/*
 * Copyright (C) 1999/2000 Tatsuyuki Satoh
 * Copyright (C) 2001-2016 The ScummVM project
 * Copyright (C) 2002/2016-2022 The Exult Team
 * Copyright (C) 2003 The Pentagram Team
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
 * USA.
 *
 * LGPL licensed version of MAMEs fmopl (V0.37a modified) by
 * Tatsuyuki Satoh. Included from LGPL'ed AdPlug.
 *
 */

#include "pent_include.h"

#ifdef USE_FMOPL_MIDI
#	include "fmopl.h"

#	include <array>
#	include <cmath>
#	include <cstdarg>
#	include <cstdio>
#	include <cstdlib>
#	include <cstring>
#	include <iostream>

#	ifndef M_PI
#		define M_PI 3.14159265358979323846
#	endif

namespace FMOpl_Pentagram {

/* -------------------- preliminary define section --------------------- */
/* attack/decay rate time rate */
#	define OPL_ARRATE 141280  /* RATE 4 =  2826.24ms @ 3.6MHz */
#	define OPL_DRRATE 1956000 /* RATE 4 = 39280.64ms @ 3.6MHz */

#	define FREQ_BITS 24 /* frequency turn          */

/* counter bits = 20 , octerve 7 */
#	define FREQ_RATE (1 << (FREQ_BITS - 20))
#	define TL_BITS   (FREQ_BITS + 2)

/* final output shift , limit minimum and maximum */
#	define OPL_OUTSB  (TL_BITS + 3 - 16) /* OPL output final shift 16bit */
#	define OPL_MAXOUT (0x7fff << OPL_OUTSB)
#	define OPL_MINOUT (-(0x8000 << OPL_OUTSB))

/* -------------------- quality selection --------------------- */

/* sinwave entries */
/* used static memory = SIN_ENT * 4 (byte) */
#	define SIN_ENT_SHIFT 11
#	define SIN_ENT       (1 << SIN_ENT_SHIFT)

	/* output level entries (envelope,sinwave) */
	/* envelope counter lower bits */
	uint32 ENV_BITS;
	/* envelope output entries */
	uint32 EG_ENT;

	/* used dynamic memory = EG_ENT*4*4(byte)or EG_ENT*6*4(byte) */
	/* used static  memory = EG_ENT*4 (byte)                     */
	uint32 EG_OFF; /* OFF */
	uint32 EG_DED;
	uint32 EG_DST; /* DECAY START */
	uint32 EG_AED;
#	define EG_AST 0 /* ATTACK START */

#	define EG_STEP (96.0 / EG_ENT) /* OPL is 0.1875 dB step  */

/* LFO table entries */
#	define VIB_ENT   512
#	define VIB_SHIFT (32 - 9)
#	define AMS_ENT   512
#	define AMS_SHIFT (32 - 9)

#	define VIB_RATE_SHIFT 8
#	define VIB_RATE       (1 << VIB_RATE_SHIFT)

/* -------------------- local defines , macros --------------------- */

/* register number to channel number , slot offset */
#	define SLOT1 0
#	define SLOT2 1

/* envelope phase */
#	define ENV_MOD_RR 0x00
#	define ENV_MOD_DR 0x01
#	define ENV_MOD_AR 0x02

	/* -------------------- tables --------------------- */
	constexpr static const std::array slot_array{
			0,  2,  4,  1,  3,  5,  -1, -1, 6,  8,  10, 7,  9,  11, -1, -1,
			12, 14, 16, 13, 15, 17, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1};
	static_assert(slot_array.size() == 32);

	static std::array<uint32, 8 * 16> KSL_TABLE;

	constexpr static const std::array KSL_TABLE_SEED{
			/* OCT 0 */
			0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000,
			0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000,
			/* OCT 1 */
			0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000, 0.000,
			0.750, 1.125, 1.500, 1.875, 2.250, 2.625, 3.000,
			/* OCT 2 */
			0.000, 0.000, 0.000, 0.000, 0.000, 1.125, 1.875, 2.625, 3.000,
			3.750, 4.125, 4.500, 4.875, 5.250, 5.625, 6.000,
			/* OCT 3 */
			0.000, 0.000, 0.000, 1.875, 3.000, 4.125, 4.875, 5.625, 6.000,
			6.750, 7.125, 7.500, 7.875, 8.250, 8.625, 9.000,
			/* OCT 4 */
			0.000, 0.000, 3.000, 4.875, 6.000, 7.125, 7.875, 8.625, 9.000,
			9.750, 10.125, 10.500, 10.875, 11.250, 11.625, 12.000,
			/* OCT 5 */
			0.000, 3.000, 6.000, 7.875, 9.000, 10.125, 10.875, 11.625, 12.000,
			12.750, 13.125, 13.500, 13.875, 14.250, 14.625, 15.000,
			/* OCT 6 */
			0.000, 6.000, 9.000, 10.875, 12.000, 13.125, 13.875, 14.625, 15.000,
			15.750, 16.125, 16.500, 16.875, 17.250, 17.625, 18.000,
			/* OCT 7 */
			0.000, 9.000, 12.000, 13.875, 15.000, 16.125, 16.875, 17.625,
			18.000, 18.750, 19.125, 19.500, 19.875, 20.250, 20.625, 21.000};
	static_assert(KSL_TABLE.size() == KSL_TABLE_SEED.size());

	/* sustain level table (3db per step) */
	/* 0 - 15: 0, 3, 6, 9,12,15,18,21,24,27,30,33,36,39,42,93 (dB)*/

	static std::array<int, 16> SL_TABLE;

	constexpr static const std::array SL_TABLE_SEED{0u,  1u,  2u,  3u, 4u,  5u,
													6u,  7u,  8u,  9u, 10u, 11u,
													12u, 13u, 14u, 31u};
	static_assert(SL_TABLE.size() == SL_TABLE_SEED.size());

#	define TL_MAX (EG_ENT * 2) /* limit(tl + ksr + envelope) + sinwave */
	/* TotalLevel : 48 24 12  6  3 1.5 0.75 (dB) */
	/* TL_TABLE[ 0      to TL_MAX          ] : plus  section */
	/* TL_TABLE[ TL_MAX to TL_MAX+TL_MAX-1 ] : minus section */
	static int* TL_TABLE;

	/* pointers to TL_TABLE with sinwave output offset */
	static int** SIN_TABLE;

	/* LFO table */
	static int* AMS_TABLE;
	static int* VIB_TABLE;

	/* envelope output curve table */
	/* attack + decay + OFF */
	// static int ENV_CURVE[2*EG_ENT+1];
	// static int ENV_CURVE[2 * 4096 + 1];   // to keep it static ...
	static int* ENV_CURVE;

/* multiple table */
#	define ML(a) static_cast<uint32>((a) * 2)
	constexpr static const std::array MUL_TABLE{
			/* 1/2, 1, 2, 3, 4, 5, 6, 7, 8, 9,10,11,12,13,14,15 */
			ML(0.50),  ML(1.00),  ML(2.00),  ML(3.00), ML(4.00),  ML(5.00),
			ML(6.00),  ML(7.00),  ML(8.00),  ML(9.00), ML(10.00), ML(10.00),
			ML(12.00), ML(12.00), ML(15.00), ML(15.00)};
	static_assert(MUL_TABLE.size() == 16);
#	undef ML

	/* dummy attack / decay rate ( when rate == 0 ) */
	static std::array RATE_0{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
	static_assert(RATE_0.size() == 16);

	/* -------------------- static state --------------------- */

	/* lock level of common table */
	static int num_lock = 0;

	/* work table */
	static void* cur_chip = nullptr; /* current chip point */
	/* currenct chip state */
	/* static OPLSAMPLE  *bufL,*bufR; */
	static OPL_CH* S_CH;
	static OPL_CH* E_CH;
	OPL_SLOT *     SLOT7_1, *SLOT7_2, *SLOT8_1, *SLOT8_2;

	static int outd[1];
	static int ams;
	static int vib;
	int*       ams_table;
	int*       vib_table;
	static int amsIncr;
	static int vibIncr;
	static int feedback2; /* connect for SLOT 2 */

	/* --------------------- subroutines  --------------------- */

	inline int CLIP(int val, int min, int max) {
		if (val > max) {
			val = max;
		} else if (val < min) {
			val = min;
		}

		return val;
	}

	/* --------------------- rebuild tables ------------------- */

#	define SC_KSL(mydb) (static_cast<uint32>((mydb) / (EG_STEP / 2)))
#	define SC_SL(db) \
		(static_cast<int>((db) * ((3 / EG_STEP) * (1 << ENV_BITS))) + EG_DST)

	void OPLBuildTables(uint32 ENV_BITS_PARAM, uint32 EG_ENT_PARAM) {
		ENV_BITS = ENV_BITS_PARAM;
		EG_ENT   = EG_ENT_PARAM;
		EG_OFF   = ((2u * EG_ENT) << ENV_BITS); /* OFF          */
		EG_DED   = EG_OFF;
		EG_DST   = (EG_ENT << ENV_BITS); /* DECAY  START */
		EG_AED   = EG_DST;
		// EG_STEP = (96.0/EG_ENT);

		for (size_t i = 0; i < KSL_TABLE_SEED.size(); i++) {
			KSL_TABLE[i] = SC_KSL(KSL_TABLE_SEED[i]);
		}

		for (size_t i = 0; i < SL_TABLE_SEED.size(); i++) {
			SL_TABLE[i] = SC_SL(SL_TABLE_SEED[i]);
		}
	}

#	undef SC_KSL
#	undef SC_SL

	/* --------------------- subroutines  --------------------- */

	/* status set and IRQ handling */
	inline void OPL_STATUS_SET(FM_OPL* OPL, int flag) {
		/* set status flag */
		OPL->status |= flag;
		if (!(OPL->status & 0x80)) {
			if (OPL->status & OPL->statusmask) { /* IRQ on */
				OPL->status |= 0x80;
				/* callback user interrupt handler (IRQ is OFF to ON) */
				if (OPL->IRQHandler) {
					(OPL->IRQHandler)(OPL->IRQParam, 1);
				}
			}
		}
	}

	/* status reset and IRQ handling */
	inline void OPL_STATUS_RESET(FM_OPL* OPL, int flag) {
		/* reset status flag */
		OPL->status &= ~flag;
		if ((OPL->status & 0x80)) {
			if (!(OPL->status & OPL->statusmask)) {
				OPL->status &= 0x7f;
				/* callback user interrupt handler (IRQ is ON to OFF) */
				if (OPL->IRQHandler) {
					(OPL->IRQHandler)(OPL->IRQParam, 0);
				}
			}
		}
	}

	/* IRQ mask set */
	inline void OPL_STATUSMASK_SET(FM_OPL* OPL, int flag) {
		OPL->statusmask = flag;
		/* IRQ handling check */
		OPL_STATUS_SET(OPL, 0);
		OPL_STATUS_RESET(OPL, 0);
	}

	/* ----- key on  ----- */
	inline 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;
	}

	/* ----- key off ----- */
	inline void OPL_KEYOFF(OPL_SLOT* SLOT) {
		if (SLOT->evm > ENV_MOD_RR) {
			/* set envelope counter from envleope output */

			// WORKAROUND: The Kyra engine does something very strange when
			// starting a new song. For each channel:
			//
			// * The release rate is set to "fastest".
			// * Any note is keyed off.
			// * A very low-frequency note is keyed on.
			//
			// Usually, what happens next is that the real notes is keyed
			// on immediately, in which case there's no problem.
			//
			// However, if the note is again keyed off (because the channel
			// begins on a rest rather than a note), the envelope counter
			// was moved from the very lowest point on the attack curve to
			// the very highest point on the release curve.
			//
			// Again, this might not be a problem, if the release rate is
			// still set to "fastest". But in many cases, it had already
			// been increased. And, possibly because of inaccuracies in the
			// envelope generator, that would cause the note to "fade out"
			// for quite a long time.
			//
			// What we really need is a way to find the correct starting
			// point for the envelope counter, and that may be what the
			// commented-out line below is meant to do. For now, simply
			// handle the pathological case.

			if (SLOT->evm == ENV_MOD_AR && SLOT->evc == EG_AST) {
				SLOT->evc = EG_DED;
			} else if (!(SLOT->evc & EG_DST)) {
				// SLOT->evc = (ENV_CURVE[SLOT->evc>>ENV_BITS]<<ENV_BITS) +
				// EG_DST;
				SLOT->evc = EG_DST;
			}
			SLOT->eve = EG_DED;
			SLOT->evs = SLOT->evsr;
			SLOT->evm = ENV_MOD_RR;
		}
	}

	/* ---------- calcrate Envelope Generator & Phase Generator ---------- */

	/* return : envelope output */
	inline uint32 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) {
					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 SLOT->TLL + ENV_CURVE[SLOT->evc >> ENV_BITS]
			   + (SLOT->ams ? ams : 0);
	}

	/* set algorythm connection */
	static void set_algorythm(OPL_CH* CH) {
		int* carrier = &outd[0];
		CH->connect1 = CH->CON ? carrier : &feedback2;
		CH->connect2 = carrier;
	}

	/* ---------- frequency counter for operater update ---------- */
	inline 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 = ksr;
			/* attack , decay rate recalcration */
			SLOT->evsa = SLOT->AR[ksr];
			SLOT->evsd = SLOT->DR[ksr];
			SLOT->evsr = SLOT->RR[ksr];
		}
		SLOT->TLL = SLOT->TL + (CH->ksl_base >> SLOT->ksl);
	}

	/* set multi,am,vib,EG-TYP,KSR,mul */
	inline void set_mul(FM_OPL* OPL, int slot, int v) {
		OPL_CH*   CH   = &OPL->P_CH[slot >> 1];
		OPL_SLOT* SLOT = &CH->SLOT[slot & 1];

		SLOT->mul    = MUL_TABLE[v & 0x0f];
		SLOT->KSR    = (v & 0x10) ? 0 : 2;
		SLOT->eg_typ = (v & 0x20) >> 5;
		SLOT->vib    = (v & 0x40);
		SLOT->ams    = (v & 0x80);
		CALC_FCSLOT(CH, SLOT);
	}

	/* set ksl & tl */
	inline void set_ksl_tl(FM_OPL* OPL, int slot, int v) {
		OPL_CH*   CH   = &OPL->P_CH[slot >> 1];
		OPL_SLOT* SLOT = &CH->SLOT[slot & 1];
		const int ksl  = v >> 6; /* 0 / 1.5 / 3 / 6 db/OCT */

		SLOT->ksl = ksl ? 3 - ksl : 31;
		SLOT->TL  = static_cast<int>(
                (v & 0x3f) * (0.75 / EG_STEP)); /* 0.75db step */

		if (!(OPL->mode & 0x80)) { /* not CSM latch total level */
			SLOT->TLL = SLOT->TL + (CH->ksl_base >> SLOT->ksl);
		}
	}

	/* set attack rate & decay rate  */
	inline void set_ar_dr(FM_OPL* OPL, int slot, int v) {
		OPL_CH*   CH   = &OPL->P_CH[slot >> 1];
		OPL_SLOT* SLOT = &CH->SLOT[slot & 1];
		const int ar   = v >> 4;
		const int dr   = v & 0x0f;

		SLOT->AR   = ar ? &OPL->AR_TABLE[ar << 2] : RATE_0.data();
		SLOT->evsa = SLOT->AR[SLOT->ksr];
		if (SLOT->evm == ENV_MOD_AR) {
			SLOT->evs = SLOT->evsa;
		}

		SLOT->DR   = dr ? &OPL->DR_TABLE[dr << 2] : RATE_0.data();
		SLOT->evsd = SLOT->DR[SLOT->ksr];
		if (SLOT->evm == ENV_MOD_DR) {
			SLOT->evs = SLOT->evsd;
		}
	}

	/* set sustain level & release rate */
	inline void set_sl_rr(FM_OPL* OPL, int slot, int v) {
		OPL_CH*   CH   = &OPL->P_CH[slot >> 1];
		OPL_SLOT* SLOT = &CH->SLOT[slot & 1];
		const int sl   = v >> 4;
		const int rr   = v & 0x0f;

		SLOT->SL = SL_TABLE[sl];
		if (SLOT->evm == ENV_MOD_DR) {
			SLOT->eve = SLOT->SL;
		}
		SLOT->RR   = &OPL->DR_TABLE[rr << 2];
		SLOT->evsr = SLOT->RR[SLOT->ksr];
		if (SLOT->evm == ENV_MOD_RR) {
			SLOT->evs = SLOT->evsr;
		}
	}

	/* operator output calcrator */

#	define OP_OUT(slot, env, con)                               \
		slot->wavetable                                          \
				[(((slot)->Cnt + (con)) >> (24 - SIN_ENT_SHIFT)) \
				 & (SIN_ENT - 1)][env]

	/* ---------- calcrate one of channel ---------- */
	inline void OPL_CALC_CH(OPL_CH* CH) {
		uint32    env_out;
		OPL_SLOT* SLOT;

		feedback2 = 0;
		/* SLOT 1 */
		SLOT    = &CH->SLOT[SLOT1];
		env_out = OPL_CALC_SLOT(SLOT);
		if (env_out < (EG_ENT - 1)) {
			/* PG */
			if (SLOT->vib) {
				SLOT->Cnt += (SLOT->Incr * vib) >> VIB_RATE_SHIFT;
			} else {
				SLOT->Cnt += SLOT->Incr;
			}
			/* connection */
			if (CH->FB) {
				const int feedback1
						= (CH->op1_out[0] + CH->op1_out[1]) >> CH->FB;
				CH->op1_out[1] = CH->op1_out[0];
				*CH->connect1 += CH->op1_out[0]
						= OP_OUT(SLOT, env_out, feedback1);
			} else {
				*CH->connect1 += OP_OUT(SLOT, env_out, 0);
			}
		} else {
			CH->op1_out[1] = CH->op1_out[0];
			CH->op1_out[0] = 0;
		}
		/* SLOT 2 */
		SLOT    = &CH->SLOT[SLOT2];
		env_out = OPL_CALC_SLOT(SLOT);
		if (env_out < (EG_ENT - 1)) {
			/* PG */
			if (SLOT->vib) {
				SLOT->Cnt += (SLOT->Incr * vib) >> VIB_RATE_SHIFT;
			} else {
				SLOT->Cnt += SLOT->Incr;
			}
			/* connection */
			outd[0] += OP_OUT(SLOT, env_out, feedback2);
		}
	}

/* ---------- calcrate rythm block ---------- */
#	define WHITE_NOISE_db 6.0

	inline void OPL_CALC_RH(OPL_CH* CH) {
		uint32 env_tam;
		uint32 env_sd;
		uint32 env_top;
		uint32 env_hh;
		// This code used to do int(OPL->rnd.getRandomBit() * (WHITE_NOISE_db /
		// EG_STEP)), but EG_STEP = 96.0/EG_ENT, and WHITE_NOISE_db=6.0. So,
		// that's equivalent to int(OPL->rnd.getRandomBit() * EG_ENT/16). We
		// know that EG_ENT is 4096, or 1024, or 128, so we can safely avoid any
		// FP ops.
		const int whitenoise
				= int((std::rand() & 1) * (WHITE_NOISE_db / EG_STEP));

		int tone8;

		OPL_SLOT* SLOT;
		uint32    env_out;

		/* BD : same as FM serial mode and output level is large */
		feedback2 = 0;
		/* SLOT 1 */
		SLOT    = &CH[6].SLOT[SLOT1];
		env_out = OPL_CALC_SLOT(SLOT);
		if (env_out < EG_ENT - 1) {
			/* PG */
			if (SLOT->vib) {
				SLOT->Cnt += (SLOT->Incr * vib) >> VIB_RATE_SHIFT;
			} else {
				SLOT->Cnt += SLOT->Incr;
			}
			/* connection */
			if (CH[6].FB) {
				const int feedback1
						= (CH[6].op1_out[0] + CH[6].op1_out[1]) >> CH[6].FB;
				CH[6].op1_out[1] = CH[6].op1_out[0];
				feedback2 = CH[6].op1_out[0] = OP_OUT(SLOT, env_out, feedback1);
			} else {
				feedback2 = OP_OUT(SLOT, env_out, 0);
			}
		} else {
			feedback2        = 0;
			CH[6].op1_out[1] = CH[6].op1_out[0];
			CH[6].op1_out[0] = 0;
		}
		/* SLOT 2 */
		SLOT    = &CH[6].SLOT[SLOT2];
		env_out = OPL_CALC_SLOT(SLOT);
		if (env_out < EG_ENT - 1) {
			/* PG */
			if (SLOT->vib) {
				SLOT->Cnt += (SLOT->Incr * vib) >> VIB_RATE_SHIFT;
			} else {
				SLOT->Cnt += SLOT->Incr;
			}
			/* connection */
			outd[0] += OP_OUT(SLOT, env_out, feedback2) * 2;
		}

		// SD  (17) = mul14[fnum7] + white noise
		// TAM (15) = mul15[fnum8]
		// TOP (18) = fnum6(mul18[fnum8]+whitenoise)
		// HH  (14) = fnum7(mul18[fnum8]+whitenoise) + white noise
		env_sd  = OPL_CALC_SLOT(SLOT7_2) + whitenoise;
		env_tam = OPL_CALC_SLOT(SLOT8_1);
		env_top = OPL_CALC_SLOT(SLOT8_2);
		env_hh  = OPL_CALC_SLOT(SLOT7_1) + whitenoise;

		/* PG */
		if (SLOT7_1->vib) {
			SLOT7_1->Cnt += (SLOT7_1->Incr * vib) >> (VIB_RATE_SHIFT - 1);
		} else {
			SLOT7_1->Cnt += 2 * SLOT7_1->Incr;
		}
		if (SLOT7_2->vib) {
			SLOT7_2->Cnt += (CH[7].fc * vib) >> (VIB_RATE_SHIFT - 3);
		} else {
			SLOT7_2->Cnt += (CH[7].fc * 8);
		}
		if (SLOT8_1->vib) {
			SLOT8_1->Cnt += (SLOT8_1->Incr * vib) >> VIB_RATE_SHIFT;
		} else {
			SLOT8_1->Cnt += SLOT8_1->Incr;
		}
		if (SLOT8_2->vib) {
			SLOT8_2->Cnt += ((CH[8].fc * 3) * vib) >> (VIB_RATE_SHIFT - 4);
		} else {
			SLOT8_2->Cnt += (CH[8].fc * 48);
		}

		tone8 = OP_OUT(SLOT8_2, whitenoise, 0);

		/* SD */
		if (env_sd < (EG_ENT - 1)) {
			outd[0] += OP_OUT(SLOT7_1, env_sd, 0) * 8;
		}
		/* TAM */
		if (env_tam < (EG_ENT - 1)) {
			outd[0] += OP_OUT(SLOT8_1, env_tam, 0) * 2;
		}
		/* TOP-CY */
		if (env_top < (EG_ENT - 1)) {
			outd[0] += OP_OUT(SLOT7_2, env_top, tone8) * 2;
		}
		/* HH */
		if (env_hh < (EG_ENT - 1)) {
			outd[0] += OP_OUT(SLOT7_2, env_hh, tone8) * 2;
		}
	}

	/* ----------- initialize time tabls ----------- */
	static void init_timetables(FM_OPL* OPL, int ARRATE, int DRRATE) {
		/* make attack rate & decay rate tables */
		for (int i = 0; i < 4; i++) {
			OPL->AR_TABLE[i] = OPL->DR_TABLE[i] = 0;
		}
		for (int i = 4; i <= 60; i++) {
			double rate = OPL->freqbase; /* frequency rate */
			if (i < 60) {
				rate *= 1.0
						+ (i & 3) * 0.25; /* b0-1 : x1 , x1.25 , x1.5 , x1.75 */
			}
			rate *= 1 << ((i >> 2) - 1); /* b2-5 : shift bit */
			rate *= static_cast<double>(EG_ENT << ENV_BITS);
			OPL->AR_TABLE[i] = static_cast<int>(rate / ARRATE);
			OPL->DR_TABLE[i] = static_cast<int>(rate / DRRATE);
		}
		for (int i = 60; i < 76; i++) {
			OPL->AR_TABLE[i] = EG_AED - 1;
			OPL->DR_TABLE[i] = OPL->DR_TABLE[60];
		}
	}

	/* ---------- generic table initialize ---------- */
	static int OPLOpenTable() {
		/* allocate dynamic tables */
		TL_TABLE  = new int[TL_MAX * 2];
		SIN_TABLE = new int*[SIN_ENT * 4];
		AMS_TABLE = new int[AMS_ENT * 2];
		VIB_TABLE = new int[VIB_ENT * 2];
		ENV_CURVE = new int[2 * EG_ENT + 1];
		/* make total level table */
		for (uint32 t = 0; t < EG_ENT - 1; t++) {
			const double rate
					= ((1 << TL_BITS) - 1)
					  / pow(10.0, EG_STEP * t / 20); /* dB -> voltage */
			TL_TABLE[t]          = static_cast<int>(rate);
			TL_TABLE[TL_MAX + t] = -TL_TABLE[t];
		}
		/* fill volume off area */
		for (uint32 t = EG_ENT - 1; t < TL_MAX; t++) {
			TL_TABLE[t] = TL_TABLE[TL_MAX + t] = 0;
		}

		/* make sinwave table (total level offet) */
		/* degree 0 = degree 180                   = off */
		SIN_TABLE[0] = SIN_TABLE[SIN_ENT / 2] = &TL_TABLE[EG_ENT - 1];
		for (uint32 s = 1; s <= SIN_ENT / 4; s++) {
			double pom  = sin(2 * M_PI * s / SIN_ENT); /* sin     */
			pom         = 20 * log10(1 / pom);         /* decibel */
			const int j = int(pom / EG_STEP);          /* TL_TABLE steps */

			/* degree 0   -  90    , degree 180 -  90 : plus section */
			SIN_TABLE[s] = SIN_TABLE[SIN_ENT / 2 - s] = &TL_TABLE[j];
			/* degree 180 - 270    , degree 360 - 270 : minus section */
			SIN_TABLE[SIN_ENT / 2 + s] = SIN_TABLE[SIN_ENT - s]
					= &TL_TABLE[TL_MAX + j];
		}
		for (uint32 s = 0; s < SIN_ENT; s++) {
			SIN_TABLE[SIN_ENT * 1 + s]
					= s < (SIN_ENT / 2) ? SIN_TABLE[s] : &TL_TABLE[EG_ENT];
			SIN_TABLE[SIN_ENT * 2 + s] = SIN_TABLE[s % (SIN_ENT / 2)];
			SIN_TABLE[SIN_ENT * 3 + s] = (s / (SIN_ENT / 4)) & 1
												 ? &TL_TABLE[EG_ENT]
												 : SIN_TABLE[SIN_ENT * 2 + s];
		}

		/* envelope counter -> envelope output table */
		for (uint32 i = 0; i < EG_ENT; i++) {
			/* ATTACK curve */
			const double pom
					= pow((static_cast<double>(EG_ENT - 1 - i) / EG_ENT), 8)
					  * EG_ENT;
			/* if (pom >= EG_ENT) pom = EG_ENT-1; */
			ENV_CURVE[i] = static_cast<int>(pom);
			/* DECAY ,RELEASE curve */
			ENV_CURVE[(EG_DST >> ENV_BITS) + i] = i;
		}
		/* off */
		ENV_CURVE[EG_OFF >> ENV_BITS] = EG_ENT - 1;
		/* make LFO ams table */
		for (uint32 i = 0; i < AMS_ENT; i++) {
			const double pom
					= (1.0 + sin(2 * M_PI * i / AMS_ENT)) / 2;      /* sin */
			AMS_TABLE[i] = static_cast<int>((1.0 / EG_STEP) * pom); /* 1dB   */
			AMS_TABLE[AMS_ENT + i]
					= static_cast<int>((4.8 / EG_STEP) * pom); /* 4.8dB */
		}
		/* make LFO vibrate table */
		for (uint32 i = 0; i < VIB_ENT; i++) {
			/* 100cent = 1seminote = 6% ?? */
			const double pom
					= VIB_RATE * 0.06
					  * sin(2 * M_PI * i / VIB_ENT); /* +-100sect step */
			VIB_TABLE[i]
					= static_cast<int>(VIB_RATE + (pom * 0.07)); /* +- 7cent */
			VIB_TABLE[VIB_ENT + i]
					= static_cast<int>(VIB_RATE + (pom * 0.14)); /* +-14cent */
		}
		return 1;
	}

	static void OPLCloseTable() {
		delete[] TL_TABLE;
		delete[] SIN_TABLE;
		delete[] AMS_TABLE;
		delete[] VIB_TABLE;
		delete[] ENV_CURVE;
	}

	/* CSM Key Controll */
	inline void CSMKeyControll(OPL_CH* CH) {
		OPL_SLOT* slot1 = &CH->SLOT[SLOT1];
		OPL_SLOT* slot2 = &CH->SLOT[SLOT2];
		/* all key off */
		OPL_KEYOFF(slot1);
		OPL_KEYOFF(slot2);
		/* total level latch */
		slot1->TLL = slot1->TL + (CH->ksl_base >> slot1->ksl);
		slot1->TLL = slot1->TL + (CH->ksl_base >> slot1->ksl);
		/* key on */
		CH->op1_out[0] = CH->op1_out[1] = 0;
		OPL_KEYON(slot1);
		OPL_KEYON(slot2);
	}

	/* ---------- opl initialize ---------- */
	static void OPL_initalize(FM_OPL* OPL) {
		int fn;

		/* frequency base */
		OPL->freqbase
				= (OPL->rate)
						  ? (static_cast<double>(OPL->clock) / OPL->rate) / 72
						  : 0;
		/* Timer base time */
		OPL->TimerBase = 1.0 / (static_cast<double>(OPL->clock) / 72.0);
		/* make time tables */
		init_timetables(OPL, OPL_ARRATE, OPL_DRRATE);
		/* make fnumber -> increment counter table */
		for (fn = 0; fn < 1024; fn++) {
			OPL->FN_TABLE[fn] = static_cast<uint32>(
					OPL->freqbase * fn * FREQ_RATE * (1 << 7) / 2);
		}
		/* LFO freq.table */
		OPL->amsIncr = static_cast<int>(
				OPL->rate ? static_cast<double>(AMS_ENT) * (1 << AMS_SHIFT)
									/ OPL->rate * 3.7 * (OPL->clock / 3600000.0)
						  : 0);
		OPL->vibIncr = static_cast<int>(
				OPL->rate ? static_cast<double>(VIB_ENT) * (1 << VIB_SHIFT)
									/ OPL->rate * 6.4 * (OPL->clock / 3600000.0)
						  : 0);
	}

	/* ---------- write a OPL registers ---------- */
	void OPLWriteReg(FM_OPL* OPL, int r, int v) {
		OPL_CH* CH;
		int     slot;
		uint32  block_fnum;

		switch (r & 0xe0) {
		case 0x00: /* 00-1f:controll */
			switch (r & 0x1f) {
			case 0x01:
				/* wave selector enable */
				if (OPL->type & OPL_TYPE_WAVESEL) {
					OPL->wavesel = v & 0x20;
					if (!OPL->wavesel) {
						/* preset compatible mode */
						int c;
						for (c = 0; c < OPL->max_ch; c++) {
							OPL->P_CH[c].SLOT[SLOT1].wavetable = &SIN_TABLE[0];
							OPL->P_CH[c].SLOT[SLOT2].wavetable = &SIN_TABLE[0];
						}
					}
				}
				return;
			case 0x02: /* Timer 1 */
				OPL->T[0] = (256 - v) * 4;
				break;
			case 0x03: /* Timer 2 */
				OPL->T[1] = (256 - v) * 16;
				return;
			case 0x04:          /* IRQ clear / mask and Timer enable */
				if (v & 0x80) { /* IRQ flag clear */
					OPL_STATUS_RESET(OPL, 0x7f);
				} else { /* set IRQ mask ,timer enable*/
					const uint8 st1 = v & 1;
					const uint8 st2 = (v >> 1) & 1;
					/* IRQRST,T1MSK,t2MSK,EOSMSK,BRMSK,x,ST2,ST1 */
					OPL_STATUS_RESET(OPL, v & 0x78);
					OPL_STATUSMASK_SET(OPL, ((~v) & 0x78) | 0x01);
					/* timer 2 */
					if (OPL->st[1] != st2) {
						const double interval
								= st2 ? (OPL->T[1] * OPL->TimerBase) : 0.0;
						OPL->st[1] = st2;
						if (OPL->TimerHandler) {
							(OPL->TimerHandler)(OPL->TimerParam + 1, interval);
						}
					}
					/* timer 1 */
					if (OPL->st[0] != st1) {
						const double interval
								= st1 ? (OPL->T[0] * OPL->TimerBase) : 0.0;
						OPL->st[0] = st1;
						if (OPL->TimerHandler) {
							(OPL->TimerHandler)(OPL->TimerParam + 0, interval);
						}
					}
				}
				return;
			}
			break;
		case 0x20: /* am,vib,ksr,eg type,mul */
			slot = slot_array[r & 0x1f];
			if (slot == -1) {
				return;
			}
			set_mul(OPL, slot, v);
			return;
		case 0x40:
			slot = slot_array[r & 0x1f];
			if (slot == -1) {
				return;
			}
			set_ksl_tl(OPL, slot, v);
			return;
		case 0x60:
			slot = slot_array[r & 0x1f];
			if (slot == -1) {
				return;
			}
			set_ar_dr(OPL, slot, v);
			return;
		case 0x80:
			slot = slot_array[r & 0x1f];
			if (slot == -1) {
				return;
			}
			set_sl_rr(OPL, slot, v);
			return;
		case 0xa0:
			switch (r) {
			case 0xbd:
				/* amsep,vibdep,r,bd,sd,tom,tc,hh */
				{
					const uint8 rkey = OPL->rythm ^ v;
					OPL->ams_table   = &AMS_TABLE[v & 0x80 ? AMS_ENT : 0];
					OPL->vib_table   = &VIB_TABLE[v & 0x40 ? VIB_ENT : 0];
					OPL->rythm       = v & 0x3f;
					if (OPL->rythm & 0x20) {
						/* BD key on/off */
						if (rkey & 0x10) {
							if (v & 0x10) {
								OPL->P_CH[6].op1_out[0]
										= OPL->P_CH[6].op1_out[1] = 0;
								OPL_KEYON(&OPL->P_CH[6].SLOT[SLOT1]);
								OPL_KEYON(&OPL->P_CH[6].SLOT[SLOT2]);
							} else {
								OPL_KEYOFF(&OPL->P_CH[6].SLOT[SLOT1]);
								OPL_KEYOFF(&OPL->P_CH[6].SLOT[SLOT2]);
							}
						}
						/* SD key on/off */
						if (rkey & 0x08) {
							if (v & 0x08) {
								OPL_KEYON(&OPL->P_CH[7].SLOT[SLOT2]);
							} else {
								OPL_KEYOFF(&OPL->P_CH[7].SLOT[SLOT2]);
							}
						} /* TAM key on/off */
						if (rkey & 0x04) {
							if (v & 0x04) {
								OPL_KEYON(&OPL->P_CH[8].SLOT[SLOT1]);
							} else {
								OPL_KEYOFF(&OPL->P_CH[8].SLOT[SLOT1]);
							}
						}
						/* TOP-CY key on/off */
						if (rkey & 0x02) {
							if (v & 0x02) {
								OPL_KEYON(&OPL->P_CH[8].SLOT[SLOT2]);
							} else {
								OPL_KEYOFF(&OPL->P_CH[8].SLOT[SLOT2]);
							}
						}
						/* HH key on/off */
						if (rkey & 0x01) {
							if (v & 0x01) {
								OPL_KEYON(&OPL->P_CH[7].SLOT[SLOT1]);
							} else {
								OPL_KEYOFF(&OPL->P_CH[7].SLOT[SLOT1]);
							}
						}
					}
				}
				return;

			default:
				break;
			}
			/* keyon,block,fnum */
			if ((r & 0x0f) > 8) {
				return;
			}
			CH = &OPL->P_CH[r & 0x0f];
			if (!(r & 0x10)) { /* a0-a8 */
				block_fnum = (CH->block_fnum & 0x1f00) | v;
			} else { /* b0-b8 */
				const int keyon = (v >> 5) & 1;
				block_fnum      = ((v & 0x1f) << 8) | (CH->block_fnum & 0xff);
				if (CH->keyon != keyon) {
					if ((CH->keyon = keyon)) {
						CH->op1_out[0] = CH->op1_out[1] = 0;
						OPL_KEYON(&CH->SLOT[SLOT1]);
						OPL_KEYON(&CH->SLOT[SLOT2]);
					} else {
						OPL_KEYOFF(&CH->SLOT[SLOT1]);
						OPL_KEYOFF(&CH->SLOT[SLOT2]);
					}
				}
			}
			/* update */
			if (CH->block_fnum != block_fnum) {
				const int blockRv = 7 - (block_fnum >> 10);
				const int fnum    = block_fnum & 0x3ff;
				CH->block_fnum    = block_fnum;
				CH->ksl_base      = KSL_TABLE[block_fnum >> 6];
				CH->fc            = OPL->FN_TABLE[fnum] >> blockRv;
				CH->kcode         = CH->block_fnum >> 9;
				if ((OPL->mode & 0x40) && CH->block_fnum & 0x100) {
					CH->kcode |= 1;
				}
				CALC_FCSLOT(CH, &CH->SLOT[SLOT1]);
				CALC_FCSLOT(CH, &CH->SLOT[SLOT2]);
			}
			return;
		case 0xc0:
			/* FB,C */
			if ((r & 0x0f) > 8) {
				return;
			}
			CH = &OPL->P_CH[r & 0x0f];
			{
				const int feedback = (v >> 1) & 7;
				CH->FB             = feedback ? (8 + 1) - feedback : 0;
				CH->CON            = v & 1;
				set_algorythm(CH);
			}
			return;
		case 0xe0: /* wave type */
			slot = slot_array[r & 0x1f];
			if (slot == -1) {
				return;
			}
			CH = &OPL->P_CH[slot >> 1];
			if (OPL->wavesel) {
				CH->SLOT[slot & 1].wavetable = &SIN_TABLE[(v & 0x03) * SIN_ENT];
			}
			return;
		}
	}

	/* lock/unlock for common table */
	static int OPL_LockTable() {
		num_lock++;
		if (num_lock > 1) {
			return 0;
		}
		/* first time */
		cur_chip = nullptr;
		/* allocate total level table (128kb space) */
		if (!OPLOpenTable()) {
			num_lock--;
			return -1;
		}
		return 0;
	}

	static void OPL_UnLockTable() {
		if (num_lock) {
			num_lock--;
		}
		if (num_lock) {
			return;
		}
		/* last time */
		cur_chip = nullptr;
		OPLCloseTable();
	}

	/*******************************************************************************/
	/*		YM3812 local section */
	/*******************************************************************************/

	/* ---------- update one of chip ----------- */
	void YM3812UpdateOne_Mono(FM_OPL* OPL, sint16* buffer, int length) {
		sint16*     buf    = buffer;
		uint32      amsCnt = OPL->amsCnt;
		uint32      vibCnt = OPL->vibCnt;
		const uint8 rythm  = OPL->rythm & 0x20;

		if (OPL != cur_chip) {
			cur_chip = OPL;
			/* channel pointers */
			S_CH = OPL->P_CH;
			E_CH = &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;
		}
		OPL_CH* R_CH = rythm ? &S_CH[6] : E_CH;
		for (int i = 0; i < length; i++) {
			/*            channel A         channel B         channel C      */
			/* LFO */
			ams     = ams_table[(amsCnt += amsIncr) >> AMS_SHIFT];
			vib     = vib_table[(vibCnt += vibIncr) >> VIB_SHIFT];
			outd[0] = 0;
			/* FM part */
			for (OPL_CH* CH = S_CH; CH < R_CH; CH++) {
				OPL_CALC_CH(CH);
			}
			/* Rythn part */
			if (rythm) {
				OPL_CALC_RH(S_CH);
			}
			/* limit check */
			const int data = CLIP(outd[0], OPL_MINOUT, OPL_MAXOUT);
			/* store to sound buffer */
			buf[i] = data >> OPL_OUTSB;
		}

		OPL->amsCnt = amsCnt;
		OPL->vibCnt = vibCnt;
	}

	void YM3812UpdateOne_Stereo(FM_OPL* OPL, sint16* buffer, int length) {
		sint16*     buf    = buffer;
		uint32      amsCnt = OPL->amsCnt;
		uint32      vibCnt = OPL->vibCnt;
		const uint8 rythm  = OPL->rythm & 0x20;

		if (OPL != cur_chip) {
			cur_chip = OPL;
			/* channel pointers */
			S_CH = OPL->P_CH;
			E_CH = &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;
		}
		OPL_CH* R_CH = rythm ? &S_CH[6] : E_CH;
		for (int i = 0; i < length; i++) {
			/*            channel A         channel B         channel C      */
			/* LFO */
			ams       = ams_table[(amsCnt += amsIncr) >> AMS_SHIFT];
			vib       = vib_table[(vibCnt += vibIncr) >> VIB_SHIFT];
			int left  = 0;
			int right = 0;
			/* FM part */
			for (OPL_CH* CH = S_CH; CH < R_CH; CH++) {
				outd[0] = 0;
				OPL_CALC_CH(CH);
				if (CH->PAN <= 64) {
					left += outd[0];
				} else {
					left += (outd[0] >> 6) * (127 - CH->PAN);
				}
				if (CH->PAN >= 64) {
					right += outd[0];
				} else {
					right += (outd[0] >> 6) * (CH->PAN);
				}
			}
			/* Rythn part */
			if (rythm) {
				outd[0] = 0;
				OPL_CALC_RH(S_CH);
				left += outd[0];
				right += outd[0];
			}
			/* limit check */
			int data = CLIP(left, OPL_MINOUT, OPL_MAXOUT);
			/* store to sound buffer */
			buf[i * 2] = data >> OPL_OUTSB;

			/* limit check */
			data = CLIP(right, OPL_MINOUT, OPL_MAXOUT);
			/* store to sound buffer */
			buf[i * 2 + 1] = data >> OPL_OUTSB;
		}

		OPL->amsCnt = amsCnt;
		OPL->vibCnt = vibCnt;
	}

	/* ---------- reset a chip ---------- */
	void OPLResetChip(FM_OPL* OPL) {
		int c;
		int s;
		int i;

		/* reset chip */
		OPL->mode = 0; /* normal mode */
		OPL_STATUS_RESET(OPL, 0x7f);
		/* reset with register write */
		OPLWriteReg(OPL, 0x01, 0); /* wabesel disable */
		OPLWriteReg(OPL, 0x02, 0); /* Timer1 */
		OPLWriteReg(OPL, 0x03, 0); /* Timer2 */
		OPLWriteReg(OPL, 0x04, 0); /* IRQ mask clear */
		for (i = 0xff; i >= 0x20; i--) {
			OPLWriteReg(OPL, i, 0);
		}
		/* reset OPerator parameter */
		for (c = 0; c < OPL->max_ch; c++) {
			OPL_CH* CH       = &OPL->P_CH[c];
			OPL->P_CH[c].PAN = 64;
			for (s = 0; s < 2; s++) {
				/* wave table */
				CH->SLOT[s].wavetable = &SIN_TABLE[0];
				/* CH->SLOT[s].evm = ENV_MOD_RR; */
				CH->SLOT[s].evc = EG_OFF;
				CH->SLOT[s].eve = EG_OFF + 1;
				CH->SLOT[s].evs = 0;
			}
		}
	}

	/* ----------  Create a virtual YM3812 ----------       */
	/* 'rate'  is sampling rate and 'bufsiz' is the size of the  */
	FM_OPL* OPLCreate(int type, int clock, int rate) {
		if (OPL_LockTable() == -1) {
			return nullptr;
		}

		auto* OPL = new FM_OPL{};
		OPL->P_CH = OPL->channels;

		/* set channel state pointer */
		OPL->type   = type;
		OPL->clock  = clock;
		OPL->rate   = rate;
		OPL->max_ch = max_opl_channels;

		/* init grobal tables */
		OPL_initalize(OPL);

		/* reset chip */
		OPLResetChip(OPL);
		return OPL;
	}

	/* ----------  Destroy one of virtual YM3812 ----------       */
	void OPLDestroy(FM_OPL* OPL) {
		OPL_UnLockTable();
		delete OPL;
	}

	/* ----------  Option handlers ----------       */
	void OPLSetTimerHandler(
			FM_OPL* OPL, OPL_TIMERHANDLER TimerHandler, int channelOffset) {
		OPL->TimerHandler = TimerHandler;
		OPL->TimerParam   = channelOffset;
	}

	void OPLSetIRQHandler(FM_OPL* OPL, OPL_IRQHANDLER IRQHandler, int param) {
		OPL->IRQHandler = IRQHandler;
		OPL->IRQParam   = param;
	}

	void OPLSetUpdateHandler(
			FM_OPL* OPL, OPL_UPDATEHANDLER UpdateHandler, int param) {
		OPL->UpdateHandler = UpdateHandler;
		OPL->UpdateParam   = param;
	}

	/* ---------- YM3812 I/O interface ---------- */
	int OPLWrite(FM_OPL* OPL, int a, int v) {
		if (!(a & 1)) { /* address port */
			OPL->address = v & 0xff;
		} else { /* data port */
			if (OPL->UpdateHandler) {
				OPL->UpdateHandler(OPL->UpdateParam, 0);
			}
			OPLWriteReg(OPL, OPL->address, v);
		}
		return OPL->status >> 7;
	}

	unsigned char OPLRead(FM_OPL* OPL, int a) {
		if (!(a & 1)) { /* status port */
			return OPL->status & (OPL->statusmask | 0x80);
		}
		/* data port */
		switch (OPL->address) {
		case 0x05: /* KeyBoard IN */
			PERR(("OPL:read unmapped KEYBOARD port\n"));
			return 0;
		case 0x19: /* I/O DATA    */
			PERR(("OPL:read unmapped I/O port\n"));
			return 0;
		case 0x1a: /* PCM-DATA    */
			return 0;
		default:
			break;
		}
		return 0;
	}

	int OPLTimerOver(FM_OPL* OPL, int c) {
		if (c) { /* Timer B */
			OPL_STATUS_SET(OPL, 0x20);
		} else { /* Timer A */
			OPL_STATUS_SET(OPL, 0x40);
			/* CSM mode key,TL controll */
			if (OPL->mode
				& 0x80) { /* CSM mode total level latch and auto key on */
				int ch;
				if (OPL->UpdateHandler) {
					OPL->UpdateHandler(OPL->UpdateParam, 0);
				}
				for (ch = 0; ch < 9; ch++) {
					CSMKeyControll(&OPL->P_CH[ch]);
				}
			}
		}
		/* reload timer */
		if (OPL->TimerHandler) {
			(OPL->TimerHandler)(
					OPL->TimerParam + c,
					static_cast<double>(OPL->T[c]) * OPL->TimerBase);
		}
		return OPL->status >> 7;
	}

	void OPLSetPan(FM_OPL* OPL, int c, int pan) {
		if (c > 0 && c < OPL->max_ch) {
			OPL->P_CH[c].PAN = pan;
		}
	}

	FM_OPL* makeAdLibOPL(int rate) {
		// We need to emulate one YM3812 chip
		OPLBuildTables(FMOPL_ENV_BITS_HQ, FMOPL_EG_ENT_HQ);
		return OPLCreate(OPL_TYPE_YM3812, 3579545, rate);
	}

}    // namespace FMOpl_Pentagram

#endif    // USE_FMOPL_MIDI
