Qt: Support for multiple saves per game using .sa2, .sa3, etc.

CHANGES

@@ -11,6 +11,7 @@ Features:
  - Discord Rich Presence now supports time elapsed
  - Additional scaling shaders
  - Support for GameShark Advance SP (.gsv) save file importing
+ - Support for multiple saves per game using .sa2, .sa3, etc.
 Emulation fixes:
  - ARM7: Fix unsigned multiply timing
  - GB Memory: Add cursory cartridge open bus emulation (fixes mgba.io/i/2032)

src/core/core.c

@@ -223,7 +223,13 @@ bool mCoreAutoloadSave(struct mCore* core) {
 	if (!core->dirs.save) {
 		return false;
 	}
-	return core->loadSave(core, mDirectorySetOpenSuffix(&core->dirs, core->dirs.save, ".sav", O_CREAT | O_RDWR));
+	int savePlayerId = 0;
+	char sav[16] = ".sav";
+	mCoreConfigGetIntValue(&core->config, "savePlayerId", &savePlayerId);
+	if (savePlayerId > 1) {
+		snprintf(sav, sizeof(sav), ".sa%i", savePlayerId);
+	}
+	return core->loadSave(core, mDirectorySetOpenSuffix(&core->dirs, core->dirs.save, sav, O_CREAT | O_RDWR));
 }
 
 bool mCoreAutoloadPatch(struct mCore* core) {
@@ -365,6 +371,7 @@ void mCoreLoadForeignConfig(struct mCore* core, const struct mCoreConfig* config
 
 	mCoreConfigCopyValue(&core->config, config, "cheatAutosave");
 	mCoreConfigCopyValue(&core->config, config, "cheatAutoload");
+	mCoreConfigCopyValue(&core->config, config, "savePlayerId");
 
 	core->loadConfig(core, config);
 }

src/platform/qt/CoreController.cpp

@@ -11,7 +11,9 @@
 #include "MultiplayerController.h"
 #include "Override.h"
 
+#include <QAbstractButton>
 #include <QDateTime>
+#include <QMessageBox>
 #include <QMutexLocker>
 
 #include <mgba/core/serialize.h>
@@ -70,6 +72,7 @@ CoreController::CoreController(mCore* core, QObject* parent)
 
 		if (controller->m_multiplayer) {
 			controller->m_multiplayer->attachGame(controller);
+			controller->updatePlayerSave();
 		}
 
 		QMetaObject::invokeMethod(controller, "started");
@@ -285,6 +288,13 @@ void CoreController::loadConfig(ConfigController* config) {
 	mCoreConfigCopyValue(&m_threadContext.core->config, config->config(), "volume");
 	mCoreConfigCopyValue(&m_threadContext.core->config, config->config(), "mute");
 
+	int playerId = m_multiplayer->playerId(this) + 1;
+	QVariant savePlayerId = config->getOption("savePlayerId");
+	if (m_multiplayer->attached() < 2 && savePlayerId.canConvert<int>()) {
+		playerId = savePlayerId.toInt();
+	}
+	mCoreConfigSetOverrideIntValue(&m_threadContext.core->config, "savePlayerId", playerId);
+
 	QSize sizeBefore = screenDimensions();
 	m_activeBuffer.resize(256 * 224 * sizeof(color_t));
 	m_threadContext.core->setVideoBuffer(m_threadContext.core, reinterpret_cast<color_t*>(m_activeBuffer.data()), sizeBefore.width());
@@ -537,6 +547,41 @@ void CoreController::forceFastForward(bool enable) {
 	emit fastForwardChanged(enable || m_fastForward);
 }
 
+void CoreController::changePlayer(int id) {
+	Interrupter interrupter(this);
+	int playerId = 0;
+	mCoreConfigGetIntValue(&m_threadContext.core->config, "savePlayerId", &playerId);
+	if (id == playerId) {
+		return;
+	}
+	interrupter.resume();
+
+	QMessageBox* resetPrompt = new QMessageBox(QMessageBox::Question, tr("Reset the game?"),
+		tr("Most games will require a reset to load the new save. Do you want to reset now?"),
+		QMessageBox::Yes | QMessageBox::No | QMessageBox::Cancel);
+	connect(resetPrompt, &QMessageBox::buttonClicked, this, [this, resetPrompt, id](QAbstractButton* button) {
+		Interrupter interrupter(this);
+		switch (resetPrompt->standardButton(button)) {
+		default:
+			return;
+		case QMessageBox::Yes:
+			mCoreConfigSetOverrideIntValue(&m_threadContext.core->config, "savePlayerId", id);
+			m_resetActions.append([this]() {
+				updatePlayerSave();
+			});
+			interrupter.resume();
+			reset();
+			break;
+		case QMessageBox::No:
+			mCoreConfigSetOverrideIntValue(&m_threadContext.core->config, "savePlayerId", id);
+			updatePlayerSave();
+			break;
+		}
+	});
+	resetPrompt->setAttribute(Qt::WA_DeleteOnClose);
+	resetPrompt->show();
+}
+
 void CoreController::overrideMute(bool override) {
 	m_mute = override;
 
@@ -734,7 +779,22 @@ void CoreController::loadSave(const QString& path, bool temporary) {
 			m_threadContext.core->loadSave(m_threadContext.core, vf);
 		}
 	});
-	reset();
+	if (hasStarted()) {
+		reset();
+	}
+}
+
+void CoreController::loadSave(VFile* vf, bool temporary) {
+	m_resetActions.append([this, vf, temporary]() {
+		if (temporary) {
+			m_threadContext.core->loadTemporarySave(m_threadContext.core, vf);
+		} else {
+			m_threadContext.core->loadSave(m_threadContext.core, vf);
+		}
+	});
+	if (hasStarted()) {
+		reset();
+	}
 }
 
 void CoreController::loadPatch(const QString& patchPath) {
@@ -1098,6 +1158,26 @@ void CoreController::finishFrame() {
 	QMetaObject::invokeMethod(this, "frameAvailable");
 }
 
+void CoreController::updatePlayerSave() {
+	int savePlayerId = 0;
+	mCoreConfigGetIntValue(&m_threadContext.core->config, "savePlayerId", &savePlayerId);
+	if (savePlayerId == 0 || m_multiplayer->attached() > 1) {
+		savePlayerId = m_multiplayer->playerId(this) + 1;
+	}
+
+	QString saveSuffix;
+	if (savePlayerId < 2) {
+		saveSuffix = QLatin1String(".sav");
+	} else {
+		saveSuffix = QString(".sa%1").arg(savePlayerId);
+	}
+	QByteArray saveSuffixBin(saveSuffix.toUtf8());
+	VFile* save = mDirectorySetOpenSuffix(&m_threadContext.core->dirs, m_threadContext.core->dirs.save, saveSuffixBin.constData(), O_CREAT | O_RDWR);
+	if (save) {
+		m_threadContext.core->loadSave(m_threadContext.core, save);
+	}
+}
+
 void CoreController::updateFastForward() {
 	// If we have "Fast forward" checked in the menu (m_fastForwardForced)
 	// or are holding the fast forward button (m_fastForward):

src/platform/qt/CoreController.h

@@ -142,6 +142,8 @@ public slots:
 	void setFastForward(bool);
 	void forceFastForward(bool);
 
+	void changePlayer(int id);
+
 	void overrideMute(bool);
 
 	void loadState(int slot = 0);
@@ -154,6 +156,7 @@ public slots:
 	void saveBackupState();
 
 	void loadSave(const QString&, bool temporary);
+	void loadSave(VFile*, bool temporary);
 	void loadPatch(const QString&);
 	void scanCard(const QString&);
 	void replaceGame(const QString&);
@@ -227,6 +230,8 @@ public slots:
 	int updateAutofire();
 	void finishFrame();
 
+	void updatePlayerSave();
+
 	void updateFastForward();
 
 	void updateROMInfo();

src/platform/qt/Window.cpp

@@ -1218,6 +1218,23 @@ void Window::setupMenu(QMenuBar* menubar) {
 	m_platformActions.insert(mPLATFORM_GBA, exportShark);
 #endif
 
+	m_actions.addSeparator("saves");
+	Action* savePlayerAction;
+	ConfigOption* savePlayer = m_config->addOption("savePlayerId");
+	savePlayerAction = savePlayer->addValue(tr("Automatically determine"), 0, &m_actions, "saves");
+	m_nonMpActions.append(savePlayerAction);
+
+	for (int i = 1; i < 5; ++i) {
+		savePlayerAction = savePlayer->addValue(tr("Use player %0 save game").arg(i), i, &m_actions, "saves");
+		m_nonMpActions.append(savePlayerAction);
+	}
+	savePlayer->connect([this](const QVariant& value) {
+		if (m_controller) {
+			m_controller->changePlayer(value.toInt());
+		}
+	}, this);
+	m_config->updateOption("savePlayerId");
+
 	m_actions.addAction(tr("Load &patch..."), "loadPatch", this, &Window::selectPatch, "file");
 
 #ifdef M_CORE_GBA