1 files changed, 107 insertions, 0 deletions
diff --git a/plugins/gme/game-music-emu-0.6.0/gme/Ay_Apu.h b/plugins/gme/game-music-emu-0.6.0/gme/Ay_Apu.h
new file mode 100644
index 00000000..42395e37
--- /dev/null
+++ b/plugins/gme/game-music-emu-0.6.0/gme/Ay_Apu.h
@@ -0,0 +1,107 @@
+// AY-3-8910 sound chip emulator
+
+// Game_Music_Emu 0.5.5
+#ifndef AY_APU_H
+#define AY_APU_H
+
+#include "blargg_common.h"
+#include "Blip_Buffer.h"
+
+class Ay_Apu {
+public:
+	// Set buffer to generate all sound into, or disable sound if NULL
+	void output( Blip_Buffer* );
+	
+	// Reset sound chip
+	void reset();
+	
+	// Write to register at specified time
+	enum { reg_count = 16 };
+	void write( blip_time_t time, int addr, int data );
+	
+	// Run sound to specified time, end current time frame, then start a new
+	// time frame at time 0. Time frames have no effect on emulation and each
+	// can be whatever length is convenient.
+	void end_frame( blip_time_t length );
+	
+// Additional features
+	
+	// Set sound output of specific oscillator to buffer, where index is
+	// 0, 1, or 2. If buffer is NULL, the specified oscillator is muted.
+	enum { osc_count = 3 };
+	void osc_output( int index, Blip_Buffer* );
+	
+	// Set overall volume (default is 1.0)
+	void volume( double );
+	
+	// Set treble equalization (see documentation)
+	void treble_eq( blip_eq_t const& );
+	
+public:
+	Ay_Apu();
+	typedef unsigned char 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 latch;
+	byte regs [reg_count];
+	
+	struct {
+		blip_time_t delay;
+		blargg_ulong lfsr;
+	} noise;
+	
+	struct {
+		blip_time_t delay;
+		byte const* wave;
+		int pos;
+		byte modes [8] [48]; // values already passed through volume table
+	} env;
+	
+	void run_until( blip_time_t );
+	void write_data_( int addr, int data );
+public:
+	enum { amp_range = 255 };
+	Blip_Synth<blip_good_quality,1> synth_;
+};
+
+inline void Ay_Apu::volume( double v ) { synth_.volume( 0.7 / osc_count / amp_range * v ); }
+
+inline void Ay_Apu::treble_eq( blip_eq_t const& eq ) { synth_.treble_eq( eq ); }
+
+inline void Ay_Apu::write( blip_time_t time, int addr, int data )
+{
+	run_until( time );
+	write_data_( addr, data );
+}
+
+inline void Ay_Apu::osc_output( int i, Blip_Buffer* buf )
+{
+	assert( (unsigned) i < osc_count );
+	oscs [i].output = buf;
+}
+
+inline void Ay_Apu::output( Blip_Buffer* buf )
+{
+	osc_output( 0, buf );
+	osc_output( 1, buf );
+	osc_output( 2, buf );
+}
+
+inline void Ay_Apu::end_frame( blip_time_t time )
+{
+	if ( time > last_time )
+		run_until( time );
+	
+	assert( last_time >= time );
+	last_time -= time;
+}
+
+#endif