QtOpenGL. Почему-то сегфолтится на glBegin()

#include "scene.h"
#include <QWidget>
#include <QtOpenGL>
Scene3d::Scene3d(QWidget *obj)
{

}

void Scene3d::initializeGL()
{
 qglClearColor(Qt::white);
 glEnable(GL_DEPTH_TEST|GL_CULL_FACE|GL_DOUBLE);
}
void Scene3d::resizeGL(int w, int h)
{
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluPerspective(65.0,w/h,1,100);
    glViewport(0,0,(GLint)w,(GLint)h);
}
void Scene3d::paintGL()
{
    glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
    glFrontFace(GL_CCW);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    glColor4f(0.5,0.2,0.2,0.5);
    glInit();
    glBegin(GL_TRIANGLES);
    glVertex3f(0,0,2);
    glVertex3f(5,5,5);
    glVertex3f(-5,-5,2);
    glEnd();
    updateGL();
}