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Diffstat (limited to 'plugins/gme/game-music-emu-0.6.0/gme/Vgm_Emu_Impl.cpp')
-rw-r--r--plugins/gme/game-music-emu-0.6.0/gme/Vgm_Emu_Impl.cpp314
1 files changed, 314 insertions, 0 deletions
diff --git a/plugins/gme/game-music-emu-0.6.0/gme/Vgm_Emu_Impl.cpp b/plugins/gme/game-music-emu-0.6.0/gme/Vgm_Emu_Impl.cpp
new file mode 100644
index 00000000..5a9b724a
--- /dev/null
+++ b/plugins/gme/game-music-emu-0.6.0/gme/Vgm_Emu_Impl.cpp
@@ -0,0 +1,314 @@
+// Game_Music_Emu 0.5.5. http://www.slack.net/~ant/
+
+#include "Vgm_Emu.h"
+
+#include <math.h>
+#include <string.h>
+#include "blargg_endian.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"
+
+enum {
+ cmd_gg_stereo = 0x4F,
+ cmd_psg = 0x50,
+ cmd_ym2413 = 0x51,
+ cmd_ym2612_port0 = 0x52,
+ cmd_ym2612_port1 = 0x53,
+ cmd_ym2151 = 0x54,
+ cmd_delay = 0x61,
+ cmd_delay_735 = 0x62,
+ cmd_delay_882 = 0x63,
+ cmd_byte_delay = 0x64,
+ cmd_end = 0x66,
+ cmd_data_block = 0x67,
+ cmd_short_delay = 0x70,
+ cmd_pcm_delay = 0x80,
+ cmd_pcm_seek = 0xE0,
+
+ pcm_block_type = 0x00,
+ ym2612_dac_port = 0x2A
+};
+
+inline int command_len( int command )
+{
+ switch ( command >> 4 )
+ {
+ case 0x03:
+ case 0x04:
+ return 2;
+
+ case 0x05:
+ case 0x0A:
+ case 0x0B:
+ return 3;
+
+ case 0x0C:
+ case 0x0D:
+ return 4;
+
+ case 0x0E:
+ case 0x0F:
+ return 5;
+ }
+
+ check( false );
+ return 1;
+}
+
+template<class Emu>
+inline void Ym_Emu<Emu>::begin_frame( short* p )
+{
+ require( enabled() );
+ out = p;
+ last_time = 0;
+}
+
+template<class Emu>
+inline int Ym_Emu<Emu>::run_until( int time )
+{
+ int count = time - last_time;
+ if ( count > 0 )
+ {
+ if ( last_time < 0 )
+ return false;
+ last_time = time;
+ short* p = out;
+ out += count * Emu::out_chan_count;
+ Emu::run( count, p );
+ }
+ return true;
+}
+
+inline Vgm_Emu_Impl::fm_time_t Vgm_Emu_Impl::to_fm_time( vgm_time_t t ) const
+{
+ return (t * fm_time_factor + fm_time_offset) >> fm_time_bits;
+}
+
+inline blip_time_t Vgm_Emu_Impl::to_blip_time( vgm_time_t t ) const
+{
+ return (t * blip_time_factor) >> blip_time_bits;
+}
+
+void Vgm_Emu_Impl::write_pcm( vgm_time_t vgm_time, int amp )
+{
+ blip_time_t blip_time = to_blip_time( vgm_time );
+ int old = dac_amp;
+ int delta = amp - old;
+ dac_amp = amp;
+ if ( old >= 0 )
+ dac_synth.offset_inline( blip_time, delta, &blip_buf );
+ else
+ dac_amp |= dac_disabled;
+}
+
+blip_time_t Vgm_Emu_Impl::run_commands( vgm_time_t end_time )
+{
+ vgm_time_t vgm_time = this->vgm_time;
+ byte const* pos = this->pos;
+ if ( pos >= data_end )
+ {
+ set_track_ended();
+ if ( pos > data_end )
+ set_warning( "Stream lacked end event" );
+ }
+
+ while ( vgm_time < end_time && pos < data_end )
+ {
+ // TODO: be sure there are enough bytes left in stream for particular command
+ // so we don't read past end
+ switch ( *pos++ )
+ {
+ case cmd_end:
+ pos = loop_begin; // if not looped, loop_begin == data_end
+ break;
+
+ case cmd_delay_735:
+ vgm_time += 735;
+ break;
+
+ case cmd_delay_882:
+ vgm_time += 882;
+ break;
+
+ case cmd_gg_stereo:
+ psg.write_ggstereo( to_blip_time( vgm_time ), *pos++ );
+ break;
+
+ case cmd_psg:
+ psg.write_data( to_blip_time( vgm_time ), *pos++ );
+ break;
+
+ case cmd_delay:
+ vgm_time += pos [1] * 0x100L + pos [0];
+ pos += 2;
+ break;
+
+ case cmd_byte_delay:
+ vgm_time += *pos++;
+ break;
+
+ case cmd_ym2413:
+ if ( ym2413.run_until( to_fm_time( vgm_time ) ) )
+ ym2413.write( pos [0], pos [1] );
+ pos += 2;
+ break;
+
+ case cmd_ym2612_port0:
+ if ( pos [0] == ym2612_dac_port )
+ {
+ write_pcm( vgm_time, pos [1] );
+ }
+ else if ( ym2612.run_until( to_fm_time( vgm_time ) ) )
+ {
+ if ( pos [0] == 0x2B )
+ {
+ dac_disabled = (pos [1] >> 7 & 1) - 1;
+ dac_amp |= dac_disabled;
+ }
+ ym2612.write0( pos [0], pos [1] );
+ }
+ pos += 2;
+ break;
+
+ case cmd_ym2612_port1:
+ if ( ym2612.run_until( to_fm_time( vgm_time ) ) )
+ ym2612.write1( pos [0], pos [1] );
+ pos += 2;
+ break;
+
+ case cmd_data_block: {
+ check( *pos == cmd_end );
+ int type = pos [1];
+ long size = get_le32( pos + 2 );
+ pos += 6;
+ if ( type == pcm_block_type )
+ pcm_data = pos;
+ pos += size;
+ break;
+ }
+
+ case cmd_pcm_seek:
+ pcm_pos = pcm_data + pos [3] * 0x1000000L + pos [2] * 0x10000L +
+ pos [1] * 0x100L + pos [0];
+ pos += 4;
+ break;
+
+ default:
+ int cmd = pos [-1];
+ switch ( cmd & 0xF0 )
+ {
+ case cmd_pcm_delay:
+ write_pcm( vgm_time, *pcm_pos++ );
+ vgm_time += cmd & 0x0F;
+ break;
+
+ case cmd_short_delay:
+ vgm_time += (cmd & 0x0F) + 1;
+ break;
+
+ case 0x50:
+ pos += 2;
+ break;
+
+ default:
+ pos += command_len( cmd ) - 1;
+ set_warning( "Unknown stream event" );
+ }
+ }
+ }
+ vgm_time -= end_time;
+ this->pos = pos;
+ this->vgm_time = vgm_time;
+
+ return to_blip_time( end_time );
+}
+
+int Vgm_Emu_Impl::play_frame( blip_time_t blip_time, int sample_count, sample_t* buf )
+{
+ // to do: timing is working mostly by luck
+
+ int min_pairs = sample_count >> 1;
+ int vgm_time = ((long) min_pairs << fm_time_bits) / fm_time_factor - 1;
+ assert( to_fm_time( vgm_time ) <= min_pairs );
+ int pairs = min_pairs;
+ while ( (pairs = to_fm_time( vgm_time )) < min_pairs )
+ vgm_time++;
+ //debug_printf( "pairs: %d, min_pairs: %d\n", pairs, min_pairs );
+
+ if ( ym2612.enabled() )
+ {
+ ym2612.begin_frame( buf );
+ memset( buf, 0, pairs * stereo * sizeof *buf );
+ }
+ else if ( ym2413.enabled() )
+ {
+ ym2413.begin_frame( buf );
+ }
+
+ run_commands( vgm_time );
+ ym2612.run_until( pairs );
+ ym2413.run_until( pairs );
+
+ fm_time_offset = (vgm_time * fm_time_factor + fm_time_offset) -
+ ((long) pairs << fm_time_bits);
+
+ psg.end_frame( blip_time );
+
+ return pairs * stereo;
+}
+
+// Update pre-1.10 header FM rates by scanning commands
+void Vgm_Emu_Impl::update_fm_rates( long* ym2413_rate, long* ym2612_rate ) const
+{
+ byte const* p = data + 0x40;
+ while ( p < data_end )
+ {
+ switch ( *p )
+ {
+ case cmd_end:
+ return;
+
+ case cmd_psg:
+ case cmd_byte_delay:
+ p += 2;
+ break;
+
+ case cmd_delay:
+ p += 3;
+ break;
+
+ case cmd_data_block:
+ p += 7 + get_le32( p + 3 );
+ break;
+
+ case cmd_ym2413:
+ *ym2612_rate = 0;
+ return;
+
+ case cmd_ym2612_port0:
+ case cmd_ym2612_port1:
+ *ym2612_rate = *ym2413_rate;
+ *ym2413_rate = 0;
+ return;
+
+ case cmd_ym2151:
+ *ym2413_rate = 0;
+ *ym2612_rate = 0;
+ return;
+
+ default:
+ p += command_len( *p );
+ }
+ }
+}
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