414 lines
9.9 KiB
C++
414 lines
9.9 KiB
C++
// SPC emulation support: init, sample buffering, reset, SPC loading
|
|
|
|
// snes_spc 0.9.0. http://www.slack.net/~ant/
|
|
|
|
#include "SNES_SPC.h"
|
|
|
|
#include <string.h>
|
|
|
|
/* Copyright (C) 2004-2007 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"
|
|
|
|
#define RAM (m.ram.ram)
|
|
#define REGS (m.smp_regs [0])
|
|
#define REGS_IN (m.smp_regs [1])
|
|
|
|
// (n ? n : 256)
|
|
#define IF_0_THEN_256( n ) ((uint8_t) ((n) - 1) + 1)
|
|
|
|
|
|
//// Init
|
|
|
|
blargg_err_t SNES_SPC::init()
|
|
{
|
|
memset( &m, 0, sizeof m );
|
|
dsp.init( RAM );
|
|
|
|
m.tempo = tempo_unit;
|
|
|
|
// Most SPC music doesn't need ROM, and almost all the rest only rely
|
|
// on these two bytes
|
|
m.rom [0x3E] = 0xFF;
|
|
m.rom [0x3F] = 0xC0;
|
|
|
|
static unsigned char const cycle_table [128] =
|
|
{// 01 23 45 67 89 AB CD EF
|
|
0x28,0x47,0x34,0x36,0x26,0x54,0x54,0x68, // 0
|
|
0x48,0x47,0x45,0x56,0x55,0x65,0x22,0x46, // 1
|
|
0x28,0x47,0x34,0x36,0x26,0x54,0x54,0x74, // 2
|
|
0x48,0x47,0x45,0x56,0x55,0x65,0x22,0x38, // 3
|
|
0x28,0x47,0x34,0x36,0x26,0x44,0x54,0x66, // 4
|
|
0x48,0x47,0x45,0x56,0x55,0x45,0x22,0x43, // 5
|
|
0x28,0x47,0x34,0x36,0x26,0x44,0x54,0x75, // 6
|
|
0x48,0x47,0x45,0x56,0x55,0x55,0x22,0x36, // 7
|
|
0x28,0x47,0x34,0x36,0x26,0x54,0x52,0x45, // 8
|
|
0x48,0x47,0x45,0x56,0x55,0x55,0x22,0xC5, // 9
|
|
0x38,0x47,0x34,0x36,0x26,0x44,0x52,0x44, // A
|
|
0x48,0x47,0x45,0x56,0x55,0x55,0x22,0x34, // B
|
|
0x38,0x47,0x45,0x47,0x25,0x64,0x52,0x49, // C
|
|
0x48,0x47,0x56,0x67,0x45,0x55,0x22,0x83, // D
|
|
0x28,0x47,0x34,0x36,0x24,0x53,0x43,0x40, // E
|
|
0x48,0x47,0x45,0x56,0x34,0x54,0x22,0x60, // F
|
|
};
|
|
|
|
// unpack cycle table
|
|
for ( int i = 0; i < 128; i++ )
|
|
{
|
|
int n = cycle_table [i];
|
|
m.cycle_table [i * 2 + 0] = n >> 4;
|
|
m.cycle_table [i * 2 + 1] = n & 0x0F;
|
|
}
|
|
|
|
#if SPC_LESS_ACCURATE
|
|
memcpy( reg_times, reg_times_, sizeof reg_times );
|
|
#endif
|
|
|
|
reset();
|
|
return 0;
|
|
}
|
|
|
|
void SNES_SPC::init_rom( uint8_t const in [rom_size] )
|
|
{
|
|
memcpy( m.rom, in, sizeof m.rom );
|
|
}
|
|
|
|
void SNES_SPC::set_tempo( int t )
|
|
{
|
|
m.tempo = t;
|
|
int const timer2_shift = 4; // 64 kHz
|
|
int const other_shift = 3; // 8 kHz
|
|
|
|
#if SPC_DISABLE_TEMPO
|
|
m.timers [2].prescaler = timer2_shift;
|
|
m.timers [1].prescaler = timer2_shift + other_shift;
|
|
m.timers [0].prescaler = timer2_shift + other_shift;
|
|
#else
|
|
if ( !t )
|
|
t = 1;
|
|
int const timer2_rate = 1 << timer2_shift;
|
|
int rate = (timer2_rate * tempo_unit + (t >> 1)) / t;
|
|
if ( rate < timer2_rate / 4 )
|
|
rate = timer2_rate / 4; // max 4x tempo
|
|
m.timers [2].prescaler = rate;
|
|
m.timers [1].prescaler = rate << other_shift;
|
|
m.timers [0].prescaler = rate << other_shift;
|
|
#endif
|
|
}
|
|
|
|
// Timer registers have been loaded. Applies these to the timers. Does not
|
|
// reset timer prescalers or dividers.
|
|
void SNES_SPC::timers_loaded()
|
|
{
|
|
int i;
|
|
for ( i = 0; i < timer_count; i++ )
|
|
{
|
|
Timer* t = &m.timers [i];
|
|
t->period = IF_0_THEN_256( REGS [r_t0target + i] );
|
|
t->enabled = REGS [r_control] >> i & 1;
|
|
t->counter = REGS_IN [r_t0out + i] & 0x0F;
|
|
}
|
|
|
|
set_tempo( m.tempo );
|
|
}
|
|
|
|
// Loads registers from unified 16-byte format
|
|
void SNES_SPC::load_regs( uint8_t const in [reg_count] )
|
|
{
|
|
memcpy( REGS, in, reg_count );
|
|
memcpy( REGS_IN, REGS, reg_count );
|
|
|
|
// These always read back as 0
|
|
REGS_IN [r_test ] = 0;
|
|
REGS_IN [r_control ] = 0;
|
|
REGS_IN [r_t0target] = 0;
|
|
REGS_IN [r_t1target] = 0;
|
|
REGS_IN [r_t2target] = 0;
|
|
}
|
|
|
|
// RAM was just loaded from SPC, with $F0-$FF containing SMP registers
|
|
// and timer counts. Copies these to proper registers.
|
|
void SNES_SPC::ram_loaded()
|
|
{
|
|
m.rom_enabled = 0;
|
|
load_regs( &RAM [0xF0] );
|
|
|
|
// Put STOP instruction around memory to catch PC underflow/overflow
|
|
memset( m.ram.padding1, cpu_pad_fill, sizeof m.ram.padding1 );
|
|
memset( m.ram.padding2, cpu_pad_fill, sizeof m.ram.padding2 );
|
|
}
|
|
|
|
// Registers were just loaded. Applies these new values.
|
|
void SNES_SPC::regs_loaded()
|
|
{
|
|
enable_rom( REGS [r_control] & 0x80 );
|
|
timers_loaded();
|
|
}
|
|
|
|
void SNES_SPC::reset_time_regs()
|
|
{
|
|
m.cpu_error = 0;
|
|
m.echo_accessed = 0;
|
|
m.spc_time = 0;
|
|
m.dsp_time = 0;
|
|
#if SPC_LESS_ACCURATE
|
|
m.dsp_time = clocks_per_sample + 1;
|
|
#endif
|
|
|
|
for ( int i = 0; i < timer_count; i++ )
|
|
{
|
|
Timer* t = &m.timers [i];
|
|
t->next_time = 1;
|
|
t->divider = 0;
|
|
}
|
|
|
|
regs_loaded();
|
|
|
|
m.extra_clocks = 0;
|
|
reset_buf();
|
|
}
|
|
|
|
void SNES_SPC::reset_common( int timer_counter_init )
|
|
{
|
|
int i;
|
|
for ( i = 0; i < timer_count; i++ )
|
|
REGS_IN [r_t0out + i] = timer_counter_init;
|
|
|
|
// Run IPL ROM
|
|
memset( &m.cpu_regs, 0, sizeof m.cpu_regs );
|
|
m.cpu_regs.pc = rom_addr;
|
|
|
|
REGS [r_test ] = 0x0A;
|
|
REGS [r_control] = 0xB0; // ROM enabled, clear ports
|
|
for ( i = 0; i < port_count; i++ )
|
|
REGS_IN [r_cpuio0 + i] = 0;
|
|
|
|
reset_time_regs();
|
|
}
|
|
|
|
void SNES_SPC::soft_reset()
|
|
{
|
|
reset_common( 0 );
|
|
dsp.soft_reset();
|
|
}
|
|
|
|
void SNES_SPC::reset()
|
|
{
|
|
m.cpu_regs.pc = 0xFFC0;
|
|
m.cpu_regs.a = 0x00;
|
|
m.cpu_regs.x = 0x00;
|
|
m.cpu_regs.y = 0x00;
|
|
m.cpu_regs.psw = 0x02;
|
|
m.cpu_regs.sp = 0xEF;
|
|
memset( RAM, 0x00, 0x10000 );
|
|
ram_loaded();
|
|
reset_common( 0x0F );
|
|
dsp.reset();
|
|
}
|
|
|
|
char const SNES_SPC::signature [signature_size + 1] =
|
|
"SNES-SPC700 Sound File Data v0.30\x1A\x1A";
|
|
|
|
blargg_err_t SNES_SPC::load_spc( void const* data, long size )
|
|
{
|
|
spc_file_t const* const spc = (spc_file_t const*) data;
|
|
|
|
// be sure compiler didn't insert any padding into fle_t
|
|
assert( sizeof (spc_file_t) == spc_min_file_size + 0x80 );
|
|
|
|
// Check signature and file size
|
|
if ( size < signature_size || memcmp( spc, signature, 27 ) )
|
|
return "Not an SPC file";
|
|
|
|
if ( size < spc_min_file_size )
|
|
return "Corrupt SPC file";
|
|
|
|
// CPU registers
|
|
m.cpu_regs.pc = spc->pch * 0x100 + spc->pcl;
|
|
m.cpu_regs.a = spc->a;
|
|
m.cpu_regs.x = spc->x;
|
|
m.cpu_regs.y = spc->y;
|
|
m.cpu_regs.psw = spc->psw;
|
|
m.cpu_regs.sp = spc->sp;
|
|
|
|
// RAM and registers
|
|
memcpy( RAM, spc->ram, 0x10000 );
|
|
ram_loaded();
|
|
|
|
// DSP registers
|
|
dsp.load( spc->dsp );
|
|
|
|
reset_time_regs();
|
|
|
|
return 0;
|
|
}
|
|
|
|
void SNES_SPC::clear_echo()
|
|
{
|
|
if ( !(dsp.read( SPC_DSP::r_flg ) & 0x20) )
|
|
{
|
|
int addr = 0x100 * dsp.read( SPC_DSP::r_esa );
|
|
int end = addr + 0x800 * (dsp.read( SPC_DSP::r_edl ) & 0x0F);
|
|
if ( end > 0x10000 )
|
|
end = 0x10000;
|
|
memset( &RAM [addr], 0xFF, end - addr );
|
|
}
|
|
}
|
|
|
|
|
|
//// Sample output
|
|
|
|
void SNES_SPC::reset_buf()
|
|
{
|
|
// Start with half extra buffer of silence
|
|
sample_t* out = m.extra_buf;
|
|
while ( out < &m.extra_buf [extra_size / 2] )
|
|
*out++ = 0;
|
|
|
|
m.extra_pos = out;
|
|
m.buf_begin = 0;
|
|
|
|
dsp.set_output( 0, 0 );
|
|
}
|
|
|
|
void SNES_SPC::set_output( sample_t* out, int size )
|
|
{
|
|
require( (size & 1) == 0 ); // size must be even
|
|
|
|
m.extra_clocks &= clocks_per_sample - 1;
|
|
if ( out )
|
|
{
|
|
sample_t const* out_end = out + size;
|
|
m.buf_begin = out;
|
|
m.buf_end = out_end;
|
|
|
|
// Copy extra to output
|
|
sample_t const* in = m.extra_buf;
|
|
while ( in < m.extra_pos && out < out_end )
|
|
*out++ = *in++;
|
|
|
|
// Handle output being full already
|
|
if ( out >= out_end )
|
|
{
|
|
// Have DSP write to remaining extra space
|
|
out = dsp.extra();
|
|
out_end = &dsp.extra() [extra_size];
|
|
|
|
// Copy any remaining extra samples as if DSP wrote them
|
|
while ( in < m.extra_pos )
|
|
*out++ = *in++;
|
|
assert( out <= out_end );
|
|
}
|
|
|
|
dsp.set_output( out, out_end - out );
|
|
}
|
|
else
|
|
{
|
|
reset_buf();
|
|
}
|
|
}
|
|
|
|
void SNES_SPC::save_extra()
|
|
{
|
|
// Get end pointers
|
|
sample_t const* main_end = m.buf_end; // end of data written to buf
|
|
sample_t const* dsp_end = dsp.out_pos(); // end of data written to dsp.extra()
|
|
if ( m.buf_begin <= dsp_end && dsp_end <= main_end )
|
|
{
|
|
main_end = dsp_end;
|
|
dsp_end = dsp.extra(); // nothing in DSP's extra
|
|
}
|
|
|
|
// Copy any extra samples at these ends into extra_buf
|
|
sample_t* out = m.extra_buf;
|
|
sample_t const* in;
|
|
for ( in = m.buf_begin + sample_count(); in < main_end; in++ )
|
|
*out++ = *in;
|
|
for ( in = dsp.extra(); in < dsp_end ; in++ )
|
|
*out++ = *in;
|
|
|
|
m.extra_pos = out;
|
|
assert( out <= &m.extra_buf [extra_size] );
|
|
}
|
|
|
|
blargg_err_t SNES_SPC::play( int count, sample_t* out )
|
|
{
|
|
require( (count & 1) == 0 ); // must be even
|
|
if ( count )
|
|
{
|
|
set_output( out, count );
|
|
end_frame( count * (clocks_per_sample / 2) );
|
|
}
|
|
|
|
const char* err = m.cpu_error;
|
|
m.cpu_error = 0;
|
|
return err;
|
|
}
|
|
|
|
blargg_err_t SNES_SPC::skip( int count )
|
|
{
|
|
#if SPC_LESS_ACCURATE
|
|
if ( count > 2 * sample_rate * 2 )
|
|
{
|
|
set_output( 0, 0 );
|
|
|
|
// Skip a multiple of 4 samples
|
|
time_t end = count;
|
|
count = (count & 3) + 1 * sample_rate * 2;
|
|
end = (end - count) * (clocks_per_sample / 2);
|
|
|
|
m.skipped_kon = 0;
|
|
m.skipped_koff = 0;
|
|
|
|
// Preserve DSP and timer synchronization
|
|
// TODO: verify that this really preserves it
|
|
int old_dsp_time = m.dsp_time + m.spc_time;
|
|
m.dsp_time = end - m.spc_time + skipping_time;
|
|
end_frame( end );
|
|
m.dsp_time = m.dsp_time - skipping_time + old_dsp_time;
|
|
|
|
dsp.write( SPC_DSP::r_koff, m.skipped_koff & ~m.skipped_kon );
|
|
dsp.write( SPC_DSP::r_kon , m.skipped_kon );
|
|
clear_echo();
|
|
}
|
|
#endif
|
|
|
|
return play( count, 0 );
|
|
}
|
|
|
|
//// Snes9x Accessor
|
|
|
|
void SNES_SPC::dsp_set_spc_snapshot_callback( void (*callback) (void) )
|
|
{
|
|
dsp.set_spc_snapshot_callback( callback );
|
|
}
|
|
|
|
void SNES_SPC::dsp_dump_spc_snapshot( void )
|
|
{
|
|
dsp.dump_spc_snapshot();
|
|
}
|
|
|
|
void SNES_SPC::dsp_set_stereo_switch( int value )
|
|
{
|
|
dsp.set_stereo_switch( value );
|
|
}
|
|
|
|
SNES_SPC::uint8_t SNES_SPC::dsp_reg_value( int ch, int addr )
|
|
{
|
|
return dsp.reg_value( ch, addr );
|
|
}
|
|
|
|
int SNES_SPC::dsp_envx_value( int ch )
|
|
{
|
|
return dsp.envx_value( ch );
|
|
}
|