1 files changed, 87 insertions, 0 deletions
diff --git a/plugins/gme/game-music-emu-0.6pre/gme/Hes_Apu.h b/plugins/gme/game-music-emu-0.6pre/gme/Hes_Apu.h
new file mode 100644
index 00000000..6375993c
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+++ b/plugins/gme/game-music-emu-0.6pre/gme/Hes_Apu.h
@@ -0,0 +1,87 @@
+// Turbo Grafx 16 (PC Engine) PSG sound chip emulator
+
+// Game_Music_Emu 0.6-pre
+#ifndef HES_APU_H
+#define HES_APU_H
+
+#include "blargg_common.h"
+#include "Blip_Buffer.h"
+
+class Hes_Apu {
+public:
+// Basics
+
+	// Sets buffer(s) to generate sound into, or 0 to mute. If only center is not 0,
+	// output is mono.
+	void set_output( Blip_Buffer* center, Blip_Buffer* left = NULL, Blip_Buffer* right = NULL );
+
+	// Emulates to time t, then writes data to addr
+	void write_data( blip_time_t t, int addr, int 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
+	
+	// Resets sound chip
+	void reset();
+	
+	// Same as set_output(), but for a particular channel
+	enum { osc_count = 6 }; // 0 <= chan < osc_count
+	void set_output( int chan, Blip_Buffer* center, Blip_Buffer* left = NULL, Blip_Buffer* right = NULL );
+	
+	// Sets treble equalization
+	void treble_eq( blip_eq_t const& eq )   { synth.treble_eq( eq ); }
+	
+	// Sets overall volume, where 1.0 is normal
+	void volume( double v )                 { synth.volume( 1.8 / osc_count / amp_range * v ); }
+	
+	// Registers are at io_addr to io_addr+io_size-1
+	enum { io_addr = 0x0800 };
+	enum { io_size = 10 };
+	
+// Implementation
+public:
+	Hes_Apu();
+	typedef BOOST::uint8_t byte;
+
+private:
+	enum { amp_range = 0x8000 };
+	struct Osc
+	{
+		byte wave [32];
+		int  delay;
+		int  period;
+		int  phase;
+		
+		int  noise_delay;
+		byte noise;
+		unsigned lfsr;
+		
+		byte control;
+		byte balance;
+		byte dac;
+		short volume [2];
+		int last_amp [2];
+		
+		blip_time_t last_time;
+		Blip_Buffer* output [2];
+		Blip_Buffer* outputs [3];
+	};
+	Osc oscs [osc_count];
+	int latch;
+	int balance;
+	Blip_Synth_Fast synth;
+	
+	void balance_changed( Osc& );
+	static void run_osc( Blip_Synth_Fast&, Osc&, blip_time_t );
+};
+
+inline void Hes_Apu::set_output( Blip_Buffer* c, Blip_Buffer* l, Blip_Buffer* r )
+{
+	for ( int i = osc_count; --i >= 0; )
+		set_output( i, c, l, r );
+}
+
+#endif