mirror of
https://github.com/DrBeef/Raze.git
synced 2024-12-15 23:21:21 +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.
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;
|
|
}
|