qbplay.cs

using System;
using System.Text;
using System.Collections.Generic;
using System.IO;
using System.Runtime.InteropServices;

namespace PlayString
{
    static class qbplay
    {
        //--------------------------------------------------------------------------
        //       ACTUAL DIRECT QB PLAY AUDIO IN WINDOWS
        //
        //   basically just call qbplay.PLAY("AB CD etc etc");   anytime u want in ur project
        //   note that by default (like qbasic) its synchronous playback.  call qbplay.PLAY("MB");  OR qbplay.Background=true;   to switch to background audio
        //
        //   ideally, u call qbplay.Init()  and qbplay.Shutdown()  from ur program lifespan, so u dont leak any resources
        //
        //   u can change the volume anytime by setting qbplay.Volume  to  0.0 - 1.0   the default is 0.3
        //
        //   this is a state machine, so any PLAY statements that change tempo, octave, etc.  will remain.
        //   if you need to reset them, u can call qbplay.Defaults()
        //
        //   u can also query qbplay.IsPlaying   and call qbplay.Stop()   if u want finer control over audio playback
        //
        //--------------------------------------------------------------------------
        //       BASIC USAGE WITHOUT BUILT-IN AUDIO
        //
        //   u can directly call qbplay.GenerateWAVFile() OR qbplay.ParseExecuteGenerate()  to just make a *.wav file or generate a PCM sample buffer from text;  does not require audio engine initialization, but state machine properties still apply
        //
        //--------------------------------------------------------------------------
        //       FINAL NOTES
        //   this module is not multithread-safe;  it is intended to be called by main thread only.   internal critical section is only for audio driver callback synchronization
        //
        //--------------------------------------------------------------------------

        public static double Volume = 0.3;

        public static void Defaults()
        {
            Background = false;
            notelength = 4;
            octave = 4;
            NoteDuration = NoteDurations.Normal;
            tempo = 120;
        }

        public static bool Init()
        {
            Shutdown();// double-init protection

            Defaults();


            critSect = Marshal.AllocHGlobal(64);// eyy, she'll be right m8
            InitializeCriticalSection(critSect);


            WAVEFORMATEX wf = new WAVEFORMATEX();

            wf.cbSize = 0;
            wf.wFormatTag = 1;
            wf.nAvgBytesPerSec = 44100;
            wf.nBlockAlign = 1;
            wf.nChannels = 1;
            wf.nSamplesPerSec = 44100;
            wf.wBitsPerSample = 8;

            waveOutOpen(ref hWaveOut, -1/*WAVE_MAPPER*/, wf, Marshal.GetFunctionPointerForDelegate(pwaveOutProc), 0, 0x00030000/*CALLBACK_FUNCTION*/);
            return (hWaveOut != IntPtr.Zero);
        }

        public static bool IsPlaying
        {
            get
            {
                if (hWaveOut == IntPtr.Zero)
                    return false;

                if (wavehdr == null && PCMSampleQueue.Count == 0)
                    return false;

                return true;
            }
        }

        public static void Stop()
        {
            if (hWaveOut != IntPtr.Zero)
            {
                waveOutReset(hWaveOut);

                CleanupWaveHdr();
                PCMSampleQueue.Clear();
            }
        }

        public static void Shutdown()
        {
            if (hWaveOut != IntPtr.Zero)
            {
                Stop();

                waveOutClose(hWaveOut);
                hWaveOut = IntPtr.Zero;
            }

            if (critSect != IntPtr.Zero)
            {
                DeleteCriticalSection(critSect);

                Marshal.FreeHGlobal(critSect);
                critSect = IntPtr.Zero;
            }
        }

        public static void PLAY(string s)
        {
            if (hWaveOut == IntPtr.Zero)
            {
                // auto init?
                if(!Init())
                    return;
            }

            byte[] pcm = ParseExecuteGenerate(s);

            if (pcm == null || pcm.Length <= 0)
                return;

            PCMSampleQueue.Add(pcm);

            DoNextOutputBuffer();

            while (!Background && IsPlaying)
                System.Threading.Thread.Sleep(0);//release context
        }


        public static void GenerateWAVFile(string snd, string outpath)
        {
            FileStream f = new FileStream(outpath, FileMode.Create);
            byte[] pcm = qbplay.ParseExecuteGenerate(snd);

            UInt32 SubChunk2Size = (uint)pcm.Length;
            UInt16 AudioFormat = 1; // PCM
            UInt16 NumChannels = 1; // Mono
            UInt16 BitsPerSample = 8; // 8 bit
            UInt32 SampleRate = 44100;
            UInt32 ByteRate = (UInt32)(SampleRate * NumChannels * (BitsPerSample / 8));
            UInt32 SubChunk1Size = 16;
            UInt32 ChunkSize = 36 + SubChunk2Size;
            UInt16 BlockAlign = (UInt16)(NumChannels * (BitsPerSample / 8));
            BinaryWriter wr = new BinaryWriter(f);

            wr.Write(Encoding.ASCII.GetBytes("RIFF"));
            wr.Write(ChunkSize);
            wr.Write(Encoding.ASCII.GetBytes("WAVE"));
            wr.Write(Encoding.ASCII.GetBytes("fmt "));
            wr.Write(SubChunk1Size);
            wr.Write(AudioFormat);
            wr.Write(NumChannels);
            wr.Write(SampleRate);
            wr.Write(ByteRate);
            wr.Write(BlockAlign);
            wr.Write(BitsPerSample);
            wr.Write(Encoding.ASCII.GetBytes("data"));
            wr.Write(pcm);


            f.Close();
        }




        //--------------------------------------------------------------------------
        // THE REAL MAGIC
        //--------------------------------------------------------------------------



        //private List<byte[]> data = new List<byte[]>();
        private static double[] FREQ = new double[] {
        // C, C#, D, D#, E,F, F#, G, G#, A, A#, H
        16.35, 17.32, 18.35, 19.45, 20.60, 21.83, 23.12, 24.50, 25.96, 27.50, 29.14, 30.87, // Octave 0
        32.70, 34.65, 36.71, 38.89, 41.20, 43.65, 46.25, 49.00, 51.91,  55.00, 58.27, 61.74, // Octave 1
        65.41, 69.30, 73.42, 77.78, 82.41, 87.31, 92.50, 98.00, 103.83, 110.00, 116.54, 123.47, // Octave 2
        130.81, 138.59, 146.83, 155.56, 164.81, 174.61, 185.00, 196.00, 207.65, 220.00, 233.08, 246.94, // Octave 3
        261.63, 277.18, 293.66, 311.13, 329.63, 349.23, 369.99, 392.00, 415.30, 440.00, 466.16, 493.88, // Octave 4
        523.25,  554.37, 587.33, 622.25, 659.25, 698.46,  739.99, 783.99, 830.61, 880.00, 932.33, 987.77, // Octave 5
        1046.50, 1108.73, 1174.66, 1244.51, 1318.51, 1396.91, 1479.98, 1567.98, 1661.22, 1760.00, 1864.66, 1975.53, // Octave 6
        2093.00, 2217.46, 2349.32, 2489.02, 2637.02, 2793.83, 2959.96, 3135.96, 3322.44, 3520.00, 3729.31, 3951.07, // Octave 7
        4186.01,  4434.92, 4698.63, 4978.03, 5274.04, 5587.65, 5919.91, 6271.93, 6644.88, 7040.00, 7458.62, 7902.13 // Octave 8
    };
        enum NoteDurations { Normal, Legato, Staccato };

        static int notelength;
        static int octave;
        static NoteDurations NoteDuration;
        static int tempo;
        public static bool Background;

        /*
Ln     Sets the duration (length) of the notes. The variable n does not indicate an actual duration
        amount but rather a note type; L1 - whole note, L2 - half note, L4 - quarter note, etc.
        (L8, L16, L32, L64, ...). By default, n = 4.
        For triplets and quintets, use L3, L6, L12, ... and L5, L10, L20, ... series respectively.
        The shorthand notation of length is also provided for a note. For example, "L4 CDE L8 FG L4 AB"
        can be shortened to "L4 CDE F8G8 AB". F and G play as eighth notes while others play as quarter notes.
On     Sets the current octave. Valid values for n are 0 through 6. An octave begins with C and ends with B.
        Remember that C- is equivalent to B. 
< >    Changes the current octave respectively down or up one level.
Nn     Plays a specified note in the seven-octave range. Valid values are from 0 to 84. (0 is a pause.)
        Cannot use with sharp and flat. Cannot use with the shorthand notation neither.
MN     Stand for Music Normal. Note duration is 7/8ths of the length indicated by Ln. It is the default mode.
ML     Stand for Music Legato. Note duration is full length of that indicated by Ln.
MS     Stand for Music Staccato. Note duration is 3/4ths of the length indicated by Ln.
Pn     Causes a silence (pause) for the length of note indicated (same as Ln). 
Tn     Sets the number of "L4"s per minute (tempo). Valid values are from 32 to 255. The default value is T120. 
.      When placed after a note, it causes the duration of the note to be 3/2 of the set duration.
        This is how to get "dotted" notes. "L4 C#." would play C sharp as a dotted quarter note.
        It can be used for a pause as well.
MB MF  Stand for Music Background and Music Foreground. MB places a maximum of 32 notes in the music buffer
        and plays them while executing other statements. Works very well for games.
        MF switches the PLAY mode back to normal. Default is MF.
            */
        public static byte[] ParseExecuteGenerate(string snd)
        {
            List<byte[]> sampleQueue = new List<byte[]>();

            // dude just get rid of all the spaces-  so parser doesnt have to deal with any of them
            for (; ;)
            {
                int i = snd.IndexOf(' ');
                if (i == -1)
                    break;
                snd = snd.Remove(i, 1);
            }

            snd = snd.ToUpper();
            for (int i = 0; i < snd.Length; i++)
            {
                char c = snd[i];
                switch (c)
                {
                    case 'L':
                        {
                            i++;
                            string val = "";
                            while (i < snd.Length && char.IsDigit(snd[i]))
                            {
                                val += snd[i];
                                i++;
                            }
                            notelength = int.Parse(val);
                            i--;
                        }
                        break;
                    case 'T':
                        {
                            i++;
                            string val = "";
                            while (i < snd.Length && char.IsDigit(snd[i]))
                            {
                                val += snd[i];
                                i++;
                            }
                            tempo = int.Parse(val);
                            i--;
                        }
                        break;
                    case 'M':
                        {
                            i++;
                            switch (snd[i])
                            {
                                case 'L':
                                    NoteDuration = NoteDurations.Legato;
                                    break;
                                case 'N':
                                    NoteDuration = NoteDurations.Normal;
                                    break;
                                case 'S':
                                    NoteDuration = NoteDurations.Staccato;
                                    break;
                                case 'B':
                                    Background = true;
                                    break;
                                case 'F':
                                    Background = false;
                                    break;
                                default:
                                    throw new Exception("Invalid duration " + snd[i] + "!");
                            }
                        }
                        break;
                    case 'A':
                    case 'B':
                    case 'C':
                    case 'D':
                    case 'E':
                    case 'F':
                    case 'G':
                        {
                            bool flat = false;
                            bool sharp = false;
                            bool dotted = false;
                            bool doubledotted = false;
                            PlayNoteInfo n = new PlayNoteInfo();
                            i++;
                            if (i < snd.Length && snd[i] == '+') { sharp = true; i++; }
                            if (i < snd.Length && snd[i] == '-') { flat = true; i++; }
                            if (i < snd.Length && snd[i] == '.')
                            {
                                dotted = true; i++;
                                if (snd[i] == '.')
                                {
                                    doubledotted = true;
                                    i++;
                                }
                            }

                            if (i < snd.Length && char.IsDigit(snd[i]))
                            {
                                string val = "";
                                while (i < snd.Length && char.IsDigit(snd[i]))
                                {
                                    val += snd[i];
                                    i++;
                                }
                                int duration = int.Parse(val);

                                if (i < snd.Length && snd[i] == '+') { sharp = true; i++; }
                                if (i < snd.Length && snd[i] == '-') { flat = true; i++; }
                                if (i < snd.Length && snd[i] == '.')
                                {
                                    dotted = true; i++;
                                    if (snd[i] == '.')
                                    {
                                        doubledotted = true;
                                        i++;
                                    }
                                }

                                n.Note = c;
                                n.Length = duration;
                            }
                            else
                                n.Note = c;
                            n.Flat = flat;
                            n.Sharp = sharp;
                            n.Dotted = dotted;
                            n.DoubleDotted = doubledotted;
                            playnote(sampleQueue, n);
                            i--;

                        }
                        break;
                    case 'O':
                        {
                            i++;
                            string val = "";
                            while (i < snd.Length && char.IsDigit(snd[i]))
                            {
                                val += snd[i];
                                i++;
                            }
                            octave = int.Parse(val);
                            i--;
                        }
                        break;
                    case '>':
                        octave++;
                        break;
                    case '<':
                        octave--;
                        break;
                    case 'P':
                        {
                            i++;
                            string val = "";
                            while (i < snd.Length && char.IsDigit(snd[i]))
                            {
                                val += snd[i];
                                i++;
                            }
                            int pause = int.Parse(val);

                            double totalseconds = (1.0 / (tempo / 60.0)) * (4.0 / pause);
                            sampleQueue.Add(Tone(0, totalseconds));

                            i--;
                        }
                        break;
                    default:
                        throw new Exception("Command " + c + " not implemented!");
                }
            }



            // combine everything we did into a simple byte buffer
            int totalbytes = 0;
            foreach (byte[] d in sampleQueue)
                totalbytes += d.Length;

            byte[] ret = new byte[totalbytes];

            int pos = 0;
            foreach (byte[] d in sampleQueue)
            {
                Array.Copy(d, 0, ret, pos, d.Length);
                pos += d.Length;
            }

            return ret;


        }

        private class PlayNoteInfo
        {
            public char Note;
            public int Length;
            public bool Dotted;
            public bool DoubleDotted;
            public bool Sharp;
            public bool Flat;

            public PlayNoteInfo(char note)
            {
                Note = note;
                Length = -1; // Note length is set by the Ln command 
            }
            public PlayNoteInfo(char note, int length)
            {
                Note = note;
                Length = length;
            }

            public PlayNoteInfo()
            {

            }

            public int getNumber()
            {

                // C, C#, D, D#, E,F, F#, G, G#, A, A#, H
                int number = 0;
                switch (Note)
                {
                    case 'C': number = 0; break;
                    case 'D': number = 2; break;
                    case 'E': number = 4; break;
                    case 'F': number = 5; break;
                    case 'G': number = 7; break;
                    case 'A': number = 9; break;
                    case 'B': number = 11; break;
                }
                if (Sharp)
                    number++;
                if (Flat)
                    number--;
                return number;
            }

        }

        private static void playnote(List<byte[]> data, PlayNoteInfo n)
        {
            int noteno = n.getNumber();
            double herz = FREQ[(12 * (octave + 2)) + noteno];
            int thisnotelength = notelength;
            if (n.Length > 0)
                thisnotelength = n.Length;
            double totalseconds = (1.0 / (tempo / 60.0)) * (4.0 / thisnotelength);
            double noteseconds = totalseconds;
            double pause = 0.0;
            if (NoteDuration == NoteDurations.Normal)
            {
                noteseconds = noteseconds * (7.0 / 8.0);
                pause = totalseconds - noteseconds;
            }
            else if (NoteDuration == NoteDurations.Staccato)
            {
                noteseconds = noteseconds * (3.0 / 4.0);
                pause = totalseconds - noteseconds;
            }
            if (n.DoubleDotted)
                noteseconds += (noteseconds / 2.0) + (noteseconds / 4.0);
            else if (n.Dotted)
                noteseconds += (noteseconds / 2.0);
            data.Add(Tone(herz, noteseconds));
            if (pause > 0.0)
                data.Add(Tone(0, pause));
        }


        private static byte[] Tone(double hz, double seconds)
        {
            double sampleRate = 44100;
            int duration = (int)(sampleRate * seconds);
            byte[] d = new byte[duration];
            double amplitude = Math.Max(0.0, Math.Min(127.0, 127 * Volume));
            for (int n = 0; n < duration; n++)
            {
                int value = (int)(amplitude * Math.Sin((2.0 * Math.PI * n * hz) / sampleRate));
                if (value > 4)
                    value = (int)amplitude;
                else
                if (value < -4)
                    value = -(int)amplitude;
                else value = 0;
                d[n] = (byte)(128 - value);
            }
            return d;
        }




        //--------------------------------------------------------------------------
        // THE BLACK MAGIC
        //--------------------------------------------------------------------------


        static IntPtr critSect = IntPtr.Zero;
        static IntPtr hWaveOut = IntPtr.Zero;
        static volatile WAVEHDR wavehdr = null;

        static void CleanupWaveHdr()
        {
            if (wavehdr != null)
            {
                waveOutUnprepareHeader(hWaveOut, wavehdr, (uint)Marshal.SizeOf(typeof(WAVEHDR)));

                Marshal.FreeHGlobal(wavehdr.lpData);

                wavehdr = null;
            }
        }

        static List<byte[]> PCMSampleQueue = new List<byte[]>();
        static void DoNextOutputBuffer(bool playImmediatelyIfPossible=true/*false only intended to be from callback*/)
        {
            EnterCriticalSection(critSect);

            // if we want to play right now, we cant if another buffer is already active-  it will just remain in the queue and play next.
            // this needs to be false for the callback, since this wavehdr check will otherwise prevent the cleanup/genbuffer logic from continuing
            if (playImmediatelyIfPossible && wavehdr != null)
                goto bail;


            // cleanup old one (if exist)
            CleanupWaveHdr();

            // if nothing queued up, bust
            if (PCMSampleQueue.Count == 0)
                goto bail;

            // get next in line
            byte[] pcm = PCMSampleQueue[0];
            PCMSampleQueue.RemoveAt(0);

            if (pcm == null || pcm.Length <= 0)
                goto bail;

            wavehdr = new WAVEHDR();
            wavehdr.lpData = Marshal.AllocHGlobal(pcm.Length);
            wavehdr.dwBufferLength = (uint)pcm.Length;

            Marshal.Copy(pcm, 0, wavehdr.lpData, pcm.Length);

            waveOutPrepareHeader(hWaveOut, wavehdr, (uint)Marshal.SizeOf(typeof(WAVEHDR)));

            waveOutWrite(hWaveOut, wavehdr, (uint)Marshal.SizeOf(typeof(WAVEHDR)));

        bail:
            LeaveCriticalSection(critSect);
        }

        delegate void dwaveOutProc(IntPtr hwo, uint uMsg, IntPtr dwInstance, IntPtr dwParam1, IntPtr dwParam2);
        static dwaveOutProc pwaveOutProc = new dwaveOutProc(waveOutProc);
        static void waveOutProc(IntPtr hwo, uint uMsg, IntPtr dwInstance, IntPtr dwParam1, IntPtr dwParam2)
        {
            if(uMsg == 0x3BD/*WOM_DONE*/)
                DoNextOutputBuffer(false);
        }

        [StructLayout(LayoutKind.Sequential)]
        class WAVEFORMATEX
        {
            public UInt16 wFormatTag;
            public UInt16 nChannels;
            public UInt32 nSamplesPerSec;
            public UInt32 nAvgBytesPerSec;
            public UInt16 nBlockAlign;
            public UInt16 wBitsPerSample;
            public UInt16 cbSize;
        }

        [StructLayout(LayoutKind.Sequential)]
        class WAVEHDR
        {
            public IntPtr lpData = IntPtr.Zero;
            public uint dwBufferLength = 0;
            public uint dwBytesRecorded = 0;
            public IntPtr dwUser = IntPtr.Zero;
            public uint dwFlags = 0;
            public uint dwLoops = 0;
            public IntPtr lpNext = IntPtr.Zero;
            private uint reserved = 0;
        }

        [DllImport("winmm.dll")]
        static extern int waveOutOpen(ref IntPtr hwo, int uDeviceID, WAVEFORMATEX wf, IntPtr dwCallback, int dwInstance, UInt32 fdwOpen);

        [DllImport("winmm.dll")]
        static extern int waveOutClose(IntPtr hwo);

        [DllImport("winmm.dll")]
        static extern int waveOutReset(IntPtr hwo);

        [DllImport("winmm.dll")]
        static extern int waveOutPrepareHeader(IntPtr hwo, WAVEHDR wh, uint cbwh);

        [DllImport("winmm.dll")]
        static extern int waveOutUnprepareHeader(IntPtr hwo, WAVEHDR wh, uint cbwh);

        [DllImport("winmm.dll")]
        static extern int waveOutWrite(IntPtr hwo, WAVEHDR wh, uint cbwh);

        [DllImport("kernel32.dll")]
        private static extern void InitializeCriticalSection(IntPtr lpCriticalSection);

        [DllImport("kernel32.dll")]
        private static extern void DeleteCriticalSection(IntPtr lpCriticalSection);

        [DllImport("kernel32.dll")]
        private static extern void EnterCriticalSection(IntPtr lpCriticalSection);

        [DllImport("kernel32.dll")]
        private static extern void LeaveCriticalSection(IntPtr lpCriticalSection);
    }
}