2 * Copyright (C) 2008 Patrik Gornicz, Gornicz_P (at) hotmail (dot) com.
4 * This program is free software: you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation, either version 3 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program. If not, see <http://www.gnu.org/licenses/>.
23 #include "handleSignal.h"
28 #include "graphics/graphics.h"
29 #include "input/inputManager.h"
30 #include "config/config.h"
32 /// ***** Private Method Headers *****
36 void sighandler( int sig );
42 void updateFPSCounters();
48 /// ***** Private Variables *****
50 // variable used to determine if it is time to shutdown
53 /* Values for the main game loop
54 * target_UPS := the amount of updates that is wanted in one second
55 * last_Update := stores the time of the last update
56 * update_Sum := used to determine the updates needs for this run
58 * ups := updates per second for the last second
59 * fps := frames per second for the last second
60 * update_Count := counts this seconds updates
61 * draw_Count := counts this seconds draws
62 * last_Second := stores the time of the last second, used for ups and fps
65 long int last_Block_Update;
69 int update_Count, draw_Count;
73 /// ***** MAIN Method *****
82 /// ***** Initializers/Cleaners *****
97 cout << "Initialization Complete" << endl;
104 cout << "Cleaning up" << endl;
116 /// ***** Private Methods *****
121 last_Block_Update = tickCountMicro();
122 last_Second = tickCountMicro();
134 long int start = tickCountMicro();
136 // Calculate the updates that should be run for the next draw
137 update_Sum += (start - last_Block_Update) / (1000000 / (float)target_UPS);
139 // insures the float to int cast is done once.
140 int iupdate_sum = (int)update_Sum;
142 // TODO the main run loop needs to be tested and pruned
145 // Calculate a time step that spreads the updates out as much as possible
146 // used because really quick updates are nearly wasted
147 float time_step = ((float)(start - last_Block_Update)) / iupdate_sum;
150 for (int i = 1; i <= iupdate_sum; i++)
153 update(time_step*i / 1000);
155 // remove the updates that where run from the sum
156 update_Sum -= iupdate_sum;
157 last_Block_Update = tickCountMicro();
161 void updateFPSCounters()
163 // Check if a second has passed to recalculate UPS and FPS
164 if (tickCountMicro() - last_Second >= 1000000)
171 last_Second = tickCountMicro();
174 cout << "ups:\t" << ups << endl;
175 cout << "fps:\t" << fps << endl;
190 void update(float time_step)
194 game::update(time_step);
203 SDL_GL_SwapBuffers();
205 glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);