MusicEngine.h

00001 ///////////////////////////////////////////////////////////////////////////////
00002 // Retro  Music Engine
00003 // Author: Chris Taylor (taylorza)
00004 
00005 #include "mbed.h"
00006 
00007 #ifndef __MUSICENGINE_H__
00008 #define __MUSICENGINE_H__
00009 
00010 /** MusicEngine provides a means to play Music Macro Language sequences asynchronously.
00011  *  Learn more about Music Macro Language (MML) on wikipedia
00012  *  http://en.wikipedia.org/wiki/Music_Macro_Language
00013 */
00014 class MusicEngine
00015 {
00016 public:
00017     /** Creates an instance of the MusicEngine
00018       * @param pin pin used to generate the note frequencies
00019     */ 
00020     MusicEngine(PinName pin);
00021     
00022     /** Starts playing a new MML sequence. If one is already playing it is stopped and the new sequences started. 
00023       * @param mml string of MML commands to be played
00024      */
00025     void play(char *mml);
00026     
00027     /** Stop a currently playing sequence */     
00028     void stop();
00029     
00030     /** Query the engine to determine if a MML sequence is currently being played. */    
00031     bool getIsPlaying() { return _isPlaying; }
00032     
00033     /** Setup a callback function that will be executed when the music sequence ends. */
00034     void setCompletionCallback(void (*function)(void))
00035     {
00036         _completionCallback.attach(function);
00037     }
00038     
00039     /** Setup a callback function that will be executed when the music sequence ends.
00040      * @note This override is used if the callback is a class member
00041      */
00042     template<typename T>
00043     void setCompletionCallback(T *object, void (T::*member)(void))
00044     {
00045         _completionCallback.attach(object, member);       
00046     }
00047 
00048 private:
00049     void executeCommand();
00050     void skipWhiteSpace();
00051     char getChar();
00052     char peekChar();
00053     void rewind();
00054     int getNumber(int min, int max);
00055     
00056 private:
00057     PwmOut      _pwm;
00058     bool        _isPlaying;
00059     char        *_mml;
00060     int         _mmlIndex;    
00061     int         _octave;
00062     float       _duration;
00063     float       _durationRatio;
00064     float       _pause;
00065     int         _tempo;
00066     Timeout     _scheduler;
00067     
00068     FunctionPointer _completionCallback;
00069     
00070     static const float PERIOD_TABLE[];
00071     
00072     static const float WHOLE_NOTE_DURATION;
00073     static const float QUARTER_NOTE_DURATION;
00074     static const float QUARTER_NOTES_PER_MINUTE;
00075     
00076     static const float DEFAULT_TIMING;
00077     static const float LEGATO_TIMING;
00078     static const float STACCATO_TIMING;
00079     
00080     static const int NOTE_REST;
00081     static const int NOTE_C;
00082     static const int NOTE_CS;
00083     static const int NOTE_D;
00084     static const int NOTE_DS;
00085     static const int NOTE_E;
00086     static const int NOTE_F;
00087     static const int NOTE_FS;
00088     static const int NOTE_G;
00089     static const int NOTE_GS;
00090     static const int NOTE_A;
00091     static const int NOTE_AS;
00092     static const int NOTE_B;
00093 };
00094 #endif //__MUSICENGINE_H__