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audio/softsynth/opl/dosbox.h

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+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * 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 3 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, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+/*
+ * Based on OPL emulation code of DOSBox
+ * Copyright (C) 2002-2009  The DOSBox Team
+ * Licensed under GPLv2+
+ * http://www.dosbox.com
+ */
+
+#ifndef AUDIO_SOFTSYNTH_OPL_DOSBOX_H
+#define AUDIO_SOFTSYNTH_OPL_DOSBOX_H
+
+#ifndef DISABLE_DOSBOX_OPL
+
+#include "audio/fmopl.h"
+
+namespace OPL {
+namespace DOSBox {
+
+struct Timer {
+	double startTime;
+	double delay;
+	bool enabled, overflow, masked;
+	uint8 counter;
+
+	Timer();
+
+	//Call update before making any further changes
+	void update(double time);
+
+	//On a reset make sure the start is in sync with the next cycle
+	void reset(double time);
+
+	void stop();
+
+	void start(double time, int scale);
+};
+
+struct Chip {
+	//Last selected register
+	Timer timer[2];
+	//Check for it being a write to the timer
+	bool write(uint32 addr, uint8 val);
+	//Read the current timer state, will use current double
+	uint8 read();
+};
+
+namespace DBOPL {
+struct Chip;
+} // end of namespace DBOPL
+
+class OPL : public ::OPL::OPL, public Audio::EmulatedChip {
+private:
+	Config::OplType _type;
+	uint _rate;
+
+	DBOPL::Chip *_emulator;
+	::OPL::DOSBox::Chip _chip[2];
+	union {
+		uint16 normal;
+		uint8 dual[2];
+	} _reg;
+
+	void free();
+	void dualWrite(uint8 index, uint8 reg, uint8 val);
+public:
+	OPL(Config::OplType type);
+	~OPL();
+
+	bool init();
+	void reset();
+
+	void write(int a, int v);
+
+	void writeReg(int r, int v);
+
+	bool isStereo() const { return _type != Config::kOpl2; }
+
+protected:
+	void generateSamples(int16 *buffer, int length);
+};
+
+} // End of namespace DOSBox
+} // End of namespace OPL
+
+#endif // !DISABLE_DOSBOX_OPL
+
+#endif