631d22b8e5
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@30278 a1c6a512-1295-4272-9138-f99709370657
90 lines
2.2 KiB
C
90 lines
2.2 KiB
C
// Sunsoft FME-7 sound emulator
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// Game_Music_Emu 0.5.5
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#ifndef NES_FME7_APU_H
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#define NES_FME7_APU_H
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#include "blargg_common.h"
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#include "blip_buffer.h"
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enum { fme7_reg_count = 14 };
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// Mask and addresses of registers
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enum { fme7_addr_mask = 0xE000 };
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enum { fme7_data_addr = 0xE000 };
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enum { fme7_latch_addr = 0xC000 };
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enum { fme7_osc_count = 3 };
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enum { amp_range = 192 }; // can be any value; this gives best error/quality tradeoff
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struct osc_t {
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struct Blip_Buffer* output;
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int last_amp;
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};
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// static unsigned char const amp_table [16];
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struct Nes_Fme7_Apu {
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// fme7 apu state
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uint8_t regs [fme7_reg_count];
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uint8_t phases [3]; // 0 or 1
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uint8_t latch;
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uint16_t delays [3]; // a, b, c
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struct osc_t oscs [fme7_osc_count];
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blip_time_t last_time;
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struct Blip_Synth synth;
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};
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// See Nes_Apu.h for reference
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void Fme7_init( struct Nes_Fme7_Apu* this );
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void Fme7_reset( struct Nes_Fme7_Apu* this );
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static inline void Fme7_volume( struct Nes_Fme7_Apu* this, int v )
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{
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Synth_volume( &this->synth, (v/2 - (v*3)/25) / amp_range ); // to do: fine-tune
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}
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static inline void Fme7_osc_output( struct Nes_Fme7_Apu* this, int i, struct Blip_Buffer* buf )
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{
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assert( (unsigned) i < fme7_osc_count );
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this->oscs [i].output = buf;
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}
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static inline void Fme7_output( struct Nes_Fme7_Apu* this, struct Blip_Buffer* buf )
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{
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int i;
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for ( i = 0; i < fme7_osc_count; i++ )
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Fme7_osc_output( this, i, buf );
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}
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// (addr & addr_mask) == latch_addr
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static inline void Fme7_write_latch( struct Nes_Fme7_Apu* this, int data ) { this->latch = data; }
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// (addr & addr_mask) == data_addr
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void Fme7_run_until( struct Nes_Fme7_Apu* this, blip_time_t end_time ) ICODE_ATTR;
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static inline void Fme7_write_data( struct Nes_Fme7_Apu* this, blip_time_t time, int data )
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{
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if ( (unsigned) this->latch >= fme7_reg_count )
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{
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#ifdef debug_printf
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debug_printf( "FME7 write to %02X (past end of sound registers)\n", (int) latch );
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#endif
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return;
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}
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Fme7_run_until( this, time );
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this->regs [this->latch] = data;
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}
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static inline void Fme7_end_frame( struct Nes_Fme7_Apu* this, blip_time_t time )
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{
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if ( time > this->last_time )
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Fme7_run_until( this, time );
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assert( this->last_time >= time );
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this->last_time -= time;
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}
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#endif
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