QT 5.7 - Error C2061 Unidentified identifier GLdouble (qopenglfunctions.h)

Question

So i am attempting to upgrade our QT 5.5 project using VS2013 to use QT 5.7 using VS2015. After getting everything installed and setup properly during the compile some of my files error out with the error

Severity Code Description Project File Line Suppression State Error (active) identifier "GLdouble" is undefined myProject c:\Qt\5.7\msvc2015_64\include\QtGui\qopenglfunctions.h 587

Im at a bit of a loss where to even begin looking to fix this as it seems to be an issue with QT itself?

Using the web installer for QT 5.7 i have every QT Library selected under QT 5.7 as i wasnt sure if i was just missing a library.

Answer 1

Just upgraded to Qt 5.12.1 and VS 2017 15.9.6 from Qt 5.2.0 and VS 2012. In my case, the error was "syntax error: identifier 'GLdouble'" - I just needed to add a new pre-processor directive, QT_OPENGL_ES.

Answer 2

I think you built your Qt libraries with ANGLE frame work included.

By default, Qt is configured to use ANGLE, which is bundled with Qt and depends on the DirectX SDK (from documetation)

http://doc.qt.io/qt-5/configure-options.html

Remove the dependency on ANGLE.

If you configure your Qt libraries:

You have to use the -opengl option to configure Qt to use the OpenGL in the target system.

While configuring your Qt build, (before using nmake), try something like below.

configure -debug-and-release -opengl desktop (along with other options).

This excludes ANGLE from your built Qt libraries, and your OpenGL functions work as expected.

What is ANGLE?:

ANGLE stands for Almost Native Graphics Layer Engine.

A kind of cross plat form graphics library, which uses hardware supported graphic APIs.

A brief information about each platform's ANGLE support, there is a table available in below link.

https://chromium.googlesource.com/angle/angle/+/master/README.md