148 lines
2.9 KiB
C++
148 lines
2.9 KiB
C++
// Private oscillators used by Nes_Apu
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// Nes_Snd_Emu $vers
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#ifndef NES_OSCS_H
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#define NES_OSCS_H
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#include "blargg_common.h"
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#include "Blip_Buffer.h"
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class Nes_Apu;
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struct Nes_Osc
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{
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typedef int nes_time_t;
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unsigned char regs [4];
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bool reg_written [4];
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Blip_Buffer* output;
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int length_counter;// length counter (0 if unused by oscillator)
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int delay; // delay until next (potential) transition
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int last_amp; // last amplitude oscillator was outputting
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void clock_length( int halt_mask );
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int period() const {
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return (regs [3] & 7) * 0x100 + (regs [2] & 0xFF);
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}
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void reset() {
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delay = 0;
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last_amp = 0;
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}
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int update_amp( int amp ) {
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int delta = amp - last_amp;
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last_amp = amp;
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return delta;
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}
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};
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struct Nes_Envelope : Nes_Osc
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{
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int envelope;
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int env_delay;
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void clock_envelope();
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int volume() const;
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void reset() {
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envelope = 0;
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env_delay = 0;
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Nes_Osc::reset();
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}
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};
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// Nes_Square
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struct Nes_Square : Nes_Envelope
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{
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enum { negate_flag = 0x08 };
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enum { shift_mask = 0x07 };
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enum { phase_range = 8 };
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int phase;
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int sweep_delay;
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typedef Blip_Synth_Norm Synth;
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Synth const& synth; // shared between squares
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Nes_Square( Synth const* s ) : synth( *s ) { }
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void clock_sweep( int adjust );
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void run( nes_time_t, nes_time_t );
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void reset() {
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sweep_delay = 0;
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Nes_Envelope::reset();
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}
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nes_time_t maintain_phase( nes_time_t time, nes_time_t end_time,
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nes_time_t timer_period );
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};
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// Nes_Triangle
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struct Nes_Triangle : Nes_Osc
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{
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enum { phase_range = 16 };
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int phase;
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int linear_counter;
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Blip_Synth_Fast synth;
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int calc_amp() const;
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void run( nes_time_t, nes_time_t );
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void clock_linear_counter();
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void reset() {
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linear_counter = 0;
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phase = 1;
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Nes_Osc::reset();
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}
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nes_time_t maintain_phase( nes_time_t time, nes_time_t end_time,
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nes_time_t timer_period );
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};
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// Nes_Noise
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struct Nes_Noise : Nes_Envelope
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{
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int noise;
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Blip_Synth_Fast synth;
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void run( nes_time_t, nes_time_t );
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void reset() {
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noise = 1 << 14;
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Nes_Envelope::reset();
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}
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};
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// Nes_Dmc
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struct Nes_Dmc : Nes_Osc
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{
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int address; // address of next byte to read
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int period;
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//int length_counter; // bytes remaining to play (already defined in Nes_Osc)
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int buf;
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int bits_remain;
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int bits;
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bool buf_full;
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bool silence;
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enum { loop_flag = 0x40 };
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int dac;
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nes_time_t next_irq;
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bool irq_enabled;
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bool irq_flag;
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bool pal_mode;
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bool nonlinear;
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Nes_Apu* apu;
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Blip_Synth_Fast synth;
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int update_amp_nonlinear( int dac_in );
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void start();
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void write_register( int, int );
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void run( nes_time_t, nes_time_t );
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void recalc_irq();
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void fill_buffer();
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void reload_sample();
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void reset();
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int count_reads( nes_time_t, nes_time_t* ) const;
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nes_time_t next_read_time() const;
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};
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#endif
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