free-tutorials.org

Today I will try to use GLFW library.

GLFW is a C library that lets you using an OpenGL context and window, display modes and inputs like keyboard, mouse, joystick and time.

GLFW supports Windows, Mac OS X and Unix, Linux and FreeBSD and any operating systems with the X Window System.

Also you can read more about this library here.

First install the library using root account.

# yum install libglfw-devel.i386

Now let’s see the source code.

First I includes all librarys I need.

/* 
 * File:   main.cpp
 * Author: free-tutorials.org
 *
 * Created on May 15, 2013, 2:54 PM
 */

#include <cstdlib>
// my c++ include headers 
#include <iostream>
#include <stdio.h>
#include <stdlib.h>
#include <GL/glew.h>
#include <GL/glfw.h>
using namespace std;

In the main function I start to see if the library is working.

int main() {
if( !glfwInit() )
{
    fprintf( stderr, "Failed to initialize GLFW Init \n" );
    return -1;
}

The next step is to set some settings, see:

// 4x antialiasing because I use NVIDIA FX5500
glfwOpenWindowHint(GLFW_FSAA_SAMPLES, 4); 

… and also testing the desktop settings.

// get infos about desktop 
GLFWvidmode desktop;
glfwGetDesktopMode( &desktop );

The settings it’s show on console with cout function.

// show infos about your desktop
cout << "Width : " << desktop.Width << "\n";
cout << "Height : " << desktop.Height << "\n";
cout << "RedBits : " << desktop.RedBits << "\n";
cout << "GreenBits : " << desktop.GreenBits << "\n";
cout << "BlueBits : " << desktop.BlueBits << "\n";

Now I make the window context using fullscreen option.

if ( !glfwOpenWindow(
    desktop.Width,
    desktop.Height,
    desktop.RedBits,
    desktop.GreenBits,
    desktop.BlueBits,
    32,          // alpha bits
    32,         // depth bits
    0,          // stencil bits
    GLFW_FULLSCREEN
) ) {
    // error if failed 
}

I set the title of the window.

glfwSetWindowTitle( "opengl-shader test" );

I enable the keys.

glfwEnable( GLFW_STICKY_KEYS );

do{
    // draw something sexy 
 
    // Swap buffers need it 
    glfwSwapBuffers();
 
}

The next source code it’s close the window.

// When ESC key was pressed or the window was closed
while( glfwGetKey( GLFW_KEY_ESC ) != GLFW_PRESS &&
glfwGetWindowParam( GLFW_OPENED ) );

}

Testing with time command to see how fast working.

$ time ./opengl-shader 
Width : 1280
Height : 1024
RedBits : 8
GreenBits : 8
BlueBits : 8

real	0m2.358s
user	0m0.341s
sys	0m1.240s

The netbeans IDE make the package in this path.

$cd /opengl-shader/dist/Debug/GNU-Linux-x86/package

I make RPM package for Fedora distro.

# rpm -ivh opengl-shader-1.0-1.i386.rpm 
Preparing...                ########################################### [100%]
   1:opengl-shader          ########################################### [100%]

I test my example and working well.