1 // Sega Genesis/Mega Drive GYM music file emulator
2 // Includes with PCM timing recovery to improve sample quality.
3 
4 // Game_Music_Emu https://bitbucket.org/mpyne/game-music-emu/
5 #ifndef GYM_EMU_H
6 #define GYM_EMU_H
7 
8 #include "Dual_Resampler.h"
9 #include "Ym2612_Emu.h"
10 #include "Music_Emu.h"
11 #include "Sms_Apu.h"
12 
13 class Gym_Emu : public Music_Emu, private Dual_Resampler {
14 public:
15 	// GYM file header
16 	enum { header_size = 428 };
17 	struct header_t
18 	{
19 	    char tag [4];
20 	    char song [32];
21 	    char game [32];
22 	    char copyright [32];
23 	    char emulator [32];
24 	    char dumper [32];
25 	    char comment [256];
26 	    byte loop_start [4]; // in 1/60 seconds, 0 if not looped
27 	    byte packed [4];
28 	};
29 
30 	// Header for currently loaded file
header()31 	header_t const& header() const { return header_; }
32 
static_type()33 	static gme_type_t static_type() { return gme_gym_type; }
34 
35 public:
36 	// deprecated
37 	using Music_Emu::load;
load(header_t const & h,Data_Reader & in)38 	blargg_err_t load( header_t const& h, Data_Reader& in ) // use Remaining_Reader
39 			{ return load_remaining_( &h, sizeof h, in ); }
40 	enum { gym_rate = 60 };
41 	long track_length() const; // use track_info()
42 
43 public:
44 	Gym_Emu();
45 	~Gym_Emu();
46 protected:
47 	blargg_err_t load_mem_( byte const*, long );
48 	blargg_err_t track_info_( track_info_t*, int track ) const;
49 	blargg_err_t set_sample_rate_( long sample_rate );
50 	blargg_err_t start_track_( int );
51 	blargg_err_t play_( long count, sample_t* );
52 	void mute_voices_( int );
53 	void set_tempo_( double );
54 	int play_frame( blip_time_t blip_time, int sample_count, sample_t* buf );
55 private:
56 	// sequence data begin, loop begin, current position, end
57 	const byte* data;
58 	const byte* loop_begin;
59 	const byte* pos;
60 	const byte* data_end;
61 	blargg_long loop_remain; // frames remaining until loop beginning has been located
62 	header_t header_;
63 	double fm_sample_rate;
64 	blargg_long clocks_per_frame;
65 	void parse_frame();
66 
67 	// dac (pcm)
68 	int dac_amp;
69 	int prev_dac_count;
70 	bool dac_enabled;
71 	bool dac_muted;
72 	void run_dac( int );
73 
74 	// sound
75 	Blip_Buffer blip_buf;
76 	Ym2612_Emu fm;
77 	Blip_Synth<blip_med_quality,1> dac_synth;
78 	Sms_Apu apu;
79 	byte dac_buf [1024];
80 };
81 
82 #endif
83