1 files changed, 379 insertions, 0 deletions
diff --git a/plugins/gme/Game_Music_Emu-0.5.2/gme/Gym_Emu.cpp b/plugins/gme/Game_Music_Emu-0.5.2/gme/Gym_Emu.cpp
new file mode 100644
index 00000000..499a9ca2
--- /dev/null
+++ b/plugins/gme/Game_Music_Emu-0.5.2/gme/Gym_Emu.cpp
@@ -0,0 +1,379 @@
+// Game_Music_Emu 0.5.2. http://www.slack.net/~ant/
+
+#include "Gym_Emu.h"
+
+#include "blargg_endian.h"
+#include <string.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"
+
+double const min_tempo = 0.25;
+double const oversample_factor = 5 / 3.0;
+double const fm_gain = 3.0;
+
+const long base_clock = 53700300;
+const long clock_rate = base_clock / 15;
+
+Gym_Emu::Gym_Emu()
+{
+	data = 0;
+	pos  = 0;
+	set_type( gme_gym_type );
+	
+	static const char* const names [] = {
+		"FM 1", "FM 2", "FM 3", "FM 4", "FM 5", "FM 6", "PCM", "PSG"
+	};
+	set_voice_names( names );
+	set_silence_lookahead( 1 ); // tracks should already be trimmed
+}
+
+Gym_Emu::~Gym_Emu() { }
+
+// Track info
+
+static void get_gym_info( Gym_Emu::header_t const& h, long length, track_info_t* out )
+{
+	if ( !memcmp( h.tag, "GYMX", 4 ) )
+	{
+		length = length * 50 / 3; // 1000 / 60
+		long 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
+		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 );
+	}
+}
+
+blargg_err_t Gym_Emu::track_info_( track_info_t* out, int ) const
+{
+	get_gym_info( header_, track_length(), out );
+	return 0;
+}
+
+static long gym_track_length( byte const* p, byte const* end )
+{
+	long 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;
+}
+
+long Gym_Emu::track_length() const { return gym_track_length( data, data_end ); }
+
+static blargg_err_t check_header( byte const* in, long size, int* data_offset = 0 )
+{
+	if ( size < 4 )
+		return gme_wrong_file_type;
+	
+	if ( memcmp( in, "GYMX", 4 ) == 0 )
+	{
+		if ( size < Gym_Emu::header_size + 1 )
+			return gme_wrong_file_type;
+		
+		if ( memcmp( ((Gym_Emu::header_t const*) in)->packed, "\0\0\0\0", 4 ) != 0 )
+			return "Packed GYM file not supported";
+		
+		if ( data_offset )
+			*data_offset = Gym_Emu::header_size;
+	}
+	else if ( *in > 3 )
+	{
+		return gme_wrong_file_type;
+	}
+	
+	return 0;
+}
+
+struct Gym_File : Gme_Info_
+{
+	byte const* file_begin;
+	byte const* file_end;
+	int data_offset;
+	
+	Gym_File() { set_type( gme_gym_type ); }
+	
+	blargg_err_t load_mem_( byte const* in, long size )
+	{
+		file_begin = in;
+		file_end   = in + size;
+		data_offset = 0;
+		return check_header( in, size, &data_offset );
+	}
+	
+	blargg_err_t track_info_( track_info_t* out, int ) const
+	{
+		long length = gym_track_length( &file_begin [data_offset], file_end );
+		get_gym_info( *(Gym_Emu::header_t const*) file_begin, length, out );
+		return 0;
+	}
+};
+
+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_( long sample_rate )
+{
+	blip_eq_t eq( -32, 8000, sample_rate );
+	apu.treble_eq( eq );
+	dac_synth.treble_eq( eq );
+	apu.volume( 0.135 * fm_gain * gain() );
+	dac_synth.volume( 0.125 / 256 * fm_gain * gain() );
+	double factor = Dual_Resampler::setup( oversample_factor, 0.990, fm_gain * gain() );
+	fm_sample_rate = sample_rate * factor;
+	
+	RETURN_ERR( blip_buf.set_sample_rate( sample_rate, int (1000 / 60.0 / min_tempo) ) );
+	blip_buf.clock_rate( clock_rate );
+	
+	RETURN_ERR( fm.set_rate( fm_sample_rate, base_clock / 7.0 ) );
+	RETURN_ERR( Dual_Resampler::reset( long (1.0 / 60 / min_tempo * sample_rate) ) );
+	
+	return 0;
+}
+
+void Gym_Emu::set_tempo_( double t )
+{
+	if ( t < min_tempo )
+	{
+		set_tempo( min_tempo );
+		return;
+	}
+	
+	if ( blip_buf.sample_rate() )
+	{
+		clocks_per_frame = long (clock_rate / 60 / tempo());
+		Dual_Resampler::resize( long (sample_rate() / (60.0 * tempo())) );
+	}
+}
+
+void Gym_Emu::mute_voices_( int mask )
+{
+	Music_Emu::mute_voices_( mask );
+	fm.mute_voices( mask );
+	dac_muted = (mask & 0x40) != 0;
+	apu.output( (mask & 0x80) ? 0 : &blip_buf );
+}
+
+blargg_err_t Gym_Emu::load_mem_( byte const* in, long size )
+{
+	assert( offsetof (header_t,packed [4]) == header_size );
+	int offset = 0;
+	RETURN_ERR( check_header( in, size, &offset ) );
+	set_voice_count( 8 );
+	
+	data     = in + offset;
+	data_end = in + size;
+	loop_begin = 0;
+	
+	if ( offset )
+		header_ = *(header_t const*) in;
+	else
+		memset( &header_, 0, sizeof header_ );
+	
+	return 0;
+}
+
+// Emulation
+
+blargg_err_t Gym_Emu::start_track_( int track )
+{
+	RETURN_ERR( Music_Emu::start_track_( track ) );
+	
+	pos         = data;
+	loop_remain = get_le32( header_.loop_start );
+	
+	prev_dac_count = 0;
+	dac_enabled    = false;
+	dac_amp        = -1;
+	
+	fm.reset();
+	apu.reset();
+	blip_buf.clear();
+	Dual_Resampler::clear();
+	return 0;
+}
+
+void Gym_Emu::run_dac( int dac_count )
+{
+	// Guess beginning and end of sample and adjust rate and buffer position accordingly.
+	
+	// count dac samples in next frame
+	int next_dac_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_dac_count++;
+	}
+	
+	// detect beginning and end of sample
+	int rate_count = dac_count;
+	int start = 0;
+	if ( !prev_dac_count && next_dac_count && dac_count < next_dac_count )
+	{
+		rate_count = next_dac_count;
+		start = next_dac_count - dac_count;
+	}
+	else if ( prev_dac_count && !next_dac_count && dac_count < prev_dac_count )
+	{
+		rate_count = prev_dac_count;
+	}
+	
+	// Evenly space samples within buffer section being used
+	blip_resampled_time_t period = blip_buf.resampled_duration( clocks_per_frame ) / rate_count;
+	
+	blip_resampled_time_t time = blip_buf.resampled_time( 0 ) +
+			period * start + (period >> 1);
+	
+	int dac_amp = this->dac_amp;
+	if ( dac_amp < 0 )
+		dac_amp = dac_buf [0];
+	
+	for ( int i = 0; i < dac_count; i++ )
+	{
+		int delta = dac_buf [i] - dac_amp;
+		dac_amp += delta;
+		dac_synth.offset_resampled( time, delta, &blip_buf );
+		time += period;
+	}
+	this->dac_amp = dac_amp;
+}
+
+void Gym_Emu::parse_frame()
+{
+	int dac_count = 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 )
+			{
+				if ( data == 0x2B )
+					dac_enabled = (data2 & 0x80) != 0;
+				
+				fm.write0( data, data2 );
+			}
+			else if ( dac_count < (int) sizeof dac_buf )
+			{
+				dac_buf [dac_count] = data2;
+				dac_count += dac_enabled;
+			}
+		}
+		else if ( cmd == 2 )
+		{
+			fm.write1( data, *pos++ );
+		}
+		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
+		}
+	}
+	
+	// loop
+	if ( pos >= data_end )
+	{
+		check( pos == data_end );
+		
+		if ( loop_begin )
+			pos = loop_begin;
+		else
+			set_track_ended();
+	}
+	this->pos = pos;
+	
+	// dac
+	if ( dac_count && !dac_muted )
+		run_dac( dac_count );
+	prev_dac_count = dac_count;
+}
+
+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;
+}
+
+blargg_err_t Gym_Emu::play_( long count, sample_t* out )
+{
+	Dual_Resampler::dual_play( count, out, blip_buf );
+	return 0;
+}