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/*
* Created by: Leslie Sanford
*
* Contact: jabberdabber@hotmail.com
*
* Last modified: 05/08/2004
*/
using System;
using System.Collections;
namespace Multimedia.Midi
{
/// <summary>
/// Represents a collection of Tracks.
/// </summary>
public class Sequence
{
#region Sequence Members
#region Constants
// Number of bits to shift for splitting division value.
private const int DivisionShift = 8;
#endregion
#region Fields
// The resolution of the sequence.
private int division;
// The collection of tracks for the sequence.
private ArrayList tracks = new ArrayList();
// All of the tracks for the sequence merged into one track.
private Track mergedTrack;
// Indicates whether or not the sequence has been changed since the
// last time all of the tracks were merged.
private bool dirty = true;
#endregion
#region Classes
/// <summary>
/// Represents information about each track.
/// </summary>
private class TrackInfo
{
// The Track.
public Track trk;
// The track version. Used for comparision to see if the track has
// changed.
public int version;
/// <summary>
/// Initializes a new instance of the TrackInfo class with the
/// specified track.
/// </summary>
/// <param name="trk">
/// The Track.
/// </param>
public TrackInfo(Track trk)
{
this.trk = trk;
version = trk.Version;
}
}
#endregion
#region Construction
/// <summary>
/// Initializes a new instance of the Sequence class with the
/// specified division.
/// </summary>
/// <param name="division">
/// The division value for the sequence.
/// </param>
public Sequence(int division)
{
this.division = division;
}
#endregion
#region Methods
/// <summary>
/// Adds a track to the Sequence.
/// </summary>
/// <param name="trk">
/// The track to add to the Sequence.
/// </param>
public void Add(Track trk)
{
tracks.Add(new TrackInfo(trk));
// Indicate that the sequence has changed.
dirty = true;
}
/// <summary>
/// Remove the Track at the specified index.
/// </summary>
/// <param name="index">
/// The zero-based index of the Track to remove.
/// </param>
/// <exception cref="ArgumentOutOfRangeException">
/// Thrown if index is less than zero or greater or equal to Count.
/// </exception>
public void RemoveAt(int index)
{
// Enforce preconditions.
if(index < 0 || index >= Count)
throw new ArgumentOutOfRangeException("index", index,
"Index for removing track from sequence out of range.");
tracks.RemoveAt(index);
// Indicate that the sequence has changed.
dirty = true;
}
/// <summary>
/// Gets all of the Tracks in the Sequence merged into one Track.
/// </summary>
/// <returns>
/// The Tracks in the Sequence merged into one Track.
/// </returns>
/// <remarks>
/// Only Tracks that are not muted are merged into one Track. Also, if
/// any of the Tracks have been soloed, only those Tracks are merged.
/// </remarks>
public Track GetMergedTrack()
{
// If the Sequence has been changed.
if(IsDirty())
{
mergedTrack = new Track();
// If any of the tracks have been soloed.
if(IsSolo())
{
// Merge only the solo tracks.
MergeSoloTracks();
}
// Else none of the tracks have been soloed.
else
{
// For each track in the sequence.
foreach(TrackInfo info in tracks)
{
// If the track is not muted.
if(!info.trk.Mute)
{
// Merge track.
mergedTrack = Track.Merge(mergedTrack, info.trk);
}
}
}
// Update versioning information.
foreach(TrackInfo info in tracks)
{
info.version = info.trk.Version;
}
// Indicate that the merged track has been updated.
dirty = false;
}
return mergedTrack;
}
/// <summary>
/// Gets the length of the Sequence in ticks.
/// </summary>
/// <returns>
/// The length of the Sequence in ticks.
/// </returns>
/// <remarks>
/// The length of the Sequence is represented by the longest Track in
/// the Sequence.
/// </remarks>
public int GetLength()
{
int length = 0;
// For each track in the Sequence.
foreach(TrackInfo info in tracks)
{
// Get the length of the track.
int trkLength = info.trk.GetLength();
// If this is the longest track so far, update length value.
if(length < trkLength)
{
length = trkLength;
}
}
return length;
}
/// <summary>
/// Determines whether or not this is a Smpte sequence.
/// </summary>
/// <returns>
/// <b>true</b> if this is a Smpte sequence; otherwise, <b>false</b>.
/// </returns>
public bool IsSmpte()
{
bool result = false;
// The upper byte of the division value will be negative if this is
// a Smpte sequence.
if((sbyte)(division >> DivisionShift) < 0)
{
result = true;
}
return result;
}
/// <summary>
/// Determines whether or not any of the Tracks in the Sequence are
/// soloed.
/// </summary>
/// <returns>
/// <b>true</b> if any of the Tracks are soloed; otherwise, <b>false</b>.
/// </returns>
private bool IsSolo()
{
bool solo = false;
// Check to see if any of the tracks are soloed.
for(int i = 0; i < Count && !solo; i++)
{
// If the track is soloed.
if(this[i].Solo)
{
// Indicate that the track is soloed.
solo = true;
}
}
return solo;
}
/// <summary>
/// Determines whether or not the Sequence has changed since the
/// last time the Tracks in the Sequence were merged.
/// </summary>
/// <returns>
/// <b>true</b> if the sequence is "dirty"; otherwise, <b>false</b>.
/// </returns>
private bool IsDirty()
{
// Check to see if any of the tracks have changed.
for(int i = 0; i < tracks.Count && !dirty; i++)
{
TrackInfo info = (TrackInfo)tracks[i];
// If the track has changed.
if(info.version != info.trk.Version)
{
// Indicate that the Sequence has changed since the tracks
// were last merged.
dirty = true;
}
}
return dirty;
}
/// <summary>
/// Merge only Tracks that are soloed.
/// </summary>
private void MergeSoloTracks()
{
// For each track in the Sequence.
foreach(TrackInfo info in tracks)
{
// If the track is soloed and not muted.
if(info.trk.Solo && !info.trk.Mute)
{
// Merge track.
mergedTrack = Track.Merge(mergedTrack, info.trk);
}
}
}
#endregion
#region Properties
/// <summary>
/// Gets the Track at the specified index.
/// </summary>
/// <exception cref="ArgumentOutOfRangeException">
/// Thrown if index is less than zero or greater or equal to Count.
/// </exception>
public Track this[int index]
{
get
{
// Enforce preconditions.
if(index < 0 || index >= Count)
throw new ArgumentOutOfRangeException("index", index,
"Index into sequence out of range.");
return ((TrackInfo)tracks[index]).trk;
}
}
/// <summary>
/// Gets the number of Tracks in the Sequence.
/// </summary>
public int Count
{
get
{
return tracks.Count;
}
}
/// <summary>
/// Gets the division value for the Sequence.
/// </summary>
public int Division
{
get
{
return division;
}
}
#endregion
#endregion
}
}
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Aside from dabbling in BASIC on his old Atari 1040ST years ago, Leslie's programming experience didn't really begin until he discovered the Internet in the late 90s. There he found a treasure trove of information about two of his favorite interests: MIDI and sound synthesis.
After spending a good deal of time calculating formulas he found on the Internet for creating new sounds by hand, he decided that an easier way would be to program the computer to do the work for him. This led him to learn C. He discovered that beyond using programming as a tool for synthesizing sound, he loved programming in and of itself.
Eventually he taught himself C++ and C#, and along the way he immersed himself in the ideas of object oriented programming. Like many of us, he gotten bitten by the design patterns bug and a copy of GOF is never far from his hands.
Now his primary interest is in creating a complete MIDI toolkit using the C# language. He hopes to create something that will become an indispensable tool for those wanting to write MIDI applications for the .NET framework.
Besides programming, his other interests are photography and playing his Les Paul guitars.
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