OpenGL Segmentation Fault - c++

Question

I'm following the OpenGL Programming Guide:8th edition, and I'm kind of stuck in the 1st chapter (triangles.cpp).
I'm running Ubuntu 14.04.2, and this is the code used:
// Draws 2 triangles on the screen
#include <iostream>
using namespace std;
#include "vgl.h"
#include "LoadShaders.h"
enum VAO_IDs { Triangles, NumVAOs };
enum Buffer_IDs { ArrayBuffer, NumBuffers };
enum Attrib_IDs { vPosition = 0 };
GLuint VAOs[NumVAOs];
GLuint Buffers[NumBuffers];
const GLuint NumVertices = 6;
// init
void init(void)
{
glGenVertexArrays(NumVAOs, VAOs);
glBindVertexArray(VAOs[Triangles]);
GLfloat vertices[NumVertices][2] = {
{ -0.90, -0.90 }, //Triangle 1
{ 0.85, -0.90 },
{ -0.90, 0.85 },
{ 0.90, -0.85 }, //Triangle 2
{ 0.90, 0.90 },
{ -0.85, 0.90 }
};
glGenBuffers(NumBuffers, Buffers);
glBindBuffer(GL_ARRAY_BUFFER, Buffers[ArrayBuffer]);
glBufferData(GL_ARRAY_BUFFER, sizeof(vertices),
vertices, GL_STATIC_DRAW);
ShaderInfo shaders[] = {
{ GL_VERTEX_SHADER, "trianges.vert" },
{ GL_FRAGMENT_SHADER, "triangles.frag" },
{ GL_NONE, NULL }
};
GLuint program = LoadShaders(shaders);
glUseProgram(program);
glVertexAttribPointer(vPosition, 2, GL_FLOAT,
GL_FALSE, 0, BUFFER_OFFSET(0));
glEnableVertexAttribArray(vPosition);
}
// display
void display(void)
{
glClear(GL_COLOR_BUFFER_BIT);
glBindVertexArray(VAOs[Triangles]);
glDrawArrays(GL_TRIANGLES, 0, NumVertices);
glFlush();
}
// main
int main (int argc, char** argv)
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_RGBA);
glutInitWindowSize(512, 512);
glutInitContextVersion(4, 3);
glutInitContextProfile(GLUT_CORE_PROFILE);
glutCreateWindow(argv[0]);
if (glewInit()) {
cerr << "Unable to initialize GLEW ... exiting" << '\n';
exit(EXIT_FAILURE);
}
init();
glutDisplayFunc(display);
glutMainLoop();
}
This code compiles successfully, but yields a Segmentation Fault on execution.
I used gdb to debug the error. A random window does pop up (only when I used gdb), but its simply displaying what's behind the window (so it's crashed, doesn't display the two triangles).
This is the output from gdb:
Traceback (most recent call last):
File "/usr/share/gdb/auto-load/usr/lib/x86_64-linux-gnu/libstdc++.so.6.0.19-gdb.py", line 63, in <module>
from libstdcxx.v6.printers import register_libstdcxx_printers
ImportError: No module named 'libstdcxx'
Program received signal SIGSEGV, Segmentation fault.
0x0000000000000000 in ?? ()
The program should be displaying 2 triangles on a window.
I'm relatively new to C++, and I'm very new to linking libraries and debugging with gdb. I've seen many Q&A on the Segmentation Fault. A person did have the exact same problem as I did, but unfortunately, he deleted the question.
I don't really feel like this is a duplicate, since I didn't really understand most of the answers I've read on the same topic. Please make the answer as simple as possible.
I'm using the freeglut3-dev library, and I'm using NVIDIA Driver version 346.59.
EDIT:
The exact error happens at init() in
glGenVertexArrays(NumVAOs, VAOs);
glBindVertexArray(VAOs[Triangles]);

Answer 1

The segmentation fault occurred at the very first command that used GL. So, I made sure to import freeglut, which included all the necessary libraries for opengl too.
#include freeglut
I would like to thank Mateusz Grzejek for pointing this out.