mirror of
https://github.com/ZDoom/raze-gles.git
synced 2024-12-26 19:50:45 +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.
336 lines
6.7 KiB
C++
336 lines
6.7 KiB
C++
// Gb_Snd_Emu 0.1.5. http://www.slack.net/~ant/
|
|
|
|
#include "Gb_Apu.h"
|
|
|
|
#include <string.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"
|
|
|
|
// Gb_Osc
|
|
|
|
void Gb_Osc::reset()
|
|
{
|
|
delay = 0;
|
|
last_amp = 0;
|
|
length = 0;
|
|
output_select = 3;
|
|
output = outputs [output_select];
|
|
}
|
|
|
|
void Gb_Osc::clock_length()
|
|
{
|
|
if ( (regs [4] & len_enabled_mask) && length )
|
|
length--;
|
|
}
|
|
|
|
// Gb_Env
|
|
|
|
void Gb_Env::clock_envelope()
|
|
{
|
|
if ( env_delay && !--env_delay )
|
|
{
|
|
env_delay = regs [2] & 7;
|
|
int v = volume - 1 + (regs [2] >> 2 & 2);
|
|
if ( (unsigned) v < 15 )
|
|
volume = v;
|
|
}
|
|
}
|
|
|
|
bool Gb_Env::write_register( int reg, int data )
|
|
{
|
|
switch ( reg )
|
|
{
|
|
case 1:
|
|
length = 64 - (regs [1] & 0x3F);
|
|
break;
|
|
|
|
case 2:
|
|
if ( !(data >> 4) )
|
|
enabled = false;
|
|
break;
|
|
|
|
case 4:
|
|
if ( data & trigger )
|
|
{
|
|
env_delay = regs [2] & 7;
|
|
volume = regs [2] >> 4;
|
|
enabled = true;
|
|
if ( length == 0 )
|
|
length = 64;
|
|
return true;
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
// Gb_Square
|
|
|
|
void Gb_Square::reset()
|
|
{
|
|
phase = 0;
|
|
sweep_freq = 0;
|
|
sweep_delay = 0;
|
|
Gb_Env::reset();
|
|
}
|
|
|
|
void Gb_Square::clock_sweep()
|
|
{
|
|
int sweep_period = (regs [0] & period_mask) >> 4;
|
|
if ( sweep_period && sweep_delay && !--sweep_delay )
|
|
{
|
|
sweep_delay = sweep_period;
|
|
regs [3] = sweep_freq & 0xFF;
|
|
regs [4] = (regs [4] & ~0x07) | (sweep_freq >> 8 & 0x07);
|
|
|
|
int offset = sweep_freq >> (regs [0] & shift_mask);
|
|
if ( regs [0] & 0x08 )
|
|
offset = -offset;
|
|
sweep_freq += offset;
|
|
|
|
if ( sweep_freq < 0 )
|
|
{
|
|
sweep_freq = 0;
|
|
}
|
|
else if ( sweep_freq >= 2048 )
|
|
{
|
|
sweep_delay = 0; // don't modify channel frequency any further
|
|
sweep_freq = 2048; // silence sound immediately
|
|
}
|
|
}
|
|
}
|
|
|
|
void Gb_Square::run( blip_time_t time, blip_time_t end_time, int playing )
|
|
{
|
|
if ( sweep_freq == 2048 )
|
|
playing = false;
|
|
|
|
static unsigned char const table [4] = { 1, 2, 4, 6 };
|
|
int const duty = table [regs [1] >> 6];
|
|
int amp = volume & playing;
|
|
if ( phase >= duty )
|
|
amp = -amp;
|
|
|
|
int frequency = this->frequency();
|
|
if ( unsigned (frequency - 1) > 2040 ) // frequency < 1 || frequency > 2041
|
|
{
|
|
// really high frequency results in DC at half volume
|
|
amp = volume >> 1;
|
|
playing = false;
|
|
}
|
|
|
|
{
|
|
int delta = amp - last_amp;
|
|
if ( delta )
|
|
{
|
|
last_amp = amp;
|
|
synth->offset( time, delta, output );
|
|
}
|
|
}
|
|
|
|
time += delay;
|
|
if ( !playing )
|
|
time = end_time;
|
|
|
|
if ( time < end_time )
|
|
{
|
|
int const period = (2048 - frequency) * 4;
|
|
Blip_Buffer* const output = this->output;
|
|
int phase = this->phase;
|
|
int delta = amp * 2;
|
|
do
|
|
{
|
|
phase = (phase + 1) & 7;
|
|
if ( phase == 0 || phase == duty )
|
|
{
|
|
delta = -delta;
|
|
synth->offset_inline( time, delta, output );
|
|
}
|
|
time += period;
|
|
}
|
|
while ( time < end_time );
|
|
|
|
this->phase = phase;
|
|
last_amp = delta >> 1;
|
|
}
|
|
delay = time - end_time;
|
|
}
|
|
|
|
// Gb_Noise
|
|
|
|
void Gb_Noise::run( blip_time_t time, blip_time_t end_time, int playing )
|
|
{
|
|
int amp = volume & playing;
|
|
int tap = 13 - (regs [3] & 8);
|
|
if ( bits >> tap & 2 )
|
|
amp = -amp;
|
|
|
|
{
|
|
int delta = amp - last_amp;
|
|
if ( delta )
|
|
{
|
|
last_amp = amp;
|
|
synth->offset( time, delta, output );
|
|
}
|
|
}
|
|
|
|
time += delay;
|
|
if ( !playing )
|
|
time = end_time;
|
|
|
|
if ( time < end_time )
|
|
{
|
|
static unsigned char const table [8] = { 8, 16, 32, 48, 64, 80, 96, 112 };
|
|
int period = table [regs [3] & 7] << (regs [3] >> 4);
|
|
|
|
// keep parallel resampled time to eliminate time conversion in the loop
|
|
Blip_Buffer* const output = this->output;
|
|
const blip_resampled_time_t resampled_period =
|
|
output->resampled_duration( period );
|
|
blip_resampled_time_t resampled_time = output->resampled_time( time );
|
|
unsigned bits = this->bits;
|
|
int delta = amp * 2;
|
|
|
|
do
|
|
{
|
|
unsigned changed = (bits >> tap) + 1;
|
|
time += period;
|
|
bits <<= 1;
|
|
if ( changed & 2 )
|
|
{
|
|
delta = -delta;
|
|
bits |= 1;
|
|
synth->offset_resampled( resampled_time, delta, output );
|
|
}
|
|
resampled_time += resampled_period;
|
|
}
|
|
while ( time < end_time );
|
|
|
|
this->bits = bits;
|
|
last_amp = delta >> 1;
|
|
}
|
|
delay = time - end_time;
|
|
}
|
|
|
|
// Gb_Wave
|
|
|
|
inline void Gb_Wave::write_register( int reg, int data )
|
|
{
|
|
switch ( reg )
|
|
{
|
|
case 0:
|
|
if ( !(data & 0x80) )
|
|
enabled = false;
|
|
break;
|
|
|
|
case 1:
|
|
length = 256 - regs [1];
|
|
break;
|
|
|
|
case 2:
|
|
volume = data >> 5 & 3;
|
|
break;
|
|
|
|
case 4:
|
|
if ( data & trigger & regs [0] )
|
|
{
|
|
wave_pos = 0;
|
|
enabled = true;
|
|
if ( length == 0 )
|
|
length = 256;
|
|
}
|
|
}
|
|
}
|
|
|
|
void Gb_Wave::run( blip_time_t time, blip_time_t end_time, int playing )
|
|
{
|
|
int volume_shift = (volume - 1) & 7; // volume = 0 causes shift = 7
|
|
int frequency;
|
|
{
|
|
int amp = (wave [wave_pos] >> volume_shift & playing) * 2;
|
|
|
|
frequency = this->frequency();
|
|
if ( unsigned (frequency - 1) > 2044 ) // frequency < 1 || frequency > 2045
|
|
{
|
|
amp = 30 >> volume_shift & playing;
|
|
playing = false;
|
|
}
|
|
|
|
int delta = amp - last_amp;
|
|
if ( delta )
|
|
{
|
|
last_amp = amp;
|
|
synth->offset( time, delta, output );
|
|
}
|
|
}
|
|
|
|
time += delay;
|
|
if ( !playing )
|
|
time = end_time;
|
|
|
|
if ( time < end_time )
|
|
{
|
|
Blip_Buffer* const output = this->output;
|
|
int const period = (2048 - frequency) * 2;
|
|
int wave_pos = (this->wave_pos + 1) & (wave_size - 1);
|
|
|
|
do
|
|
{
|
|
int amp = (wave [wave_pos] >> volume_shift) * 2;
|
|
wave_pos = (wave_pos + 1) & (wave_size - 1);
|
|
int delta = amp - last_amp;
|
|
if ( delta )
|
|
{
|
|
last_amp = amp;
|
|
synth->offset_inline( time, delta, output );
|
|
}
|
|
time += period;
|
|
}
|
|
while ( time < end_time );
|
|
|
|
this->wave_pos = (wave_pos - 1) & (wave_size - 1);
|
|
}
|
|
delay = time - end_time;
|
|
}
|
|
|
|
// Gb_Apu::write_osc
|
|
|
|
void Gb_Apu::write_osc( int index, int reg, int data )
|
|
{
|
|
reg -= index * 5;
|
|
Gb_Square* sq = &square2;
|
|
switch ( index )
|
|
{
|
|
case 0:
|
|
sq = &square1;
|
|
case 1:
|
|
if ( sq->write_register( reg, data ) && index == 0 )
|
|
{
|
|
square1.sweep_freq = square1.frequency();
|
|
if ( (regs [0] & sq->period_mask) && (regs [0] & sq->shift_mask) )
|
|
{
|
|
square1.sweep_delay = 1; // cause sweep to recalculate now
|
|
square1.clock_sweep();
|
|
}
|
|
}
|
|
break;
|
|
|
|
case 2:
|
|
wave.write_register( reg, data );
|
|
break;
|
|
|
|
case 3:
|
|
if ( noise.write_register( reg, data ) )
|
|
noise.bits = 0x7FFF;
|
|
}
|
|
}
|