cog/Frameworks/libsidplay/sidplay-residfp-code/.svn/pristine/e1/e1b79385f2c04d9c5f4225c2e65...

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/*
* This file is part of libsidplayfp, a SID player engine.
*
* Copyright 2011-2014 Leandro Nini <drfiemost@users.sourceforge.net>
* Copyright 2007-2010 Antti Lankila
* Copyright 2004 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#ifndef SIDFP_H
#define SIDFP_H
#include <memory>
#include "siddefs-fp.h"
namespace reSIDfp
{
class Filter;
class Filter6581;
class Filter8580;
class ExternalFilter;
class Potentiometer;
class Voice;
class Resampler;
/**
* SID error exception.
*/
class SIDError
{
private:
const char* message;
public:
SIDError(const char* msg) :
message(msg) {}
const char* getMessage() { return message; }
};
/**
* MOS6581/MOS8580 emulation.
*/
class SID
{
private:
/// Currently active filter
Filter* filter;
/// Filter used, if model is set to 6581
std::auto_ptr<Filter6581> const filter6581;
/// Filter used, if model is set to 8580
std::auto_ptr<Filter8580> const filter8580;
/**
* External filter that provides high-pass and low-pass filtering
* to adjust sound tone slightly.
*/
std::auto_ptr<ExternalFilter> const externalFilter;
/// Resampler used by audio generation code.
std::auto_ptr<Resampler> resampler;
/// Paddle X register support
std::auto_ptr<Potentiometer> const potX;
/// Paddle Y register support
std::auto_ptr<Potentiometer> const potY;
/// SID voices
std::auto_ptr<Voice> voice[3];
/// Time to live for the last written value
int busValueTtl;
/// Current chip model's bus value TTL
int modelTTL;
/// Time until #voiceSync must be run.
unsigned int nextVoiceSync;
/// Delayed MOS8580 write register
int delayedOffset;
/// Currently active chip model.
ChipModel model;
/// Delayed MOS8580 write value
unsigned char delayedValue;
/// Last written value
unsigned char busValue;
/// Flags for muted channels
bool muted[3];
private:
/**
* Write value to register during this clock cycle.
*
* @param offset chip register to write
* @param value value to write
*/
void writeImmediate(int offset, unsigned char value);
/**
* Age the bus value and zero it if it's TTL has expired.
*
* @param n the number of cycles
*/
void ageBusValue(unsigned int n);
/**
* Get output sample.
*
* @return the output sample
*/
int output() const;
/**
* Calculate the numebr of cycles according to current parameters
* that it takes to reach sync.
*
* @param sync whether to do the actual voice synchronization
*/
void voiceSync(bool sync);
public:
SID();
~SID();
/**
* Set chip model.
*
* @param model chip model to use
*/
void setChipModel(ChipModel model);
/**
* Get currently emulated chip model.
*/
ChipModel getChipModel() const { return model; }
/**
* SID reset.
*/
void reset();
/**
* 16-bit input (EXT IN). Write 16-bit sample to audio input. NB! The caller
* is responsible for keeping the value within 16 bits. Note that to mix in
* an external audio signal, the signal should be resampled to 1MHz first to
* avoid sampling noise.
*
* @param value input level to set
*/
void input(int value);
/**
* Read registers.
*
* Reading a write only register returns the last char written to any SID register.
* The individual bits in this value start to fade down towards zero after a few cycles.
* All bits reach zero within approximately $2000 - $4000 cycles.
* It has been claimed that this fading happens in an orderly fashion,
* however sampling of write only registers reveals that this is not the case.
* NOTE: This is not correctly modeled.
* The actual use of write only registers has largely been made
* in the belief that all SID registers are readable.
* To support this belief the read would have to be done immediately
* after a write to the same register (remember that an intermediate write
* to another register would yield that value instead).
* With this in mind we return the last value written to any SID register
* for $2000 cycles without modeling the bit fading.
*
* @param offset SID register to read
* @return value read from chip
*/
unsigned char read(int offset);
/**
* Write registers.
*
* @param offset chip register to write
* @param value value to write
*/
void write(int offset, unsigned char value);
/**
* SID voice muting.
*
* @param channel channel to modify
* @param enable is muted?
*/
void mute(int channel, bool enable) { muted[channel] = enable; }
/**
* Setting of SID sampling parameters.
*
* Use a clock freqency of 985248Hz for PAL C64, 1022730Hz for NTSC C64.
* The default end of passband frequency is pass_freq = 0.9*sample_freq/2
* for sample frequencies up to ~ 44.1kHz, and 20kHz for higher sample frequencies.
*
* For resampling, the ratio between the clock frequency and the sample frequency
* is limited as follows: 125*clock_freq/sample_freq < 16384
* E.g. provided a clock frequency of ~ 1MHz, the sample frequency can not be set
* lower than ~ 8kHz. A lower sample frequency would make the resampling code
* overfill its 16k sample ring buffer.
*
* The end of passband frequency is also limited: pass_freq <= 0.9*sample_freq/2
*
* E.g. for a 44.1kHz sampling rate the end of passband frequency
* is limited to slightly below 20kHz.
* This constraint ensures that the FIR table is not overfilled.
*
* @param clockFrequency System clock frequency at Hz
* @param method sampling method to use
* @param samplingFrequency Desired output sampling rate
* @param highestAccurateFrequency
*/
void setSamplingParameters(double clockFrequency, SamplingMethod method, double samplingFrequency, double highestAccurateFrequency);
/**
* Clock SID forward using chosen output sampling algorithm.
*
* @param cycles c64 clocks to clock
* @param buf audio output buffer
* @return number of samples produced
*/
int clock(unsigned int cycles, short* buf);
/**
* Clock SID forward with no audio production.
*
* _Warning_:
* You can't mix this method of clocking with the audio-producing
* clock() because components that don't affect OSC3/ENV3 are not
* emulated.
*
* @param cycles c64 clocks to clock.
*/
void clockSilent(unsigned int cycles);
/**
* Set filter curve parameter for 6581 model.
*
* @see Filter6581::setFilterCurve(double)
*/
void setFilter6581Curve(double filterCurve);
/**
* Set filter curve parameter for 8580 model.
*
* @see Filter8580::setFilterCurve(double)
*/
void setFilter8580Curve(double filterCurve);
/**
* Enable filter emulation.
*
* @param enable false to turn off filter emulation
*/
void enableFilter(bool enable);
};
} // namespace reSIDfp
#if RESID_INLINING || defined(SID_CPP)
#include <algorithm>
#include "Filter.h"
#include "ExternalFilter.h"
#include "Voice.h"
#include "resample/Resampler.h"
namespace reSIDfp
{
RESID_INLINE
void SID::ageBusValue(unsigned int n)
{
if (likely(busValueTtl != 0))
{
busValueTtl -= n;
if (unlikely(busValueTtl <= 0))
{
busValue = 0;
busValueTtl = 0;
}
}
}
RESID_INLINE
int SID::output() const
{
const int v1 = voice[0]->output(voice[2]->wave());
const int v2 = voice[1]->output(voice[0]->wave());
const int v3 = voice[2]->output(voice[1]->wave());
return externalFilter->clock(filter->clock(v1, v2, v3));
}
RESID_INLINE
int SID::clock(unsigned int cycles, short* buf)
{
ageBusValue(cycles);
int s = 0;
while (cycles != 0)
{
unsigned int delta_t = std::min(nextVoiceSync, cycles);
if (likely(delta_t > 0))
{
if (unlikely(delayedOffset != -1))
{
delta_t = 1;
}
for (unsigned int i = 0; i < delta_t; i++)
{
/* clock waveform generators */
voice[0]->wave()->clock();
voice[1]->wave()->clock();
voice[2]->wave()->clock();
/* clock envelope generators */
voice[0]->envelope()->clock();
voice[1]->envelope()->clock();
voice[2]->envelope()->clock();
if (unlikely(resampler->input(output())))
{
buf[s++] = resampler->getOutput();
}
}
if (unlikely(delayedOffset != -1))
{
writeImmediate(delayedOffset, delayedValue);
delayedOffset = -1;
}
cycles -= delta_t;
nextVoiceSync -= delta_t;
}
if (unlikely(nextVoiceSync == 0))
{
voiceSync(true);
}
}
return s;
}
} // namespace reSIDfp
#endif
#endif