public bool NES_FDS_Read(NES_FDS chip, UInt32 adr, ref UInt32 val)
{
NES_FDS fds = chip;
if (adr >= 0x4040 && adr < 0x407F)
{
// TODO: if wav_write is not enabled, the
// read address may not be reliable? need
// to test this on hardware.
val = (UInt32)fds.wave[(Int32)TG.TWAV][adr - 0x4040];
return(true);
}
if (adr == 0x4090) // $4090 read volume envelope
{
val = fds.env_out[(Int32)EG.EVOL] | 0x40;
return(true);
}
if (adr == 0x4092) // $4092 read mod envelope
{
val = fds.env_out[(Int32)EG.EMOD] | 0x40;
return(true);
}
return(false);
}
public UInt32 NES_FDS_org_Render(NES_FDS chip, Int32[] b)//b[2])
{
NES_FDS fds = chip;
/* // 8 bit approximation of master volume
* static const double MASTER_VOL = 2.4 * 1223.0; // max FDS vol vs max APU square (arbitrarily 1223)
* static const double MAX_OUT = 32.0f * 63.0f; // value that should map to master vol
* static const INT32 MASTER[4] = {
* (INT32)((MASTER_VOL / MAX_OUT) * 256.0 * 2.0f / 2.0f),
* (INT32)((MASTER_VOL / MAX_OUT) * 256.0 * 2.0f / 3.0f),
* (INT32)((MASTER_VOL / MAX_OUT) * 256.0 * 2.0f / 4.0f),
* (INT32)((MASTER_VOL / MAX_OUT) * 256.0 * 2.0f / 5.0f) };*/
//UInt32 clocks;
Int32 v, rc_out, m;
v = fds.fout * MASTER[fds.master_vol] >> 8;
// lowpass RC filter
rc_out = ((fds.rc_accum * fds.rc_k) + (v * fds.rc_l)) >> RC_BITS;
fds.rc_accum = rc_out;
v = rc_out;
// output mix
m = fds.mask != 0 ? 0 : v;
b[0] = (m * fds.sm[0]) >> (7 - 3);
b[1] = (m * fds.sm[1]) >> (7 - 3);
return(2);
}
public NES_FDS NES_FDS_Create(int clock, int rate)
{
NES_FDS fds;
fds = new NES_FDS();// (NES_FDS*)malloc(sizeof(NES_FDS));
if (fds == null)
{
return(null);
}
//memset(fds, 0x00, sizeof(NES_FDS));
fds.option[(Int32)OPT.OPT_CUTOFF] = 2000;
fds.option[(Int32)OPT.OPT_4085_RESET] = 0;
fds.option[(Int32)OPT.OPT_WRITE_PROTECT] = 0; // not used here, see nsfplay.cpp
fds.rc_k = 0;
fds.rc_l = (1 << RC_BITS);
//NES_FDS_SetClock(fds, DEFAULT_CLOCK);
//NES_FDS_SetRate(fds, DEFAULT_RATE);
NES_FDS_SetClock(fds, clock);
NES_FDS_SetRate(fds, rate);
fds.sm[0] = 128;
fds.sm[1] = 128;
NES_FDS_Reset(fds);
return(fds);
}
public void NES_FDS_Reset(NES_FDS chip)
{
NES_FDS fds = chip;
Int32 i;
fds.master_io = true;
fds.master_vol = 0;
fds.last_freq = 0;
fds.last_vol = 0;
fds.rc_accum = 0;
for (i = 0; i < 2; ++i)
{
for (int j = 0; j < fds.wave[i].Length; j++)
{
fds.wave[i][j] = 0; //memset(fds->wave[i], 0, sizeof(fds->wave[i]));
}
fds.freq[i] = 0;
fds.phase[i] = 0;
}
fds.wav_write = false;
fds.wav_halt = true;
fds.env_halt = true;
fds.mod_halt = true;
fds.mod_pos = 0;
fds.mod_write_pos = 0;
for (i = 0; i < 2; ++i)
{
fds.env_mode[i] = false;
fds.env_disable[i] = true;
fds.env_timer[i] = 0;
fds.env_speed[i] = 0;
fds.env_out[i] = 0;
}
fds.master_env_speed = 0xFF;
// NOTE: the FDS BIOS reset only does the following related to audio:
// $4023 = $00
// $4023 = $83 enables master_io
// $4080 = $80 output volume = 0, envelope disabled
// $408A = $FF master envelope speed set to slowest
NES_FDS_Write(fds, 0x4023, 0x00);
NES_FDS_Write(fds, 0x4023, 0x83);
NES_FDS_Write(fds, 0x4080, 0x80);
NES_FDS_Write(fds, 0x408A, 0xFF);
// reset other stuff
NES_FDS_Write(fds, 0x4082, 0x00); // wav freq 0
NES_FDS_Write(fds, 0x4083, 0x80); // wav disable
NES_FDS_Write(fds, 0x4084, 0x80); // mod strength 0
NES_FDS_Write(fds, 0x4085, 0x00); // mod position 0
NES_FDS_Write(fds, 0x4086, 0x00); // mod freq 0
NES_FDS_Write(fds, 0x4087, 0x80); // mod disable
NES_FDS_Write(fds, 0x4089, 0x00); // wav write disable, max global volume}
}
public void NES_FDS_SetOption(NES_FDS chip, int id, int val)
{
NES_FDS fds = chip;
if (id < (Int32)OPT.OPT_END)
{
fds.option[id] = val;
}
// update cutoff immediately
if (id == (Int32)OPT.OPT_CUTOFF)
{
NES_FDS_SetRate(fds, fds.rate);
}
}
public void NES_FDS_SetStereoMix(NES_FDS chip, int trk, Int16 mixl, Int16 mixr)
{
NES_FDS fds = chip;
if (trk < 0)
{
return;
}
if (trk > 1)
{
return;
}
fds.sm[0] = mixl;
fds.sm[1] = mixr;
}
public void NES_FDS_SetRate(NES_FDS chip, double r)
{
NES_FDS fds = chip;
double cutoff, leak;
fds.rate = r;
COUNTER_init(fds.tick_count, fds.clock, fds.rate);
fds.tick_last = 0;
// configure lowpass filter
cutoff = (double)fds.option[(Int32)OPT.OPT_CUTOFF];
leak = 0.0;
if (cutoff > 0)
{
leak = Math.Exp(-2.0 * 3.14159 * cutoff / fds.rate);
}
fds.rc_k = (Int32)(leak * (double)(1 << RC_BITS));
fds.rc_l = (1 << RC_BITS) - fds.rc_k;
}
public bool NES_FDS_Write(NES_FDS chip, UInt32 adr, UInt32 val)
{
NES_FDS fds = chip;
// $4023 master I/O enable/disable
if (adr == 0x4023)
{
fds.master_io = ((val & 2) != 0);
return(true);
}
if (!fds.master_io)
{
return(false);
}
if (adr < 0x4040 || adr > 0x408A)
{
return(false);
}
if (adr < 0x4080) // $4040-407F wave table write
{
if (fds.wav_write)
{
fds.wave[(Int32)TG.TWAV][adr - 0x4040] = (Int32)(val & 0x3F);
}
return(true);
}
switch (adr & 0x00FF)
{
case 0x80: // $4080 volume envelope
fds.env_disable[(Int32)EG.EVOL] = ((val & 0x80) != 0);
fds.env_mode[(Int32)EG.EVOL] = ((val & 0x40) != 0);
fds.env_timer[(Int32)EG.EVOL] = 0;
fds.env_speed[(Int32)EG.EVOL] = val & 0x3F;
if (fds.env_disable[(Int32)EG.EVOL])
{
fds.env_out[(Int32)EG.EVOL] = fds.env_speed[(Int32)EG.EVOL];
}
return(true);
case 0x81: // $4081 ---
return(false);
case 0x82: // $4082 wave frequency low
fds.freq[(Int32)TG.TWAV] = (fds.freq[(Int32)TG.TWAV] & 0xF00) | val;
return(true);
case 0x83: // $4083 wave frequency high / enables
fds.freq[(Int32)TG.TWAV] = (fds.freq[(Int32)TG.TWAV] & 0x0FF) | ((val & 0x0F) << 8);
fds.wav_halt = ((val & 0x80) != 0);
fds.env_halt = ((val & 0x40) != 0);
if (fds.wav_halt)
{
fds.phase[(Int32)TG.TWAV] = 0;
}
if (fds.env_halt)
{
fds.env_timer[(Int32)EG.EMOD] = 0;
fds.env_timer[(Int32)EG.EVOL] = 0;
}
return(true);
case 0x84: // $4084 mod envelope
fds.env_disable[(Int32)EG.EMOD] = ((val & 0x80) != 0);
fds.env_mode[(Int32)EG.EMOD] = ((val & 0x40) != 0);
fds.env_timer[(Int32)EG.EMOD] = 0;
fds.env_speed[(Int32)EG.EMOD] = val & 0x3F;
if (fds.env_disable[(Int32)EG.EMOD])
{
fds.env_out[(Int32)EG.EMOD] = fds.env_speed[(Int32)EG.EMOD];
}
return(true);
case 0x85: // $4085 mod position
fds.mod_pos = val & 0x7F;
// not hardware accurate., but prevents detune due to cycle inaccuracies
// (notably in Bio Miracle Bokutte Upa)
if (fds.option[(Int32)OPT.OPT_4085_RESET] != 0)
{
fds.phase[(Int32)TG.TMOD] = fds.mod_write_pos << 16;
}
return(true);
case 0x86: // $4086 mod frequency low
fds.freq[(Int32)TG.TMOD] = (fds.freq[(Int32)TG.TMOD] & 0xF00) | val;
return(true);
case 0x87: // $4087 mod frequency high / enable
fds.freq[(Int32)TG.TMOD] = (fds.freq[(Int32)TG.TMOD] & 0x0FF) | ((val & 0x0F) << 8);
fds.mod_halt = ((val & 0x80) != 0);
if (fds.mod_halt)
{
fds.phase[(Int32)TG.TMOD] = fds.phase[(Int32)TG.TMOD] & 0x3F0000; // reset accumulator phase
}
return(true);
case 0x88: // $4088 mod table write
if (fds.mod_halt)
{
// writes to current playback position (there is no direct way to set phase)
fds.wave[(Int32)TG.TMOD][(fds.phase[(Int32)TG.TMOD] >> 16) & 0x3F] = (Int32)(val & 0x7F);
fds.phase[(Int32)TG.TMOD] = (fds.phase[(Int32)TG.TMOD] + 0x010000) & 0x3FFFFF;
fds.wave[(Int32)TG.TMOD][(fds.phase[(Int32)TG.TMOD] >> 16) & 0x3F] = (Int32)(val & 0x7F);
fds.phase[(Int32)TG.TMOD] = (fds.phase[(Int32)TG.TMOD] + 0x010000) & 0x3FFFFF;
fds.mod_write_pos = fds.phase[(Int32)TG.TMOD] >> 16; // used by OPT_4085_RESET
}
return(true);
case 0x89: // $4089 wave write enable, master volume
fds.wav_write = ((val & 0x80) != 0);
fds.master_vol = (byte)(val & 0x03);
return(true);
case 0x8A: // $408A envelope speed
fds.master_env_speed = val;
// haven't tested whether this register resets phase on hardware,
// but this ensures my inplementation won't spam envelope clocks
// if this value suddenly goes low.
fds.env_timer[(Int32)EG.EMOD] = 0;
fds.env_timer[(Int32)EG.EVOL] = 0;
return(true);
default:
return(false);
}
//return false;
}
public void Tick(NES_FDS fds, UInt32 clocks)
{
Int32 vol_out;
// clock envelopes
if (!fds.env_halt && !fds.wav_halt && (fds.master_env_speed != 0))
{
int i;
for (i = 0; i < 2; ++i)
{
if (!fds.env_disable[i])
{
UInt32 period;
fds.env_timer[i] += clocks;
period = ((fds.env_speed[i] + 1) * fds.master_env_speed) << 3;
while (fds.env_timer[i] >= period)
{
// clock the envelope
if (fds.env_mode[i])
{
if (fds.env_out[i] < 32)
{
++fds.env_out[i];
}
}
else
{
if (fds.env_out[i] > 0)
{
--fds.env_out[i];
}
}
fds.env_timer[i] -= period;
}
}
}
}
// clock the mod table
if (!fds.mod_halt)
{
UInt32 start_pos, end_pos, p;
// advance phase, adjust for modulator
start_pos = fds.phase[(Int32)TG.TMOD] >> 16;
fds.phase[(Int32)TG.TMOD] += (clocks * fds.freq[(Int32)TG.TMOD]);
end_pos = fds.phase[(Int32)TG.TMOD] >> 16;
// wrap the phase to the 64-step table (+ 16 bit accumulator)
fds.phase[(Int32)TG.TMOD] = fds.phase[(Int32)TG.TMOD] & 0x3FFFFF;
// execute all clocked steps
for (p = start_pos; p < end_pos; ++p)
{
Int32 wv = fds.wave[(Int32)TG.TMOD][p & 0x3F];
if (wv == 4) // 4 resets mod position
{
fds.mod_pos = 0;
}
else
{
Int32[] BIAS = new Int32[8] {
0, 1, 2, 4, 0, -4, -2, -1
};
fds.mod_pos += (UInt32)BIAS[wv];
fds.mod_pos &= 0x7F; // 7-bit clamp
}
}
}
// clock the wav table
if (!fds.wav_halt)
{
Int32 mod, f;
// complex mod calculation
mod = 0;
if (fds.env_out[(Int32)EG.EMOD] != 0) // skip if modulator off
{
// convert mod_pos to 7-bit signed
Int32 pos = (Int32)((fds.mod_pos < 64) ? fds.mod_pos : (fds.mod_pos - 128));
// multiply pos by gain,
// shift off 4 bits but with odd "rounding" behaviour
Int32 temp = (Int32)(pos * fds.env_out[(Int32)EG.EMOD]);
Int32 rem = temp & 0x0F;
temp >>= 4;
if ((rem > 0) && ((temp & 0x80) == 0))
{
if (pos < 0)
{
temp -= 1;
}
else
{
temp += 2;
}
}
// wrap if range is exceeded
while (temp >= 192)
{
temp -= 256;
}
while (temp < -64)
{
temp += 256;
}
// multiply result by pitch,
// shift off 6 bits, round to nearest
temp = (Int32)(fds.freq[(Int32)TG.TWAV] * temp);
rem = temp & 0x3F;
temp >>= 6;
if (rem >= 32)
{
temp += 1;
}
mod = temp;
}
// advance wavetable position
f = (Int32)(fds.freq[(Int32)TG.TWAV] + mod);
fds.phase[(Int32)TG.TWAV] = (UInt32)(fds.phase[(Int32)TG.TWAV] + (clocks * f));
fds.phase[(Int32)TG.TWAV] = fds.phase[(Int32)TG.TWAV] & 0x3FFFFF; // wrap
// store for trackinfo
fds.last_freq = (UInt32)f;
}
// output volume caps at 32
vol_out = (Int32)(fds.env_out[(Int32)EG.EVOL]);
if (vol_out > 32)
{
vol_out = 32;
}
// final output
if (!fds.wav_write)
{
fds.fout = fds.wave[(Int32)TG.TWAV][(fds.phase[(Int32)TG.TWAV] >> 16) & 0x3F] * vol_out;
}
// NOTE: during wav_halt, the unit still outputs (at phase 0)
// and volume can affect it if the first sample is nonzero.
// haven't worked out 100% of the conditions for volume to
// effect (vol envelope does not seem to run, but am unsure)
// but this implementation is very close to correct
// store for trackinfo
fds.last_vol = (UInt32)vol_out;
}
public void NES_FDS_SetClock(NES_FDS chip, double c)
{
NES_FDS fds = chip;
fds.clock = c;
}
public void NES_FDS_SetMask(NES_FDS chip, int m)
{
NES_FDS fds = chip;
fds.mask = m & 1;
}
public void NES_FDS_Destroy(NES_FDS chip)
{
chip = null;//無意味
//free(chip);
}