libsegl/fpsmanager.cpp

60 lines
1.5 KiB
C++

/* libsegl - Sebas Extended GL Library
* Collection of Opengl/3D-Math helpers
*
* Copyright (c) 2008 by Sebastian Lohff, seba@seba-geek.de
* http://www.seba-geek.de
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#include "fpsmanager.h"
namespace segl {
FPSManager::FPSManager(int _fps) {
setFPS(_fps);
frames = 0;
framerate = 0;
lastticks = SDL_GetTicks();
}
void FPSManager::setFPS(int _fps) {
if(_fps<1 || _fps > 500)
return;
tickrate = 1000.0f/(float)_fps;
}
void FPSManager::delay() {
frames++;
Uint32 now = SDL_GetTicks();
Uint32 target = lastticks + (Uint32)(tickrate * (float)frames);
if(now <= target) {
SDL_Delay(target-now);
} else {
framerate = frames/((now-lastticks)/1000.0f);
frames = 0;
lastticks = SDL_GetTicks();
}
}
float FPSManager::getFPS() {
return framerate;
}
} // namespace segl