QOpenGLWidget stereo rendering using glDrawBuffer

[Nicolas]

Hello,

i'm trying to draw in the GL_BACK_LEFT and GL_BACK_RIGHT but i get a GL_INVALID_OPERATION just after calling glDrawBuffer.
It seems that the framebuffer does not support GL_BACK_LEFT and GL_BACK_RIGHT buffers.
I've set up the QSurfaceFormat like this:

QSurfaceFormat format = QSurfaceFormat::defaultFormat();
format.setOption(QSurfaceFormat::StereoBuffers);
format.setStereo(true);
QSurfaceFormat::setDefaultFormat(format);**

so that all my QOpenGLWidgets have the same pixel format.
The stereo is correctly activated because Areo is disabled at launch

for the rendering (in the painGL method), i simply do a texture draw using the fixed pipeline:

void draw(int w, int h, float u, float v, int textureId, int buffer)
{
  glViewport(0, 0, w, h);
  glDrawBuffer(buffer); // Generate the GL_INVALID_OPERATION
  GLenum error = glGetError();

  if (error != GL_NO_ERROR)
    std::cout << "GL ERROR: " << error << std::endl;

  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

  glEnable(GL_TEXTURE_2D);
  glBindTexture(GL_TEXTURE_2D, textureId);
  glBegin(GL_QUADS);

  glTexCoord2f(0, 0);
  glVertex2f(-1, -1);

  glTexCoord2f(u, 0);
  glVertex2f(1, -1);

  glTexCoord2f(u, v);
  glVertex2f(1, 1);

  glTexCoord2f(0, v);
  glVertex2f(-1, 1);

  glEnd();

  glBindTexture(GL_TEXTURE_2D, 0);
  glDisable(GL_TEXTURE_2D);
}

Pretty simple.... Is there a known issue with the defaultFramebufferObject when stereo is enabled?

Sincerelly

PS: i use Qt 5.4.1 under Windows 8.1

[Nicolas]

Up

No one?

[SGaist]

Hi and welcome to devnet,

Sorry I can't help you on that matter, however you can also try the #qt irc channel on freenode

[aamesAtTanzle]

This issue is getting some love in the form of a bug report: https://bugreports.qt.io/browse/QTBUG-64587