QVTKOpenGLWidget: error calling "versionFunctions" when OpenGL ES is being used.

From Antonio Orlando aorlando@herrera.unt.edu.ar on the paraview mailing list:

I have tried to install the new version of
ParaView-5.4.1-Qt5-OpenGL2-Windows-64bit.exe on Windows 8.1, with a
64bit OS, and when I launch it I get at the end of a long error
message log the following

ERROR: In C:\bbd\7cc78367\build\superbuild\paraview\src\VTK\Rendering\OpenGL2\vtkShaderProgram.cxx,
line 409
vtkShaderProgram (000000A5CDCC3D00):

Generic Warning: In
C:\bbd\7cc78367\build\superbuild\paraview\src\VTK\Rendering\OpenGL2\vtkOpenGLRenderTimer.cxx,
line 104
vtkOpenGLRenderTimer::Stop called before vtkOpenGLRenderTimer::Start. Ignoring.

versionFunctions: Not supported on OpenGL ES

QVTKOpenGLWidget calls versionFunctions in the following:

  // blit from this->FBO to QOpenGLWidget's FBO.
  vtkQVTKOpenGLWidgetDebugMacro("paintGL::blit-to-defaultFBO");
  QOpenGLFunctions_3_2_Core* f =
    QOpenGLContext::currentContext()->versionFunctions<QOpenGLFunctions_3_2_Core>();
  if (f)
  {
    f->glBindFramebuffer(GL_DRAW_FRAMEBUFFER, this->defaultFramebufferObject());
    f->glDrawBuffer(GL_COLOR_ATTACHMENT0);
    ...

In QOpenGLContext, versionFunctions opens with

QAbstractOpenGLFunctions *QOpenGLContext::versionFunctions(const QOpenGLVersionProfile &versionProfile) const
{
#ifndef QT_OPENGL_ES_2
    if (isOpenGLES()) {
        qWarning("versionFunctions: Not supported on OpenGL ES");
        return 0;
    }
#endif // QT_OPENGL_ES_2

cc: @utkarsh.ayachit