title: Blank screen while using glGenBuffers in openGL
body: <pre><code>#include &lt;stdio.h&gt;
  #include &lt;stdlib.h&gt;
  #include &lt;GL/glew.h&gt;
  #include &lt;GL/glut.h&gt;
  
  void changeSize(int w, int h)
  {
      if(h == 0) 
          h = 1;
      float ratio = w / h;
      glMatrixMode(GL_PROJECTION);
      glLoadIdentity();
      glViewport(0, 0, w, h);
      gluPerspective(40,ratio,1.5,20);
      glMatrixMode(GL_MODELVIEW);
  }
  
  void renderScene(void)
  {
      glClear(GL_COLOR_BUFFER_BIT );
      glLoadIdentity();
      glTranslatef(0.0,0.0,-5.0);
      glDrawArrays(GL_TRIANGLES,0,3);
      glutSwapBuffers();
  }
  
  void init()
  {
      GLfloat verts[] = {
          0.0,   1.0,
         -1.0,  -1.0,
          1.0,  -1.0
      };
  
      GLuint bufferid;
      glGenBuffers(1,&amp;bufferid);
      glBindBuffer(GL_ARRAY_BUFFER,bufferid);
      glBufferData(GL_ARRAY_BUFFER,sizeof(verts),verts,GL_STATIC_DRAW);
      glEnableVertexAttribArray(0);
      glVertexAttribPointer(0,2,GL_FLOAT,GL_FALSE,0,0);
  
      if(glGetError()==GL_NO_ERROR)
          printf("no error");
  }
  
  int main(int argc, char **argv)
  {
      glutInit(&amp;argc, argv);
      glutInitDisplayMode( GLUT_DOUBLE | GLUT_RGBA);
      glutInitWindowPosition(100,100);
      glutInitWindowSize(500,500);
      glutCreateWindow("MM 2004-05");
      glewInit();
  
      init();
  
      glutDisplayFunc(renderScene);
      glutReshapeFunc(changeSize);
  
      if (GLEW_ARB_vertex_program &amp;&amp; GLEW_ARB_fragment_program)
          printf("Ready for GLSL\n");
      else {
          printf("No GLSL support\n");
          //exit(1);
      }
  
      glutMainLoop();
      return 0;
  }
  </code></pre>
  
  <p>When using glGenBuffers my screen turns out black and shows no error. If i draw some other shape without using buffers they are displayed but not with buffer objects.</p>
  
  <p>openGL version:3.0
  operating system:ubuntu
  IDE:eclipse</p>