aboutsummaryrefslogtreecommitdiff
path: root/engines/engine.h
blob: 36b04e464d8862b7dd145a0e76fd7fb9f0032772 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
/* 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 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * $URL$
 * $Id$
 */

#ifndef BASE_ENGINE_H
#define BASE_ENGINE_H

#include "common/scummsys.h"
#include "common/str.h"

class OSystem;
namespace Audio {
	class Mixer;
}
namespace Common {
	class EventManager;
	class SaveFileManager;
	class TimerManager;
}
namespace GUI {
	class Debugger;
}

class Engine {
public:
	OSystem *_system;
	Audio::Mixer *_mixer;
	Common::TimerManager * _timer;

protected:
	Common::EventManager *_eventMan;
	Common::SaveFileManager *_saveFileMan;

	const Common::String _targetName; // target name for saves
	const Common::String _gameDataPath;

private:
	/**
	 * The autosave interval, given in second. Used by shouldPerformAutoSave.
	 */
	int _autosavePeriod;

	/**
	 * The pause level, 0 means 'running', a positive value indicates
	 * how often the engine has been paused (and hence how often it has
	 * to be un-paused before it resumes running). This makes it possible
	 * to nest code which pauses the engine.
	 */
	int _pauseLevel;

public:
	Engine(OSystem *syst);
	virtual ~Engine();

	/**
	 * Init the engine.
	 * @return 0 for success, else an error code.
	 */
	virtual int init() = 0;

	/**
	 * Start the main engine loop.
	 * The return value is not yet used, but could indicate whether the user
	 * wants to return to the launch or to fully quit ScummVM.
	 * @return a result code
	 */
	virtual int go() = 0;

	/** Specific for each engine: prepare error string. */
	virtual void errorString(const char *buf_input, char *buf_output);

	/**
	 * Return the engine's debugger instance, if any. Used by error() to
	 * invoke the debugger when a severe error is reported.
	 */
	virtual GUI::Debugger *getDebugger() { return 0; }

	/**
	 * Pause or resume the engine. This should stop/resume any audio playback
	 * and other stuff. Called right before the system runs a global dialog
	 * (like a global pause, main menu, options or 'confirm exit' dialog).
	 *
	 * This is a convenience tracker which automatically keeps track on how
	 * often the engine has been paused, ensuring that after pausing an engine
	 * e.g. twice, it has to be unpaused twice before actuallying resuming.
	 *
	 * @param pause		true to pause the engine, false to resume it
	 */
	void pauseEngine(bool pause);

	/**
	 * Return whether the engine is currently paused or not.
	 */
	bool isPaused() const { return _pauseLevel != 0; }

public:

	/** Setup the backend's graphics mode. */
	void initCommonGFX(bool defaultTo1XScaler);

	/** On some systems, check if the game appears to be run from CD. */
	void checkCD();

	/** Indicate whether an autosave should be performed. */
	bool shouldPerformAutoSave(int lastSaveTime);

	/** Initialized graphics and shows error message. */
	void GUIErrorMessage(const Common::String msg);

	/**
	 * Actual implementation of pauseEngine by subclasses. See there
	 * for details.
	 */
	virtual void pauseEngineIntern(bool pause);
};

extern Engine *g_engine;

#endif