raze-gles/libraries/game-music-emu/gme/Nes_Oscs.h
Christoph Oelckers 718112a8fe - added external libraries for music format playback and decompression from GZDoom.
Currently none of these is being used, but eventually they will, once more code gets ported over.
So it's better to have them right away and avoid editing the project file too much, only to revert that later.
2019-09-22 08:59:48 +02:00

147 lines
2.8 KiB
C++

// Private oscillators used by Nes_Apu
// Nes_Snd_Emu 0.1.8
#ifndef NES_OSCS_H
#define NES_OSCS_H
#include "blargg_common.h"
#include "Blip_Buffer.h"
class Nes_Apu;
struct Nes_Osc
{
unsigned char regs [4];
bool reg_written [4];
Blip_Buffer* output;
int length_counter;// length counter (0 if unused by oscillator)
int delay; // delay until next (potential) transition
int last_amp; // last amplitude oscillator was outputting
void clock_length( int halt_mask );
int period() const {
return (regs [3] & 7) * 0x100 + (regs [2] & 0xFF);
}
void reset() {
delay = 0;
last_amp = 0;
}
int update_amp( int amp ) {
int delta = amp - last_amp;
last_amp = amp;
return delta;
}
};
struct Nes_Envelope : Nes_Osc
{
int envelope;
int env_delay;
void clock_envelope();
int volume() const;
void reset() {
envelope = 0;
env_delay = 0;
Nes_Osc::reset();
}
};
// Nes_Square
struct Nes_Square : Nes_Envelope
{
enum { negate_flag = 0x08 };
enum { shift_mask = 0x07 };
enum { phase_range = 8 };
int phase;
int sweep_delay;
typedef Blip_Synth<blip_good_quality,1> Synth;
Synth const& synth; // shared between squares
Nes_Square( Synth const* s ) : synth( *s ) { }
void clock_sweep( int adjust );
void run( nes_time_t, nes_time_t );
void reset() {
sweep_delay = 0;
Nes_Envelope::reset();
}
nes_time_t maintain_phase( nes_time_t time, nes_time_t end_time,
nes_time_t timer_period );
};
// Nes_Triangle
struct Nes_Triangle : Nes_Osc
{
enum { phase_range = 16 };
int phase;
int linear_counter;
Blip_Synth<blip_med_quality,1> synth;
int calc_amp() const;
void run( nes_time_t, nes_time_t );
void clock_linear_counter();
void reset() {
linear_counter = 0;
phase = 1;
Nes_Osc::reset();
}
nes_time_t maintain_phase( nes_time_t time, nes_time_t end_time,
nes_time_t timer_period );
};
// Nes_Noise
struct Nes_Noise : Nes_Envelope
{
int noise;
Blip_Synth<blip_med_quality,1> synth;
void run( nes_time_t, nes_time_t );
void reset() {
noise = 1 << 14;
Nes_Envelope::reset();
}
};
// Nes_Dmc
struct Nes_Dmc : Nes_Osc
{
int address; // address of next byte to read
int period;
//int length_counter; // bytes remaining to play (already defined in Nes_Osc)
int buf;
int bits_remain;
int bits;
bool buf_full;
bool silence;
enum { loop_flag = 0x40 };
int dac;
nes_time_t next_irq;
bool irq_enabled;
bool irq_flag;
bool pal_mode;
bool nonlinear;
int (*prg_reader)( void*, nes_addr_t ); // needs to be initialized to prg read function
void* prg_reader_data;
Nes_Apu* apu;
Blip_Synth<blip_med_quality,1> synth;
void start();
void write_register( int, int );
void run( nes_time_t, nes_time_t );
void recalc_irq();
void fill_buffer();
void reload_sample();
void reset();
int count_reads( nes_time_t, nes_time_t* ) const;
nes_time_t next_read_time() const;
};
#endif