scummvm/engines/sludge/timing.cpp
2021-12-26 18:48:43 +01:00

88 lines
2.0 KiB
C++

/* 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 "common/system.h"
#include "sludge/timing.h"
namespace Sludge {
Timer::Timer(){
reset();
}
void Timer::reset(void) {
_desiredFPS = 300;
_startTime = 0;
_endTime = 0;
_desiredFrameTime = 0;
_addNextTime = 0;
// FPS stats
_lastFPS = -1;
_thisFPS = -1;
_lastSeconds = 0;
}
void Timer::init(void) {
_desiredFrameTime = 1000 / _desiredFPS;
_startTime = g_system->getMillis();
}
void Timer::initSpecial(int t) {
_desiredFrameTime = 1000 / t;
_startTime = g_system->getMillis();
}
void Timer::updateFpsStats() {
uint32 currentSeconds = g_system->getMillis() / 1000;
if (_lastSeconds != currentSeconds) {
_lastSeconds = currentSeconds;
_lastFPS = _thisFPS;
_thisFPS = 1;
} else {
++_thisFPS;
}
}
void Timer::waitFrame(void) {
uint32 timetaken;
for (;;) {
_endTime = g_system->getMillis();
timetaken = _addNextTime + _endTime - _startTime;
if (timetaken >= _desiredFrameTime)
break;
g_system->delayMillis(1);
}
_addNextTime = timetaken - _desiredFrameTime;
if (_addNextTime > _desiredFrameTime)
_addNextTime = _desiredFrameTime;
_startTime = _endTime;
// Stats
updateFpsStats();
}
} // End of namespace Sludge