C# Synth Toolkit - Part I

#region License

/* Copyright (c) 2007 Leslie Sanford
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy 
 * of this software and associated documentation files (the "Software"), to 
 * deal in the Software without restriction, including without limitation the 
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or 
 * sell copies of the Software, and to permit persons to whom the Software is 
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in 
 * all copies or substantial portions of the Software. 
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE 
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 
 * THE SOFTWARE.
 */

#endregion

#region Contact

/*
 * Leslie Sanford
 * Email: jabberdabber@hotmail.com
 */

#endregion

using System;
using System.Collections.Generic;
using Sanford.Multimedia.Midi;

namespace Sanford.Multimedia.Synth
{
    /// <summary>
    /// Provides functionality for processing MIDI control messages.
    /// </summary>
    /// <remarks>
    /// Most, if not all, MIDI synthesizers respond to MIDI control messages. A 
    /// synthesizer may be setup in such a way as to use the control messages generated by
    /// the modulation wheel to control vibrato, for example. The ControlProcessor class
    /// is responsible for taking a control message and translating it into something 
    /// Voices can understand. It's then up to the Voices to decide how to respond.
    /// </remarks>
    internal class ControlProcessor
    {
        #region ControlProcessor Members

        #region Fields

        private List<Voice> voices;

        private VoiceAllocator allocator;

        #endregion

        #region Constructors

        /// <summary>
        /// Initializes a new instance of the ControlProcessor class.
        /// </summary>
        /// <param name="voices">
        /// The Voices that the ControlProcessor will process control messages for.
        /// </param>
        /// <param name="allocator">
        /// The VoiceAllocator responsible for allocating voices.
        /// </param>
        public ControlProcessor(IEnumerable<Voice> voices, VoiceAllocator allocator)
        {
            this.voices = new List<Voice>(voices);
            this.allocator = allocator;
        }

        #endregion

        #region Methods

        /// <summary>
        /// Processes a control message.
        /// </summary>
        /// <param name="type">
        /// The type of control message.
        /// </param>
        /// <param name="value">
        /// The value of the control message.
        /// </param>
        public void Process(ControllerType type, int value)
        {
            if(type == ControllerType.HoldPedal1)
            {
                // If this is a hold pedal 1 (sustain pedal) message.

                if(value < 64)                
                {
                    // If the sustain pedal is turned off.

                    allocator.SustainEnabled = false;
                }
                else
                {
                    // Else the sustain pedal is turned on.

                    allocator.SustainEnabled = true;
                }
            }
            else if(type == ControllerType.AllSoundOff)
            {
                // Else if this is an all sound off message.

                allocator.AllSoundOff();
            }
            else
            {
                // Else this is some other type of control message.

                // Convert control message value into a floating point value in the range of [0, 1].
                float fValue = (float)value / ChannelMessage.DataMaxValue;

                // For each Voice, pass along the control message.
                foreach(Voice v in voices)
                {
                    v.ProcessControllerMessage(type, fValue);
                }
            }
        }

        #endregion

        #endregion
    }
}