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Diffstat (limited to 'plugins/gme/game-music-emu-0.5.5/gme/Sap_Apu.cpp')
-rw-r--r--plugins/gme/game-music-emu-0.5.5/gme/Sap_Apu.cpp334
1 files changed, 0 insertions, 334 deletions
diff --git a/plugins/gme/game-music-emu-0.5.5/gme/Sap_Apu.cpp b/plugins/gme/game-music-emu-0.5.5/gme/Sap_Apu.cpp
deleted file mode 100644
index fb56f5dc..00000000
--- a/plugins/gme/game-music-emu-0.5.5/gme/Sap_Apu.cpp
+++ /dev/null
@@ -1,334 +0,0 @@
-// Game_Music_Emu 0.5.5. http://www.slack.net/~ant/
-
-#include "Sap_Apu.h"
-
-#include <string.h>
-
-/* Copyright (C) 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"
-
-int const max_frequency = 12000; // pure waves above this frequency are silenced
-
-static void gen_poly( blargg_ulong mask, int count, byte* out )
-{
- blargg_ulong n = 1;
- do
- {
- int bits = 0;
- int b = 0;
- do
- {
- // implemented using "Galios configuration"
- bits |= (n & 1) << b;
- n = (n >> 1) ^ (mask & -(n & 1));
- }
- while ( b++ < 7 );
- *out++ = bits;
- }
- while ( --count );
-}
-
-// poly5
-int const poly5_len = (1 << 5) - 1;
-blargg_ulong const poly5_mask = (1UL << poly5_len) - 1;
-blargg_ulong const poly5 = 0x167C6EA1;
-
-inline blargg_ulong run_poly5( blargg_ulong in, int shift )
-{
- return (in << shift & poly5_mask) | (in >> (poly5_len - shift));
-}
-
-#define POLY_MASK( width, tap1, tap2 ) \
- ((1UL << (width - 1 - tap1)) | (1UL << (width - 1 - tap2)))
-
-Sap_Apu_Impl::Sap_Apu_Impl()
-{
- gen_poly( POLY_MASK( 4, 1, 0 ), sizeof poly4, poly4 );
- gen_poly( POLY_MASK( 9, 5, 0 ), sizeof poly9, poly9 );
- gen_poly( POLY_MASK( 17, 5, 0 ), sizeof poly17, poly17 );
-
- if ( 0 ) // comment out to recauculate poly5 constant
- {
- byte poly5 [4];
- gen_poly( POLY_MASK( 5, 2, 0 ), sizeof poly5, poly5 );
- blargg_ulong n = poly5 [3] * 0x1000000L + poly5 [2] * 0x10000L +
- poly5 [1] * 0x100L + poly5 [0];
- blargg_ulong rev = n & 1;
- for ( int i = 1; i < poly5_len; i++ )
- rev |= (n >> i & 1) << (poly5_len - i);
- debug_printf( "poly5: 0x%08lX\n", rev );
- }
-}
-
-Sap_Apu::Sap_Apu()
-{
- impl = 0;
- for ( int i = 0; i < osc_count; i++ )
- osc_output( i, 0 );
-}
-
-void Sap_Apu::reset( Sap_Apu_Impl* new_impl )
-{
- impl = new_impl;
- last_time = 0;
- poly5_pos = 0;
- poly4_pos = 0;
- polym_pos = 0;
- control = 0;
-
- for ( int i = 0; i < osc_count; i++ )
- memset( &oscs [i], 0, offsetof (osc_t,output) );
-}
-
-void Sap_Apu::calc_periods()
-{
- // 15/64 kHz clock
- int divider = 28;
- if ( this->control & 1 )
- divider = 114;
-
- for ( int i = 0; i < osc_count; i++ )
- {
- osc_t* const osc = &oscs [i];
-
- int const osc_reload = osc->regs [0]; // cache
- blargg_long period = (osc_reload + 1) * divider;
- static byte const fast_bits [osc_count] = { 1 << 6, 1 << 4, 1 << 5, 1 << 3 };
- if ( this->control & fast_bits [i] )
- {
- period = osc_reload + 4;
- if ( i & 1 )
- {
- period = osc_reload * 0x100L + osc [-1].regs [0] + 7;
- if ( !(this->control & fast_bits [i - 1]) )
- period = (period - 6) * divider;
-
- if ( (osc [-1].regs [1] & 0x1F) > 0x10 )
- debug_printf( "Use of slave channel in 16-bit mode not supported\n" );
- }
- }
- osc->period = period;
- }
-}
-
-void Sap_Apu::run_until( blip_time_t end_time )
-{
- calc_periods();
- Sap_Apu_Impl* const impl = this->impl; // cache
-
- // 17/9-bit poly selection
- byte const* polym = impl->poly17;
- int polym_len = poly17_len;
- if ( this->control & 0x80 )
- {
- polym_len = poly9_len;
- polym = impl->poly9;
- }
- polym_pos %= polym_len;
-
- for ( int i = 0; i < osc_count; i++ )
- {
- osc_t* const osc = &oscs [i];
- blip_time_t time = last_time + osc->delay;
- blip_time_t const period = osc->period;
-
- // output
- Blip_Buffer* output = osc->output;
- if ( output )
- {
- output->set_modified();
-
- int const osc_control = osc->regs [1]; // cache
- int volume = (osc_control & 0x0F) * 2;
- if ( !volume || osc_control & 0x10 || // silent, DAC mode, or inaudible frequency
- ((osc_control & 0xA0) == 0xA0 && period < 1789773 / 2 / max_frequency) )
- {
- if ( !(osc_control & 0x10) )
- volume >>= 1; // inaudible frequency = half volume
-
- int delta = volume - osc->last_amp;
- if ( delta )
- {
- osc->last_amp = volume;
- impl->synth.offset( last_time, delta, output );
- }
-
- // TODO: doesn't maintain high pass flip-flop (very minor issue)
- }
- else
- {
- // high pass
- static byte const hipass_bits [osc_count] = { 1 << 2, 1 << 1, 0, 0 };
- blip_time_t period2 = 0; // unused if no high pass
- blip_time_t time2 = end_time;
- if ( this->control & hipass_bits [i] )
- {
- period2 = osc [2].period;
- time2 = last_time + osc [2].delay;
- if ( osc->invert )
- {
- // trick inner wave loop into inverting output
- osc->last_amp -= volume;
- volume = -volume;
- }
- }
-
- if ( time < end_time || time2 < end_time )
- {
- // poly source
- static byte const poly1 [] = { 0x55, 0x55 }; // square wave
- byte const* poly = poly1;
- int poly_len = 8 * sizeof poly1; // can be just 2 bits, but this is faster
- int poly_pos = osc->phase & 1;
- int poly_inc = 1;
- if ( !(osc_control & 0x20) )
- {
- poly = polym;
- poly_len = polym_len;
- poly_pos = polym_pos;
- if ( osc_control & 0x40 )
- {
- poly = impl->poly4;
- poly_len = poly4_len;
- poly_pos = poly4_pos;
- }
- poly_inc = period % poly_len;
- poly_pos = (poly_pos + osc->delay) % poly_len;
- }
- poly_inc -= poly_len; // allows more optimized inner loop below
-
- // square/poly5 wave
- blargg_ulong wave = poly5;
- check( poly5 & 1 ); // low bit is set for pure wave
- int poly5_inc = 0;
- if ( !(osc_control & 0x80) )
- {
- wave = run_poly5( wave, (osc->delay + poly5_pos) % poly5_len );
- poly5_inc = period % poly5_len;
- }
-
- // Run wave and high pass interleved with each catching up to the other.
- // Disabled high pass has no performance effect since inner wave loop
- // makes no compromise for high pass, and only runs once in that case.
- int osc_last_amp = osc->last_amp;
- do
- {
- // run high pass
- if ( time2 < time )
- {
- int delta = -osc_last_amp;
- if ( volume < 0 )
- delta += volume;
- if ( delta )
- {
- osc_last_amp += delta - volume;
- volume = -volume;
- impl->synth.offset( time2, delta, output );
- }
- }
- while ( time2 <= time ) // must advance *past* time to avoid hang
- time2 += period2;
-
- // run wave
- blip_time_t end = end_time;
- if ( end > time2 )
- end = time2;
- while ( time < end )
- {
- if ( wave & 1 )
- {
- int amp = volume & -(poly [poly_pos >> 3] >> (poly_pos & 7) & 1);
- if ( (poly_pos += poly_inc) < 0 )
- poly_pos += poly_len;
- int delta = amp - osc_last_amp;
- if ( delta )
- {
- osc_last_amp = amp;
- impl->synth.offset( time, delta, output );
- }
- }
- wave = run_poly5( wave, poly5_inc );
- time += period;
- }
- }
- while ( time < end_time || time2 < end_time );
-
- osc->phase = poly_pos;
- osc->last_amp = osc_last_amp;
- }
-
- osc->invert = 0;
- if ( volume < 0 )
- {
- // undo inversion trickery
- osc->last_amp -= volume;
- osc->invert = 1;
- }
- }
- }
-
- // maintain divider
- blip_time_t remain = end_time - time;
- if ( remain > 0 )
- {
- blargg_long count = (remain + period - 1) / period;
- osc->phase ^= count;
- time += count * period;
- }
- osc->delay = time - end_time;
- }
-
- // advance polies
- blip_time_t duration = end_time - last_time;
- last_time = end_time;
- poly4_pos = (poly4_pos + duration) % poly4_len;
- poly5_pos = (poly5_pos + duration) % poly5_len;
- polym_pos += duration; // will get %'d on next call
-}
-
-void Sap_Apu::write_data( blip_time_t time, unsigned addr, int data )
-{
- run_until( time );
- int i = (addr ^ 0xD200) >> 1;
- if ( i < osc_count )
- {
- oscs [i].regs [addr & 1] = data;
- }
- else if ( addr == 0xD208 )
- {
- control = data;
- }
- else if ( addr == 0xD209 )
- {
- oscs [0].delay = 0;
- oscs [1].delay = 0;
- oscs [2].delay = 0;
- oscs [3].delay = 0;
- }
- /*
- // TODO: are polynomials reset in this case?
- else if ( addr == 0xD20F )
- {
- if ( (data & 3) == 0 )
- polym_pos = 0;
- }
- */
-}
-
-void Sap_Apu::end_frame( blip_time_t end_time )
-{
- if ( end_time > last_time )
- run_until( end_time );
-
- last_time -= end_time;
-}
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