mirror of
https://github.com/ZDoom/qzdoom.git
synced 2024-11-29 23:41:48 +00:00
391 lines
8.7 KiB
C++
391 lines
8.7 KiB
C++
// Nes_Snd_Emu 0.1.8. http://www.slack.net/~ant/
|
|
|
|
#include "Nes_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"
|
|
|
|
int const amp_range = 15;
|
|
|
|
Nes_Apu::Nes_Apu() :
|
|
square1( &square_synth ),
|
|
square2( &square_synth )
|
|
{
|
|
tempo_ = 1.0;
|
|
dmc.apu = this;
|
|
dmc.prg_reader = NULL;
|
|
irq_notifier_ = NULL;
|
|
|
|
oscs [0] = &square1;
|
|
oscs [1] = &square2;
|
|
oscs [2] = ▵
|
|
oscs [3] = &noise;
|
|
oscs [4] = &dmc;
|
|
|
|
output( NULL );
|
|
volume( 1.0 );
|
|
reset( false );
|
|
}
|
|
|
|
void Nes_Apu::treble_eq( const blip_eq_t& eq )
|
|
{
|
|
square_synth.treble_eq( eq );
|
|
triangle.synth.treble_eq( eq );
|
|
noise.synth.treble_eq( eq );
|
|
dmc.synth.treble_eq( eq );
|
|
}
|
|
|
|
void Nes_Apu::enable_nonlinear( double v )
|
|
{
|
|
dmc.nonlinear = true;
|
|
square_synth.volume( 1.3 * 0.25751258 / 0.742467605 * 0.25 / amp_range * v );
|
|
|
|
const double tnd = 0.48 / 202 * nonlinear_tnd_gain();
|
|
triangle.synth.volume( 3.0 * tnd );
|
|
noise.synth.volume( 2.0 * tnd );
|
|
dmc.synth.volume( tnd );
|
|
|
|
square1 .last_amp = 0;
|
|
square2 .last_amp = 0;
|
|
triangle.last_amp = 0;
|
|
noise .last_amp = 0;
|
|
dmc .last_amp = 0;
|
|
}
|
|
|
|
void Nes_Apu::volume( double v )
|
|
{
|
|
dmc.nonlinear = false;
|
|
square_synth.volume( 0.1128 / amp_range * v );
|
|
triangle.synth.volume( 0.12765 / amp_range * v );
|
|
noise.synth.volume( 0.0741 / amp_range * v );
|
|
dmc.synth.volume( 0.42545 / 127 * v );
|
|
}
|
|
|
|
void Nes_Apu::output( Blip_Buffer* buffer )
|
|
{
|
|
for ( int i = 0; i < osc_count; i++ )
|
|
osc_output( i, buffer );
|
|
}
|
|
|
|
void Nes_Apu::set_tempo( double t )
|
|
{
|
|
tempo_ = t;
|
|
frame_period = (dmc.pal_mode ? 8314 : 7458);
|
|
if ( t != 1.0 )
|
|
frame_period = (int) (frame_period / t) & ~1; // must be even
|
|
}
|
|
|
|
void Nes_Apu::reset( bool pal_mode, int initial_dmc_dac )
|
|
{
|
|
dmc.pal_mode = pal_mode;
|
|
set_tempo( tempo_ );
|
|
|
|
square1.reset();
|
|
square2.reset();
|
|
triangle.reset();
|
|
noise.reset();
|
|
dmc.reset();
|
|
|
|
last_time = 0;
|
|
last_dmc_time = 0;
|
|
osc_enables = 0;
|
|
irq_flag = false;
|
|
earliest_irq_ = no_irq;
|
|
frame_delay = 1;
|
|
write_register( 0, 0x4017, 0x00 );
|
|
write_register( 0, 0x4015, 0x00 );
|
|
|
|
for ( nes_addr_t addr = start_addr; addr <= 0x4013; addr++ )
|
|
write_register( 0, addr, (addr & 3) ? 0x00 : 0x10 );
|
|
|
|
dmc.dac = initial_dmc_dac;
|
|
if ( !dmc.nonlinear )
|
|
triangle.last_amp = 15;
|
|
if ( !dmc.nonlinear ) // TODO: remove?
|
|
dmc.last_amp = initial_dmc_dac; // prevent output transition
|
|
}
|
|
|
|
void Nes_Apu::irq_changed()
|
|
{
|
|
nes_time_t new_irq = dmc.next_irq;
|
|
if ( dmc.irq_flag | irq_flag ) {
|
|
new_irq = 0;
|
|
}
|
|
else if ( new_irq > next_irq ) {
|
|
new_irq = next_irq;
|
|
}
|
|
|
|
if ( new_irq != earliest_irq_ ) {
|
|
earliest_irq_ = new_irq;
|
|
if ( irq_notifier_ )
|
|
irq_notifier_( irq_data );
|
|
}
|
|
}
|
|
|
|
// frames
|
|
|
|
void Nes_Apu::run_until( nes_time_t end_time )
|
|
{
|
|
require( end_time >= last_dmc_time );
|
|
if ( end_time > next_dmc_read_time() )
|
|
{
|
|
nes_time_t start = last_dmc_time;
|
|
last_dmc_time = end_time;
|
|
dmc.run( start, end_time );
|
|
}
|
|
}
|
|
|
|
void Nes_Apu::run_until_( nes_time_t end_time )
|
|
{
|
|
require( end_time >= last_time );
|
|
|
|
if ( end_time == last_time )
|
|
return;
|
|
|
|
if ( last_dmc_time < end_time )
|
|
{
|
|
nes_time_t start = last_dmc_time;
|
|
last_dmc_time = end_time;
|
|
dmc.run( start, end_time );
|
|
}
|
|
|
|
while ( true )
|
|
{
|
|
// earlier of next frame time or end time
|
|
nes_time_t time = last_time + frame_delay;
|
|
if ( time > end_time )
|
|
time = end_time;
|
|
frame_delay -= time - last_time;
|
|
|
|
// run oscs to present
|
|
square1.run( last_time, time );
|
|
square2.run( last_time, time );
|
|
triangle.run( last_time, time );
|
|
noise.run( last_time, time );
|
|
last_time = time;
|
|
|
|
if ( time == end_time )
|
|
break; // no more frames to run
|
|
|
|
// take frame-specific actions
|
|
frame_delay = frame_period;
|
|
switch ( frame++ )
|
|
{
|
|
case 0:
|
|
if ( !(frame_mode & 0xC0) ) {
|
|
next_irq = time + frame_period * 4 + 2;
|
|
irq_flag = true;
|
|
}
|
|
// fall through
|
|
case 2:
|
|
// clock length and sweep on frames 0 and 2
|
|
square1.clock_length( 0x20 );
|
|
square2.clock_length( 0x20 );
|
|
noise.clock_length( 0x20 );
|
|
triangle.clock_length( 0x80 ); // different bit for halt flag on triangle
|
|
|
|
square1.clock_sweep( -1 );
|
|
square2.clock_sweep( 0 );
|
|
|
|
// frame 2 is slightly shorter in mode 1
|
|
if ( dmc.pal_mode && frame == 3 )
|
|
frame_delay -= 2;
|
|
break;
|
|
|
|
case 1:
|
|
// frame 1 is slightly shorter in mode 0
|
|
if ( !dmc.pal_mode )
|
|
frame_delay -= 2;
|
|
break;
|
|
|
|
case 3:
|
|
frame = 0;
|
|
|
|
// frame 3 is almost twice as long in mode 1
|
|
if ( frame_mode & 0x80 )
|
|
frame_delay += frame_period - (dmc.pal_mode ? 2 : 6);
|
|
break;
|
|
}
|
|
|
|
// clock envelopes and linear counter every frame
|
|
triangle.clock_linear_counter();
|
|
square1.clock_envelope();
|
|
square2.clock_envelope();
|
|
noise.clock_envelope();
|
|
}
|
|
}
|
|
|
|
template<class T>
|
|
inline void zero_apu_osc( T* osc, nes_time_t time )
|
|
{
|
|
Blip_Buffer* output = osc->output;
|
|
int last_amp = osc->last_amp;
|
|
osc->last_amp = 0;
|
|
if ( output && last_amp )
|
|
osc->synth.offset( time, -last_amp, output );
|
|
}
|
|
|
|
void Nes_Apu::end_frame( nes_time_t end_time )
|
|
{
|
|
if ( end_time > last_time )
|
|
run_until_( end_time );
|
|
|
|
if ( dmc.nonlinear )
|
|
{
|
|
zero_apu_osc( &square1, last_time );
|
|
zero_apu_osc( &square2, last_time );
|
|
zero_apu_osc( &triangle, last_time );
|
|
zero_apu_osc( &noise, last_time );
|
|
zero_apu_osc( &dmc, last_time );
|
|
}
|
|
|
|
// make times relative to new frame
|
|
last_time -= end_time;
|
|
require( last_time >= 0 );
|
|
|
|
last_dmc_time -= end_time;
|
|
require( last_dmc_time >= 0 );
|
|
|
|
if ( next_irq != no_irq ) {
|
|
next_irq -= end_time;
|
|
check( next_irq >= 0 );
|
|
}
|
|
if ( dmc.next_irq != no_irq ) {
|
|
dmc.next_irq -= end_time;
|
|
check( dmc.next_irq >= 0 );
|
|
}
|
|
if ( earliest_irq_ != no_irq ) {
|
|
earliest_irq_ -= end_time;
|
|
if ( earliest_irq_ < 0 )
|
|
earliest_irq_ = 0;
|
|
}
|
|
}
|
|
|
|
// registers
|
|
|
|
static const unsigned char length_table [0x20] = {
|
|
0x0A, 0xFE, 0x14, 0x02, 0x28, 0x04, 0x50, 0x06,
|
|
0xA0, 0x08, 0x3C, 0x0A, 0x0E, 0x0C, 0x1A, 0x0E,
|
|
0x0C, 0x10, 0x18, 0x12, 0x30, 0x14, 0x60, 0x16,
|
|
0xC0, 0x18, 0x48, 0x1A, 0x10, 0x1C, 0x20, 0x1E
|
|
};
|
|
|
|
void Nes_Apu::write_register( nes_time_t time, nes_addr_t addr, int data )
|
|
{
|
|
require( addr > 0x20 ); // addr must be actual address (i.e. 0x40xx)
|
|
require( (unsigned) data <= 0xFF );
|
|
|
|
// Ignore addresses outside range
|
|
if ( unsigned (addr - start_addr) > end_addr - start_addr )
|
|
return;
|
|
|
|
run_until_( time );
|
|
|
|
if ( addr < 0x4014 )
|
|
{
|
|
// Write to channel
|
|
int osc_index = (addr - start_addr) >> 2;
|
|
Nes_Osc* osc = oscs [osc_index];
|
|
|
|
int reg = addr & 3;
|
|
osc->regs [reg] = data;
|
|
osc->reg_written [reg] = true;
|
|
|
|
if ( osc_index == 4 )
|
|
{
|
|
// handle DMC specially
|
|
dmc.write_register( reg, data );
|
|
}
|
|
else if ( reg == 3 )
|
|
{
|
|
// load length counter
|
|
if ( (osc_enables >> osc_index) & 1 )
|
|
osc->length_counter = length_table [(data >> 3) & 0x1F];
|
|
|
|
// reset square phase
|
|
if ( osc_index < 2 )
|
|
((Nes_Square*) osc)->phase = Nes_Square::phase_range - 1;
|
|
}
|
|
}
|
|
else if ( addr == 0x4015 )
|
|
{
|
|
// Channel enables
|
|
for ( int i = osc_count; i--; )
|
|
if ( !((data >> i) & 1) )
|
|
oscs [i]->length_counter = 0;
|
|
|
|
bool recalc_irq = dmc.irq_flag;
|
|
dmc.irq_flag = false;
|
|
|
|
int old_enables = osc_enables;
|
|
osc_enables = data;
|
|
if ( !(data & 0x10) ) {
|
|
dmc.next_irq = no_irq;
|
|
recalc_irq = true;
|
|
}
|
|
else if ( !(old_enables & 0x10) ) {
|
|
dmc.start(); // dmc just enabled
|
|
}
|
|
|
|
if ( recalc_irq )
|
|
irq_changed();
|
|
}
|
|
else if ( addr == 0x4017 )
|
|
{
|
|
// Frame mode
|
|
frame_mode = data;
|
|
|
|
bool irq_enabled = !(data & 0x40);
|
|
irq_flag &= irq_enabled;
|
|
next_irq = no_irq;
|
|
|
|
// mode 1
|
|
frame_delay = (frame_delay & 1);
|
|
frame = 0;
|
|
|
|
if ( !(data & 0x80) )
|
|
{
|
|
// mode 0
|
|
frame = 1;
|
|
frame_delay += frame_period;
|
|
if ( irq_enabled )
|
|
next_irq = time + frame_delay + frame_period * 3 + 1;
|
|
}
|
|
|
|
irq_changed();
|
|
}
|
|
}
|
|
|
|
int Nes_Apu::read_status( nes_time_t time )
|
|
{
|
|
run_until_( time - 1 );
|
|
|
|
int result = (dmc.irq_flag << 7) | (irq_flag << 6);
|
|
|
|
for ( int i = 0; i < osc_count; i++ )
|
|
if ( oscs [i]->length_counter )
|
|
result |= 1 << i;
|
|
|
|
run_until_( time );
|
|
|
|
if ( irq_flag )
|
|
{
|
|
result |= 0x40;
|
|
irq_flag = false;
|
|
irq_changed();
|
|
}
|
|
|
|
//debug_printf( "%6d/%d Read $4015->$%02X\n", frame_delay, frame, result );
|
|
|
|
return result;
|
|
}
|