public static void YM3812UpdateOne(FM_OPL OPL, _ShortPtr buffer, int length)
{
int i;
int data;
_ShortPtr buf = buffer;
uint amsCnt = (uint)OPL.amsCnt;
uint vibCnt = (uint)OPL.vibCnt;
byte rythm = (byte)(OPL.rythm & 0x20);
OPL_CH CH;
int R_CH;
if ((object)OPL != cur_chip)
{
cur_chip = OPL;
/* channel pointers */
S_CH = OPL.P_CH;
E_CH = 9;// S_CH[9];
/* rythm slot */
SLOT7_1 = S_CH[7].SLOT[SLOT1];
SLOT7_2 = S_CH[7].SLOT[SLOT2];
SLOT8_1 = S_CH[8].SLOT[SLOT1];
SLOT8_2 = S_CH[8].SLOT[SLOT2];
/* LFO state */
amsIncr = OPL.amsIncr;
vibIncr = OPL.vibIncr;
ams_table = OPL.ams_table;
vib_table = OPL.vib_table;
}
R_CH = rythm != 0 ? 6 : E_CH;
for (i = 0; i < length; i++)
{
/* channel A channel B channel C */
/* LFO */
ams = ams_table[(int)((amsCnt += (uint)amsIncr) >> AMS_SHIFT)];
vib = vib_table[(int)((vibCnt += (uint)vibIncr) >> VIB_SHIFT)];
outd[0] = 0;
/* FM part */
for (int k = 0; k != R_CH; k++)
{
CH = S_CH[k];
//for(CH=S_CH ; CH < R_CH ; CH++)
OPL_CALC_CH(CH);
}
/* Rythn part */
if (rythm != 0)
OPL_CALC_RH(S_CH);
/* limit check */
data = Limit(outd[0], OPL_MAXOUT, OPL_MINOUT);
/* store to sound buffer */
buf.write16(i, (ushort)(data >> OPL_OUTSB));
}
OPL.amsCnt = (int)amsCnt;
OPL.vibCnt = (int)vibCnt;
}
static void OPL_KEYOFF(OPL_SLOT SLOT)
{
if (SLOT.evm > ENV_MOD_RR)
{
/* set envelope counter from envleope output */
SLOT.evm = ENV_MOD_RR;
if ((SLOT.evc & EG_DST) == 0)
//SLOT.evc = (ENV_CURVE[SLOT.evc>>ENV_BITS]<<ENV_BITS) + EG_DST;
SLOT.evc = EG_DST;
SLOT.eve = EG_DED;
SLOT.evs = SLOT.evsr;
}
}
public OPL_CH() { SLOT[0] = new OPL_SLOT(); SLOT[1] = new OPL_SLOT(); }
static void OPL_KEYON(OPL_SLOT SLOT)
{
/* sin wave restart */
SLOT.Cnt = 0;
/* set attack */
SLOT.evm = ENV_MOD_AR;
SLOT.evs = SLOT.evsa;
SLOT.evc = EG_AST;
SLOT.eve = EG_AED;
}
static void CALC_FCSLOT(OPL_CH CH, OPL_SLOT SLOT)
{
int ksr;
/* frequency step counter */
SLOT.Incr = CH.fc * SLOT.mul;
ksr = CH.kcode >> SLOT.KSR;
if (SLOT.ksr != ksr)
{
SLOT.ksr = (byte)ksr;
/* attack , decay rate recalcration */
SLOT.evsa = SLOT.AR[ksr];
SLOT.evsd = SLOT.DR[ksr];
SLOT.evsr = SLOT.RR[ksr];
}
SLOT.TLL = (int)(SLOT.TL + (CH.ksl_base >> SLOT.ksl));
}
static uint OPL_CALC_SLOT(OPL_SLOT SLOT)
{
/* calcrate envelope generator */
if ((SLOT.evc += SLOT.evs) >= SLOT.eve)
{
switch (SLOT.evm)
{
case ENV_MOD_AR: /* ATTACK . DECAY1 */
/* next DR */
SLOT.evm = ENV_MOD_DR;
SLOT.evc = EG_DST;
SLOT.eve = SLOT.SL;
SLOT.evs = SLOT.evsd;
break;
case ENV_MOD_DR: /* DECAY . SL or RR */
SLOT.evc = SLOT.SL;
SLOT.eve = EG_DED;
if (SLOT.eg_typ != 0)
{
SLOT.evs = 0;
}
else
{
SLOT.evm = ENV_MOD_RR;
SLOT.evs = SLOT.evsr;
}
break;
case ENV_MOD_RR: /* RR . OFF */
SLOT.evc = EG_OFF;
SLOT.eve = EG_OFF + 1;
SLOT.evs = 0;
break;
}
}
/* calcrate envelope */
return (uint)(SLOT.TLL + ENV_CURVE[SLOT.evc >> ENV_BITS] + (SLOT.ams != 0 ? ams : 0));
}
static int OP_OUT(OPL_SLOT slot, int env, int con)
{
return slot.wavetable[((slot.Cnt + con) / (0x1000000 / SIN_ENT)) & (SIN_ENT - 1)][env];
}
static int OP_OUT(OPL_SLOT slot, uint env, int con)
{
return ((IntSubArray[])slot.wavetable)[((slot.Cnt + con) / (0x1000000 / SIN_ENT)) & (SIN_ENT - 1)][(int)env];
}
