public override int start(Mame.MachineSound msound)
{
int i, j, sweep, charge, countdown, generator, bit1, bit2;
int[] lfovol = { LFO_VOLUME, LFO_VOLUME, LFO_VOLUME };
#if SAMPLES
Mame.Machine.samples = Mame.readsamples(galaxian_sample_names, Mame.Machine.gamedrv.name);
#endif
channelnoise = Mame.mixer_allocate_channel(NOISE_VOLUME);
Mame.mixer_set_name(channelnoise, "Noise");
channelshoot = Mame.mixer_allocate_channel(SHOOT_VOLUME);
Mame.mixer_set_name(channelshoot, "Shoot");
channellfo = Mame.mixer_allocate_channels(3, lfovol);
Mame.mixer_set_name(channellfo + 0, "Background #0");
Mame.mixer_set_name(channellfo + 1, "Background #1");
Mame.mixer_set_name(channellfo + 2, "Background #2");
#if SAMPLES
if (Mame.Machine.samples != null && Mame.Machine.samples.sample[0] != null) /* We should check also that Samplename[0] = 0 */
shootsampleloaded = 1;
else
shootsampleloaded = 0;
if (Mame.Machine.samples != null && Mame.Machine.samples.sample[1] != null) /* We should check also that Samplename[0] = 0 */
deathsampleloaded = 1;
else
deathsampleloaded = 0;
#endif
if ((noisewave = new _ShortPtr((int)(NOISE_LENGTH * sizeof(short)))) == null)
{
return 1;
}
#if NEW_SHOOT
byte SHOOT_SEC = 2;
shoot_rate = Mame.Machine.sample_rate;
shoot_length = SHOOT_SEC * shoot_rate;
if ((shootwave = new _ShortPtr(shoot_length * sizeof(short))) == null)
#else
if( (shootwave = new _ShortPtr(SHOOT_LENGTH * sizeof(short))) == null )
#endif
{
noisewave = null;
return 1;
}
/*
* The RNG shifter is clocked with RNG_RATE, bit 17 is
* latched every 2V cycles (every 2nd scanline).
* This signal is used as a noise source.
*/
generator = 0;
countdown = (int)(NOISE_RATE / 2);
for (i = 0; i < NOISE_LENGTH; i++)
{
countdown -= (int)RNG_RATE;
while (countdown < 0)
{
generator <<= 1;
bit1 = (~generator >> 17) & 1;
bit2 = (generator >> 5) & 1;
if ((bit1 ^ bit2) != 0) generator |= 1;
countdown += (int)NOISE_RATE;
}
noisewave.write16(i, (ushort)(((generator >> 17) & 1) != 0 ? (ushort)NOISE_AMPLITUDE : -(ushort)NOISE_AMPLITUDE));
}
#if NEW_SHOOT
/* dummy */
sweep = 100;
charge = +2;
j = 0;
{
int R41__ = 100000;
int R44__ = 10000;
int R45__ = 22000;
int R46__ = 10000;
int R47__ = 2200;
int R48__ = 2200;
double C25__ = 0.000001;
double C27__ = 0.00000001;
double C28__ = 0.000047;
double C29__ = 0.00000001;
double IC8L3_L = 0.2; /* 7400 L level */
double IC8L3_H = 4.5; /* 7400 H level */
double NOISE_L = 0.2; /* 7474 L level */
double NOISE_H = 4.5; /* 7474 H level */
/*
key on/off time is programmable
Therefore, it is necessary to make separate sample with key on/off.
And, calculate the playback point according to the voltage of c28.
*/
double SHOOT_KEYON_TIME = 0.1; /* second */
/*
NE555-FM input calculation is wrong.
The frequency is not proportional to the voltage of FM input.
And, duty will be changed,too.
*/
double NE555_FM_ADJUST_RATE = 0.80;
/* discharge : 100K * 1uF */
double v = 5.0;
double vK = (shoot_rate) != 0 ? Math.Exp(-1 / (R41__ * C25__) / shoot_rate) : 0;
/* -- SHOOT KEY port -- */
double IC8L3 = IC8L3_L; /* key on */
int IC8Lcnt = (int)(SHOOT_KEYON_TIME * shoot_rate); /* count for key off */
/* C28 : KEY port capacity */
/* connection : 8L-3 - R47(2.2K) - C28(47u) - R48(2.2K) - C29 */
double c28v = IC8L3_H - (IC8L3_H - (NOISE_H + NOISE_L) / 2) / (R46__ + R47__ + R48__) * R47__;
double c28K = (shoot_rate) != 0 ? Math.Exp(-1 / (22000 * 0.000047) / shoot_rate) : 0;
/* C29 : NOISE capacity */
/* connection : NOISE - R46(10K) - C29(0.1u) - R48(2.2K) - C28 */
double c29v = IC8L3_H - (IC8L3_H - (NOISE_H + NOISE_L) / 2) / (R46__ + R47__ + R48__) * (R47__ + R48__);
double c29K1 = (shoot_rate) != 0 ? Math.Exp(-1 / (22000 * 0.00000001) / shoot_rate) : 0; /* form C28 */
double c29K2 = (shoot_rate) != 0 ? Math.Exp(-1 / (100000 * 0.00000001) / shoot_rate) : 0; /* from noise */
/* NE555 timer */
/* RA = 10K , RB = 22K , C=.01u ,FM = C29 */
double ne555cnt = 0;
double ne555step = (shoot_rate) != 0 ? ((1.44 / ((R44__ + R45__ * 2) * C27__)) / shoot_rate) : 0;
double ne555duty = (double)(R44__ + R45__) / (R44__ + R45__ * 2); /* t1 duty */
double ne555sr; /* threshold (FM) rate */
/* NOISE source */
double ncnt = 0.0;
double nstep = (shoot_rate) != 0 ? ((double)NOISE_RATE / shoot_rate) : 0;
double noise_sh2; /* voltage level */
for (i = 0; i < shoot_length; i++)
{
/* noise port */
noise_sh2 = noisewave.read16((int)(ncnt % NOISE_LENGTH)) == NOISE_AMPLITUDE ? NOISE_H : NOISE_L;
ncnt += nstep;
/* calculate NE555 threshold level by FM input */
ne555sr = c29v * NE555_FM_ADJUST_RATE / (5.0 * 2 / 3);
/* calc output */
ne555cnt += ne555step;
if (ne555cnt >= ne555sr) ne555cnt -= ne555sr;
if (ne555cnt < ne555sr * ne555duty)
{
/* t1 time */
shootwave.write16(i, (ushort)(v / 5 * 0x7fff));
/* discharge output level */
if (IC8L3 == IC8L3_H)
v *= vK;
}
else
shootwave.write16(i, 0);
/* C28 charge/discharge */
c28v += (IC8L3 - c28v) - (IC8L3 - c28v) * c28K; /* from R47 */
c28v += (c29v - c28v) - (c29v - c28v) * c28K; /* from R48 */
/* C29 charge/discharge */
c29v += (c28v - c29v) - (c28v - c29v) * c29K1; /* from R48 */
c29v += (noise_sh2 - c29v) - (noise_sh2 - c29v) * c29K2; /* from R46 */
/* key off */
if (IC8L3 == IC8L3_L && --IC8Lcnt == 0)
IC8L3 = IC8L3_H;
}
}
#else
/*
* Ra is 10k, Rb is 22k, C is 0.01uF
* charge time t1 = 0.693 * (Ra + Rb) * C . 221.76us
* discharge time t2 = 0.693 * (Rb) * C . 152.46us
* average period 374.22us . 2672Hz
* I use an array of 10 values to define some points
* of the charge/discharge curve. The wave is modulated
* using the charge/discharge timing of C28, a 47uF capacitor,
* over a 2k2 resistor. This will change the frequency from
* approx. Favg-Favg/3 up to Favg+Favg/3 down to Favg-Favg/3 again.
*/
sweep = 100;
charge = +2;
countdown = sweep / 2;
for( i = 0, j = 0; i < SHOOT_LENGTH; i++ )
{
shootwave[i] = charge_discharge[j];
LOG((errorlog, "shoot[%5d] $%04x (sweep: %3d, j:%d)\n", i, shootwave[i] & 0xffff, sweep, j));
/*
* The current sweep and a 2200/10000 fraction (R45 and R48)
* of the noise are frequency modulating the NE555 chip.
*/
countdown -= sweep + noisewave[i % NOISE_LENGTH] / (2200*NOISE_AMPLITUDE/10000);
while( countdown < 0 )
{
countdown += 100;
j = ++j % 10;
}
/* sweep from 100 to 133 and down to 66 over the time of SHOOT_LENGTH */
if( i % (SHOOT_LENGTH / 33 / 3 ) == 0 )
{
sweep += charge;
if( sweep >= 133 )
charge = -1;
}
}
#endif
//memset(tonewave, 0, sizeof(tonewave));
for (i = 0; i < TOOTHSAW_LENGTH; i++)
{
//#define V(r0,r1) 2*TOOTHSAW_AMPLITUDE*(r0)/(r0+r1)-TOOTHSAW_AMPLITUDE
double r0a = 1.0 / 1e12, r1a = 1.0 / 1e12;
double r0b = 1.0 / 1e12, r1b = 1.0 / 1e12;
/* #0: VOL1=0 and VOL2=0
* only the 33k and the 22k resistors R51 and R50
*/
if ((i & 1) != 0)
{
r1a += 1.0 / 33000;
r1b += 1.0 / 33000;
}
else
{
r0a += 1.0 / 33000;
r0b += 1.0 / 33000;
}
if ((i & 4) != 0)
{
r1a += 1.0 / 22000;
r1b += 1.0 / 22000;
}
else
{
r0a += 1.0 / 22000;
r0b += 1.0 / 22000;
}
for (int k = 0; k < 4; k++) tonewave[k] = new _BytePtr(TOOTHSAW_LENGTH);
tonewave[0][i] = (byte)V(1.0 / r0a, 1.0 / r1a);
//#define V(r0,r1) 2*TOOTHSAW_AMPLITUDE*(r0)/(r0+r1)-TOOTHSAW_AMPLITUDE
/* #1: VOL1=1 and VOL2=0
* add the 10k resistor R49 for bit QC
*/
if ((i & 4) != 0)
r1a += 1.0 / 10000;
else
r0a += 1.0 / 10000;
tonewave[1][i] = (byte)V(1.0 / r0a, 1.0 / r1a);
/* #2: VOL1=0 and VOL2=1
* add the 15k resistor R52 for bit QD
*/
if ((i & 8) != 0)
r1b += 1.0 / 15000;
else
r0b += 1.0 / 15000;
tonewave[2][i] = (byte)V(1.0 / r0b, 1.0 / r1b);
/* #3: VOL1=1 and VOL2=1
* add the 10k resistor R49 for QC
*/
if ((i & 4) != 0)
r0b += 1.0 / 10000;
else
r1b += 1.0 / 10000;
tonewave[3][i] = (byte)V(1.0 / r0b, 1.0 / r1b);
//LOG((errorlog, "tone[%2d]: $%02x $%02x $%02x $%02x\n", i, tonewave[0][i], tonewave[1][i], tonewave[2][i], tonewave[3][i]));
}
pitch = 0;
vol = 0;
tone_stream = Mame.stream_init("Tone", TOOTHSAW_VOLUME, (int)(SOUND_CLOCK / STEPS), 0, tone_update);
#if SAMPLES
if (deathsampleloaded == 0)
#endif
{
Mame.mixer_set_volume(channelnoise, 0);
Mame.mixer_play_sample_16(channelnoise, noisewave, (int)NOISE_LENGTH, (int)NOISE_RATE, true);
}
#if SAMPLES
if (shootsampleloaded == 0)
#endif
{
Mame.mixer_set_volume(channelshoot, 0);
Mame.mixer_play_sample_16(channelshoot, shootwave, SHOOT_LENGTH, SHOOT_RATE, false);
}
Mame.mixer_set_volume(channellfo + 0, 0);
Mame.mixer_play_sample_16(channellfo + 0, backgroundwave, backgroundwave.buffer.Length / 2, 1000, true);
Mame.mixer_set_volume(channellfo + 1, 0);
Mame.mixer_play_sample_16(channellfo + 1, backgroundwave, backgroundwave.buffer.Length / 2, 1000, true);
Mame.mixer_set_volume(channellfo + 2, 0);
Mame.mixer_play_sample_16(channellfo + 2, backgroundwave, backgroundwave.buffer.Length / 2, 1000, true);
return 0;
}
static void shuffle(_ShortPtr buf, int len)
{
if (len == 2) return;
if ((len % 4) != 0) throw new Exception(); /* must not happen */
len /= 2;
for (int i = 0; i < len / 2; i++)
{
ushort t = buf.read16(len / 2 + i);
buf.write16(len / 2 + i, buf.read16(len + i));
buf.write16(len + i, t);
}
shuffle(buf, len);
shuffle(new _ShortPtr(buf, len*2 ), len);
}