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
|
/* 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/>.
*
*/
#include "graphics/framelimiter.h"
#include "common/util.h"
namespace Graphics {
FrameLimiter::FrameLimiter(OSystem *system, const uint framerate, const bool vsync) :
_system(system),
_speedLimitMs(0),
_startFrameTime(0),
_lastFrameDurationMs(_speedLimitMs) {
// The frame limiter is disabled when vsync is enabled.
_enabled = !(vsync && _system->getFeatureState(OSystem::kFeatureVSync)) && (framerate != 0);
if (_enabled) {
_speedLimitMs = 1000 / CLIP<uint>(framerate, 0, 100);
}
}
void FrameLimiter::startFrame() {
uint currentTime = _system->getMillis();
if (_startFrameTime != 0) {
_lastFrameDurationMs = currentTime - _startFrameTime;
}
_startFrameTime = currentTime;
}
void FrameLimiter::delayBeforeSwap() {
uint endFrameTime = _system->getMillis();
uint frameDuration = endFrameTime - _startFrameTime;
if (_enabled && frameDuration < _speedLimitMs) {
_system->delayMillis(_speedLimitMs - frameDuration);
}
}
void FrameLimiter::pause(bool pause) {
if (!pause) {
// Make sure the frame duration value is consistent when resuming
_startFrameTime = 0;
}
}
uint FrameLimiter::getLastFrameDuration() const {
return _lastFrameDurationMs;
}
} // End of namespace Graphics
|
