diff options
Diffstat (limited to 'plugins/gme/game-music-emu-0.6pre/gme/Ay_Emu.cpp')
| -rw-r--r-- | plugins/gme/game-music-emu-0.6pre/gme/Ay_Emu.cpp | 306 |
1 files changed, 306 insertions, 0 deletions
diff --git a/plugins/gme/game-music-emu-0.6pre/gme/Ay_Emu.cpp b/plugins/gme/game-music-emu-0.6pre/gme/Ay_Emu.cpp new file mode 100644 index 00000000..fafbc4ce --- /dev/null +++ b/plugins/gme/game-music-emu-0.6pre/gme/Ay_Emu.cpp @@ -0,0 +1,306 @@ +// Game_Music_Emu 0.6-pre. http://www.slack.net/~ant/
+
+#include "Ay_Emu.h"
+
+#include "blargg_endian.h"
+
+/* Copyright (C) 2006-2009 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"
+
+// TODO: probably don't need detailed errors as to why file is corrupt
+
+int const spectrum_clock = 3546900; // 128K Spectrum
+int const spectrum_period = 70908;
+
+//int const spectrum_clock = 3500000; // 48K Spectrum
+//int const spectrum_period = 69888;
+
+int const cpc_clock = 2000000;
+
+Ay_Emu::Ay_Emu()
+{
+ core.set_cpc_callback( enable_cpc_, this );
+ set_type( gme_ay_type );
+ set_silence_lookahead( 6 );
+}
+
+Ay_Emu::~Ay_Emu() { }
+
+// Track info
+
+// Given pointer to 2-byte offset of data, returns pointer to data, or NULL if
+// offset is 0 or there is less than min_size bytes of data available.
+static byte const* get_data( Ay_Emu::file_t const& file, byte const ptr [], int min_size )
+{
+ int offset = (BOOST::int16_t) get_be16( ptr );
+ int pos = ptr - (byte const*) file.header;
+ int size = file.end - (byte const*) file.header;
+ assert( (unsigned) pos <= (unsigned) size - 2 );
+ int limit = size - min_size;
+ if ( limit < 0 || !offset || (unsigned) (pos + offset) > (unsigned) limit )
+ return NULL;
+ return ptr + offset;
+}
+
+static blargg_err_t parse_header( byte const in [], int size, Ay_Emu::file_t* out )
+{
+ typedef Ay_Emu::header_t header_t;
+ if ( size < header_t::size )
+ return blargg_err_file_type;
+
+ out->header = (header_t const*) in;
+ out->end = in + size;
+ header_t const& h = *(header_t const*) in;
+ if ( memcmp( h.tag, "ZXAYEMUL", 8 ) )
+ return blargg_err_file_type;
+
+ out->tracks = get_data( *out, h.track_info, (h.max_track + 1) * 4 );
+ if ( !out->tracks )
+ return BLARGG_ERR( BLARGG_ERR_FILE_CORRUPT, "missing track data" );
+
+ return blargg_ok;
+}
+
+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 ) * (1000 / 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 blargg_ok;
+}
+
+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 [], int size )
+ {
+ RETURN_ERR( parse_header( begin, size, &file ) );
+ set_track_count( file.header->max_track + 1 );
+ return blargg_ok;
+ }
+
+ blargg_err_t track_info_( track_info_t* out, int track ) const
+ {
+ copy_ay_fields( file, out, track );
+ return blargg_ok;
+ }
+};
+
+static Music_Emu* new_ay_emu ()
+{
+ return BLARGG_NEW Ay_Emu;
+}
+
+static Music_Emu* new_ay_file()
+{
+ return BLARGG_NEW Ay_File;
+}
+
+gme_type_t_ const gme_ay_type [1] = {{
+ "ZX Spectrum",
+ 0,
+ &new_ay_emu,
+ &new_ay_file,
+ "AY",
+ 1
+}};
+
+// Setup
+
+blargg_err_t Ay_Emu::load_mem_( byte const in [], int size )
+{
+ assert( offsetof (header_t,track_info [2]) == header_t::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" );
+
+ int const osc_count = Ay_Apu::osc_count + 1; // +1 for beeper
+
+ set_voice_count( osc_count );
+ core.apu().volume( gain() );
+
+ 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+1
+ };
+ set_voice_types( types );
+
+ return setup_buffer( spectrum_clock );
+}
+
+void Ay_Emu::update_eq( blip_eq_t const& eq )
+{
+ core.apu().treble_eq( eq );
+}
+
+void Ay_Emu::set_voice( int i, Blip_Buffer* center, Blip_Buffer*, Blip_Buffer* )
+{
+ if ( i >= Ay_Apu::osc_count )
+ core.set_beeper_output( center );
+ else
+ core.apu().set_output( i, center );
+}
+
+void Ay_Emu::set_tempo_( double t )
+{
+ int p = spectrum_period;
+ if ( clock_rate() != spectrum_clock )
+ p = clock_rate() / 50;
+
+ core.set_play_period( blip_time_t (p / t) );
+}
+
+blargg_err_t Ay_Emu::start_track_( int track )
+{
+ RETURN_ERR( Classic_Emu::start_track_( track ) );
+
+ byte* const mem = core.mem();
+
+ memset( mem + 0x0000, 0xC9, 0x100 ); // fill RST vectors with RET
+ memset( mem + 0x0100, 0xFF, 0x4000 - 0x100 );
+ memset( mem + core.ram_addr, 0x00, core.mem_size - core.ram_addr );
+
+ // locate data blocks
+ byte const* const data = get_data( file, file.tracks + track * 4 + 2, 14 );
+ if ( !data )
+ return BLARGG_ERR( BLARGG_ERR_FILE_CORRUPT, "file data missing" );
+
+ byte const* const more_data = get_data( file, data + 10, 6 );
+ if ( !more_data )
+ return BLARGG_ERR( BLARGG_ERR_FILE_CORRUPT, "file data missing" );
+
+ byte const* blocks = get_data( file, data + 12, 8 );
+ if ( !blocks )
+ return BLARGG_ERR( BLARGG_ERR_FILE_CORRUPT, "file data missing" );
+
+ // initial addresses
+ unsigned addr = get_be16( blocks );
+ if ( !addr )
+ return BLARGG_ERR( BLARGG_ERR_FILE_CORRUPT, "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 > core.mem_size )
+ {
+ set_warning( "Bad data block size" );
+ len = core.mem_size - addr;
+ }
+ check( len );
+ byte const* in = get_data( file, blocks, 0 ); blocks += 2;
+ if ( len > (unsigned) (file.end - in) )
+ {
+ set_warning( "File data missing" );
+ len = file.end - in;
+ }
+ //dprintf( "addr: $%04X, len: $%04X\n", addr, len );
+ if ( addr < core.ram_addr && addr >= 0x400 ) // several tracks use low data
+ dprintf( "Block addr in ROM\n" );
+ memcpy( mem + addr, in, len );
+
+ if ( file.end - blocks < 8 )
+ {
+ set_warning( "File data missing" );
+ 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, passive, sizeof passive );
+ int const play_addr = get_be16( more_data + 4 );
+ if ( play_addr )
+ {
+ memcpy( mem, active, sizeof active );
+ mem [ 9] = play_addr;
+ mem [10] = play_addr >> 8;
+ }
+ mem [2] = init;
+ mem [3] = init >> 8;
+
+ mem [0x38] = 0xFB; // Put EI at interrupt vector (followed by RET)
+
+ // start at spectrum speed
+ change_clock_rate( spectrum_clock );
+ set_tempo( tempo() );
+
+ Ay_Core::registers_t r = { };
+ 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;
+
+ core.start_track( r, play_addr );
+
+ return blargg_ok;
+}
+
+blargg_err_t Ay_Emu::run_clocks( blip_time_t& duration, int )
+{
+ core.end_frame( &duration );
+ return blargg_ok;
+}
+
+inline void Ay_Emu::enable_cpc()
+{
+ change_clock_rate( cpc_clock );
+ set_tempo( tempo() );
+}
+
+void Ay_Emu::enable_cpc_( void* data )
+{
+ STATIC_CAST(Ay_Emu*,data)->enable_cpc();
+}
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