1 files changed, 104 insertions, 0 deletions
diff --git a/plugins/gme/game-music-emu-0.6pre/gme/Ay_Apu.h b/plugins/gme/game-music-emu-0.6pre/gme/Ay_Apu.h
new file mode 100644
index 00000000..bafdea47
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+++ b/plugins/gme/game-music-emu-0.6pre/gme/Ay_Apu.h
@@ -0,0 +1,104 @@
+// AY-3-8910 sound chip emulator
+
+// Game_Music_Emu 0.6-pre
+#ifndef AY_APU_H
+#define AY_APU_H
+
+#include "blargg_common.h"
+#include "Blip_Buffer.h"
+
+class Ay_Apu {
+public:
+// Basics
+
+	// Sets buffer to generate sound into, or 0 to mute.
+	void set_output( Blip_Buffer* );
+	
+	// Writes to address register
+	void write_addr( int data )                 { addr_ = data & 0x0F; }
+	
+	// Emulates to time t, then writes to current data register
+	void write_data( blip_time_t t, int data )  { run_until( t ); write_data_( addr_, data ); }
+	
+	// Emulates to time t, then subtracts t from the current time.
+	// OK if previous write call had time slightly after t.
+	void end_frame( blip_time_t t );
+	
+// More features
+	
+	// Reads from current data register
+	int read();
+	
+	// Resets sound chip
+	void reset();
+	
+	// Number of registers
+	enum { reg_count = 16 };
+	
+	// Same as set_output(), but for a particular channel
+	enum { osc_count = 3 };
+	void set_output( int chan, Blip_Buffer* );
+	
+	// Sets overall volume, where 1.0 is normal
+	void volume( double v )                     { synth_.volume( 0.7/osc_count/amp_range * v ); }
+	
+	// Sets treble equalization
+	void treble_eq( blip_eq_t const& eq )       { synth_.treble_eq( eq ); }
+	
+private:
+	// noncopyable
+	Ay_Apu( const Ay_Apu& );
+	Ay_Apu& operator = ( const Ay_Apu& );
+
+// Implementation
+public:
+	Ay_Apu();
+	BLARGG_DISABLE_NOTHROW
+	typedef BOOST::uint8_t byte;
+
+private:
+	struct osc_t
+	{
+		blip_time_t  period;
+		blip_time_t  delay;
+		short        last_amp;
+		short        phase;
+		Blip_Buffer* output;
+	} oscs [osc_count];
+	
+	blip_time_t last_time;
+	byte        addr_;
+	byte        regs [reg_count];
+	
+	blip_time_t noise_delay;
+	unsigned    noise_lfsr;
+	
+	blip_time_t env_delay;
+	byte const* env_wave;
+	int         env_pos;
+	byte        env_modes [8] [48]; // values already passed through volume table
+	
+	void write_data_( int addr, int data );
+	void run_until( blip_time_t );
+	
+public:
+	enum { amp_range = 255 };
+	Blip_Synth_Norm synth_; // used by Ay_Core for beeper sound
+};
+
+inline void Ay_Apu::set_output( int i, Blip_Buffer* out )
+{
+	assert( (unsigned) i < osc_count );
+	oscs [i].output = out;
+}
+
+inline void Ay_Apu::end_frame( blip_time_t time )
+{
+	if ( time > last_time )
+		run_until( time );
+	
+	last_time -= time;
+	assert( last_time >= 0 );
+}
+
+#endif