/* ** Nofrendo (c) 1998-2000 Matthew Conte (matt@conte.com) ** ** ** This program is free software; you can redistribute it and/or ** modify it under the terms of version 2 of the GNU Library General ** Public License as published by the Free Software Foundation. ** ** This program 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 ** Library General Public License for more details. To obtain a ** copy of the GNU Library General Public License, write to the Free ** Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. ** ** Any permitted reproduction of these routines, in whole or in part, ** must bear this legend. ** ** ** vrcvisnd.c ** ** VRCVI sound hardware emulation ** $Id$ */ #include #include "types.h" #include "vrcvisnd.h" #include "nes_apu.h" static vrcvisnd_t vrcvi; static int32 vrcvi_incsize; /* VRCVI rectangle wave generation */ static int32 vrcvi_rectangle (vrcvirectangle_t * chan) { /* reg0: 0-3=volume, 4-6=duty cycle ** reg1: 8 bits of freq ** reg2: 0-3=high freq, 7=enable */ chan->phaseacc -= vrcvi_incsize; /* # of clocks per wave cycle */ while (chan->phaseacc < 0) { chan->phaseacc += chan->freq; chan->adder = (chan->adder + 1) & 0x0F; } /* return if not enabled */ if (FALSE == chan->enabled) return 0; if (chan->adder < chan->duty_flip) return -(chan->volume); else return chan->volume; } /* VRCVI sawtooth wave generation */ static int32 vrcvi_sawtooth (vrcvisawtooth_t * chan) { /* reg0: 0-5=phase accumulator bits ** reg1: 8 bits of freq ** reg2: 0-3=high freq, 7=enable */ chan->phaseacc -= vrcvi_incsize; /* # of clocks per wav cycle */ while (chan->phaseacc < 0) { chan->phaseacc += chan->freq; chan->output_acc += chan->volume; if (7 == ++chan->adder) { chan->adder = 0; chan->output_acc = 0; } } /* return if not enabled */ if (FALSE == chan->enabled) return 0; else return (chan->output_acc >> 3) << 9; } /* mix vrcvi sound channels together */ static int32 vrcvi_process (void) { int32 output; output = vrcvi_rectangle (&vrcvi.rectangle[0]); output += vrcvi_rectangle (&vrcvi.rectangle[1]); output += vrcvi_sawtooth (&vrcvi.saw); return output; } /* write to registers */ static void vrcvi_write (uint32 address, uint8 value) { int chan; switch (address & 0xB003) { case 0x9000: case 0xA000: chan = (address >> 12) - 9; vrcvi.rectangle[chan].reg[0] = value; vrcvi.rectangle[chan].volume = (value & 0x0F) << 8; vrcvi.rectangle[chan].duty_flip = (value >> 4) + 1; break; case 0x9001: case 0xA001: chan = (address >> 12) - 9; vrcvi.rectangle[chan].reg[1] = value; vrcvi.rectangle[chan].freq = APU_TO_FIXED (((vrcvi.rectangle[chan].reg[2] & 0x0F) << 8) + value + 1); break; case 0x9002: case 0xA002: chan = (address >> 12) - 9; vrcvi.rectangle[chan].reg[2] = value; vrcvi.rectangle[chan].freq = APU_TO_FIXED (((value & 0x0F) << 8) + vrcvi.rectangle[chan].reg[1] + 1); vrcvi.rectangle[chan].enabled = (value & 0x80) ? TRUE : FALSE; break; case 0xB000: vrcvi.saw.reg[0] = value; vrcvi.saw.volume = value & 0x3F; break; case 0xB001: vrcvi.saw.reg[1] = value; vrcvi.saw.freq = APU_TO_FIXED ((((vrcvi.saw.reg[2] & 0x0F) << 8) + value + 1) << 1); break; case 0xB002: vrcvi.saw.reg[2] = value; vrcvi.saw.freq = APU_TO_FIXED ((((value & 0x0F) << 8) + vrcvi.saw.reg[1] + 1) << 1); vrcvi.saw.enabled = (value & 0x80) ? TRUE : FALSE; break; default: break; } } /* reset state of vrcvi sound channels */ static void vrcvi_reset (void) { int i; /* preload regs */ for (i = 0; i < 3; i++) { vrcvi_write (0x9000 + i, 0); vrcvi_write (0xA000 + i, 0); vrcvi_write (0xB000 + i, 0); } /* get the phase period from the apu */ vrcvi_incsize = apu_getcyclerate (); } static void vrcvi_dummy (void) { } static apu_memwrite vrcvi_memwrite[] = { /* { 0x4040, 0x4092, ext_write }, *//* FDS sound regs */ {0x9000, 0x9002, vrcvi_write}, /* vrc6 */ {0xA000, 0xA002, vrcvi_write}, {0xB000, 0xB002, vrcvi_write}, {(uint32) - 1, (uint32) - 1, NULL} }; apuext_t vrcvi_ext = { vrcvi_dummy, /* no init */ vrcvi_dummy, /* no shutdown */ vrcvi_reset, vrcvi_process, NULL, /* no reads */ vrcvi_memwrite }; /* ** $Log$ ** Revision 1.4 2008/03/26 07:40:56 slomo ** * gst/nsf/Makefile.am: ** * gst/nsf/fds_snd.c: ** * gst/nsf/mmc5_snd.c: ** * gst/nsf/nsf.c: ** * gst/nsf/types.h: ** * gst/nsf/vrc7_snd.c: ** * gst/nsf/vrcvisnd.c: ** * gst/nsf/memguard.c: ** * gst/nsf/memguard.h: ** Remove memguard again and apply hopefully all previously dropped ** local patches. Should be really better than the old version now. ** ** Revision 1.3 2008-03-25 15:56:13 slomo ** Patch by: Andreas Henriksson ** * gst/nsf/Makefile.am: ** * gst/nsf/dis6502.h: ** * gst/nsf/fds_snd.c: ** * gst/nsf/fds_snd.h: ** * gst/nsf/fmopl.c: ** * gst/nsf/fmopl.h: ** * gst/nsf/gstnsf.c: ** * gst/nsf/log.c: ** * gst/nsf/log.h: ** * gst/nsf/memguard.c: ** * gst/nsf/memguard.h: ** * gst/nsf/mmc5_snd.c: ** * gst/nsf/mmc5_snd.h: ** * gst/nsf/nes6502.c: ** * gst/nsf/nes6502.h: ** * gst/nsf/nes_apu.c: ** * gst/nsf/nes_apu.h: ** * gst/nsf/nsf.c: ** * gst/nsf/nsf.h: ** * gst/nsf/osd.h: ** * gst/nsf/types.h: ** * gst/nsf/vrc7_snd.c: ** * gst/nsf/vrc7_snd.h: ** * gst/nsf/vrcvisnd.c: ** * gst/nsf/vrcvisnd.h: ** Update our internal nosefart to nosefart-2.7-mls to fix segfaults ** on some files. Fixes bug #498237. ** Remove some // comments, fix some compiler warnings and use pow() ** instead of a slow, selfmade implementation. ** ** Revision 1.1 2003/04/08 20:53:01 ben ** Adding more files... ** ** Revision 1.9 2000/07/04 04:51:41 matt ** cleanups ** ** Revision 1.8 2000/07/03 02:18:53 matt ** much better external module exporting ** ** Revision 1.7 2000/06/20 04:06:16 matt ** migrated external sound definition to apu module ** ** Revision 1.6 2000/06/20 00:08:58 matt ** changed to driver based API ** ** Revision 1.5 2000/06/09 16:49:02 matt ** removed all floating point from sound generation ** ** Revision 1.4 2000/06/09 15:12:28 matt ** initial revision ** */