diff options
Diffstat (limited to 'plugins/gme/Game_Music_Emu-0.5.2/gme/Gb_Apu.cpp')
-rw-r--r-- | plugins/gme/Game_Music_Emu-0.5.2/gme/Gb_Apu.cpp | 306 |
1 files changed, 0 insertions, 306 deletions
diff --git a/plugins/gme/Game_Music_Emu-0.5.2/gme/Gb_Apu.cpp b/plugins/gme/Game_Music_Emu-0.5.2/gme/Gb_Apu.cpp deleted file mode 100644 index 932ebb83..00000000 --- a/plugins/gme/Game_Music_Emu-0.5.2/gme/Gb_Apu.cpp +++ /dev/null @@ -1,306 +0,0 @@ -// Gb_Snd_Emu 0.1.5. http://www.slack.net/~ant/ - -#include "Gb_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" - -unsigned const vol_reg = 0xFF24; -unsigned const status_reg = 0xFF26; - -Gb_Apu::Gb_Apu() -{ - square1.synth = &square_synth; - square2.synth = &square_synth; - wave.synth = &other_synth; - noise.synth = &other_synth; - - oscs [0] = &square1; - oscs [1] = &square2; - oscs [2] = &wave; - oscs [3] = &noise; - - for ( int i = 0; i < osc_count; i++ ) - { - Gb_Osc& osc = *oscs [i]; - osc.regs = ®s [i * 5]; - osc.output = 0; - osc.outputs [0] = 0; - osc.outputs [1] = 0; - osc.outputs [2] = 0; - osc.outputs [3] = 0; - } - - set_tempo( 1.0 ); - volume( 1.0 ); - reset(); -} - -void Gb_Apu::treble_eq( const blip_eq_t& eq ) -{ - square_synth.treble_eq( eq ); - other_synth.treble_eq( eq ); -} - -void Gb_Apu::osc_output( int index, Blip_Buffer* center, Blip_Buffer* left, Blip_Buffer* right ) -{ - require( (unsigned) index < osc_count ); - require( (center && left && right) || (!center && !left && !right) ); - Gb_Osc& osc = *oscs [index]; - osc.outputs [1] = right; - osc.outputs [2] = left; - osc.outputs [3] = center; - osc.output = osc.outputs [osc.output_select]; -} - -void Gb_Apu::output( Blip_Buffer* center, Blip_Buffer* left, Blip_Buffer* right ) -{ - for ( int i = 0; i < osc_count; i++ ) - osc_output( i, center, left, right ); -} - -void Gb_Apu::update_volume() -{ - // TODO: doesn't handle differing left/right global volume (support would - // require modification to all oscillator code) - int data = regs [vol_reg - start_addr]; - double vol = (max( data & 7, data >> 4 & 7 ) + 1) * volume_unit; - square_synth.volume( vol ); - other_synth.volume( vol ); -} - -static unsigned char const powerup_regs [0x20] = { - 0x80,0x3F,0x00,0xFF,0xBF, // square 1 - 0xFF,0x3F,0x00,0xFF,0xBF, // square 2 - 0x7F,0xFF,0x9F,0xFF,0xBF, // wave - 0xFF,0xFF,0x00,0x00,0xBF, // noise - 0x00, // left/right enables - 0x77, // master volume - 0x80, // power - 0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF -}; - -void Gb_Apu::set_tempo( double t ) -{ - frame_period = 4194304 / 256; // 256 Hz - if ( t != 1.0 ) - frame_period = blip_time_t (frame_period / t); -} - -void Gb_Apu::reset() -{ - next_frame_time = 0; - last_time = 0; - frame_count = 0; - - square1.reset(); - square2.reset(); - wave.reset(); - noise.reset(); - noise.bits = 1; - wave.wave_pos = 0; - - // avoid click at beginning - regs [vol_reg - start_addr] = 0x77; - update_volume(); - - regs [status_reg - start_addr] = 0x01; // force power - write_register( 0, status_reg, 0x00 ); - - static unsigned char const initial_wave [] = { - 0x84,0x40,0x43,0xAA,0x2D,0x78,0x92,0x3C, // wave table - 0x60,0x59,0x59,0xB0,0x34,0xB8,0x2E,0xDA - }; - memcpy( wave.wave, initial_wave, sizeof wave.wave ); -} - -void Gb_Apu::run_until( blip_time_t end_time ) -{ - require( end_time >= last_time ); // end_time must not be before previous time - if ( end_time == last_time ) - return; - - while ( true ) - { - blip_time_t time = next_frame_time; - if ( time > end_time ) - time = end_time; - - // run oscillators - for ( int i = 0; i < osc_count; ++i ) - { - Gb_Osc& osc = *oscs [i]; - if ( osc.output ) - { - osc.output->set_modified(); // TODO: misses optimization opportunities? - int playing = false; - if ( osc.enabled && osc.volume && - (!(osc.regs [4] & osc.len_enabled_mask) || osc.length) ) - playing = -1; - switch ( i ) - { - case 0: square1.run( last_time, time, playing ); break; - case 1: square2.run( last_time, time, playing ); break; - case 2: wave .run( last_time, time, playing ); break; - case 3: noise .run( last_time, time, playing ); break; - } - } - } - last_time = time; - - if ( time == end_time ) - break; - - next_frame_time += frame_period; - - // 256 Hz actions - square1.clock_length(); - square2.clock_length(); - wave.clock_length(); - noise.clock_length(); - - frame_count = (frame_count + 1) & 3; - if ( frame_count == 0 ) - { - // 64 Hz actions - square1.clock_envelope(); - square2.clock_envelope(); - noise.clock_envelope(); - } - - if ( frame_count & 1 ) - square1.clock_sweep(); // 128 Hz action - } -} - -void Gb_Apu::end_frame( blip_time_t end_time ) -{ - if ( end_time > last_time ) - run_until( end_time ); - - assert( next_frame_time >= end_time ); - next_frame_time -= end_time; - - assert( last_time >= end_time ); - last_time -= end_time; -} - -void Gb_Apu::write_register( blip_time_t time, unsigned addr, int data ) -{ - require( (unsigned) data < 0x100 ); - - int reg = addr - start_addr; - if ( (unsigned) reg >= register_count ) - return; - - run_until( time ); - - int old_reg = regs [reg]; - regs [reg] = data; - - if ( addr < vol_reg ) - { - write_osc( reg / 5, reg, data ); - } - else if ( addr == vol_reg && data != old_reg ) // global volume - { - // return all oscs to 0 - for ( int i = 0; i < osc_count; i++ ) - { - Gb_Osc& osc = *oscs [i]; - int amp = osc.last_amp; - osc.last_amp = 0; - if ( amp && osc.enabled && osc.output ) - other_synth.offset( time, -amp, osc.output ); - } - - if ( wave.outputs [3] ) - other_synth.offset( time, 30, wave.outputs [3] ); - - update_volume(); - - if ( wave.outputs [3] ) - other_synth.offset( time, -30, wave.outputs [3] ); - - // oscs will update with new amplitude when next run - } - else if ( addr == 0xFF25 || addr == status_reg ) - { - int mask = (regs [status_reg - start_addr] & 0x80) ? ~0 : 0; - int flags = regs [0xFF25 - start_addr] & mask; - - // left/right assignments - for ( int i = 0; i < osc_count; i++ ) - { - Gb_Osc& osc = *oscs [i]; - osc.enabled &= mask; - int bits = flags >> i; - Blip_Buffer* old_output = osc.output; - osc.output_select = (bits >> 3 & 2) | (bits & 1); - osc.output = osc.outputs [osc.output_select]; - if ( osc.output != old_output ) - { - int amp = osc.last_amp; - osc.last_amp = 0; - if ( amp && old_output ) - other_synth.offset( time, -amp, old_output ); - } - } - - if ( addr == status_reg && data != old_reg ) - { - if ( !(data & 0x80) ) - { - for ( unsigned i = 0; i < sizeof powerup_regs; i++ ) - { - if ( i != status_reg - start_addr ) - write_register( time, i + start_addr, powerup_regs [i] ); - } - } - else - { - //dprintf( "APU powered on\n" ); - } - } - } - else if ( addr >= 0xFF30 ) - { - int index = (addr & 0x0F) * 2; - wave.wave [index] = data >> 4; - wave.wave [index + 1] = data & 0x0F; - } -} - -int Gb_Apu::read_register( blip_time_t time, unsigned addr ) -{ - run_until( time ); - - int index = addr - start_addr; - require( (unsigned) index < register_count ); - int data = regs [index]; - - if ( addr == status_reg ) - { - data = (data & 0x80) | 0x70; - for ( int i = 0; i < osc_count; i++ ) - { - const Gb_Osc& osc = *oscs [i]; - if ( osc.enabled && (osc.length || !(osc.regs [4] & osc.len_enabled_mask)) ) - data |= 1 << i; - } - } - - return data; -} |