cog/Frameworks/GME/gme/Gym_Emu.cpp

428 lines
10 KiB
C++

// Game_Music_Emu $vers. http://www.slack.net/~ant/
#include "Gym_Emu.h"
#include "blargg_endian.h"
/* Copyright (C) 2003-2008 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"
double const min_tempo = 0.25;
double const oversample = 5 / 3.0;
double const fm_gain = 3.0;
int const base_clock = 53700300;
int const clock_rate = base_clock / 15;
Gym_Emu::Gym_Emu()
{
resampler.set_callback( play_frame_, this );
pos = NULL;
disable_oversampling_ = false;
set_type( gme_gym_type );
set_silence_lookahead( 1 ); // tracks should already be trimmed
pcm_buf = stereo_buf.center();
}
Gym_Emu::~Gym_Emu() { }
// Track info
static void get_gym_info( Gym_Emu::header_t const& h, int length, track_info_t* out )
{
if ( 0 != memcmp( h.tag, "GYMX", 4 ) )
return;
length = length * 50 / 3; // 1000 / 60
int loop = get_le32( h.loop_start );
if ( loop )
{
out->intro_length = loop * 50 / 3;
out->loop_length = length - out->intro_length;
}
else
{
out->length = length;
out->intro_length = length; // make it clear that track is no longer than length
out->loop_length = 0;
}
// more stupidity where the field should have been left blank
if ( strcmp( h.song, "Unknown Song" ) )
GME_COPY_FIELD( h, out, song );
if ( strcmp( h.game, "Unknown Game" ) )
GME_COPY_FIELD( h, out, game );
if ( strcmp( h.copyright, "Unknown Publisher" ) )
GME_COPY_FIELD( h, out, copyright );
if ( strcmp( h.dumper, "Unknown Person" ) )
GME_COPY_FIELD( h, out, dumper );
if ( strcmp( h.comment, "Header added by YMAMP" ) )
GME_COPY_FIELD( h, out, comment );
}
static void hash_gym_file( Gym_Emu::header_t const& h, byte const* data, int data_size, Music_Emu::Hash_Function& out )
{
out.hash_( &h.loop_start[0], sizeof(h.loop_start) );
out.hash_( &h.packed[0], sizeof(h.packed) );
out.hash_( data, data_size );
}
static int gym_track_length( byte const p [], byte const* end )
{
int time = 0;
while ( p < end )
{
switch ( *p++ )
{
case 0:
time++;
break;
case 1:
case 2:
p += 2;
break;
case 3:
p += 1;
break;
}
}
return time;
}
blargg_err_t Gym_Emu::track_info_( track_info_t* out, int ) const
{
get_gym_info( header_, gym_track_length( log_begin(), file_end() ), out );
return blargg_ok;
}
static blargg_err_t check_header( byte const in [], int size, int* data_offset = NULL )
{
if ( size < 4 )
return blargg_err_file_type;
if ( memcmp( in, "GYMX", 4 ) == 0 )
{
if ( size < Gym_Emu::header_t::size + 1 )
return blargg_err_file_type;
if ( memcmp( ((Gym_Emu::header_t const*) in)->packed, "\0\0\0\0", 4 ) != 0 )
return BLARGG_ERR( BLARGG_ERR_FILE_FEATURE, "packed GYM file" );
if ( data_offset )
*data_offset = Gym_Emu::header_t::size;
}
else if ( *in > 3 )
{
return blargg_err_file_type;
}
return blargg_ok;
}
struct Gym_File : Gme_Info_
{
int data_offset;
Gym_File() { set_type( gme_gym_type ); }
blargg_err_t load_mem_( byte const in [], int size )
{
data_offset = 0;
return check_header( in, size, &data_offset );
}
blargg_err_t track_info_( track_info_t* out, int ) const
{
int length = gym_track_length( &file_begin() [data_offset], file_end() );
get_gym_info( *(Gym_Emu::header_t const*) file_begin(), length, out );
return blargg_ok;
}
blargg_err_t hash_( Hash_Function& out ) const
{
Gym_Emu::header_t const* h = ( Gym_Emu::header_t const* ) file_begin();
byte const* data = &file_begin() [data_offset];
hash_gym_file( *h, data, file_end() - data, out );
return blargg_ok;
}
};
static Music_Emu* new_gym_emu () { return BLARGG_NEW Gym_Emu ; }
static Music_Emu* new_gym_file() { return BLARGG_NEW Gym_File; }
gme_type_t_ const gme_gym_type [1] = {{ "Sega Genesis", 1, &new_gym_emu, &new_gym_file, "GYM", 0 }};
// Setup
blargg_err_t Gym_Emu::set_sample_rate_( int sample_rate )
{
blip_eq_t eq( -32, 8000, sample_rate );
apu.treble_eq( eq );
pcm_synth.treble_eq( eq );
apu.volume( 0.135 * fm_gain * gain() );
double factor = oversample;
if ( disable_oversampling_ )
factor = (double) base_clock / 7 / 144 / sample_rate;
RETURN_ERR( resampler.setup( factor, 0.990, fm_gain * gain() ) );
factor = resampler.rate();
double fm_rate = sample_rate * factor;
RETURN_ERR( stereo_buf.set_sample_rate( sample_rate, int (1000 / 60.0 / min_tempo) ) );
stereo_buf.clock_rate( clock_rate );
RETURN_ERR( fm.set_rate( fm_rate, base_clock / 7.0 ) );
RETURN_ERR( resampler.reset( (int) (1.0 / 60 / min_tempo * sample_rate) ) );
return blargg_ok;
}
void Gym_Emu::set_tempo_( double t )
{
if ( t < min_tempo )
{
set_tempo( min_tempo );
return;
}
if ( stereo_buf.sample_rate() )
{
double denom = tempo() * 60;
clocks_per_frame = (int) (clock_rate / denom);
resampler.resize( (int) (sample_rate() / denom) );
}
}
void Gym_Emu::mute_voices_( int mask )
{
Music_Emu::mute_voices_( mask );
fm.mute_voices( mask );
apu.set_output( (mask & 0x80) ? 0 : stereo_buf.center() );
pcm_synth.volume( (mask & 0x40) ? 0.0 : 0.125 / 256 * fm_gain * gain() );
}
blargg_err_t Gym_Emu::load_mem_( byte const in [], int size )
{
assert( offsetof (header_t,packed [4]) == header_t::size );
log_offset = 0;
RETURN_ERR( check_header( in, size, &log_offset ) );
loop_begin = NULL;
static const char* const names [] = {
"FM 1", "FM 2", "FM 3", "FM 4", "FM 5", "FM 6", "PCM", "PSG"
};
set_voice_names( names );
set_voice_count( 8 );
if ( log_offset )
header_ = *(header_t const*) in;
else
memset( &header_, 0, sizeof header_ );
return blargg_ok;
}
// Emulation
blargg_err_t Gym_Emu::start_track_( int track )
{
RETURN_ERR( Music_Emu::start_track_( track ) );
pos = log_begin();
loop_remain = get_le32( header_.loop_start );
prev_pcm_count = 0;
pcm_enabled = 0;
pcm_amp = -1;
fm.reset();
apu.reset();
stereo_buf.clear();
resampler.clear();
pcm_buf = stereo_buf.center();
return blargg_ok;
}
void Gym_Emu::run_pcm( byte const pcm_in [], int pcm_count )
{
// Guess beginning and end of sample and adjust rate and buffer position accordingly.
// count dac samples in next frame
int next_pcm_count = 0;
const byte* p = this->pos;
int cmd;
while ( (cmd = *p++) != 0 )
{
int data = *p++;
if ( cmd <= 2 )
++p;
if ( cmd == 1 && data == 0x2A )
next_pcm_count++;
}
// detect beginning and end of sample
int rate_count = pcm_count;
int start = 0;
if ( !prev_pcm_count && next_pcm_count && pcm_count < next_pcm_count )
{
rate_count = next_pcm_count;
start = next_pcm_count - pcm_count;
}
else if ( prev_pcm_count && !next_pcm_count && pcm_count < prev_pcm_count )
{
rate_count = prev_pcm_count;
}
// Evenly space samples within buffer section being used
blip_resampled_time_t period = pcm_buf->resampled_duration( clocks_per_frame ) / rate_count;
blip_resampled_time_t time = pcm_buf->resampled_time( 0 ) + period * start + (unsigned) period / 2;
int pcm_amp = this->pcm_amp;
if ( pcm_amp < 0 )
pcm_amp = pcm_in [0];
for ( int i = 0; i < pcm_count; i++ )
{
int delta = pcm_in [i] - pcm_amp;
pcm_amp += delta;
pcm_synth.offset_resampled( time, delta, pcm_buf );
time += period;
}
this->pcm_amp = pcm_amp;
pcm_buf->set_modified();
}
void Gym_Emu::parse_frame()
{
byte pcm [1024]; // all PCM writes for frame
int pcm_size = 0;
const byte* pos = this->pos;
if ( loop_remain && !--loop_remain )
loop_begin = pos; // find loop on first time through sequence
int cmd;
while ( (cmd = *pos++) != 0 )
{
int data = *pos++;
if ( cmd == 1 )
{
int data2 = *pos++;
if ( data == 0x2A )
{
pcm [pcm_size] = data2;
if ( pcm_size < (int) sizeof pcm - 1 )
pcm_size += pcm_enabled;
}
else
{
if ( data == 0x2B )
pcm_enabled = data2 >> 7 & 1;
fm.write0( data, data2 );
}
}
else if ( cmd == 2 )
{
int data2 = *pos++;
if ( data == 0xB6 )
{
Blip_Buffer * pcm_buf = NULL;
switch ( data2 >> 6 )
{
case 0: pcm_buf = NULL; break;
case 1: pcm_buf = stereo_buf.right(); break;
case 2: pcm_buf = stereo_buf.left(); break;
case 3: pcm_buf = stereo_buf.center(); break;
}
/*if ( this->pcm_buf != pcm_buf )
{
if ( this->pcm_buf ) pcm_synth.offset_inline( 0, -pcm_amp, this->pcm_buf );
if ( pcm_buf ) pcm_synth.offset_inline( 0, pcm_amp, pcm_buf );
}*/
this->pcm_buf = pcm_buf;
}
fm.write1( data, data2 );
}
else if ( cmd == 3 )
{
apu.write_data( 0, data );
}
else
{
// to do: many GYM streams are full of errors, and error count should
// reflect cases where music is really having problems
//log_error();
--pos; // put data back
}
}
if ( pos >= file_end() )
{
// Reached end
check( pos == file_end() );
if ( loop_begin )
pos = loop_begin;
else
set_track_ended();
}
this->pos = pos;
// PCM
if ( pcm_buf && pcm_size )
run_pcm( pcm, pcm_size );
prev_pcm_count = pcm_size;
}
inline int Gym_Emu::play_frame( blip_time_t blip_time, int sample_count, sample_t buf [] )
{
if ( !track_ended() )
parse_frame();
apu.end_frame( blip_time );
memset( buf, 0, sample_count * sizeof *buf );
fm.run( sample_count >> 1, buf );
return sample_count;
}
int Gym_Emu::play_frame_( void* p, blip_time_t a, int b, sample_t c [] )
{
return STATIC_CAST(Gym_Emu*,p)->play_frame( a, b, c );
}
blargg_err_t Gym_Emu::play_( int count, sample_t out [] )
{
resampler.dual_play( count, out, stereo_buf );
return blargg_ok;
}
blargg_err_t Gym_Emu::hash_( Hash_Function& out ) const
{
hash_gym_file( header(), log_begin(), file_end() - log_begin(), out );
return blargg_ok;
}