c97c5e5d17
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@30490 a1c6a512-1295-4272-9138-f99709370657
397 lines
11 KiB
C
397 lines
11 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;
|
|
|
|
void Apu_init( struct Nes_Apu* this )
|
|
{
|
|
this->tempo_ = (int)(FP_ONE_TEMPO);
|
|
this->dmc.apu = this;
|
|
this->dmc.prg_reader = NULL;
|
|
this->irq_notifier_ = NULL;
|
|
|
|
Synth_init( &this->square_synth );
|
|
Synth_init( &this->triangle.synth );
|
|
Synth_init( &this->noise.synth );
|
|
Synth_init( &this->dmc.synth );
|
|
|
|
Square_set_synth( &this->square1, &this->square_synth );
|
|
Square_set_synth( &this->square2, &this->square_synth );
|
|
|
|
this->oscs [0] = &this->square1.osc;
|
|
this->oscs [1] = &this->square2.osc;
|
|
this->oscs [2] = &this->triangle.osc;
|
|
this->oscs [3] = &this->noise.osc;
|
|
this->oscs [4] = &this->dmc.osc;
|
|
|
|
Apu_output( this, NULL );
|
|
this->dmc.nonlinear = false;
|
|
Apu_volume( this, (int)FP_ONE_VOLUME );
|
|
Apu_reset( this, false, 0 );
|
|
}
|
|
|
|
#if 0
|
|
// sq and tnd must use a fixed point frac where 1.0 = FP_ONE_VOLUME
|
|
void Apu_enable_nonlinear_( struct Nes_Apu* this, int sq, int tnd )
|
|
{
|
|
this->dmc.nonlinear = true;
|
|
Synth_volume( &this->square_synth, sq );
|
|
|
|
Synth_volume( &this->triangle.synth, (int)((long long)(FP_ONE_VOLUME * 2.752) * tnd / FP_ONE_VOLUME) );
|
|
Synth_volume( &this->noise.synth , (int)((long long)(FP_ONE_VOLUME * 1.849) * tnd / FP_ONE_VOLUME) );
|
|
Synth_volume( &this->dmc.synth , tnd );
|
|
|
|
this->square1 .osc.last_amp = 0;
|
|
this->square2 .osc.last_amp = 0;
|
|
this->triangle.osc.last_amp = 0;
|
|
this->noise .osc.last_amp = 0;
|
|
this->dmc .osc.last_amp = 0;
|
|
}
|
|
#endif
|
|
|
|
void Apu_volume( struct Nes_Apu* this, int v )
|
|
{
|
|
if ( !this->dmc.nonlinear )
|
|
{
|
|
Synth_volume( &this->square_synth, (int)((long long)((0.125 / 1.11) * FP_ONE_VOLUME) * v / amp_range / FP_ONE_VOLUME) ); // was 0.1128 1.108
|
|
Synth_volume( &this->triangle.synth,(int)((long long)((0.150 / 1.11) * FP_ONE_VOLUME) * v / amp_range / FP_ONE_VOLUME) ); // was 0.12765 1.175
|
|
Synth_volume( &this->noise.synth, (int)((long long)((0.095 / 1.11) * FP_ONE_VOLUME) * v / amp_range / FP_ONE_VOLUME) ); // was 0.0741 1.282
|
|
Synth_volume( &this->dmc.synth, (int)((long long)((0.450 / 1.11) * FP_ONE_VOLUME) * v / 2048 / FP_ONE_VOLUME) ); // was 0.42545 1.058
|
|
}
|
|
}
|
|
|
|
void Apu_output( struct Nes_Apu* this, struct Blip_Buffer* buffer )
|
|
{
|
|
int i;
|
|
for ( i = 0; i < apu_osc_count; i++ )
|
|
Apu_osc_output( this, i, buffer );
|
|
}
|
|
|
|
void Apu_set_tempo( struct Nes_Apu* this, int t )
|
|
{
|
|
this->tempo_ = t;
|
|
this->frame_period = (this->dmc.pal_mode ? 8314 : 7458);
|
|
if ( t != (int)FP_ONE_TEMPO )
|
|
this->frame_period = (int) ((this->frame_period * FP_ONE_TEMPO) / t) & ~1; // must be even
|
|
}
|
|
|
|
void Apu_reset( struct Nes_Apu* this, bool pal_mode, int initial_dmc_dac )
|
|
{
|
|
this->dmc.pal_mode = pal_mode;
|
|
Apu_set_tempo( this, this->tempo_ );
|
|
|
|
Square_reset( &this->square1 );
|
|
Square_reset( &this->square2 );
|
|
Triangle_reset( &this->triangle );
|
|
Noise_reset( &this->noise );
|
|
Dmc_reset( &this->dmc );
|
|
|
|
this->last_time = 0;
|
|
this->last_dmc_time = 0;
|
|
this->osc_enables = 0;
|
|
this->irq_flag = false;
|
|
this->earliest_irq_ = apu_no_irq;
|
|
this->frame_delay = 1;
|
|
Apu_write_register( this, 0, 0x4017, 0x00 );
|
|
Apu_write_register( this, 0, 0x4015, 0x00 );
|
|
|
|
addr_t addr;
|
|
for ( addr = apu_io_addr; addr <= 0x4013; addr++ )
|
|
Apu_write_register( this, 0, addr, (addr & 3) ? 0x00 : 0x10 );
|
|
|
|
this->dmc.dac = initial_dmc_dac;
|
|
if ( !this->dmc.nonlinear )
|
|
this->triangle.osc.last_amp = 15;
|
|
if ( !this->dmc.nonlinear ) // TODO: remove?
|
|
this->dmc.osc.last_amp = initial_dmc_dac; // prevent output transition
|
|
}
|
|
|
|
void Apu_irq_changed( struct Nes_Apu* this )
|
|
{
|
|
nes_time_t new_irq = this->dmc.next_irq;
|
|
if ( this->dmc.irq_flag | this->irq_flag ) {
|
|
new_irq = 0;
|
|
}
|
|
else if ( new_irq > this->next_irq ) {
|
|
new_irq = this->next_irq;
|
|
}
|
|
|
|
if ( new_irq != this->earliest_irq_ ) {
|
|
this->earliest_irq_ = new_irq;
|
|
if ( this->irq_notifier_ )
|
|
this->irq_notifier_( this->irq_data );
|
|
}
|
|
}
|
|
|
|
// frames
|
|
|
|
void Apu_run_until( struct Nes_Apu* this, nes_time_t end_time )
|
|
{
|
|
require( end_time >= this->last_dmc_time );
|
|
if ( end_time > Apu_next_dmc_read_time( this ) )
|
|
{
|
|
nes_time_t start = this->last_dmc_time;
|
|
this->last_dmc_time = end_time;
|
|
Dmc_run( &this->dmc, start, end_time );
|
|
}
|
|
}
|
|
|
|
static void run_until_( struct Nes_Apu* this, nes_time_t end_time )
|
|
{
|
|
require( end_time >= this->last_time );
|
|
|
|
if ( end_time == this->last_time )
|
|
return;
|
|
|
|
if ( this->last_dmc_time < end_time )
|
|
{
|
|
nes_time_t start = this->last_dmc_time;
|
|
this->last_dmc_time = end_time;
|
|
Dmc_run( &this->dmc, start, end_time );
|
|
}
|
|
|
|
while ( true )
|
|
{
|
|
// earlier of next frame time or end time
|
|
nes_time_t time = this->last_time + this->frame_delay;
|
|
if ( time > end_time )
|
|
time = end_time;
|
|
this->frame_delay -= time - this->last_time;
|
|
|
|
// run oscs to present
|
|
Square_run( &this->square1, this->last_time, time );
|
|
Square_run( &this->square2, this->last_time, time );
|
|
Triangle_run( &this->triangle, this->last_time, time );
|
|
Noise_run( &this->noise, this->last_time, time );
|
|
this->last_time = time;
|
|
|
|
if ( time == end_time )
|
|
break; // no more frames to run
|
|
|
|
// take frame-specific actions
|
|
this->frame_delay = this->frame_period;
|
|
switch ( this->frame++ )
|
|
{
|
|
case 0:
|
|
if ( !(this->frame_mode & 0xC0) ) {
|
|
this->next_irq = time + this->frame_period * 4 + 2;
|
|
this->irq_flag = true;
|
|
}
|
|
// fall through
|
|
case 2:
|
|
// clock length and sweep on frames 0 and 2
|
|
Osc_clock_length( &this->square1.osc, 0x20 );
|
|
Osc_clock_length( &this->square2.osc, 0x20 );
|
|
Osc_clock_length( &this->noise.osc, 0x20 );
|
|
Osc_clock_length( &this->triangle.osc, 0x80 ); // different bit for halt flag on triangle
|
|
|
|
Square_clock_sweep( &this->square1, -1 );
|
|
Square_clock_sweep( &this->square2, 0 );
|
|
|
|
// frame 2 is slightly shorter in mode 1
|
|
if ( this->dmc.pal_mode && this->frame == 3 )
|
|
this->frame_delay -= 2;
|
|
break;
|
|
|
|
case 1:
|
|
// frame 1 is slightly shorter in mode 0
|
|
if ( !this->dmc.pal_mode )
|
|
this->frame_delay -= 2;
|
|
break;
|
|
|
|
case 3:
|
|
this->frame = 0;
|
|
|
|
// frame 3 is almost twice as long in mode 1
|
|
if ( this->frame_mode & 0x80 )
|
|
this->frame_delay += this->frame_period - (this->dmc.pal_mode ? 2 : 6);
|
|
break;
|
|
}
|
|
|
|
// clock envelopes and linear counter every frame
|
|
Triangle_clock_linear_counter( &this->triangle );
|
|
Square_clock_envelope( &this->square1 );
|
|
Square_clock_envelope( &this->square2 );
|
|
Noise_clock_envelope( &this->noise );
|
|
}
|
|
}
|
|
|
|
static inline void zero_apu_osc( struct Nes_Osc* osc, struct Blip_Synth* synth, nes_time_t time )
|
|
{
|
|
struct Blip_Buffer* output = osc->output;
|
|
int last_amp = osc->last_amp;
|
|
osc->last_amp = 0;
|
|
if ( output && last_amp )
|
|
Synth_offset( synth, time, -osc->last_amp, output );
|
|
}
|
|
|
|
void Apu_end_frame( struct Nes_Apu* this, nes_time_t end_time )
|
|
{
|
|
if ( end_time > this->last_time )
|
|
run_until_( this, end_time );
|
|
|
|
if ( this->dmc.nonlinear )
|
|
{
|
|
zero_apu_osc( &this->square1.osc, this->square1.synth, this->last_time );
|
|
zero_apu_osc( &this->square2.osc, this->square2.synth, this->last_time );
|
|
zero_apu_osc( &this->triangle.osc, &this->triangle.synth, this->last_time );
|
|
zero_apu_osc( &this->noise.osc, &this->noise.synth, this->last_time );
|
|
zero_apu_osc( &this->dmc.osc, &this->dmc.synth, this->last_time );
|
|
}
|
|
|
|
// make times relative to new frame
|
|
this->last_time -= end_time;
|
|
require( this->last_time >= 0 );
|
|
|
|
this->last_dmc_time -= end_time;
|
|
require( this->last_dmc_time >= 0 );
|
|
|
|
if ( this->next_irq != apu_no_irq ) {
|
|
this->next_irq -= end_time;
|
|
check( this->next_irq >= 0 );
|
|
}
|
|
if ( this->dmc.next_irq != apu_no_irq ) {
|
|
this->dmc.next_irq -= end_time;
|
|
check( this->dmc.next_irq >= 0 );
|
|
}
|
|
if ( this->earliest_irq_ != apu_no_irq ) {
|
|
this->earliest_irq_ -= end_time;
|
|
if ( this->earliest_irq_ < 0 )
|
|
this->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 Apu_write_register( struct Nes_Apu* this, nes_time_t time, 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 - apu_io_addr) >= apu_io_size )
|
|
return;
|
|
|
|
run_until_( this, time );
|
|
|
|
if ( addr < 0x4014 )
|
|
{
|
|
// Write to channel
|
|
int osc_index = (addr - apu_io_addr) >> 2;
|
|
struct Nes_Osc* osc = this->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( &this->dmc, reg, data );
|
|
}
|
|
else if ( reg == 3 )
|
|
{
|
|
// load length counter
|
|
if ( (this->osc_enables >> osc_index) & 1 )
|
|
osc->length_counter = length_table [(data >> 3) & 0x1F];
|
|
|
|
// reset square phase
|
|
if ( osc_index == 0 ) this->square1.phase = square_phase_range - 1;
|
|
else if ( osc_index == 1 ) this->square2.phase = square_phase_range - 1;
|
|
}
|
|
}
|
|
else if ( addr == 0x4015 )
|
|
{
|
|
// Channel enables
|
|
int i;
|
|
for ( i = apu_osc_count; i--; )
|
|
if ( !((data >> i) & 1) )
|
|
this->oscs [i]->length_counter = 0;
|
|
|
|
bool recalc_irq = this->dmc.irq_flag;
|
|
this->dmc.irq_flag = false;
|
|
|
|
int old_enables = this->osc_enables;
|
|
this->osc_enables = data;
|
|
if ( !(data & 0x10) ) {
|
|
this->dmc.next_irq = apu_no_irq;
|
|
recalc_irq = true;
|
|
}
|
|
else if ( !(old_enables & 0x10) ) {
|
|
Dmc_start( &this->dmc ); // dmc just enabled
|
|
}
|
|
|
|
if ( recalc_irq )
|
|
Apu_irq_changed( this );
|
|
}
|
|
else if ( addr == 0x4017 )
|
|
{
|
|
// Frame mode
|
|
this->frame_mode = data;
|
|
|
|
bool irq_enabled = !(data & 0x40);
|
|
this->irq_flag &= irq_enabled;
|
|
this->next_irq = apu_no_irq;
|
|
|
|
// mode 1
|
|
this->frame_delay = (this->frame_delay & 1);
|
|
this->frame = 0;
|
|
|
|
if ( !(data & 0x80) )
|
|
{
|
|
// mode 0
|
|
this->frame = 1;
|
|
this->frame_delay += this->frame_period;
|
|
if ( irq_enabled )
|
|
this->next_irq = time + this->frame_delay + this->frame_period * 3 + 1;
|
|
}
|
|
|
|
Apu_irq_changed( this );
|
|
}
|
|
}
|
|
|
|
int Apu_read_status( struct Nes_Apu* this, nes_time_t time )
|
|
{
|
|
run_until_( this, time - 1 );
|
|
|
|
int result = (this->dmc.irq_flag << 7) | (this->irq_flag << 6);
|
|
|
|
int i;
|
|
for ( i = 0; i < apu_osc_count; i++ )
|
|
if ( this->oscs [i]->length_counter )
|
|
result |= 1 << i;
|
|
|
|
run_until_( this, time );
|
|
|
|
if ( this->irq_flag )
|
|
{
|
|
result |= 0x40;
|
|
this->irq_flag = false;
|
|
Apu_irq_changed( this );
|
|
}
|
|
|
|
//debug_printf( "%6d/%d Read $4015->$%02X\n", frame_delay, frame, result );
|
|
|
|
return result;
|
|
}
|