engine.h
/* 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/>.
*
*/
#ifndef ENGINES_ENGINE_H
#define ENGINES_ENGINE_H
#include "common/scummsys.h"
#include "common/str.h"
#include "common/language.h"
#include "common/platform.h"
#include "common/queue.h"
#include "common/singleton.h"
class OSystem;
class MetaEngineDetection;
class MetaEngine;
namespace Audio {
class Mixer;
}
namespace Common {
class Error;
class EventManager;
class SaveFileManager;
class TimerManager;
class FSNode;
class SeekableReadStream;
class WriteStream;
}
namespace GUI {
class Debugger;
class Dialog;
}
/**
* @defgroup engines_engine Engine
* @ingroup engines
*
* @brief API for managing various functions of the engine.
*
* @{
*/
/**
* Initialize graphics and show an error message.
*/
void GUIErrorMessage(const Common::U32String &msg, const char *url = nullptr);
/**
* Initialize graphics and show an error message.
*/
void GUIErrorMessage(const Common::String &msg, const char *url = nullptr);
/**
* Initialize graphics and show an error message.
*/
void GUIErrorMessageWithURL(const Common::U32String &msg, const char *url);
/**
* Initialize graphics and show an error message.
*/
void GUIErrorMessageWithURL(const Common::String &msg, const char *url);
/**
* Initialize graphics and show an error message.
*/
void GUIErrorMessageFormat(Common::U32String fmt, ...);
/**
* Initialize graphics and show an error message.
*/
void GUIErrorMessageFormat(const char *fmt, ...) GCC_PRINTF(1, 2);
class Engine;
/**
* Class for managing pausing by Engine::pauseEngine that hands out pause tokens.
*
* Each token represents one requested level of pause.
*/
class PauseToken {
public:
PauseToken();
/**
* Construct a pause token.
*/
PauseToken(const PauseToken &);
#if __cplusplus >= 201103L
PauseToken(PauseToken &&);
#endif
~PauseToken();
/**
* Assign the pause token.
*/
void operator=(const PauseToken &);
#if __cplusplus >= 201103L
void operator=(PauseToken &&);
#endif
/**
* Manually release the PauseToken.
*
* Only allowed if the token currently represents a pause request.
*/
void clear();
/**
* Return true if the PauseToken represents a pause level,
* false if it is empty.
*/
bool isActive() const { return _engine != nullptr; }
private:
PauseToken(Engine *);
Engine *_engine;
/**
* @see Engine
*/
friend class Engine;
};
class Engine {
public:
/**
* The OSystem instance used by the engine.
*/
OSystem *_system;
/**
* The Mixer instance used by the engine.
*/
Audio::Mixer *_mixer;
protected:
/**
* The TimerManager instance used by the engine.
*/
Common::TimerManager *_timer;
/**
* The EventManager instance used by the engine.
*/
Common::EventManager *_eventMan;
/**
* The SaveFileMAnager used by the engine.
*/
Common::SaveFileManager *_saveFileMan;
/**
* The Dialog instance used by the engine.
*/
GUI::Dialog *_mainMenuDialog;
/**
* Run a GUI dialog.
*/
virtual int runDialog(GUI::Dialog &dialog);
/**
* Target name for saves.
*/
const Common::String _targetName;
private:
/**
* The associated metaengine
*/
MetaEngine *_metaEngine;
/**
* The pause level.
*
* 0 means 'running'. A positive value indicates how often the engine
* has been paused and thus how many times it must be unpaused before
* it resumes running. This makes it possible to nest the code that pauses the engine.
*/
int _pauseLevel;
/**
* The time when the pause was started.
*/
uint32 _pauseStartTime;
/**
* The time when the engine was started.
*
* This value is used to calculate the current play time of the game running.
*/
int32 _engineStartTime;
/**
* Autosave interval.
*/
int _autosaveInterval;
/**
* The last time an autosave was done.
*/
int _lastAutosaveTime;
/**
* Save slot selected via the global main menu.
*
* This slot will be loaded after the main menu execution (not from inside
* the menu loop, to avoid bugs like #4420).
*/
int _saveSlotToLoad;
/**
* Used for preventing recursion during autosave.
*/
bool _autoSaving;
/**
* Optional debugger for the engine.
*/
GUI::Debugger *_debugger;
public:
/**
* Engine features.
*
* A feature in this context means an ability of the engine
* that can be either available or not.
* @see Engine::hasFeature()
*/
enum EngineFeature {
/**
* Enable the subtitle speed and toggle items in the Options section
* of the global main menu.
*/
kSupportsSubtitleOptions,
/**
* The 'Return to launcher' feature is supported.
*
* This means that EVENT_RETURN_TO_LAUNCHER is handled
* either directly, or indirectly (the engine calls and honors
* the result of the Engine::shouldQuit() method appropriately).
*/
kSupportsReturnToLauncher,
/**
* Loading save states during runtime is supported.
*
* This means that the engine implements loadGameState() and canLoadGameStateCurrently().
* If this feature is supported, then the corresponding MetaEngine *must*
* support the kSupportsListSaves feature.
*/
kSupportsLoadingDuringRuntime,
/**
* Loading save states during runtime is supported.
*
* This means that the engine implements saveGameState() and canSaveGameStateCurrently().
* If this feature is supported, then the corresponding MetaEngine *must*
* support the kSupportsListSaves feature.
*/
kSupportsSavingDuringRuntime,
/**
* Changing the game settings during runtime is supported.
*
* This enables showing the Engine Options tab in the config dialog
* accessed through the global main menu.
*/
kSupportsChangingOptionsDuringRuntime,
/**
* Arbitrary resolutions are supported.
*
* This means that the engine allows the backend to override the resolution
* passed to OSystem::setupScreen.
* The engine will need to read the actual resolution used by the
* backend using OSystem::getWidth and OSystem::getHeight.
*/
kSupportsArbitraryResolutions
};
/** @name Overloadable methods
*
* All Engine subclasses should consider overloading some or all of the following methods.
* @{
*/
/**
* Create an instance of the engine.
*/
Engine(OSystem *syst);
/**
* Destroy the engine instance.
*/
virtual ~Engine();
/**
* Initialize SearchMan according to the game path.
*
* By default, this adds the directory in non-flat mode with a depth of 4 as
* priority 0 to SearchMan.
*
* @param gamePath The base directory of the game data.
*/
virtual void initializePath(const Common::FSNode &gamePath);
/**
* Initialize the engine and start its main loop.
*
* @return kNoError on success, otherwise an error code.
*/
virtual Common::Error run() = 0;
/**
* Prepare an error string that is printed by the error() function.
*/
virtual void errorString(const char *buf_input, char *buf_output, int buf_output_size);
/**
* Return the engine's debugger instance, if any.
*/
virtual GUI::Debugger *getDebugger() final { return _debugger; }
/**
* Set the engine's debugger.
*
* Once set, the Engine class is responsible for managing
* the debugger, and freeing it on exit.
*/
void setDebugger(GUI::Debugger *debugger) {
assert(!_debugger);
_debugger = debugger;
}
/**
* Return the engine's debugger instance, or create one if none is present.
*
* Used by error() to invoke the debugger when a severe error is reported.
*/
GUI::Debugger *getOrCreateDebugger();
/**
* Determine whether the engine supports the specified feature.
*/
virtual bool hasFeature(EngineFeature f) const { return false; }
/**
* Notify the engine that the sound settings in the config manager might have
* changed and that it should adjust any internal volume (and other) values
* accordingly.
*
* The default implementation sets the volume levels of all mixer sound
* types according to the config entries of the active domain.
* When overwriting, call the default implementation first, then adjust the
* volumes further (if required).
*
* @note When setting volume levels, respect the "mute" config entry.
*
* @note The volume for the plain sound type is reset to the maximum
* volume. If the engine can associate its own value for this
* type, it needs to overwrite this member and set it accordingly.
* @todo find a better name for this
*/
virtual void syncSoundSettings();
/**
* Notify the engine that the settings editable from the Game tab in the
* in-game options dialog might have changed and that they need to be applied
* if necessary.
*/
virtual void applyGameSettings() {}
/**
* Flip mute all sound options.
*/
virtual void flipMute();
/**
* Generate the savegame filename.
*/
virtual Common::String getSaveStateName(int slot) const {
return Common::String::format("%s.%03d", _targetName.c_str(), slot);
}
/**
* Load a game state.
*
* @param slot The slot from which a save state should be loaded.
*
* @return kNoError on success, otherwise an error code.
*/
virtual Common::Error loadGameState(int slot);
/**
* Load a game state.
*
* @param stream The stream to load the save state from.
*
* @return kNoError on success, otherwise an error code.
*/
virtual Common::Error loadGameStream(Common::SeekableReadStream *stream);
/**
* Set the game slot for a savegame to be loaded after the global
* main menu execution.
*
* This is to avoid loading a savegame from
* inside the menu loop which causes bugs like #4420.
*
* @param slot The slot from which a save state should be loaded.
*/
void setGameToLoadSlot(int slot);
/**
* Indicate whether a game state can be loaded.
*/
virtual bool canLoadGameStateCurrently();
/**
* Save a game state.
*
* @param slot The slot into which the save state should be stored.
* @param desc Description for the save state, entered by the user.
* @param isAutosave Expected to be true if an autosave is being created.
*
* @return kNoError on success, otherwise an error code.
*/
virtual Common::Error saveGameState(int slot, const Common::String &desc, bool isAutosave = false);
/**
* Save a game state.
*
* @param stream The write stream to save the savegame data to.
* @param isAutosave Expected to be true if an autosave is being created.
*
* @return kNoError on success, otherwise an error code.
*/
virtual Common::Error saveGameStream(Common::WriteStream *stream, bool isAutosave = false);
/**
* Indicate whether a game state can be saved.
*/
virtual bool canSaveGameStateCurrently();
/**
* Show the ScummVM save dialog, allowing users to save their game.
*/
bool saveGameDialog();
/**
* Show the ScummVM Restore dialog, allowing users to load a game.
*/
bool loadGameDialog();
protected:
/**
* Actual implementation of pauseEngine by subclasses.
*
* @see Engine::pauseEngine
*/
virtual void pauseEngineIntern(bool pause);
/** @} */
public:
/**
* Request the engine to quit.
*
* Sends an EVENT_QUIT event to the Event Manager.
*/
static void quitGame();
/**
* Return whether the engine should quit.
*
* This can mean either quitting ScummVM altogether, or returning to the launcher.
*/
static bool shouldQuit();
/**
* Return the MetaEngineDetection instance used by this engine.
*/
static MetaEngineDetection &getMetaEngineDetection();
/**
* Return the MetaEngine instance used by this engine.
*/
inline MetaEngine *getMetaEngine() const { return _metaEngine; }
/**
* Set the MetaEngine instance used by this engine.
*/
inline void setMetaEngine(MetaEngine *metaEngine) { _metaEngine = metaEngine; }
/**
* Pause the engine.
*
* This should stop any audio playback and other operations.
* Called right before the system runs a global dialog
* (like a global pause, main menu, options, or 'confirm exit' dialog).
*
* Returns a PauseToken. Multiple pause tokens can exist. The engine will
* be resumed when all associated pause tokens reach the end of their lives.
*/
PauseToken pauseEngine();
private:
/** Resume the engine.
*
* This should resume any audio playback and other operations.
* Only PauseToken is allowed to call this member function. Use the PauseToken
* that you got from pauseEngine to resume the engine.
*/
void resumeEngine();
/**
* @see Engine::PauseToken
*/
friend class PauseToken;
/**
* Warns before overwriting autosave.
*
* @return true if it is safe to save, false to avoid saving.
*/
bool warnBeforeOverwritingAutosave();
public:
/**
* Return whether the engine is currently paused or not.
*/
bool isPaused() const { return _pauseLevel != 0; }
/**
* Run the global main menu dialog.
*/
void openMainMenuDialog();
/**
* Display a warning to the user that the game is not fully supported.
*
* @param msg A message that will be presented to user. If empty, then
* generic message regarding unsupported game is presented
*
* @return True if the user chooses to start anyway, false otherwise.
*/
static bool warnUserAboutUnsupportedGame(Common::String msg = Common::String());
/**
* Display an error message to the user that the game is not supported.
*
* @param extraMsg An extra message that will be appended to the default message.
*/
static void errorUnsupportedGame(Common::String extraMsg);
/**
* Get the total play time.
*
* @return How long the player has been playing in ms.
*/
uint32 getTotalPlayTime() const;
/**
* Set the game time counter to the specified time.
*
* This can be used to set the play time counter after loading a savegame,
* for example. Another use case is when the engine wants to exclude from
* the counter the time that the user spent in original engine dialogs.
*
* @param time Play time to set up in ms.
*/
void setTotalPlayTime(uint32 time = 0);
/**
* Return the TimerManager instance used by this engine.
*/
inline Common::TimerManager *getTimerManager() { return _timer; }
/**
* Return the EventManager instance used by this engine.
*/
inline Common::EventManager *getEventManager() { return _eventMan; }
/**
* Return the SaveFileManager instance used by this engine.
*/
inline Common::SaveFileManager *getSaveFileManager() { return _saveFileMan; }
public:
/**
* Check if extracted CD Audio files are found.
*/
bool existExtractedCDAudioFiles(uint track = 1);
/**
* On some systems, check whether the game appears to be run
* from the same CD drive, which also should play CD audio.
*/
bool isDataAndCDAudioReadFromSameCD();
/**
*Display a warning for no extracted CD Audio files found.
*/
void warnMissingExtractedCDAudio();
/**
* Check whether it is time to autosave, and if so, do it.
*/
void handleAutoSave();
/**
* Autosave immediately if autosaves are enabled.
*/
void saveAutosaveIfEnabled();
/**
* Indicate whether an autosave can currently be done.
*/
virtual bool canSaveAutosaveCurrently() {
return canSaveGameStateCurrently();
}
/**
* Return the slot that should be used for autosaves, or -1 for engines that
* don't support autosave.
*
* @note This should match the meta engine getAutosaveSlot() method.
*/
virtual int getAutosaveSlot() const {
return 0;
}
};
/** @name Chained games
*
* @{
*/
/**
* Singleton class which manages chained games.
*
* A chained game is one that starts automatically, optionally loading
* a saved game, instead of returning to the launcher.
*/
class ChainedGamesManager : public Common::Singleton<ChainedGamesManager> {
private:
struct Game {
Common::String target;
int slot;
};
Common::Queue<Game> _chainedGames;
public:
ChainedGamesManager();
/** Clear the chained games manager of any games. */
void clear();
/** Load a game into a slot in the chained games manager. */
void push(const Common::String target, const int slot = -1);
/** Pop the last game loaded into the chained games manager. */
bool pop(Common::String &target, int &slot);
};
/** Convenience shortcut for accessing the chained games manager. */
#define ChainedGamesMan ChainedGamesManager::instance()
/** @} */
/** Current workaround for MidiEmu & error(). */ //FIXME
extern Engine *g_engine;
/** @} */
#endif
