From acb0917556fc33681c1df5a530cf754193e67705 Mon Sep 17 00:00:00 2001 From: Andree Buschmann 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_namco_apu.c | 133 +++++++++++++++++++++++++++++++++++++ 1 file changed, 133 insertions(+) create mode 100644 apps/codecs/libgme/nes_namco_apu.c (limited to 'apps/codecs/libgme/nes_namco_apu.c') diff --git a/apps/codecs/libgme/nes_namco_apu.c b/apps/codecs/libgme/nes_namco_apu.c new file mode 100644 index 0000000000..0fca501eff --- /dev/null +++ b/apps/codecs/libgme/nes_namco_apu.c @@ -0,0 +1,133 @@ +// Nes_Snd_Emu 0.1.8. http://www.slack.net/~ant/ + +#include "nes_namco_apu.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 Namco_init( struct Nes_Namco_Apu* this ) +{ + Synth_init( &this->synth ); + + Namco_output( this, NULL ); + Namco_volume( this, 1.0 ); + Namco_reset( this ); +} + +void Namco_reset( struct Nes_Namco_Apu* this ) +{ + this->last_time = 0; + this->addr_reg = 0; + + int i; + for ( i = 0; i < namco_reg_count; i++ ) + this->reg [i] = 0; + + for ( i = 0; i < namco_osc_count; i++ ) + { + struct Namco_Osc* osc = &this->oscs [i]; + osc->delay = 0; + osc->last_amp = 0; + osc->wave_pos = 0; + } +} + +void Namco_output( struct Nes_Namco_Apu* this, struct Blip_Buffer* buf ) +{ + int i; + for ( i = 0; i < namco_osc_count; i++ ) + Namco_osc_output( this, i, buf ); +} + +void Namco_end_frame( struct Nes_Namco_Apu* this, blip_time_t time ) +{ + if ( time > this->last_time ) + Namco_run_until( this, time ); + + assert( this->last_time >= time ); + this->last_time -= time; +} + +void Namco_run_until( struct Nes_Namco_Apu* this, blip_time_t nes_end_time ) +{ + int active_oscs = (this->reg [0x7F] >> 4 & 7) + 1; + int i; + for ( i = namco_osc_count - active_oscs; i < namco_osc_count; i++ ) + { + struct Namco_Osc* osc = &this->oscs [i]; + struct Blip_Buffer* output = osc->output; + if ( !output ) + continue; + /* output->set_modified(); */ + Blip_set_modified( output ); + + blip_resampled_time_t time = + Blip_resampled_time( output, this->last_time ) + osc->delay; + blip_resampled_time_t end_time = Blip_resampled_time( output, nes_end_time ); + osc->delay = 0; + if ( time < end_time ) + { + const uint8_t* osc_reg = &this->reg [i * 8 + 0x40]; + if ( !(osc_reg [4] & 0xE0) ) + continue; + + int volume = osc_reg [7] & 15; + if ( !volume ) + continue; + + blargg_long freq = (osc_reg [4] & 3) * 0x10000 + osc_reg [2] * 0x100L + osc_reg [0]; + if ( freq < 64 * active_oscs ) + continue; // prevent low frequencies from excessively delaying freq changes + blip_resampled_time_t period = + /* output->resampled_duration( 983040 ) / freq * active_oscs; */ + Blip_resampled_duration( output, 983040 ) / freq * active_oscs; + + int wave_size = 32 - (osc_reg [4] >> 2 & 7) * 4; + if ( !wave_size ) + continue; + + int last_amp = osc->last_amp; + int wave_pos = osc->wave_pos; + + do + { + // read wave sample + int addr = wave_pos + osc_reg [6]; + int sample = this->reg [addr >> 1] >> (addr << 2 & 4); + wave_pos++; + sample = (sample & 15) * volume; + + // output impulse if amplitude changed + int delta = sample - last_amp; + if ( delta ) + { + last_amp = sample; + Synth_offset_resampled( &this->synth, time, delta, output ); + } + + // next sample + time += period; + if ( wave_pos >= wave_size ) + wave_pos = 0; + } + while ( time < end_time ); + + osc->wave_pos = wave_pos; + osc->last_amp = last_amp; + } + osc->delay = time - end_time; + } + + this->last_time = nes_end_time; +} + -- cgit v1.2.3