190 lines
4.3 KiB
C++
190 lines
4.3 KiB
C++
|
|
// Nes_Emu 0.5.6. http://www.slack.net/~ant/libs/
|
|
|
|
#include "Nonlinear_Buffer.h"
|
|
|
|
#include "Nes_Apu.h"
|
|
|
|
/* Library Copyright (C) 2003-2005 Shay Green. This library is free software;
|
|
you can redistribute it and/or modify it under the terms of the GNU Lesser
|
|
General Public License as published by the Free Software Foundation; either
|
|
version 2.1 of the License, or (at your option) any later version. This
|
|
module 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 Lesser General Public License for more
|
|
details. You should have received a copy of the GNU Lesser General Public
|
|
License along with this library; if not, write to the Free Software
|
|
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
|
|
|
|
#include BLARGG_SOURCE_BEGIN
|
|
|
|
// Nonlinear_Buffer
|
|
|
|
Nonlinear_Buffer::Nonlinear_Buffer() :
|
|
Multi_Buffer( 1 )
|
|
{
|
|
}
|
|
|
|
Nonlinear_Buffer::~Nonlinear_Buffer()
|
|
{
|
|
}
|
|
|
|
void Nonlinear_Buffer::enable_nonlinearity( Nes_Apu& apu, bool b )
|
|
{
|
|
if ( b )
|
|
clear();
|
|
nonlinearizer.enable( apu, b );
|
|
for ( int i = 0; i < apu.osc_count; i++ )
|
|
apu.osc_output( i, (i >= 2 ? &tnd : &buf) );
|
|
}
|
|
|
|
blargg_err_t Nonlinear_Buffer::sample_rate( long rate, int msec )
|
|
{
|
|
BLARGG_RETURN_ERR( buf.sample_rate( rate, msec ) );
|
|
BLARGG_RETURN_ERR( tnd.sample_rate( rate, msec ) );
|
|
return Multi_Buffer::sample_rate( buf.sample_rate(), buf.length() );
|
|
}
|
|
|
|
void Nonlinear_Buffer::clock_rate( long rate )
|
|
{
|
|
buf.clock_rate( rate );
|
|
tnd.clock_rate( rate );
|
|
}
|
|
|
|
void Nonlinear_Buffer::bass_freq( int freq )
|
|
{
|
|
buf.bass_freq( freq );
|
|
tnd.bass_freq( freq );
|
|
}
|
|
|
|
void Nonlinear_Buffer::clear()
|
|
{
|
|
nonlinearizer.clear();
|
|
buf.clear();
|
|
tnd.clear();
|
|
}
|
|
|
|
Nonlinear_Buffer::channel_t Nonlinear_Buffer::channel( int i )
|
|
{
|
|
channel_t c;
|
|
c.center = &buf;
|
|
if ( 2 <= i && i <= 4 )
|
|
c.center = &tnd; // only use for triangle, noise, and dmc
|
|
c.left = c.center;
|
|
c.right = c.center;
|
|
return c;
|
|
}
|
|
|
|
void Nonlinear_Buffer::end_frame( blip_time_t length, bool )
|
|
{
|
|
buf.end_frame( length );
|
|
tnd.end_frame( length );
|
|
}
|
|
|
|
long Nonlinear_Buffer::samples_avail() const
|
|
{
|
|
return buf.samples_avail();
|
|
}
|
|
|
|
#include BLARGG_ENABLE_OPTIMIZER
|
|
|
|
long Nonlinear_Buffer::read_samples( blip_sample_t* out, long count )
|
|
{
|
|
count = nonlinearizer.make_nonlinear( tnd, count );
|
|
if ( count )
|
|
{
|
|
Blip_Reader lin;
|
|
Blip_Reader nonlin;
|
|
|
|
int lin_bass = lin.begin( buf );
|
|
int nonlin_bass = nonlin.begin( tnd );
|
|
|
|
for ( int n = count; n--; )
|
|
{
|
|
int s = lin.read() + nonlin.read();
|
|
lin.next( lin_bass );
|
|
nonlin.next( nonlin_bass );
|
|
*out++ = s;
|
|
|
|
if ( (BOOST::int16_t) s != s )
|
|
out [-1] = 0x7FFF - (s >> 24);
|
|
}
|
|
|
|
lin.end( buf );
|
|
nonlin.end( tnd );
|
|
|
|
buf.remove_samples( count );
|
|
tnd.remove_samples( count );
|
|
}
|
|
|
|
return count;
|
|
}
|
|
|
|
// Nes_Nonlinearizer
|
|
|
|
Nes_Nonlinearizer::Nes_Nonlinearizer()
|
|
{
|
|
nonlinear = false;
|
|
|
|
double gain = 0x7fff * 1.3;
|
|
// don't use entire range, so any overflow will stay within table
|
|
int const range = half * Nes_Apu::nonlinear_tnd_gain();
|
|
for ( int i = 0; i < half * 2; i++ )
|
|
{
|
|
int out = i << shift;
|
|
if ( i > half )
|
|
{
|
|
int j = i - half;
|
|
if ( j >= range )
|
|
j = range - 1;
|
|
double n = 202.0 / (range - 1) * j;
|
|
double d = 163.67 / (24329.0 / n + 100);
|
|
out = int (d * gain) + 0x8000;
|
|
assert( out < 0x10000 );
|
|
}
|
|
table [i] = out;
|
|
}
|
|
clear();
|
|
}
|
|
|
|
void Nes_Nonlinearizer::enable( Nes_Apu& apu, bool b )
|
|
{
|
|
nonlinear = b;
|
|
if ( b )
|
|
apu.enable_nonlinear( 1.0 );
|
|
else
|
|
apu.volume( 1.0 );
|
|
}
|
|
|
|
long Nes_Nonlinearizer::make_nonlinear( Blip_Buffer& buf, long count )
|
|
{
|
|
long avail = buf.samples_avail();
|
|
if ( count > avail )
|
|
count = avail;
|
|
|
|
if ( count && nonlinear )
|
|
{
|
|
const int zero_offset = Blip_Buffer::sample_offset_;
|
|
|
|
#define ENTRY( s ) (table [((s) >> shift) & entry_mask])
|
|
|
|
BOOST::uint16_t* p = buf.buffer_;
|
|
unsigned prev = ENTRY( accum );
|
|
long accum = this->accum;
|
|
|
|
for ( unsigned n = count; n--; )
|
|
{
|
|
accum += (long) *p - zero_offset;
|
|
check( (accum >> shift) < half * 2 );
|
|
unsigned entry = ENTRY( accum );
|
|
*p++ = entry - prev + zero_offset;
|
|
prev = entry;
|
|
}
|
|
|
|
this->accum = accum;
|
|
}
|
|
|
|
return count;
|
|
}
|
|
|