mirror of
https://github.com/ZDoom/raze-gles.git
synced 2024-12-27 04:00:42 +00:00
718112a8fe
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.
330 lines
6.6 KiB
C++
330 lines
6.6 KiB
C++
// Sms_Snd_Emu 0.1.4. http://www.slack.net/~ant/
|
|
|
|
#include "Sms_Apu.h"
|
|
|
|
/* Copyright (C) 2003-2006 Shay Green. This module 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 module; if not, write to the Free Software Foundation,
|
|
Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */
|
|
|
|
#include "blargg_source.h"
|
|
|
|
// Sms_Osc
|
|
|
|
Sms_Osc::Sms_Osc()
|
|
{
|
|
output = 0;
|
|
outputs [0] = 0; // always stays NULL
|
|
outputs [1] = 0;
|
|
outputs [2] = 0;
|
|
outputs [3] = 0;
|
|
}
|
|
|
|
void Sms_Osc::reset()
|
|
{
|
|
delay = 0;
|
|
last_amp = 0;
|
|
volume = 0;
|
|
output_select = 3;
|
|
output = outputs [3];
|
|
}
|
|
|
|
// Sms_Square
|
|
|
|
inline void Sms_Square::reset()
|
|
{
|
|
period = 0;
|
|
phase = 0;
|
|
Sms_Osc::reset();
|
|
}
|
|
|
|
void Sms_Square::run( blip_time_t time, blip_time_t end_time )
|
|
{
|
|
if ( !volume || period <= 128 )
|
|
{
|
|
// ignore 16kHz and higher
|
|
if ( last_amp )
|
|
{
|
|
synth->offset( time, -last_amp, output );
|
|
last_amp = 0;
|
|
}
|
|
time += delay;
|
|
if ( !period )
|
|
{
|
|
time = end_time;
|
|
}
|
|
else if ( time < end_time )
|
|
{
|
|
// keep calculating phase
|
|
int count = (end_time - time + period - 1) / period;
|
|
phase = (phase + count) & 1;
|
|
time += count * period;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
int amp = phase ? volume : -volume;
|
|
{
|
|
int delta = amp - last_amp;
|
|
if ( delta )
|
|
{
|
|
last_amp = amp;
|
|
synth->offset( time, delta, output );
|
|
}
|
|
}
|
|
|
|
time += delay;
|
|
if ( time < end_time )
|
|
{
|
|
Blip_Buffer* const output = this->output;
|
|
int delta = amp * 2;
|
|
do
|
|
{
|
|
delta = -delta;
|
|
synth->offset_inline( time, delta, output );
|
|
time += period;
|
|
phase ^= 1;
|
|
}
|
|
while ( time < end_time );
|
|
this->last_amp = phase ? volume : -volume;
|
|
}
|
|
}
|
|
delay = time - end_time;
|
|
}
|
|
|
|
// Sms_Noise
|
|
|
|
static int const noise_periods [3] = { 0x100, 0x200, 0x400 };
|
|
|
|
inline void Sms_Noise::reset()
|
|
{
|
|
period = &noise_periods [0];
|
|
shifter = 0x8000;
|
|
feedback = 0x9000;
|
|
Sms_Osc::reset();
|
|
}
|
|
|
|
void Sms_Noise::run( blip_time_t time, blip_time_t end_time )
|
|
{
|
|
int amp = volume;
|
|
if ( shifter & 1 )
|
|
amp = -amp;
|
|
|
|
{
|
|
int delta = amp - last_amp;
|
|
if ( delta )
|
|
{
|
|
last_amp = amp;
|
|
synth.offset( time, delta, output );
|
|
}
|
|
}
|
|
|
|
time += delay;
|
|
if ( !volume )
|
|
time = end_time;
|
|
|
|
if ( time < end_time )
|
|
{
|
|
Blip_Buffer* const output = this->output;
|
|
unsigned shifter = this->shifter;
|
|
int delta = amp * 2;
|
|
int period = *this->period * 2;
|
|
if ( !period )
|
|
period = 16;
|
|
|
|
do
|
|
{
|
|
int changed = shifter + 1;
|
|
shifter = (feedback & -(shifter & 1)) ^ (shifter >> 1);
|
|
if ( changed & 2 ) // true if bits 0 and 1 differ
|
|
{
|
|
delta = -delta;
|
|
synth.offset_inline( time, delta, output );
|
|
}
|
|
time += period;
|
|
}
|
|
while ( time < end_time );
|
|
|
|
this->shifter = shifter;
|
|
this->last_amp = delta >> 1;
|
|
}
|
|
delay = time - end_time;
|
|
}
|
|
|
|
// Sms_Apu
|
|
|
|
Sms_Apu::Sms_Apu()
|
|
{
|
|
for ( int i = 0; i < 3; i++ )
|
|
{
|
|
squares [i].synth = &square_synth;
|
|
oscs [i] = &squares [i];
|
|
}
|
|
oscs [3] = &noise;
|
|
|
|
volume( 1.0 );
|
|
reset();
|
|
}
|
|
|
|
Sms_Apu::~Sms_Apu()
|
|
{
|
|
}
|
|
|
|
void Sms_Apu::volume( double vol )
|
|
{
|
|
vol *= 0.85 / (osc_count * 64 * 2);
|
|
square_synth.volume( vol );
|
|
noise.synth.volume( vol );
|
|
}
|
|
|
|
void Sms_Apu::treble_eq( const blip_eq_t& eq )
|
|
{
|
|
square_synth.treble_eq( eq );
|
|
noise.synth.treble_eq( eq );
|
|
}
|
|
|
|
void Sms_Apu::osc_output( int index, Blip_Buffer* center, Blip_Buffer* left, Blip_Buffer* right )
|
|
{
|
|
require( (unsigned) index < osc_count );
|
|
require( (center && left && right) || (!center && !left && !right) );
|
|
Sms_Osc& osc = *oscs [index];
|
|
osc.outputs [1] = right;
|
|
osc.outputs [2] = left;
|
|
osc.outputs [3] = center;
|
|
osc.output = osc.outputs [osc.output_select];
|
|
}
|
|
|
|
void Sms_Apu::output( Blip_Buffer* center, Blip_Buffer* left, Blip_Buffer* right )
|
|
{
|
|
for ( int i = 0; i < osc_count; i++ )
|
|
osc_output( i, center, left, right );
|
|
}
|
|
|
|
void Sms_Apu::reset( unsigned feedback, int noise_width )
|
|
{
|
|
last_time = 0;
|
|
latch = 0;
|
|
|
|
if ( !feedback || !noise_width )
|
|
{
|
|
feedback = 0x0009;
|
|
noise_width = 16;
|
|
}
|
|
// convert to "Galios configuration"
|
|
looped_feedback = 1 << (noise_width - 1);
|
|
noise_feedback = 0;
|
|
while ( noise_width-- )
|
|
{
|
|
noise_feedback = (noise_feedback << 1) | (feedback & 1);
|
|
feedback >>= 1;
|
|
}
|
|
|
|
squares [0].reset();
|
|
squares [1].reset();
|
|
squares [2].reset();
|
|
noise.reset();
|
|
}
|
|
|
|
void Sms_Apu::run_until( blip_time_t end_time )
|
|
{
|
|
require( end_time >= last_time ); // end_time must not be before previous time
|
|
|
|
if ( end_time > last_time )
|
|
{
|
|
// run oscillators
|
|
for ( int i = 0; i < osc_count; ++i )
|
|
{
|
|
Sms_Osc& osc = *oscs [i];
|
|
if ( osc.output )
|
|
{
|
|
osc.output->set_modified();
|
|
if ( i < 3 )
|
|
squares [i].run( last_time, end_time );
|
|
else
|
|
noise.run( last_time, end_time );
|
|
}
|
|
}
|
|
|
|
last_time = end_time;
|
|
}
|
|
}
|
|
|
|
void Sms_Apu::end_frame( blip_time_t end_time )
|
|
{
|
|
if ( end_time > last_time )
|
|
run_until( end_time );
|
|
|
|
assert( last_time >= end_time );
|
|
last_time -= end_time;
|
|
}
|
|
|
|
void Sms_Apu::write_ggstereo( blip_time_t time, int data )
|
|
{
|
|
require( (unsigned) data <= 0xFF );
|
|
|
|
run_until( time );
|
|
|
|
for ( int i = 0; i < osc_count; i++ )
|
|
{
|
|
Sms_Osc& osc = *oscs [i];
|
|
int flags = data >> i;
|
|
Blip_Buffer* old_output = osc.output;
|
|
osc.output_select = (flags >> 3 & 2) | (flags & 1);
|
|
osc.output = osc.outputs [osc.output_select];
|
|
if ( osc.output != old_output && osc.last_amp )
|
|
{
|
|
if ( old_output )
|
|
{
|
|
old_output->set_modified();
|
|
square_synth.offset( time, -osc.last_amp, old_output );
|
|
}
|
|
osc.last_amp = 0;
|
|
}
|
|
}
|
|
}
|
|
|
|
// volumes [i] = 64 * pow( 1.26, 15 - i ) / pow( 1.26, 15 )
|
|
static unsigned char const volumes [16] = {
|
|
64, 50, 39, 31, 24, 19, 15, 12, 9, 7, 5, 4, 3, 2, 1, 0
|
|
};
|
|
|
|
void Sms_Apu::write_data( blip_time_t time, int data )
|
|
{
|
|
require( (unsigned) data <= 0xFF );
|
|
|
|
run_until( time );
|
|
|
|
if ( data & 0x80 )
|
|
latch = data;
|
|
|
|
int index = (latch >> 5) & 3;
|
|
if ( latch & 0x10 )
|
|
{
|
|
oscs [index]->volume = volumes [data & 15];
|
|
}
|
|
else if ( index < 3 )
|
|
{
|
|
Sms_Square& sq = squares [index];
|
|
if ( data & 0x80 )
|
|
sq.period = (sq.period & 0xFF00) | (data << 4 & 0x00FF);
|
|
else
|
|
sq.period = (sq.period & 0x00FF) | (data << 8 & 0x3F00);
|
|
}
|
|
else
|
|
{
|
|
int select = data & 3;
|
|
if ( select < 3 )
|
|
noise.period = &noise_periods [select];
|
|
else
|
|
noise.period = &squares [2].period;
|
|
|
|
noise.feedback = (data & 0x04) ? noise_feedback : looped_feedback;
|
|
noise.shifter = 0x8000;
|
|
}
|
|
}
|