1 files changed, 89 insertions, 15 deletions

diff --git a/sound/fmopl.cpp b/sound/fmopl.cpp
index eb84d37366..f0f7327fd4 100644
--- a/sound/fmopl.cpp
+++ b/sound/fmopl.cpp
@@ -27,27 +27,101 @@
 #include "sound/softsynth/opl/dosbox.h"
 #include "sound/softsynth/opl/mame.h"
 
+#include "common/config-manager.h"
+
 namespace OPL {
 
-bool OPL::_hasInstance = false;
+// Config implementation
 
-OPL *OPL::create(kOplType type) {
-	// Simple hack to assure we only create one instance,
-	// since the DOSBox OPL emulator does not allow more than
-	// one instance.
-	assert(!_hasInstance);
-	_hasInstance = true;
+enum OplEmulator {
+	kMame = 0,
+	kDOSBox = 1
+};
 
-#ifdef DISABLE_DOSBOX_OPL
-	if (type != kOpl2)
-		return 0;
-	else
-		return new MAME::OPL();
-#else
-	return new DOSBox::OPL(type);
+const Config::EmulatorDescription Config::_drivers[] = {
+	{ "auto", "<default>", 0, kFlagOpl2 | kFlagDualOpl2 | kFlagOpl3 },
+	{ "mame", "MAME OPL emulator", kMame, kFlagOpl2 },
+#ifndef DISABLE_DOSBOX_OPL
+	{ "db", "DOSBox OPL emulator (experimental)", kDOSBox, kFlagOpl2 | kFlagDualOpl2 | kFlagOpl3 },
 #endif
+	{ 0, 0, 0, 0 }
+};
+
+Config::DriverId Config::parse(const Common::String &name) {
+	for (int i = 0; _drivers[i].name; ++i) {
+		if (name.equalsIgnoreCase(_drivers[i].name))
+			return _drivers[i].id;
+	}
+
+	return 0;
 }
 
+Config::DriverId Config::detect(OplType type) {
+	uint32 flags = 0;
+	switch (type) {
+	case kOpl2:
+		flags = kFlagOpl2;
+		break;
+
+	case kDualOpl2:
+		flags = kFlagDualOpl2;
+		break;
+
+	case kOpl3:
+		flags = kFlagOpl3;
+		break;
+	}
+
+	DriverId drv = parse(ConfMan.get("opl_driver"));
+
+	// When a valid driver is selected, check whether it supports
+	// the requested OPL chip.
+	if (validDriver(drv)) {
+		// If the chip is supported, just use the driver.
+		if ((flags & _drivers[drv].flags))
+			return drv;
+
+		// When it doesn't support the flags fall back to auto detection
+	}
+
+	// Detect the first matching emulator
+	for (int i = 1; _drivers[i].name; ++i) {
+		if (_drivers[i].flags & flags) {
+			drv = _drivers[i].id;
+			break;
+		}
+	}
+
+	return drv;
+}
+
+OPL *Config::create(DriverId driver, OplType type) {
+	if (!validDriver(driver))
+		driver = detect(type);
+
+	switch (driver)  {
+	case kMame:
+		if (type == kOpl2)
+			return new MAME::OPL();
+		else
+			warning("MAME OPL emulator only supports OPL2 emulation.");
+			return 0;
+
+#ifndef DISABLE_DOSBOX_OPL
+	case kDOSBox:
+		return new DOSBox::OPL(type);
+#endif
+
+	default:
+		warning("Unsupported OPL emulator %d", driver);
+		// TODO: Maybe we should add some dummy emulator too, which just outputs
+		// silence as sound?
+		return 0;
+	}
+}
+
+bool OPL::_hasInstance = false;
+
 } // end of namespace OPL
 
 void OPLDestroy(FM_OPL *OPL) {
@@ -75,7 +149,7 @@ void YM3812UpdateOne(FM_OPL *OPL, int16 *buffer, int length) {
 }
 
 FM_OPL *makeAdlibOPL(int rate) {
-	FM_OPL *opl = OPL::OPL::create(OPL::OPL::kOpl2);
+	FM_OPL *opl = OPL::Config::create(OPL::Config::kOpl2);
 
 	if (opl) {
 		if (!opl->init(rate)) {