CODEWITHSUNDEEP
c++openglglewglfw
0x_Anakin
0x_Anakin

Reputation: 3269

glfw openGL c++ window background and title

This is my source code from a series of tutorials I'm taking a look regarding opengl 3+.

//#include <stdio.h>
//#include <stdlib.h>

#include <GL/glew.h>
#include <GL/glfw.h>
#include <glm/glm.hpp>
using namespace glm;

#include <iostream>
using namespace std;



int main()
{

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

    glfwOpenWindowHint(GLFW_FSAA_SAMPLES, 4); // 4x antialiasing
    glfwOpenWindowHint(GLFW_OPENGL_VERSION_MAJOR, 3); // We want OpenGL 3.3
    glfwOpenWindowHint(GLFW_OPENGL_VERSION_MINOR, 2);
    glfwOpenWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE); //We don't want the old OpenGL

    // Open a window and create its OpenGL context
    if( !glfwOpenWindow( 1024, 768, 0,0,0,0, 32,0, GLFW_WINDOW ) )
    {
        fprintf( stderr, "Failed to open GLFW window\n" );
        glfwTerminate();
        return -1;
    }
    else
    {
        glfwSetWindowTitle( "Tutorial 01" );
    }

    // Initialize GLEW
    glewExperimental=true; // Needed in core profile
    if (glewInit() != GLEW_OK) {
        fprintf(stderr, "Failed to initialize GLEW\n");
        return -1;
    }



    glfwEnable( GLFW_STICKY_KEYS );

    do{
        // Draw nothing, see you in tutorial 2 !

        // Swap buffers
        glfwSwapBuffers();

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

    return 0;
}

Everything works great except that when the window initializes it has a background color of white and the title 'GLFW WINDOW' and but after 1-2 secs the title changes to Tutorial 01 as it should have been in the first place and the background becomes black, as it should have been also.

In previous studies of opengl (2.x) with glut that I did a couple of years back I didnt have issues like that could someone explain what is wrong here?

Upvotes: 0

Views: 8604

Answers (4)

Samuel Harmer
Samuel Harmer

Reputation: 4412

I get the same behaviour (even running a release exe outside of the IDE) on an ATI FirePro V5700. If you're really bothered by it, download the GLFW source and change line 764 of carbon_window.c, line 1210 of win32_window.c, and line 962 of x11_window.c.

.\lib\carbon\carbon_window.c

(void)SetWindowTitleWithCFString( _glfwWin.window, CFSTR( "GLFW Window" ) );

.\lib\win32\win32_window.c

_glfwWin.window = CreateWindowEx( _glfwWin.dwExStyle,    // Extended style
                                  _GLFW_WNDCLASSNAME,    // Class name
                                  "GLFW Window",         // Window title
                                  _glfwWin.dwStyle,      // Defined window style
                                  wa.left, wa.top,       // Window position
                                  fullWidth,             // Decorated window width
                                  fullHeight,            // Decorated window height
                                  NULL,                  // No parent window
                                  NULL,                  // No menu
                                  _glfwLibrary.instance, // Instance
                                  NULL );                // Nothing to WM_CREATE

.\lib\x11\x11_window.c

_glfwPlatformSetWindowTitle( "GLFW Window" );

Upvotes: 2

0x_Anakin
0x_Anakin

Reputation: 3269

Well as it seems it has to do with the IDE, if you run the actual .exe it works as intended and with no delay at all.

Upvotes: 0

Victor Zamanian
Victor Zamanian

Reputation: 3180

I'm not experiencing any problems that you describe. I copied and pasted, compiled, then ran your code as you posted it (commenting out references to GLM as I don't have that library installed). The title changes instantaneously for me -- I never even see the window having the title "GLFW WINDOW", and the color of the graphics area is immediately black. Could it be that your computer simply isn't very fast?

What happens if you do the following?

do{
    // Draw nothing, see you in tutorial 2 !
    glClear(GL_COLOR_BUFFER_BIT);
    // Swap buffers
    glfwSwapBuffers();
    glfwSleep(0.016);
} // Check if the ESC key was pressed or the window was closed
while( glfwGetKey( GLFW_KEY_ESC ) != GLFW_PRESS && glfwGetWindowParam( GLFW_OPENED ) );

Edit: My GPU is an Nvidia GTX 580 (capable of at least OpenGL 4.3).

Upvotes: 1

Grieverheart
Grieverheart

Reputation: 510

The background color of the window is configured by the call to the openGL function glClearColor() and refreshed with the glClear() function.

The delay in the changing of the title of the window may perhaps have something to do with the fact that to create a openGL 3.x it is required to create a standard OpenGL context (version 1.x or 2.x) and then get your application to opt-in to using an OpenGL 3.x context. A 1-2 sec delay though seems a lot.

Upvotes: 0

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