1 files changed, 405 insertions, 0 deletions
diff --git a/plugins/gme/game-music-emu-0.6.0/gme/Ay_Emu.cpp b/plugins/gme/game-music-emu-0.6.0/gme/Ay_Emu.cpp
new file mode 100644
index 00000000..0ee592e3
--- /dev/null
+++ b/plugins/gme/game-music-emu-0.6.0/gme/Ay_Emu.cpp
@@ -0,0 +1,405 @@
+// Game_Music_Emu 0.5.5. http://www.slack.net/~ant/
+
+#include "Ay_Emu.h"
+
+#include "blargg_endian.h"
+#include <string.h>
+
+/* Copyright (C) 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"
+
+long const spectrum_clock = 3546900;
+long const cpc_clock      = 2000000;
+
+unsigned const ram_start = 0x4000;
+int const osc_count = Ay_Apu::osc_count + 1;
+
+Ay_Emu::Ay_Emu()
+{
+	beeper_output = 0;
+	set_type( gme_ay_type );
+	
+	static const char* const names [osc_count] = {
+		"Wave 1", "Wave 2", "Wave 3", "Beeper"
+	};
+	set_voice_names( names );
+	
+	static int const types [osc_count] = {
+		wave_type | 0, wave_type | 1, wave_type | 2, mixed_type | 0
+	};
+	set_voice_types( types );
+	set_silence_lookahead( 6 );
+}
+
+Ay_Emu::~Ay_Emu() { }
+
+// Track info
+
+static byte const* get_data( Ay_Emu::file_t const& file, byte const* ptr, int min_size )
+{
+	long pos = ptr - (byte const*) file.header;
+	long file_size = file.end - (byte const*) file.header;
+	assert( (unsigned long) pos <= (unsigned long) file_size - 2 );
+	int offset = (BOOST::int16_t) get_be16( ptr );
+	if ( !offset || blargg_ulong (pos + offset) > blargg_ulong (file_size - min_size) )
+		return 0;
+	return ptr + offset;
+}
+
+static blargg_err_t parse_header( byte const* in, long size, Ay_Emu::file_t* out )
+{
+	typedef Ay_Emu::header_t header_t;
+	out->header = (header_t const*) in;
+	out->end    = in + size;
+	
+	if ( size < Ay_Emu::header_size )
+		return gme_wrong_file_type;
+	
+	header_t const& h = *(header_t const*) in;
+	if ( memcmp( h.tag, "ZXAYEMUL", 8 ) )
+		return gme_wrong_file_type;
+	
+	out->tracks = get_data( *out, h.track_info, (h.max_track + 1) * 4 );
+	if ( !out->tracks )
+		return "Missing track data";
+	
+	return 0;
+}
+
+static void copy_ay_fields( Ay_Emu::file_t const& file, track_info_t* out, int track )
+{
+	Gme_File::copy_field_( out->song, (char const*) get_data( file, file.tracks + track * 4, 1 ) );
+	byte const* track_info = get_data( file, file.tracks + track * 4 + 2, 6 );
+	if ( track_info )
+		out->length = get_be16( track_info + 4 ) * (1000L / 50); // frames to msec
+	
+	Gme_File::copy_field_( out->author,  (char const*) get_data( file, file.header->author, 1 ) );
+	Gme_File::copy_field_( out->comment, (char const*) get_data( file, file.header->comment, 1 ) );
+}
+
+blargg_err_t Ay_Emu::track_info_( track_info_t* out, int track ) const
+{
+	copy_ay_fields( file, out, track );
+	return 0;
+}
+
+struct Ay_File : Gme_Info_
+{
+	Ay_Emu::file_t file;
+	
+	Ay_File() { set_type( gme_ay_type ); }
+	
+	blargg_err_t load_mem_( byte const* begin, long size )
+	{
+		RETURN_ERR( parse_header( begin, size, &file ) );
+		set_track_count( file.header->max_track + 1 );
+		return 0;
+	}
+	
+	blargg_err_t track_info_( track_info_t* out, int track ) const
+	{
+		copy_ay_fields( file, out, track );
+		return 0;
+	}
+};
+
+static Music_Emu* new_ay_emu () { return BLARGG_NEW Ay_Emu ; }
+static Music_Emu* new_ay_file() { return BLARGG_NEW Ay_File; }
+
+static gme_type_t_ const gme_ay_type_ = { "ZX Spectrum", 0, &new_ay_emu, &new_ay_file, "AY", 1 };
+gme_type_t const gme_ay_type = &gme_ay_type_;
+
+// Setup
+
+blargg_err_t Ay_Emu::load_mem_( byte const* in, long size )
+{
+	assert( offsetof (header_t,track_info [2]) == header_size );
+	
+	RETURN_ERR( parse_header( in, size, &file ) );
+	set_track_count( file.header->max_track + 1 );
+	
+	if ( file.header->vers > 2 )
+		set_warning( "Unknown file version" );
+	
+	set_voice_count( osc_count );
+	apu.volume( gain() );
+	
+	return setup_buffer( spectrum_clock );
+}
+	
+void Ay_Emu::update_eq( blip_eq_t const& eq )
+{
+	apu.treble_eq( eq );
+}
+
+void Ay_Emu::set_voice( int i, Blip_Buffer* center, Blip_Buffer*, Blip_Buffer* )
+{
+	if ( i >= Ay_Apu::osc_count )
+		beeper_output = center;
+	else
+		apu.osc_output( i, center );
+}
+
+// Emulation
+
+void Ay_Emu::set_tempo_( double t )
+{
+	play_period = blip_time_t (clock_rate() / 50 / t);
+}
+
+blargg_err_t Ay_Emu::start_track_( int track )
+{
+	RETURN_ERR( Classic_Emu::start_track_( track ) );
+	
+	memset( mem.ram + 0x0000, 0xC9, 0x100 ); // fill RST vectors with RET
+	memset( mem.ram + 0x0100, 0xFF, 0x4000 - 0x100 );
+	memset( mem.ram + ram_start, 0x00, sizeof mem.ram - ram_start );
+	memset( mem.padding1, 0xFF, sizeof mem.padding1 );
+	memset( mem.ram + 0x10000, 0xFF, sizeof mem.ram - 0x10000 );
+	
+	// locate data blocks
+	byte const* const data = get_data( file, file.tracks + track * 4 + 2, 14 );
+	if ( !data ) return "File data missing";
+	
+	byte const* const more_data = get_data( file, data + 10, 6 );
+	if ( !more_data ) return "File data missing";
+	
+	byte const* blocks = get_data( file, data + 12, 8 );
+	if ( !blocks ) return "File data missing";
+	
+	// initial addresses
+	cpu::reset( mem.ram );
+	r.sp = get_be16( more_data );
+	r.b.a = r.b.b = r.b.d = r.b.h = data [8];
+	r.b.flags = r.b.c = r.b.e = r.b.l = data [9];
+	r.alt.w = r.w;
+	r.ix = r.iy = r.w.hl;
+	
+	unsigned addr = get_be16( blocks );
+	if ( !addr ) return "File data missing";
+	
+	unsigned init = get_be16( more_data + 2 );
+	if ( !init )
+		init = addr;
+	
+	// copy blocks into memory
+	do
+	{
+		blocks += 2;
+		unsigned len = get_be16( blocks ); blocks += 2;
+		if ( addr + len > 0x10000 )
+		{
+			set_warning( "Bad data block size" );
+			len = 0x10000 - addr;
+		}
+		check( len );
+		byte const* in = get_data( file, blocks, 0 ); blocks += 2;
+		if ( len > blargg_ulong (file.end - in) )
+		{
+			set_warning( "Missing file data" );
+			len = file.end - in;
+		}
+		//debug_printf( "addr: $%04X, len: $%04X\n", addr, len );
+		if ( addr < ram_start && addr >= 0x400 ) // several tracks use low data
+			debug_printf( "Block addr in ROM\n" );
+		memcpy( mem.ram + addr, in, len );
+		
+		if ( file.end - blocks < 8 )
+		{
+			set_warning( "Missing file data" );
+			break;
+		}
+	}
+	while ( (addr = get_be16( blocks )) != 0 );
+	
+	// copy and configure driver
+	static byte const passive [] = {
+		0xF3,       // DI
+		0xCD, 0, 0, // CALL init
+		0xED, 0x5E, // LOOP: IM 2
+		0xFB,       // EI
+		0x76,       // HALT
+		0x18, 0xFA  // JR LOOP
+	};
+	static byte const active [] = {
+		0xF3,       // DI
+		0xCD, 0, 0, // CALL init
+		0xED, 0x56, // LOOP: IM 1
+		0xFB,       // EI
+		0x76,       // HALT
+		0xCD, 0, 0, // CALL play
+		0x18, 0xF7  // JR LOOP
+	};
+	memcpy( mem.ram, passive, sizeof passive );
+	unsigned play_addr = get_be16( more_data + 4 );
+	//debug_printf( "Play: $%04X\n", play_addr );
+	if ( play_addr )
+	{
+		memcpy( mem.ram, active, sizeof active );
+		mem.ram [ 9] = play_addr;
+		mem.ram [10] = play_addr >> 8;
+	}
+	mem.ram [2] = init;
+	mem.ram [3] = init >> 8;
+	
+	mem.ram [0x38] = 0xFB; // Put EI at interrupt vector (followed by RET)
+	
+	memcpy( mem.ram + 0x10000, mem.ram, 0x80 ); // some code wraps around (ugh)
+	
+	beeper_delta = int (apu.amp_range * 0.65);
+	last_beeper = 0;
+	apu.reset();
+	next_play = play_period;
+	
+	// start at spectrum speed
+	change_clock_rate( spectrum_clock );
+	set_tempo( tempo() );
+	
+	spectrum_mode = false;
+	cpc_mode      = false;
+	cpc_latch     = 0;
+	
+	return 0;
+}
+
+// Emulation
+
+void Ay_Emu::cpu_out_misc( cpu_time_t time, unsigned addr, int data )
+{
+	if ( !cpc_mode )
+	{
+		switch ( addr & 0xFEFF )
+		{
+		case 0xFEFD:
+			spectrum_mode = true;
+			apu_addr = data & 0x0F;
+			return;
+		
+		case 0xBEFD:
+			spectrum_mode = true;
+			apu.write( time, apu_addr, data );
+			return;
+		}
+	}
+	
+	if ( !spectrum_mode )
+	{
+		switch ( addr >> 8 )
+		{
+		case 0xF6:
+			switch ( data & 0xC0 )
+			{
+			case 0xC0:
+				apu_addr = cpc_latch & 0x0F;
+				goto enable_cpc;
+			
+			case 0x80:
+				apu.write( time, apu_addr, cpc_latch );
+				goto enable_cpc;
+			}
+			break;
+		
+		case 0xF4:
+			cpc_latch = data;
+			goto enable_cpc;
+		}
+	}
+	
+	debug_printf( "Unmapped OUT: $%04X <- $%02X\n", addr, data );
+	return;
+	
+enable_cpc:
+	if ( !cpc_mode )
+	{
+		cpc_mode = true;
+		change_clock_rate( cpc_clock );
+		set_tempo( tempo() );
+	}
+}
+
+void ay_cpu_out( Ay_Cpu* cpu, cpu_time_t time, unsigned addr, int data )
+{
+	Ay_Emu& emu = STATIC_CAST(Ay_Emu&,*cpu);
+	
+	if ( (addr & 0xFF) == 0xFE && !emu.cpc_mode )
+	{
+		int delta = emu.beeper_delta;
+		data &= 0x10;
+		if ( emu.last_beeper != data )
+		{
+			emu.last_beeper = data;
+			emu.beeper_delta = -delta;
+			emu.spectrum_mode = true;
+			if ( emu.beeper_output )
+				emu.apu.synth_.offset( time, delta, emu.beeper_output );
+		}
+	}
+	else
+	{
+		emu.cpu_out_misc( time, addr, data );
+	}
+}
+
+int ay_cpu_in( Ay_Cpu*, unsigned addr )
+{
+	// keyboard read and other things
+	if ( (addr & 0xFF) == 0xFE )
+		return 0xFF; // other values break some beeper tunes
+	
+	debug_printf( "Unmapped IN : $%04X\n", addr );
+	return 0xFF;
+}
+
+blargg_err_t Ay_Emu::run_clocks( blip_time_t& duration, int )
+{
+	set_time( 0 );
+	if ( !(spectrum_mode | cpc_mode) )
+		duration /= 2; // until mode is set, leave room for halved clock rate
+	
+	while ( time() < duration )
+	{
+		cpu::run( min( duration, (blip_time_t) next_play ) );
+		
+		if ( time() >= next_play )
+		{
+			next_play += play_period;
+			
+			if ( r.iff1 )
+			{
+				if ( mem.ram [r.pc] == 0x76 )
+					r.pc++;
+				
+				r.iff1 = r.iff2 = 0;
+				
+				mem.ram [--r.sp] = uint8_t (r.pc >> 8);
+				mem.ram [--r.sp] = uint8_t (r.pc);
+				r.pc = 0x38;
+				cpu::adjust_time( 12 );
+				if ( r.im == 2 )
+				{
+					cpu::adjust_time( 6 );
+					unsigned addr = r.i * 0x100u + 0xFF;
+					r.pc = mem.ram [(addr + 1) & 0xFFFF] * 0x100u + mem.ram [addr];
+				}
+			}
+		}
+	}
+	duration = time();
+	next_play -= duration;
+	check( next_play >= 0 );
+	adjust_time( -duration );
+	
+	apu.end_frame( duration );
+	
+	return 0;
+}