1 /* ResidualVM - A 3D game interpreter
2  *
3  * ResidualVM is the legal property of its developers, whose names
4  * are too numerous to list here. Please refer to the AUTHORS
5  * file distributed with this source distribution.
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License
9  * as published by the Free Software Foundation; either version 2
10  * of the License, or (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
20  *
21  */
22 
23 #ifndef STARK_GFX_FRAMELIMITER_H
24 #define STARK_GFX_FRAMELIMITER_H
25 
26 #include "common/system.h"
27 
28 namespace Stark {
29 
30 namespace Gfx {
31 
32 /**
33  * A framerate limiter
34  *
35  * Ensures the framerate does not exceed the specified value
36  * by delaying until all of the timeslot allocated to the frame
37  * is consumed.
38  * Allows to curb CPU usage and have a stable framerate.
39  */
40 class FrameLimiter {
41 public:
42 	FrameLimiter(OSystem *system, const uint framerate);
43 
44 	void startFrame();
45 	void delayBeforeSwap();
46 
47 	void pause(bool pause);
48 
49 	uint getLastFrameDuration() const;
50 private:
51 	OSystem *_system;
52 
53 	bool _enabled;
54 	uint _speedLimitMs;
55 	uint _startFrameTime;
56 	uint _lastFrameDurationMs;
57 };
58 
59 } // End of namespace Gfx
60 } // End of namespace Stark
61 
62 #endif // STARK_GFX_FRAMELIMITER_H
63