<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> <html> <head> <META http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <title>Tips and tricks - ClanLib Game SDK</title> <link rel="stylesheet" type="text/css" href="../../default.css"> </head> <body style="background-color: #a4daea; color: black; margin: 1em 3em 1em 3em;"> <div style="border-style: solid; border-width:thin; border-color: black;"> <div style="background-color: white; color: black; padding: .3em 1em .3em 1em; border-bottom-style: dotted; border-bottom-width: 2px;"> <table cellspacing="0" cellpadding="0" border="0" width="100%"> <tr> <td align="center"> <h1> <a href="http://www.clanlib.org"><img style="border-style: none; padding-right: 130px;" src="../../gfx/clanlib.png" alt="ClanLib"></a> </h1> </td> </tr> </table> <!--<div class="menu"> <a href="index.html">News</a> <a href="intro.html">About</a> <a href="download.html">Download</a> <a href="cvs.html">CVS</a> <a class="active" href="docs.html">Docs</a> <a href="games.html">Games</a> <a href="contact.html">Contact</a> <a href="links.html">Links</a> </div>--> </div> <div style="background-color: white; padding: 1em 3em 1em 3em;"> <!-- clanlib header end --> <div style="border-bottom-style: dotted; border-bottom-width: 1px; margin-bottom: 1em;"><h2>Tips and tricks</h2></div> <div style="border-bottom-style: dotted; border-bottom-width: 1px;"><h3>Calculating frames per second (fps)</h3></div> <p>Author: Sphair</p> <p>Often you want to know how fast or slow your game is running, and displaying a FPS counter can be a handy debug-tool.</p> <ul><pre><font face="Arial,Courier New,Courier">class Game { public: void run(); void update(); void draw(); int calc_fps(int frame_time); CL_Font font_fps; int fps; }; void Game::run() { CL_ResourceManager resources("resources.xml"); font_fps = CL_Font("font_gray", &resources); while(!CL_Keyboard::get_keycode(CL_KEY_ESCAPE)) { update(); draw(); CL_Display::flip(); CL_System::keep_alive(); }; } void Game::update() { // Calculate time since last update static int start_time = CL_System::get_time(); int cur_time = CL_System::get_time(); int delta_time = cur_time - start_time; start_time = cur_time; fps = calc_fps(delta_time); } int Game::calc_fps(int frame_time) { static int fps_result = 0; static int fps_counter = 0; static int total_time = 0; total_time += frame_time; if(total_time >= 1000) // One second has passed { fps_result = fps_counter + 1; fps_counter = total_time = 0; } fps_counter++; // Increase fps return fps_result; } void Game::draw() { CL_Display::clear(); font_fps.draw(0, 0, "fps: " + CL_String::from_int(fps)); } </font></pre></ul> <!-- clanlib footer begin --> <div style="margin-top: 0em; text-align: center; color: #a0a0a0; border-top-style: dotted; border-top-width: 1px;"> Questions or comments, write to the <a href="http://clanlib.org/contact.html">ClanLib mailing list</a>. </div> </div> </div> </body> </html>