refs #386

refs #386

refs #386

Removed oblivious tgt::QtContextManager and merged functionality into tgt::GLCanvas and tgt::GlContextManager. Meanwhile, improved OpenGL context initialization and pipeline creation in CampvisApplication.

Fixes -Wreorder

Previously, QtCanvas' init() would call show() on its underlying widget
and cause it to appear as a top-level window for a split second, before
the canvas was docked. To avoid this flicker, show() is now only called
on the canvas after it's been added to the MDI area.

Work on Issue #44: Removed GLContext interface and merged functionality into GlCanvas. Introducing abstract (Qt-free) tgt::GlContextManager interface, being implemented by tgt::QtContextManager. Further clean up of related code.

Revised event handling system: Got rid of campvis::AbstractEventHandler and replaced with functionality of tgt::EventListener and tgt::EventHandler

The QtCanvas class didn't previously implement the sizeHint method. As
a result, Qt would allot it no display space if there were other widgets
competing for it (e.g. the main window's central widget).

Now QtCanvas has a sizeHint implementation that returns a size hint that
is in line with what the canvas' getSize method reports. Moreover,
QtCanvas now uses the `Expanding` size policy to inform Qt that it would
like to get as much display space as possible.

git-svn-id: https://camplinux.in.tum.de/svn/campvis/branches/gui-redux@519 bb408c1c-ae56-11e1-83d9-df6b3e0c105e

git-svn-id: https://camplinux.in.tum.de/svn/campvis/trunk@470 bb408c1c-ae56-11e1-83d9-df6b3e0c105e

 * Fixed Issue #38: Made common GLSL header conform to the standards (no samplers in structs)
 * Fixed failing destruction of OpenGL buffers when destructing GeometryData from threads without OpenGL context
 * Fixed wrong pointers in GLContexts due to using this pointer of incompletely constructed class

git-svn-id: https://camplinux.in.tum.de/svn/campvis/trunk@463 bb408c1c-ae56-11e1-83d9-df6b3e0c105e

git-svn-id: https://camplinux.in.tum.de/svn/campvis/trunk@335 bb408c1c-ae56-11e1-83d9-df6b3e0c105e

 * introduced abstract tgt::GLContext for thread-safe management of an OpenGL context
 * introduced Qt-threading based tgt::QtGLContext, tgt::QtThreadedCanvas and tgt::QtThreadedPainter
 * adapted tumvis-core and tumvis-application to new OpenGL context handling

git-svn-id: https://camplinux.in.tum.de/svn/campvis/trunk@194 bb408c1c-ae56-11e1-83d9-df6b3e0c105e

git-svn-id: https://camplinux.in.tum.de/svn/campvis/trunk@160 bb408c1c-ae56-11e1-83d9-df6b3e0c105e