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 System.Diagnostics;
using System.Threading;
using Sanford.Multimedia.Midi;

namespace Sanford.Multimedia.Synth
{
    public partial class Synthesizer
    {
        /// <summary>
        /// Converts a value to a string representation of a decibel.
        /// </summary>
        /// <param name="value">
        /// The value to convert.
        /// </param>
        /// <returns>
        /// A string representation of the value as a decibel.
        /// </returns>
        public static string DecibelToString(float value)
        {
            string result;

            if(value <= 0)
            {
                result = "-oo";
            }
            else
            {
                float decibel = (float)(20.0 * Math.Log(value, 10));

                result = "-" + decibel.ToString(FormatInfo);
            }

            return result;
        }

        /// <summary>
        /// Performs linear interpolation between two values.
        /// </summary>
        /// <param name="index">
        /// The floating point index to use for performaing the interpolation.
        /// </param>
        /// <param name="x1">
        /// The first value.
        /// </param>
        /// <param name="x2">
        /// The second value.
        /// </param>
        /// <returns>
        /// A linear interpolated value that lies between x1 and x2.
        /// </returns>
        public static float LinearInterpolate(float index, float x1, float x2)
        {
            float fractional = index - (int)index;
            float difference = x1 - x2;
            
            return x1 - difference * fractional;
        }
    }
}