OSX and opengl profile > 2.1 on Qt 4.8

[bms20]

Hi All,

I'm not working on a game, but rather tools for games.

I'm curious: Is there a way in OSX to get access to opengl > 2.1 using Qt 4.8?

I'm running a modern Intel HD5000 graphics laptop, and GLView reports that OpenGL 4.1 is available. However, when I attempt to set QGL to any core profile above 2.1 I end up with the version string reporting 2.1; which can't be right.

Do any of you have example code that can set the GL context up in something higher than 2.1 on an OSX machine?

My particulars are:

•  OSX 10.9.3, XCode 5
  

• Qt 4.8.6
  

• Intel HD 5000 graphics.
  

Thanks,

-bms20

[bms20]

Ok - I'll answer my own question.

The answer is that QGL in Qt 4.8 does not support profiles above compatibility 2.1.

To do so requires hacking the file qgl_mac.mm and adding NSOpenGLPFAOpenGLProfile and NSOpenGLProfileVersion3_2Core to the NSOpenGLPixelFormatAttributes structures used.

Don't treat the following diff as a complete solution - it will break any old style OpenGL on mac:

diff --git a/build/packages/qt-everywhere-opensource-src-4.8.6/src/opengl/qgl_mac.mm b/build/packages/qt-everywhere-opensource-src-4.8.6/src/opengl/qgl_mac.mm
index 4ecf888..52b24ed 100644
--- a/build/packages/qt-everywhere-opensource-src-4.8.6/src/opengl/qgl_mac.mm
+++ b/build/packages/qt-everywhere-opensource-src-4.8.6/src/opengl/qgl_mac.mm
@@ -148,7 +148,11 @@ QGLTemporaryContext::QGLTemporaryContext(bool, QWidget *)
aglDestroyPixelFormat(fmt);
#else
QMacCocoaAutoReleasePool pool;

• NSOpenGLPixelFormatAttribute attribs[] = { 0 };

• NSOpenGLPixelFormatAttribute attribs[] = {

•           NSOpenGLPFAOpenGLProfile,
  

•           NSOpenGLProfileVersion3_2Core,
  

•           0
  

• };
  NSOpenGLPixelFormat *fmt = [[NSOpenGLPixelFormat alloc] initWithAttributes:attribs];
  if (!fmt) {
  qWarning("QGLTemporaryContext: Cannot find any visuals");
  @@ -350,7 +354,7 @@ bool QGLContext::chooseContext(const QGLContext *shareContext)

void *QGLContextPrivate::tryFormat(const QGLFormat &format)
{

• static const int Max = 40;

• static const int Max = 42;
  #ifndef QT_MAC_USE_COCOA
  GLint attribs[Max], cnt = 0;
  bool device_is_pixmap = (paintDevice->devType() == QInternal::Pixmap);
  @@ -464,6 +468,10 @@ void *QGLContextPrivate::tryFormat(const QGLFormat &format)
  if (devType == QInternal::Pbuffer)
  attribs[cnt++] = NSOpenGLPFAPixelBuffer;

• attribs[cnt++] = NSOpenGLPFAOpenGLProfile;

• attribs[cnt++] = NSOpenGLProfileVersion3_2Core;

• attribs[cnt] = 0;
  Q_ASSERT(cnt < Max);
  return [[NSOpenGLPixelFormat alloc] initWithAttributes:attribs];