Segmentation fault

[romulosd]

Hi all!
So i´m trying to make an aplication here using fbo
but in this line:

Object* fbo = new FBO(m);

CodeBlocks send me a segmentaion fault error
How can i resolve this?

this is the class where all is rendering on the screen

#include "sg3d.h"


#include <SDL/SDL.h>
#include "gl_util.h"
#include "immediate.h"
#include "DisplayList.h"
#include "vertex_buffer_object.h"
#include "loader.h"
#include "Texture.h"
#include "FBO.h"

#include <iostream>

namespace topicos
{
SG3D::SG3D()
{
    _end = false;
    _rotation = 0;
    start();
}

SG3D::~SG3D()
{
    for (unsigned i = 0; i < _sceneObject.size(); ++i)
    {
        delete _sceneObject[i];
    }
}

void SG3D::start()
{
    unsigned w, h;
    w = 800;
    h = 600;
    _sdl.videoMode(w, h);
    GLUtil::initGL();
    GLUtil::setView(w, h);
    GLUtil::initGlew();
    initTexture();
    initObjects();
    // initLight();
    // initShader();
    mainLoop();


}
void SG3D::initTexture()
{
    ///drawing a simple cube with texture
    text = new Texture("data/test.png");
    text->genTexture();

}
/**
* Inicia aqui os diferentes objetos
**/
void SG3D::initObjects()
{


    std::cout << "loading obj" << std::endl;
    Mesh m = Loader::loadObj("build/obj/cavalo1.obj");
    std::cout << "\t\t\tend." << std::endl;

    std::cout << "creating FBO mode" << std::endl;
    Object* fbo = new FBO(m);
    fbo->translate(Vec3(8, 0, 0));
    fbo->color(Vec3(0, 1, 0));
    fbo->rotate(-90, Vec3(1, 0, 0));
    _sceneObject.push_back(fbo);
    std::cout << "\t\t\tend." << std::endl;


}
void SG3D::mainLoop()
{
    SDL_Event e;
    while(!_end)
    {
        while(SDL_PollEvent(&e))
        {
            switch(e.type)
            {
            case SDL_QUIT:
                _end = true;
                break;
            case SDL_KEYDOWN:
                switch(e.key.keysym.sym)
                {
                case SDLK_ESCAPE:
                    _end = true;
                    break;
                } //END keydow check
                break;
            default:
                break;
            } //END type check
        }//END while poll
        update();
        draw();
    }//END while end
    _sdl.quit();
}

/**
 * Funcao responsavel por atualizacoes.
 *
 **/
void SG3D::update()
{
    //Esse update eh para bonito. Nao seria legal ficar fazendo esse tipo de verificacao dentro do update.
    if (_sceneObject.size() == 0)
    {
        std::cout << "Voce nao pode acessar o elemento zero. O tamanho da sua lista eh zero" << std::endl;
    }
    else
    {
        Object* obj = _sceneObject[0]; //Pegando o elemento zero (Erro caso não tenhamos objetos)
        obj->rotate((_rotation++), Vec3(1, 0, 0)); //Rodando o elemento zero.
    }
}


/**
 * Funcao responsavel por chamar a lista de objetos que serao desenhados.
 *
 **/
void SG3D::draw()
{
    GLUtil::resetDraw();


    text->TexturedCube();
    for (std::vector<Object*>::iterator it = _sceneObject.begin(); it != _sceneObject.end(); ++it)
    {
        (*it)->draw();
    }

    _sdl.swap();
}

}

And this is the FBO class

#include <GL/glew.h>
#include "FBO.h"
#include "mesh.h"
#include "Vertex_buffer_object.h"
#include "loader.h"
#include <iostream>

FBO::FBO(const Mesh& m): Object(m)
{
    this->initTex();
    this->initFBO();
    this->mesh = m;
}

FBO::~FBO()
{
    //dtor
}
void FBO::initTex()
{
    Texture* tex = new Texture("data/test.png");
    textId = tex->genTexture();

}
void FBO::initFBO()
{
    glGenFramebuffers(1, &_fbo);
    glBindFramebuffer(GL_FRAMEBUFFER, _fbo);
    // attach a texture to FBO color attachment point
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, textId, 0);

    checkFramebufferStatus();

}
void FBO::draw()
{
    // set the rendering destination to FBO
    glBindFramebuffer(GL_FRAMEBUFFER, _fbo);
    // clear buffer
    glClearColor(1, 1, 1, 1);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);


    std::cout << "creating VBO mode" << std::endl;
    Object* vbo = new Vertex_buffer_object(this->mesh);
    vbo->translate(Vec3(8, 0, 0));
    vbo->color(Vec3(0, 1, 0));
    vbo->rotate(-90, Vec3(1, 0, 0));
    vbo->draw();
    std::cout << "\t\t\tend." << std::endl;

    // back to normal window-system-provided framebuffer
    glBindFramebuffer(GL_FRAMEBUFFER, 0); // unbind
}
void FBO::checkFramebufferStatus()
{
    // check FBO status
    GLenum status = glCheckFramebufferStatus(GL_FRAMEBUFFER);
    switch(status)
    {
    case GL_FRAMEBUFFER_COMPLETE:
        std::cout << "Framebuffer complete." << std::endl;
        break;
    case GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT:
        std::cout << "[ERROR] Framebuffer incomplete: Attachment is NOT complete." << std::endl;
        break;

    case GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT:
        std::cout << "[ERROR] Framebuffer incomplete: No image is attached to FBO." << std::endl;
        break;

    case GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER:
        std::cout << "[ERROR] Framebuffer incomplete: Draw buffer." << std::endl;
        break;

    case GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER:
        std::cout << "[ERROR] Framebuffer incomplete: Read buffer." << std::endl;
        break;

    case GL_FRAMEBUFFER_UNSUPPORTED:
        std::cout << "[ERROR] Framebuffer incomplete: Unsupported by FBO implementation." << std::endl;
        break;

    default:
        std::cout << "[ERROR] Framebuffer incomplete: Unknown error." << std::endl;
        break;
    }
}

Thank you very much!

[Computergeek01]

'FBO' inherits from 'Object'. So logically a variable of type 'Object' is too small to hold a variable of type 'FBO'. Why did you try to do it this way?

Not sure where I was going with that. A pointer is only ever a certain size.

[romulosd]

yes 'FBO' inherits from 'Object' so FBO is a Object,Object can hold fbo object logically.
I'm doing this because Object is an abstract class and i need to override the draw function

[Computergeek01]

That's crap logic, but ignore what I wrote before anyway.

What you did has nothing to do with overriding a member function. A call to a member function of a pointer to a base class will use the most derived version of the function being called. So by declaring that FBO has it's own 'draw()' function, you've already overridden it. http://en.cppreference.com/w/cpp/language/virtual

[romulosd]

yes i know so what is causing my problem?

[dhayden]

The heap is probably corrupted before you create the new FBO. Can you run the program with heap checking?

BTW FBO::InitTex() appears to leak the tex object.