Create a new shared pointer type stdext::shared_object_ptr and stdext::shared_obj
using boost::intrusive_ptr
Advantages:
* half memory usage
* faster and lightweight
Disadvantages:
* using weak_ptr is not supported anymore
* compiling seems slower
* the rendering now consits of two panes
- the background pane (for animated stuff like the map)
- the foreground pane (for steady stuff, like UI)
each pane has it own max FPS and works idependently
this may increase graphics performance on many platforms
* option to pass -opengl1 or -opengl2 as argument
* note that with this commit there are a lot of graphics regressions and the master will remaing unstable for a while
* shaders disabled for a while
* zooming without real FBOs kinda works, but with lower quality
* hardware detection for glGenerateMipmaps
* possibility to disable bilinear filtering, mipmaps, framebuffers, and realtime mipmap generation in g_graphics
* otclient works well using 3D acceleration in VirtualBox again
* many fixes regarding FBOs fallback implementation