1 files changed, 95 insertions, 0 deletions
diff --git a/plugins/gme/game-music-emu-0.6.0/gme/Nes_Vrc6_Apu.h b/plugins/gme/game-music-emu-0.6.0/gme/Nes_Vrc6_Apu.h
new file mode 100644
index 00000000..18722233
--- /dev/null
+++ b/plugins/gme/game-music-emu-0.6.0/gme/Nes_Vrc6_Apu.h
@@ -0,0 +1,95 @@
+// Konami VRC6 sound chip emulator
+
+// Nes_Snd_Emu 0.1.8
+#ifndef NES_VRC6_APU_H
+#define NES_VRC6_APU_H
+
+#include "blargg_common.h"
+#include "Blip_Buffer.h"
+
+struct vrc6_apu_state_t;
+
+class Nes_Vrc6_Apu {
+public:
+	// See Nes_Apu.h for reference
+	void reset();
+	void volume( double );
+	void treble_eq( blip_eq_t const& );
+	void output( Blip_Buffer* );
+	enum { osc_count = 3 };
+	void osc_output( int index, Blip_Buffer* );
+	void end_frame( blip_time_t );
+	void save_state( vrc6_apu_state_t* ) const;
+	void load_state( vrc6_apu_state_t const& );
+	
+	// Oscillator 0 write-only registers are at $9000-$9002
+	// Oscillator 1 write-only registers are at $A000-$A002
+	// Oscillator 2 write-only registers are at $B000-$B002
+	enum { reg_count = 3 };
+	enum { base_addr = 0x9000 };
+	enum { addr_step = 0x1000 };
+	void write_osc( blip_time_t, int osc, int reg, int data );
+	
+public:
+	Nes_Vrc6_Apu();
+	BLARGG_DISABLE_NOTHROW
+private:
+	// noncopyable
+	Nes_Vrc6_Apu( const Nes_Vrc6_Apu& );
+	Nes_Vrc6_Apu& operator = ( const Nes_Vrc6_Apu& );
+	
+	struct Vrc6_Osc
+	{
+		BOOST::uint8_t regs [3];
+		Blip_Buffer* output;
+		int delay;
+		int last_amp;
+		int phase;
+		int amp; // only used by saw
+		
+		int period() const
+		{
+			return (regs [2] & 0x0F) * 0x100L + regs [1] + 1;
+		}
+	};
+	
+	Vrc6_Osc oscs [osc_count];
+	blip_time_t last_time;
+	
+	Blip_Synth<blip_med_quality,1> saw_synth;
+	Blip_Synth<blip_good_quality,1> square_synth;
+	
+	void run_until( blip_time_t );
+	void run_square( Vrc6_Osc& osc, blip_time_t );
+	void run_saw( blip_time_t );
+};
+
+struct vrc6_apu_state_t
+{
+	BOOST::uint8_t regs [3] [3];
+	BOOST::uint8_t saw_amp;
+	BOOST::uint16_t delays [3];
+	BOOST::uint8_t phases [3];
+	BOOST::uint8_t unused;
+};
+
+inline void Nes_Vrc6_Apu::osc_output( int i, Blip_Buffer* buf )
+{
+	assert( (unsigned) i < osc_count );
+	oscs [i].output = buf;
+}
+
+inline void Nes_Vrc6_Apu::volume( double v )
+{
+	double const factor = 0.0967 * 2;
+	saw_synth.volume( factor / 31 * v );
+	square_synth.volume( factor * 0.5 / 15 * v );
+}
+
+inline void Nes_Vrc6_Apu::treble_eq( blip_eq_t const& eq )
+{
+	saw_synth.treble_eq( eq );
+	square_synth.treble_eq( eq );
+}
+
+#endif