Add Nuked OPL3 emulator v1.8

Set oplemu to nuked in config file. Also set oplrate and mixer rate
to 49716 for best sound quality.

Changelog for v1.8:

- New envelope generator.
- Rhythm mode emulation is 100% correct now.

Vogons thread: https://www.vogons.org/viewtopic.php?f=9&t=37782

Imported-from: https://www.vogons.org/viewtopic.php?p=661417#p661417

src/dosbox.cpp

@@ -604,7 +604,7 @@ void DOSBOX_Init(void) {
 	Pstring->Set_values(oplmodes);
 	Pstring->Set_help("Type of OPL emulation. On 'auto' the mode is determined by sblaster type. All OPL modes are Adlib-compatible, except for 'cms'.");
 
-	const char* oplemus[]={ "default", "compat", "fast", "mame", 0};
+	const char* oplemus[]={ "default", "compat", "fast", "mame", "nuked", 0};
 	Pstring = secprop->Add_string("oplemu",Property::Changeable::WhenIdle,"default");
 	Pstring->Set_values(oplemus);
 	Pstring->Set_help("Provider for the OPL emulation. compat might provide better quality (see oplrate as well).");

src/hardware/Makefile.am

@@ -2,7 +2,7 @@ AM_CPPFLAGS = -I$(top_srcdir)/include
 
 SUBDIRS = serialport mame
 
-EXTRA_DIST = opl.cpp opl.h adlib.h dbopl.h pci_devices.h
+EXTRA_DIST = opl.cpp opl.h adlib.h dbopl.h pci_devices.h nukedopl.h
 
 noinst_LIBRARIES = libhardware.a
 
@@ -10,6 +10,4 @@ libhardware_a_SOURCES = adlib.cpp dma.cpp gameblaster.cpp hardware.cpp iohandler
                         memory.cpp mixer.cpp pcspeaker.cpp pci_bus.cpp pic.cpp sblaster.cpp tandy_sound.cpp timer.cpp \
 			vga.cpp vga_attr.cpp vga_crtc.cpp vga_dac.cpp vga_draw.cpp vga_gfx.cpp vga_other.cpp \
 			vga_memory.cpp vga_misc.cpp vga_seq.cpp vga_xga.cpp vga_s3.cpp vga_tseng.cpp vga_paradise.cpp \
-			cmos.cpp disney.cpp gus.cpp mpu401.cpp ipx.cpp ipxserver.cpp dbopl.cpp
-
-
+			cmos.cpp disney.cpp gus.cpp mpu401.cpp ipx.cpp ipxserver.cpp dbopl.cpp nukedopl.cpp

src/hardware/adlib.cpp

@@ -27,6 +27,7 @@
 #include "mapper.h"
 #include "mem.h"
 #include "dbopl.h"
+#include "nukedopl.h"
 
 #include "mame/emu.h"
 #include "mame/fmopl.h"
@@ -164,6 +165,42 @@ struct Handler : public Adlib::Handler {
 
 }
 
+namespace NukedOPL {
+struct Handler : public Adlib::Handler {
+	opl3_chip chip;
+	Bit8u newm;
+	virtual void WriteReg( Bit32u reg, Bit8u val ) {
+		OPL3_WriteRegBuffered(&chip, (Bit16u)reg, val);
+		if (reg == 0x105)
+			newm = reg & 0x01;
+	}
+	virtual Bit32u WriteAddr( Bit32u port, Bit8u val ) {
+		Bit16u addr;
+		addr = val;
+		if ((port & 2) && (addr == 0x05 || newm)) {
+			addr |= 0x100;
+		}
+		return addr;
+	}
+	virtual void Generate( MixerChannel* chan, Bitu samples ) {
+		Bit16s buf[1024*2];
+		while( samples > 0 ) {
+			Bitu todo = samples > 1024 ? 1024 : samples;
+			samples -= todo;
+			OPL3_GenerateStream(&chip, buf, todo);
+			chan->AddSamples_s16( todo, buf );
+		}
+	}
+	virtual void Init( Bitu rate ) {
+		newm = 0;
+		OPL3_Reset(&chip, rate);
+	}
+	~Handler() {
+	}
+};
+
+}
+
 
 
 #define RAW_SIZE 1024
@@ -806,6 +843,9 @@ Module::Module(Section *configuration)
 		else {
 			handler = new MAMEOPL3::Handler();
 		}
+	}
+	else if (oplemu == "nuked") {
+		handler = new NukedOPL::Handler();
 	} else {
 		handler = new DBOPL::Handler();
 	}

src/hardware/nukedopl.h

@@ -0,0 +1,138 @@
+//
+// Copyright (C) 2013-2018 Alexey Khokholov (Nuke.YKT)
+//
+// 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.
+//
+//
+//  Nuked OPL3 emulator.
+//  Thanks:
+//      MAME Development Team(Jarek Burczynski, Tatsuyuki Satoh):
+//          Feedback and Rhythm part calculation information.
+//      forums.submarine.org.uk(carbon14, opl3):
+//          Tremolo and phase generator calculation information.
+//      OPLx decapsulated(Matthew Gambrell, Olli Niemitalo):
+//          OPL2 ROMs.
+//      siliconpr0n.org(John McMaster, digshadow):
+//          YMF262 and VRC VII decaps and die shots.
+//
+// version: 1.8
+//
+
+#ifndef OPL_OPL3_H
+#define OPL_OPL3_H
+#define OPL_WRITEBUF_SIZE   1024
+#define OPL_WRITEBUF_DELAY  1
+
+#include "dosbox.h"
+
+typedef struct _opl3_slot opl3_slot;
+typedef struct _opl3_channel opl3_channel;
+typedef struct _opl3_chip opl3_chip;
+
+struct _opl3_slot {
+    opl3_channel *channel;
+    opl3_chip *chip;
+    Bit16s out;
+    Bit16s fbmod;
+    Bit16s *mod;
+    Bit16s prout;
+    Bit16s eg_rout;
+    Bit16s eg_out;
+    Bit8u eg_inc;
+    Bit8u eg_gen;
+    Bit8u eg_rate;
+    Bit8u eg_ksl;
+    Bit8u *trem;
+    Bit8u reg_vib;
+    Bit8u reg_type;
+    Bit8u reg_ksr;
+    Bit8u reg_mult;
+    Bit8u reg_ksl;
+    Bit8u reg_tl;
+    Bit8u reg_ar;
+    Bit8u reg_dr;
+    Bit8u reg_sl;
+    Bit8u reg_rr;
+    Bit8u reg_wf;
+    Bit8u key;
+    Bit32u pg_reset;
+    Bit32u pg_phase;
+    Bit16u pg_phase_out;
+    Bit8u slot_num;
+};
+
+struct _opl3_channel {
+    opl3_slot *slots[2];
+    opl3_channel *pair;
+    opl3_chip *chip;
+    Bit16s *out[4];
+    Bit8u chtype;
+    Bit16u f_num;
+    Bit8u block;
+    Bit8u fb;
+    Bit8u con;
+    Bit8u alg;
+    Bit8u ksv;
+    Bit16u cha, chb;
+    Bit8u ch_num;
+};
+
+typedef struct _opl3_writebuf {
+    Bit64u time;
+    Bit16u reg;
+    Bit8u data;
+} opl3_writebuf;
+
+struct _opl3_chip {
+    opl3_channel channel[18];
+    opl3_slot slot[36];
+    Bit16u timer;
+    Bit64u eg_timer;
+    Bit8u eg_timerrem;
+    Bit8u eg_state;
+    Bit8u eg_add;
+    Bit8u newm;
+    Bit8u nts;
+    Bit8u rhy;
+    Bit8u vibpos;
+    Bit8u vibshift;
+    Bit8u tremolo;
+    Bit8u tremolopos;
+    Bit8u tremoloshift;
+    Bit32u noise;
+    Bit16s zeromod;
+    Bit32s mixbuff[2];
+    Bit8u rm_hh_bit2;
+    Bit8u rm_hh_bit3;
+    Bit8u rm_hh_bit7;
+    Bit8u rm_hh_bit8;
+    Bit8u rm_tc_bit3;
+    Bit8u rm_tc_bit5;
+    //OPL3L
+    Bit32s rateratio;
+    Bit32s samplecnt;
+    Bit16s oldsamples[2];
+    Bit16s samples[2];
+
+    Bit64u writebuf_samplecnt;
+    Bit32u writebuf_cur;
+    Bit32u writebuf_last;
+    Bit64u writebuf_lasttime;
+    opl3_writebuf writebuf[OPL_WRITEBUF_SIZE];
+};
+
+void OPL3_Generate(opl3_chip *chip, Bit16s *buf);
+void OPL3_GenerateResampled(opl3_chip *chip, Bit16s *buf);
+void OPL3_Reset(opl3_chip *chip, Bit32u samplerate);
+void OPL3_WriteReg(opl3_chip *chip, Bit16u reg, Bit8u v);
+void OPL3_WriteRegBuffered(opl3_chip *chip, Bit16u reg, Bit8u v);
+void OPL3_GenerateStream(opl3_chip *chip, Bit16s *sndptr, Bit32u numsamples);
+#endif