OpenGL ES2.0 offscreen context for FBO rendering

Question

I would like to do offscreen rendering (in console environment without any WS) with FBOs. I know that it is necessary to create an OpenGL context, and at least a dummy window fo

Answer 1

The solution was the following (without error handling):

    #ifdef CONTEXT_ES20
    EGLint ai32ContextAttribs[] = { EGL_CONTEXT_CLIENT_VERSION, 2, 
                                                           EGL_NONE };
    #endif

// Step 1 - Get the default display.
    eglDisplay = eglGetDisplay((EGLNativeDisplayType)0);

// Step 2 - Initialize EGL.
    eglInitialize(eglDisplay, 0, 0);

    #ifdef CONTEXT_ES20
// Step 3 - Make OpenGL ES the current API.
    eglBindAPI(EGL_OPENGL_ES_API);

// Step 4 - Specify the required configuration attributes.
    EGLint pi32ConfigAttribs[5];
    pi32ConfigAttribs[0] = EGL_SURFACE_TYPE;
    pi32ConfigAttribs[1] = EGL_WINDOW_BIT;
    pi32ConfigAttribs[2] = EGL_RENDERABLE_TYPE;
    pi32ConfigAttribs[3] = EGL_OPENGL_ES2_BIT;
    pi32ConfigAttribs[4] = EGL_NONE;
    #else
    EGLint pi32ConfigAttribs[3];
    pi32ConfigAttribs[0] = EGL_SURFACE_TYPE;
    pi32ConfigAttribs[1] = EGL_WINDOW_BIT;
    pi32ConfigAttribs[2] = EGL_NONE;
    #endif

// Step 5 - Find a config that matches all requirements.
    int iConfigs;
    eglChooseConfig(eglDisplay, pi32ConfigAttribs, &eglConfig, 1, 
                                                          &iConfigs);

    if (iConfigs != 1) {
        printf("Error: eglChooseConfig(): config not found.\n"); 
        exit(-1);
    }

// Step 6 - Create a surface to draw to.
    EGLSurface eglSurface;
    eglSurface = eglCreateWindowSurface(eglDisplay, eglConfig, 
                                        (EGLNativeWindowType)NULL, NULL);

// Step 7 - Create a context.
    #ifdef CONTEXT_ES20
    eglContext = eglCreateContext(eglDisplay, eglConfig, NULL, 
                                                     ai32ContextAttribs);
    #else
    eglContext = eglCreateContext(eglDisplay, eglConfig, NULL, NULL);
    #endif

// Step 8 - Bind the context to the current thread
    eglMakeCurrent(eglDisplay, eglSurface, eglSurface, eglContext);