OpenGL vs. Qt4 OpenGL

[Michael Pyne]

On Thursday 13 December 2007, Allen Winter wrote:
> What is libQtOpenGL.so that I find in my qt-copy/lib?
> And how does it differ from /usr/lib/libGL.so that I also find on my
> system?

libQtOpenGL.so is the library that implements the Qt OpenGL module support.  
i.e. QGLWidget and its related code.

/usr/lib/libGL.so is the OpenGL library itself.  i.e. the C language library 
which provides the OpenGL graphics primitives.  Qt's OpenGL module uses this 
library to provide OpenGL support.

> kpat links against ${QT_QTOPENGL_LIBRARY}, which points to
> qt-copy/lib/libQtOpenGL.so

As it should.

> should we permit stuff to build against QT_QTOPENGL?
> so far, the only instance I've seen of this is in kpat

Yes, this should be allowed.

Basically, Qt's OpenGL module depends on the system libGL.so.  An application 
could conceivably use libGL.so in addition to Qt's support (i.e. Qt's 
QGLWidget is useful but doesn't expose enough of the OpenGL API) or instead 
of Qt's support.

But libGL.so is required in all cases, either directly by the application or 
indirectly through Qt's OpenGL module.

Regards,
 - Michael Pyne
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: This is a digitally signed message part.
Url : http://mail.kde.org/pipermail/kde-buildsystem/attachments/20071217/02fc42b9/attachment.pgp