From acb0917556fc33681c1df5a530cf754193e67705 Mon Sep 17 00:00:00 2001
From: Andree Buschmann <AndreeBuschmann@t-online.de>
Date: Sun, 7 Aug 2011 20:01:04 +0000
Subject: Submit initial patch from FS#12176. Adds support for several new game
 music formats (AY, GBS, HES, KSS, SGC, VGM and VGZ) and replaces the current
 NSF and NSFE with a new implementation based on a port of the Game Music Emu
 library 'GME'. This first submit does not cover the full functionality
 provided by the author's original patch: Coleco-SGV is not supported, some
 GME-specific m3u-support has been removed and IRAM is not used yet. Further
 changes are very likely to follow this submit. Thanks to Mauricio Garrido.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@30264 a1c6a512-1295-4272-9138-f99709370657
---
 apps/codecs/libgme/nes_fme7_apu.h | 90 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 90 insertions(+)
 create mode 100644 apps/codecs/libgme/nes_fme7_apu.h

(limited to 'apps/codecs/libgme/nes_fme7_apu.h')

diff --git a/apps/codecs/libgme/nes_fme7_apu.h b/apps/codecs/libgme/nes_fme7_apu.h
new file mode 100644
index 0000000000..47b93e5cfe
--- /dev/null
+++ b/apps/codecs/libgme/nes_fme7_apu.h
@@ -0,0 +1,90 @@
+// Sunsoft FME-7 sound emulator
+
+// Game_Music_Emu 0.5.5
+#ifndef NES_FME7_APU_H
+#define NES_FME7_APU_H
+
+#include "blargg_common.h"
+#include "blip_buffer.h"
+
+enum { fme7_reg_count = 14 };
+
+// Mask and addresses of registers
+enum { fme7_addr_mask = 0xE000 };
+enum { fme7_data_addr = 0xE000 };
+enum { fme7_latch_addr = 0xC000 };
+enum { fme7_osc_count = 3 };
+
+enum { amp_range = 192 }; // can be any value; this gives best error/quality tradeoff
+
+struct osc_t {
+	struct Blip_Buffer* output;
+	int last_amp;
+};
+
+// static unsigned char const amp_table [16];
+
+struct Nes_Fme7_Apu {
+	// fme7 apu state
+	uint8_t regs [fme7_reg_count];
+	uint8_t phases [3]; // 0 or 1
+	uint8_t latch;
+	uint16_t delays [3]; // a, b, c
+	
+	struct osc_t oscs [fme7_osc_count];
+	blip_time_t last_time;
+	
+	struct Blip_Synth synth;
+};
+
+// See Nes_Apu.h for reference
+void Fme7_init( struct Nes_Fme7_Apu* this );
+void Fme7_reset( struct Nes_Fme7_Apu* this );
+	
+static inline void Fme7_volume( struct Nes_Fme7_Apu* this, double v )
+{
+	Synth_volume( &this->synth, 0.38 / amp_range * v ); // to do: fine-tune
+}
+
+static inline void Fme7_osc_output( struct Nes_Fme7_Apu* this, int i, struct Blip_Buffer* buf )
+{
+	assert( (unsigned) i < fme7_osc_count );
+	this->oscs [i].output = buf;
+}
+
+static inline void Fme7_output( struct Nes_Fme7_Apu* this, struct Blip_Buffer* buf )
+{
+	int i;
+	for ( i = 0; i < fme7_osc_count; i++ )
+		Fme7_osc_output( this, i, buf );
+}
+
+// (addr & addr_mask) == latch_addr
+static inline void Fme7_write_latch( struct Nes_Fme7_Apu* this, int data ) { this->latch = data; }
+
+// (addr & addr_mask) == data_addr
+void Fme7_run_until( struct Nes_Fme7_Apu* this, blip_time_t end_time ) ICODE_ATTR;
+static inline void Fme7_write_data( struct Nes_Fme7_Apu* this, blip_time_t time, int data )
+{
+	if ( (unsigned) this->latch >= fme7_reg_count )
+	{
+		#ifdef debug_printf
+			debug_printf( "FME7 write to %02X (past end of sound registers)\n", (int) latch );
+		#endif
+		return;
+	}
+	
+	Fme7_run_until( this, time );
+	this->regs [this->latch] = data;
+}
+
+static inline void Fme7_end_frame( struct Nes_Fme7_Apu* this, blip_time_t time )
+{
+	if ( time > this->last_time )
+		Fme7_run_until( this, time );
+	
+	assert( this->last_time >= time );
+	this->last_time -= time;
+}
+
+#endif
-- 
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