[Development] Qt 5.5.0 build issue on OS X (10.9): OpenGL libraries

[Sorvig Morten]

> On 15 Sep 2015, at 03:51, Thiago Macieira <thiago.macieira at intel.com> wrote:
> 
> On Monday 14 September 2015 08:09:28 Sorvig Morten wrote:
>> Then the question is: which ones should QtGui link against? On other words
>> OpenGL usage is not confined to platform plugins only.
>> 
>> To me this points to Xcb or Cocoa being a configure-time choice.
> 
> Shouldn't the OpenGL functions be resolved dynamically by the platform plugin? 
> QtGui should not link to the GL library. We had to implement that 
> functionality for Windows, so that desktop GL and ANGLE could be selected at 
> runtime.
> 
> This would also allow one QtGui to work with both desktop GL as well as GL ES 
> in one build (though it could be disabled if one of the two can never happen).

I did a quick survey of OpenGL usage by removing the frameworks from the linker line:

QtGui : OpenGL function usage  sems mostly contained to QOpenGLFunctions(Private): https://paste.kde.org/posonryeq
QtQuick: Links against OpenGL and AGL but does not appear to use any symbols.
Qt3D (core, render): Links against OpenGL and AGL but does not appear to use any symbols.

What do we do for OpenGL headers? Looks like src/gui/opengl/opengl.h uses native headers for Q_OS_MAC and the official Khronos headers for other platforms.

Morten