sid.h
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// ---------------------------------------------------------------------------
// This file is part of reSID, a MOS6581 SID emulator engine.
// Copyright (C) 2010 Dag Lem <resid@nimrod.no>
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
// ---------------------------------------------------------------------------
#ifndef RESID_SID_H
#define RESID_SID_H
#include "resid-config.h"
#include "voice.h"
#if NEW_8580_FILTER
#include "filter8580new.h"
#else
#include "filter.h"
#endif
#include "extfilt.h"
#include "pot.h"
namespace reSID
{
class SID
{
public:
SID();
~SID();
void set_chip_model(chip_model model);
void set_voice_mask(reg4 mask);
void enable_filter(bool enable);
void adjust_filter_bias(double dac_bias);
void enable_external_filter(bool enable);
bool set_sampling_parameters(double clock_freq, sampling_method method,
double sample_freq, double pass_freq = -1,
double filter_scale = 0.97);
void adjust_sampling_frequency(double sample_freq);
void enable_raw_debug_output(bool enable);
void clock();
void clock(cycle_count delta_t);
int clock(cycle_count& delta_t, short* buf, int n, int interleave = 1);
void reset();
// Read/write registers.
reg8 read(reg8 offset);
void write(reg8 offset, reg8 value);
// Read/write state.
class State
{
public:
State();
char sid_register[0x20];
reg8 bus_value;
cycle_count bus_value_ttl;
cycle_count write_pipeline;
reg8 write_address;
reg4 voice_mask;
reg24 accumulator[3];
reg24 shift_register[3];
cycle_count shift_register_reset[3];
cycle_count shift_pipeline[3];
reg16 pulse_output[3];
cycle_count floating_output_ttl[3];
reg16 rate_counter[3];
reg16 rate_counter_period[3];
reg16 exponential_counter[3];
reg16 exponential_counter_period[3];
reg8 envelope_counter[3];
EnvelopeGenerator::State envelope_state[3];
bool hold_zero[3];
cycle_count envelope_pipeline[3];
};
State read_state();
void write_state(const State& state);
// 16-bit input (EXT IN).
void input(short sample);
// 16-bit output (AUDIO OUT).
int output();
void debugoutput(void);
protected:
static double I0(double x);
int clock_fast(cycle_count& delta_t, short* buf, int n, int interleave);
int clock_interpolate(cycle_count& delta_t, short* buf, int n, int interleave);
int clock_resample(cycle_count& delta_t, short* buf, int n, int interleave);
int clock_resample_fastmem(cycle_count& delta_t, short* buf, int n, int interleave);
void write();
chip_model sid_model;
Voice voice[3];
Filter filter;
ExternalFilter extfilt;
Potentiometer potx;
Potentiometer poty;
reg8 bus_value;
cycle_count bus_value_ttl;
// The data bus TTL for the selected chip model
cycle_count databus_ttl;
// Pipeline for writes on the MOS8580.
cycle_count write_pipeline;
reg8 write_address;
double clock_frequency;
// Used to amplify the output by scaleFactor/2 to get an adequate playback volume
int scaleFactor;
enum {
// Resampling constants.
// The error in interpolated lookup is bounded by 1.234/L^2,
// while the error in non-interpolated lookup is bounded by
// 0.7854/L + 0.4113/L^2, see
// http://www-ccrma.stanford.edu/~jos/resample/Choice_Table_Size.html
// For a resolution of 16 bits this yields L >= 285 and L >= 51473,
// respectively.
FIR_N = 125,
FIR_RES = 285,
FIR_RES_FASTMEM = 51473,
FIR_SHIFT = 15,
RINGSIZE = 1 << 14,
RINGMASK = RINGSIZE - 1,
// Fixed point constants (16.16 bits).
FIXP_SHIFT = 16,
FIXP_MASK = 0xffff
};
// Sampling variables.
sampling_method sampling;
cycle_count cycles_per_sample;
cycle_count sample_offset;
int sample_index;
short sample_prev, sample_now;
int fir_N;
int fir_RES;
double fir_beta;
double fir_f_cycles_per_sample;
double fir_filter_scale;
// Ring buffer with overflow for contiguous storage of RINGSIZE samples.
short* sample;
// FIR_RES filter tables (FIR_N*FIR_RES).
short* fir;
bool raw_debug_output; // FIXME: should be private?
};
// ----------------------------------------------------------------------------
// Inline functions.
// The following functions are defined inline because they are called every
// time a sample is calculated.
// ----------------------------------------------------------------------------
#if RESID_INLINING || defined(RESID_SID_CC)
// ----------------------------------------------------------------------------
// Read 16-bit sample from audio output.
// ----------------------------------------------------------------------------
RESID_INLINE
int SID::output()
{
return extfilt.output();
}
// ----------------------------------------------------------------------------
// SID clocking - 1 cycle.
// ----------------------------------------------------------------------------
RESID_INLINE
void SID::clock()
{
int i;
// Clock amplitude modulators.
for (i = 0; i < 3; i++) {
voice[i].envelope.clock();
}
// Clock oscillators.
for (i = 0; i < 3; i++) {
voice[i].wave.clock();
}
// Synchronize oscillators.
for (i = 0; i < 3; i++) {
voice[i].wave.synchronize();
}
// Calculate waveform output.
for (i = 0; i < 3; i++) {
voice[i].wave.set_waveform_output();
}
// Clock filter.
filter.clock(voice[0].output(), voice[1].output(), voice[2].output());
// Clock external filter.
extfilt.clock(filter.output());
// Pipelined writes on the MOS8580.
if (unlikely(write_pipeline)) {
write();
}
// Age bus value.
if (unlikely(!--bus_value_ttl)) {
bus_value = 0;
}
if (unlikely(raw_debug_output)) {
debugoutput();
}
}
#endif // RESID_INLINING || defined(RESID_SID_CC)
} // namespace reSID
#endif // not RESID_SID_H
reSID::ExternalFilter
Definition extfilt.h:56
reSID::Filter
Definition filter.h:347
reSID::Potentiometer
Definition pot.h:29
reSID::SID::State
Definition sid.h:66
reSID::Voice
Definition voice.h:31