1 files changed, 121 insertions, 0 deletions
diff --git a/plugins/gme/game-music-emu-0.6.0/gme/Nes_Fme7_Apu.cpp b/plugins/gme/game-music-emu-0.6.0/gme/Nes_Fme7_Apu.cpp
new file mode 100644
index 00000000..62594fc2
--- /dev/null
+++ b/plugins/gme/game-music-emu-0.6.0/gme/Nes_Fme7_Apu.cpp
@@ -0,0 +1,121 @@
+// Game_Music_Emu 0.5.5. http://www.slack.net/~ant/
+
+#include "Nes_Fme7_Apu.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"
+
+void Nes_Fme7_Apu::reset()
+{
+	last_time = 0;
+	
+	for ( int i = 0; i < osc_count; i++ )
+		oscs [i].last_amp = 0;
+	
+	fme7_apu_state_t* state = this;
+	memset( state, 0, sizeof *state );
+}
+
+unsigned char const Nes_Fme7_Apu::amp_table [16] =
+{
+	#define ENTRY( n ) (unsigned char) (n * amp_range + 0.5)
+	ENTRY(0.0000), ENTRY(0.0078), ENTRY(0.0110), ENTRY(0.0156),
+	ENTRY(0.0221), ENTRY(0.0312), ENTRY(0.0441), ENTRY(0.0624),
+	ENTRY(0.0883), ENTRY(0.1249), ENTRY(0.1766), ENTRY(0.2498),
+	ENTRY(0.3534), ENTRY(0.4998), ENTRY(0.7070), ENTRY(1.0000)
+	#undef ENTRY
+};
+
+void Nes_Fme7_Apu::run_until( blip_time_t end_time )
+{
+	require( end_time >= last_time );
+	
+	for ( int index = 0; index < osc_count; index++ )
+	{
+		int mode = regs [7] >> index;
+		int vol_mode = regs [010 + index];
+		int volume = amp_table [vol_mode & 0x0F];
+		
+		Blip_Buffer* const osc_output = oscs [index].output;
+		if ( !osc_output )
+			continue;
+		osc_output->set_modified();
+		
+		// check for unsupported mode
+		#ifndef NDEBUG
+			if ( (mode & 011) <= 001 && vol_mode & 0x1F )
+				debug_printf( "FME7 used unimplemented sound mode: %02X, vol_mode: %02X\n",
+						mode, vol_mode & 0x1F );
+		#endif
+		
+		if ( (mode & 001) | (vol_mode & 0x10) )
+			volume = 0; // noise and envelope aren't supported
+		
+		// period
+		int const period_factor = 16;
+		unsigned period = (regs [index * 2 + 1] & 0x0F) * 0x100 * period_factor +
+				regs [index * 2] * period_factor;
+		if ( period < 50 ) // around 22 kHz
+		{
+			volume = 0;
+			if ( !period ) // on my AY-3-8910A, period doesn't have extra one added
+				period = period_factor;
+		}
+		
+		// current amplitude
+		int amp = volume;
+		if ( !phases [index] )
+			amp = 0;
+		{
+			int delta = amp - oscs [index].last_amp;
+			if ( delta )
+			{
+				oscs [index].last_amp = amp;
+				synth.offset( last_time, delta, osc_output );
+			}
+		}
+		
+		blip_time_t time = last_time + delays [index];
+		if ( time < end_time )
+		{
+			int delta = amp * 2 - volume;
+			if ( volume )
+			{
+				do
+				{
+					delta = -delta;
+					synth.offset_inline( time, delta, osc_output );
+					time += period;
+				}
+				while ( time < end_time );
+				
+				oscs [index].last_amp = (delta + volume) >> 1;
+				phases [index] = (delta > 0);
+			}
+			else
+			{
+				// maintain phase when silent
+				int count = (end_time - time + period - 1) / period;
+				phases [index] ^= count & 1;
+				time += (blargg_long) count * period;
+			}
+		}
+		
+		delays [index] = time - end_time;
+	}
+	
+	last_time = end_time;
+}
+