1 files changed, 179 insertions, 0 deletions
diff --git a/plugins/gme/game-music-emu-0.6.0/gme/Nes_Apu.h b/plugins/gme/game-music-emu-0.6.0/gme/Nes_Apu.h
new file mode 100644
index 00000000..5e722248
--- /dev/null
+++ b/plugins/gme/game-music-emu-0.6.0/gme/Nes_Apu.h
@@ -0,0 +1,179 @@
+// NES 2A03 APU sound chip emulator
+
+// Nes_Snd_Emu 0.1.8
+#ifndef NES_APU_H
+#define NES_APU_H
+
+#include "blargg_common.h"
+
+typedef blargg_long nes_time_t; // CPU clock cycle count
+typedef unsigned nes_addr_t; // 16-bit memory address
+
+#include "Nes_Oscs.h"
+
+struct apu_state_t;
+class Nes_Buffer;
+
+class Nes_Apu {
+public:
+	// Set buffer to generate all sound into, or disable sound if NULL
+	void output( Blip_Buffer* );
+	
+	// Set memory reader callback used by DMC oscillator to fetch samples.
+	// When callback is invoked, 'user_data' is passed unchanged as the
+	// first parameter.
+	void dmc_reader( int (*callback)( void* user_data, nes_addr_t ), void* user_data = NULL );
+	
+	// All time values are the number of CPU clock cycles relative to the
+	// beginning of the current time frame. Before resetting the CPU clock
+	// count, call end_frame( last_cpu_time ).
+	
+	// Write to register (0x4000-0x4017, except 0x4014 and 0x4016)
+	enum { start_addr = 0x4000 };
+	enum { end_addr   = 0x4017 };
+	void write_register( nes_time_t, nes_addr_t, int data );
+	
+	// Read from status register at 0x4015
+	enum { status_addr = 0x4015 };
+	int read_status( nes_time_t );
+	
+	// Run all oscillators up 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( nes_time_t );
+	
+// Additional optional features (can be ignored without any problem)
+
+	// Reset internal frame counter, registers, and all oscillators.
+	// Use PAL timing if pal_timing is true, otherwise use NTSC timing.
+	// Set the DMC oscillator's initial DAC value to initial_dmc_dac without
+	// any audible click.
+	void reset( bool pal_mode = false, int initial_dmc_dac = 0 );
+	
+	// Adjust frame period
+	void set_tempo( double );
+	
+	// Save/load exact emulation state
+	void save_state( apu_state_t* out ) const;
+	void load_state( apu_state_t const& );
+	
+	// Set overall volume (default is 1.0)
+	void volume( double );
+	
+	// Set treble equalization (see notes.txt)
+	void treble_eq( const blip_eq_t& );
+	
+	// Set sound output of specific oscillator to buffer. If buffer is NULL,
+	// the specified oscillator is muted and emulation accuracy is reduced.
+	// The oscillators are indexed as follows: 0) Square 1, 1) Square 2,
+	// 2) Triangle, 3) Noise, 4) DMC.
+	enum { osc_count = 5 };
+	void osc_output( int index, Blip_Buffer* buffer );
+	
+	// Set IRQ time callback that is invoked when the time of earliest IRQ
+	// may have changed, or NULL to disable. When callback is invoked,
+	// 'user_data' is passed unchanged as the first parameter.
+	void irq_notifier( void (*callback)( void* user_data ), void* user_data = NULL );
+	
+	// Get time that APU-generated IRQ will occur if no further register reads
+	// or writes occur. If IRQ is already pending, returns irq_waiting. If no
+	// IRQ will occur, returns no_irq.
+	enum { no_irq = INT_MAX / 2 + 1 };
+	enum { irq_waiting = 0 };
+	nes_time_t earliest_irq( nes_time_t ) const;
+	
+	// Count number of DMC reads that would occur if 'run_until( t )' were executed.
+	// If last_read is not NULL, set *last_read to the earliest time that
+	// 'count_dmc_reads( time )' would result in the same result.
+	int count_dmc_reads( nes_time_t t, nes_time_t* last_read = NULL ) const;
+	
+	// Time when next DMC memory read will occur
+	nes_time_t next_dmc_read_time() const;
+	
+	// Run DMC until specified time, so that any DMC memory reads can be
+	// accounted for (i.e. inserting CPU wait states).
+	void run_until( nes_time_t );
+	
+public:
+	Nes_Apu();
+	BLARGG_DISABLE_NOTHROW
+private:
+	friend class Nes_Nonlinearizer;
+	void enable_nonlinear( double volume );
+	static double nonlinear_tnd_gain() { return 0.75; }
+private:
+	friend struct Nes_Dmc;
+	
+	// noncopyable
+	Nes_Apu( const Nes_Apu& );
+	Nes_Apu& operator = ( const Nes_Apu& );
+	
+	Nes_Osc*            oscs [osc_count];
+	Nes_Square          square1;
+	Nes_Square          square2;
+	Nes_Noise           noise;
+	Nes_Triangle        triangle;
+	Nes_Dmc             dmc;
+	
+	double tempo_;
+	nes_time_t last_time; // has been run until this time in current frame
+	nes_time_t last_dmc_time;
+	nes_time_t earliest_irq_;
+	nes_time_t next_irq;
+	int frame_period;
+	int frame_delay; // cycles until frame counter runs next
+	int frame; // current frame (0-3)
+	int osc_enables;
+	int frame_mode;
+	bool irq_flag;
+	void (*irq_notifier_)( void* user_data );
+	void* irq_data;
+	Nes_Square::Synth square_synth; // shared by squares
+	
+	void irq_changed();
+	void state_restored();
+	void run_until_( nes_time_t );
+	
+	// TODO: remove
+	friend class Nes_Core;
+};
+
+inline void Nes_Apu::osc_output( int osc, Blip_Buffer* buf )
+{
+	assert( (unsigned) osc < osc_count );
+	oscs [osc]->output = buf;
+}
+
+inline nes_time_t Nes_Apu::earliest_irq( nes_time_t ) const
+{
+	return earliest_irq_;
+}
+
+inline void Nes_Apu::dmc_reader( int (*func)( void*, nes_addr_t ), void* user_data )
+{
+	dmc.prg_reader_data = user_data;
+	dmc.prg_reader = func;
+}
+
+inline void Nes_Apu::irq_notifier( void (*func)( void* user_data ), void* user_data )
+{
+	irq_notifier_ = func;
+	irq_data = user_data;
+}
+
+inline int Nes_Apu::count_dmc_reads( nes_time_t time, nes_time_t* last_read ) const
+{
+	return dmc.count_reads( time, last_read );
+}
+	
+inline nes_time_t Nes_Dmc::next_read_time() const
+{
+	if ( length_counter == 0 )
+		return Nes_Apu::no_irq; // not reading
+	
+	return apu->last_dmc_time + delay + long (bits_remain - 1) * period;
+}
+
+inline nes_time_t Nes_Apu::next_dmc_read_time() const { return dmc.next_read_time(); }
+
+#endif