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Timestamp:
11/21/09 17:41:02 (4 years ago)
Author:
robert
Message:

From Colin MacDonald?, "In my application I have a custom graphics context class, derived from
osg::GraphicsContext?, in order to give good integration with the
application's GUI toolkit. This works really well.

However, I need to share OpenGL texture resources with the standard
osgViewer GraphicsContext? implementations, in particular the
PixelBuffers?. This is essential for my application to conserve graphics
memory on low-end hardware. Currently the standard osg implementations
will not share resources with another derived osg::GraphicsContext?,
other than the pre-defined osgViewer classes e.g. PixelBufferX11 is
hardcoded to only share resources with GraphicsWindowX11 and
PixelBufferX11 objects, and no other osg::GraphicsContext? object.

To address this in the cleanest way I could think of, I have moved the
OpenGL handle variables for each platform into a small utility class,
e.g. GraphicsHandleX11 for unix. Then GraphicsWindowX11, PixelBufferX11
and any other derived osg::GraphicsContext? class can inherit from
GraphicsHandleX11 to share OpenGL resources.

I have updated the X11, Win32 and Carbon implementations to use this.
The changes are minor. I haven't touched the Cocoa implmentation as
I'm not familiar with it at all and couldn't test it - it will work
unchanged.

Without this I had some horrible hacks in my application, this greatly
simplifies things for me. It also simplifies the osgViewer
implementations slightly. Perhaps it may help with other users'
desires to share resources with external graphics contexts, as was
discussed on the user list recently."

Notes from Robert Osfield, adapted Colin's submission to work with the new EGL related changes.

Files:
1 modified

Legend:

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  • OpenSceneGraph/trunk/include/osgViewer/api/Carbon/PixelBufferCarbon

    r9904 r10813  
    2020 
    2121#include <osg/GraphicsContext> 
    22 #include <osgViewer/Export> 
    23  
    24 #include <Carbon/Carbon.h> 
    25 #include <AGL/agl.h> 
     22#include <osgViewer/api/Carbon/GraphicsHandleCarbon> 
    2623 
    2724 
     
    2926{ 
    3027 
    31 class OSGVIEWER_EXPORT PixelBufferCarbon : public osg::GraphicsContext 
     28class OSGVIEWER_EXPORT PixelBufferCarbon : public osg::GraphicsContext, public osgViewer::GraphicsHandleCarbon 
    3229{ 
    3330    public: 
     
    3835            _realized(false), 
    3936            _pixelformat(0), 
    40             _pbuffer(0), 
    41             _context(0) 
     37            _pbuffer(0) 
    4238        { 
    4339            _traits = traits; 
     
    9288        /** Swap the front and back buffers.*/ 
    9389        virtual void swapBuffersImplementation(); 
    94          
     90        
    9591        static AGLPixelFormat createPixelFormat(osg::GraphicsContext::Traits* traits); 
    96          
    97         AGLContext getAGLContext() { return _context; } 
    9892 
    9993    public: 
     
    113107         
    114108        AGLPixelFormat    _pixelformat; 
    115         AGLPbuffer        _pbuffer; 
    116         AGLContext        _context; 
    117          
     109        AGLPbuffer        _pbuffer;         
    118110}; 
    119111