a range in which to vary randomly. The reset functions calculates
* a new random target value (this.End), a random duration in which to
* run (this.Dur, expressed as # of audio blocks to last in duration), and
* calculates the increment value to apply to the current value per audio-block.
* When the target is met, the Randomline will reset itself to a new target
* value and duration.
*
* In this example, we use two RandomLine objects, one for amplitude and
* another for frequency. We start a Csound instrument instance that reads
* from two channels using the chnget opcode. In turn, we update the values
* to the channel from the host program. In this case, because we want to
* keep our values generating in sync with the audio engine, we use a
* while-loop instead of a CsoundPerformanceThread. To update the channel,
* we call the SoftwareBus's channel indexer methods with new values.
*
* Note: The Value property on the RandomLine objects not only gets
* us the current value, but also advances the internal state by the increment
* and by decrementing the duration.
*
* In the C# object wrappers, channels are objects which are most easily used
* via a software bus object as this implemetation demonstrates.
*/
public void Example7()
{
using (var c = new Csound6NetRealtime())
{
c.SetOption("-odac"); // Set option for Csound
c.SetOption("-m7"); // Set option for Csound
c.CompileOrc(orc3); // Compile Orchestra from String
c.ReadScore("i1 0 10\n");//Read in a score to run for 10 seconds
c.Start(); //Must call Start() explicitly when compiling from a string
var amp = new RandomLine(.4, .2); // create RandomLine for use with Amplitude
var freq = new RandomLine(400, 80); // create RandomLine for use with Frequency
var bus = c.GetSoftwareBus();
//Channels can be created explicitly:
bus.AddControlChannel("amp", ChannelDirection.Input);
bus["amp"] = amp.Value; //Add an initial value: Value property changes after each use
//Or channels can be created implicitly just by using it:
//The bus's channels can be accessed by name like a dictionary.
//If they don't yet exist, they will be defined (input/output as default)
bus["freq"] = freq.Value;//Create and provide and initial value in one call
//Now we have our channels: update them with new RandomLine values after each ksmps cycle:
while (!c.PerformKsmps())
{
bus["amp"] = amp.Value;
bus["freq"] = freq.Value;
}
c.Stop();
}
}
/* Example 7 - Communicating continuous values with Csound's Channel System
*
* This example introduces using Csound's Channel System to communicate
* continuous control data (k-rate) from a host program to Csound. The
* first thing to note is the RandomLine class. It takes in a base value
* and a range in which to vary randomly. The reset functions calculates
* a new random target value (self.end), a random duration in which to
* run (self.dur, expressed as # of audio blocks to last in duration), and
* calculates the increment value to apply to the current value per audio-block.
* When the target is met, the Randomline will reset itself to a new target
* value and duration.
*
* In this example, we use two RandomLine objects, one for amplitude and
* another for frequency. We start a Csound instrument instance that reads
* from two channels using the chnget opcode. In turn, we update the values
* to the channel from the host program. In this case, because we want to
* keep our values generating in sync with the audio engine, we use a
* while-loop instead of a CsoundPerformanceThread. To update the channel,
* we call the SetChannel method on the Csound object, passing a channel name
* and value. Note: The getValue method on the RandomLine not only gets
* us the current value, but also advances the internal state by the increment
* and by decrementing the duration.
*
* In the C# object wrappers, channels are objects which are most easily used
* via a software bus object as this implemetation demonstrates.
*/
public void Example7()
{
using (var c = new Csound6NetRealtime())
{
c.SetOption("-odac"); // Set option for Csound
c.SetOption("-m7"); // Set option for Csound
c.CompileOrc(orc3); // Compile Orchestra from String
c.ReadScore("i1 0 10\n");//Read in a score to run for 10 seconds
c.Start(); //Must call Start() explicitly when compiling from a string
var amp = new RandomLine(.4, .2); // create RandomLine for use with Amplitude
var freq = new RandomLine(400, 80); // create RandomLine for use with Frequency
var bus = c.GetSoftwareBus();
//The bus's channels can be accessed by name like a dictionary.
//If they don't yet exist, they will be defined (input/output as default)
bus["amp"] = amp.Value; //Create and provide and initial value for an amplitude channel
bus["freq"] = freq.Value;//Create and provide and initial value for a frequency channel
while (!c.PerformKsmps())
{
bus["amp"] = amp.Value;
bus["freq"] = freq.Value;
}
c.Stop();
}
}
/* Example 7 - Communicating continuous values with Csound's Channel System
*
* This example introduces using Csound's Channel System to communicate
* continuous control data (k-rate) from a host program to Csound. The
* first thing to note is the RandomLine class. It takes in a base value
* and a range in which to vary randomly. The reset functions calculates
* a new random target value (self.end), a random duration in which to
* run (self.dur, expressed as # of audio blocks to last in duration), and
* calculates the increment value to apply to the current value per audio-block.
* When the target is met, the Randomline will reset itself to a new target
* value and duration.
*
* In this example, we use two RandomLine objects, one for amplitude and
* another for frequency. We start a Csound instrument instance that reads
* from two channels using the chnget opcode. In turn, we update the values
* to the channel from the host program. In this case, because we want to
* keep our values generating in sync with the audio engine, we use a
* while-loop instead of a CsoundPerformanceThread. To update the channel,
* we call the SetChannel method on the Csound object, passing a channel name
* and value. Note: The getValue method on the RandomLine not only gets
* us the current value, but also advances the internal state by the increment
* and by decrementing the duration.
*
* In the C# object wrappers, channels are objects which are most easily used
* via a software bus object as this implemetation demonstrates.
*/
public void Example7()
{
using (var c = new Csound6NetRealtime())
{
c.SetOption("-odac"); // Set option for Csound
c.SetOption("-m7"); // Set option for Csound
c.CompileOrc(orc3); // Compile Orchestra from String
c.ReadScore("i1 0 10\n"); //Read in a score to run for 10 seconds
c.Start(); //Must call Start() explicitly when compiling from a string
var amp = new RandomLine(.4, .2); // create RandomLine for use with Amplitude
var freq = new RandomLine(400, 80); // create RandomLine for use with Frequency
var bus = c.GetSoftwareBus();
//The bus's channels can be accessed by name like a dictionary.
//If they don't yet exist, they will be defined (input/output as default)
bus["amp"] = amp.Value; //Create and provide and initial value for an amplitude channel
bus["freq"] = freq.Value; //Create and provide and initial value for a frequency channel
while (!c.PerformKsmps())
{
bus["amp"] = amp.Value;
bus["freq"] = freq.Value;
}
c.Stop();
}
}
/* Example 7 - Communicating continuous values with Csound's Channel System
*
* This example introduces using Csound's Channel System to communicate
* continuous control data (k-rate) from a host program to Csound. The
* first thing to note is the RandomLine class. It takes in a base value
* and a range in which to vary randomly. The reset functions calculates
* a new random target value (this.End), a random duration in which to
* run (this.Dur, expressed as # of audio blocks to last in duration), and
* calculates the increment value to apply to the current value per audio-block.
* When the target is met, the Randomline will reset itself to a new target
* value and duration.
*
* In this example, we use two RandomLine objects, one for amplitude and
* another for frequency. We start a Csound instrument instance that reads
* from two channels using the chnget opcode. In turn, we update the values
* to the channel from the host program. In this case, because we want to
* keep our values generating in sync with the audio engine, we use a
* while-loop instead of a CsoundPerformanceThread. To update the channel,
* we call the SoftwareBus's channel indexer methods with new values.
*
* Note: The Value property on the RandomLine objects not only gets
* us the current value, but also advances the internal state by the increment
* and by decrementing the duration.
*
* In the C# object wrappers, channels are objects which are most easily used
* via a software bus object as this implemetation demonstrates.
*/
public void Example7()
{
using (var c = new Csound6NetRealtime())
{
c.SetOption("-odac"); // Set option for Csound
c.SetOption("-m7"); // Set option for Csound
c.CompileOrc(orc3); // Compile Orchestra from String
c.ReadScore("i1 0 10\n"); //Read in a score to run for 10 seconds
c.Start(); //Must call Start() explicitly when compiling from a string
var amp = new RandomLine(.4, .2); // create RandomLine for use with Amplitude
var freq = new RandomLine(400, 80); // create RandomLine for use with Frequency
var bus = c.GetSoftwareBus();
//Channels can be created explicitly:
bus.AddControlChannel("amp", ChannelDirection.Input);
bus["amp"] = amp.Value; //Add an initial value: Value property changes after each use
//Or channels can be created implicitly just by using it:
//The bus's channels can be accessed by name like a dictionary.
//If they don't yet exist, they will be defined (input/output as default)
bus["freq"] = freq.Value;//Create and provide and initial value in one call
//Now we have our channels: update them with new RandomLine values after each ksmps cycle:
while (!c.PerformKsmps())
{
bus["amp"] = amp.Value;
bus["freq"] = freq.Value;
}
c.Stop();
}
}
/**
* Example 8 - More efficient Channel Communications (in a single threaded host)
*
* This example builds on Example 7 by replacing the calls to SetChannel
* with using GetChannelPtr. In the Csound API, using SetChannel and GetChannel
* is great for quick work, but ultimately it is slower than pre-fetching the
* actual channel pointer. This is because Set/GetChannel operates by doing a
* lookup of the Channel Pointer, then setting or getting the value. This
* happens on each call. The alternative is to use GetChannelPtr, which fetches
* the Channel Pointer and lets you directly set and get the value on the pointer.
* The approach shown here is only safe if you remain in a single thread
* such as managing channel values in between calls to PerformKsmps.
*
* The thread-safe method shown in Example6 is preferred when using events in
* a multithreaded environment such as was hinted at in Example4.
* You can use the Channel Pointer technique when using threads but you must use
* a channel lock to take care in not to creating a race condition while using
* memory shared between host and csound itself thereby causing potential glitches
* in your music. Further, since you write directly into unmanaged memory when
* using this technique, getting even one byte of data wrong can crash your program.
*
* Like other managed hosts (like python), C# provides mechanisms that attempt
* to contain your ability to do this.
* The C# version supplies Get/SetValueDirect methods for channels which use
* the channel objects declared name and direction and limits memory access to the
* actual size defined for the channel's type.
* The call to the memory pointer (GetChannelPtr) is internal and the returned pointer
* is used whenever GetValueDirect or SetValueDirect is called thereby preserving
* the speed advantage mentioned in the python example.
*
* Managing thread locks in host code is beyond the scope of this tutorial.
* Use the method shown in Example6 when using more than one thread.
*
* The code below shows how to make indirect use of the .net Csound6Channel
* object's GetChannelPtr function to touch channel memory directly.
*
*/
public void Example8()
{
using (var c = new Csound6NetRealtime())
{
c.SetOutputDac(0);
c.SetOption("-m7");
c.CompileOrc(orc3); // Compile Orchestra from String
c.ReadScore("i1 0 10\n"); //Read in a score to run for 10 seconds
c.Start(); //Must call Start() explicitly when compiling from a string
var amps = new RandomLine(.4, .2); // create RandomLine for use with Amplitude
var freqs = new RandomLine(400, 80); // create RandomLine for use with Frequency
var bus = c.GetSoftwareBus(); //Get bus and define the "amp" and "freq" channels of orc3
//Since orc3 instrument doesn't declare channels directly, define them here
var ampChannel = bus.AddControlChannel("amp", ChannelDirection.Input);
var freqChannel = bus.AddControlChannel("freq", ChannelDirection.Input);
//Prime with initial values accessing channel memory directly
ampChannel.SetValueDirect(amps.Value); //Use
freqChannel.SetValueDirect(freqs.Value);
while (!c.PerformKsmps())
{
//continue to update memory for the two channels directly
ampChannel.SetValueDirect(amps.Value);
freqChannel.SetValueDirect(freqs.Value);
}
c.Stop();
}
}
/**
* Example 8 - More efficient Channel Communications (in a single threaded host)
*
* This example builds on Example 7 by replacing the calls to SetChannel
* with using GetChannelPtr. In the Csound API, using SetChannel and GetChannel
* is great for quick work, but ultimately it is slower than pre-fetching the
* actual channel pointer. This is because Set/GetChannel operates by doing a
* lookup of the Channel Pointer, then setting or getting the value. This
* happens on each call. The alternative is to use GetChannelPtr, which fetches
* the Channel Pointer and lets you directly set and get the value on the pointer.
* The approach shown here is only safe if you remain in a single thread
* such as managing channel values in between calls to PerformKsmps.
*
* The thread-safe method shown in Example6 is preferred when using events in
* a multithreaded environment such as was hinted at in Example4.
* You can use the Channel Pointer technique when using threads but you must use
* a channel lock to take care in not to creating a race condition while using
* memory shared between host and csound itself thereby causing potential glitches
* in your music. Further, since you write directly into unmanaged memory when
* using this technique, getting even one byte of data wrong can crash your program.
*
* Like other managed hosts (like python), C# provides mechanisms that attempt
* to contain your ability to do this.
* The C# version supplies Get/SetValueDirect methods for channels which use
* the channel objects declared name and direction and limits memory access to the
* actual size defined for the channel's type.
* The call to the memory pointer (GetChannelPtr) is internal and the returned pointer
* is used whenever GetValueDirect or SetValueDirect is called thereby preserving
* the speed advantage mentioned in the python example.
*
* Managing thread locks in host code is beyond the scope of this tutorial.
* Use the method shown in Example6 when using more than one thread.
*
* The code below shows how to make indirect use of the .net Csound6Channel
* object's GetChannelPtr function to touch channel memory directly.
*
*/
public void Example8()
{
using (var c = new Csound6NetRealtime())
{
c.SetOutputDac(0);
c.SetOption("-m7");
c.CompileOrc(orc3); // Compile Orchestra from String
c.ReadScore("i1 0 10\n");//Read in a score to run for 10 seconds
c.Start(); //Must call Start() explicitly when compiling from a string
var amps = new RandomLine(.4, .2); // create RandomLine for use with Amplitude
var freqs = new RandomLine(400, 80); // create RandomLine for use with Frequency
var bus = c.GetSoftwareBus();//Get bus and define the "amp" and "freq" channels of orc3
//Since orc3 instrument doesn't declare channels directly, define them here
var ampChannel = bus.AddControlChannel("amp", ChannelDirection.Input);
var freqChannel = bus.AddControlChannel("freq", ChannelDirection.Input);
//Prime with initial values accessing channel memory directly
ampChannel.SetValueDirect(amps.Value); //Use
freqChannel.SetValueDirect(freqs.Value);
while (!c.PerformKsmps())
{
//continue to update memory for the two channels directly
ampChannel.SetValueDirect(amps.Value);
freqChannel.SetValueDirect(freqs.Value);
}
c.Stop();
}
}