osgWidget handles this by using a custom EventHandler:
http://code.google.com/p/osgwidget/source/browse/trunk/src/ViewerEventHandlers.cpp#165
...the idea being that it's generally the case you want to adjust your
orthographic display by responding to the RESIZE event, and that you'll
almost never get the results you want otherwise (at least in my
experience :)).
On Tue, 2008-05-06 at 09:26 +0800, Wu Xiaodong wrote:
>
> All. I try to render a hud-text;
> I created a hud text in a geode and added it to a
> slave-camera. It's good. but when i resize the view and set a new
> position to the text bases on the new window rect. The text's position
> seems based on the old window rect when when the slave-camera is
> created.
> when created, window rect is (0,0, 100,100) and the text
> position is : 50,50, it's good;
> when resize the window to rect (0,0,200,200) and i try to set
> the text position (100,100); I hope the text should be in the center
> of window, but it's out of the window range and I can see it in the
> view.
> how can I fix my problem?
>
> Thanks.
>
>
> xiaodong
>
> the codes is following.
>
> if( _hudCamera.valid() ) _hudCamera.release();
> _hudCamera = new osg::Camera;
> _hudCamera->setReferenceFrame(osg::Transform::ABSOLUTE_RF);
> osg::ref_ptr<osg::Camera> camera = this->getCamera();
> //update the main camera;
> osg::ref_ptr<osg::GraphicsContext::Traits> traits;
> if( camera.valid() )
> {
> osg::ref_ptr<osg::GraphicsContext> context =
> camera->getGraphicsContext();
> if( context.valid() )
> {
> traits =
> const_cast<osg::GraphicsContext::Traits*>( context->getTraits() );
> if( traits.valid() )
> {
> _hudCamera->setGraphicsContext( context.get() );
> _hudCamera->setViewport(0,0,traits->width,
> traits->height );
> }
> }
> }
> if( traits.valid() ) {
>
> _hudCamera->setProjectionMatrixAsOrtho2D(0,traits->width,0,traits->height);
> _hudCamera->setViewMatrix(osg::Matrix::identity());
> _hudCamera->setRenderOrder(osg::Camera::POST_RENDER);
> _hudCamera->setClearMask(GL_DEPTH_BUFFER_BIT);
>
> std::string timesFont("fonts/times.ttf");
>
> turn lighting off for the text and disable depth test to
> ensure its always ontop.
> osg::Vec3 position( 10.0f,traits->height/2.0,0.0f);
> osg::Geode* geode = new osg::Geode();
> osg::StateSet* stateset = geode->getOrCreateStateSet();
> stateset->setMode(GL_LIGHTING,osg::StateAttribute::OFF);
> stateset->setMode(GL_DEPTH_TEST,osg::StateAttribute::OFF);
> //--
> stateset->setRenderBinDetails(11, "RenderBin");
> _hudCamera->addChild( geode );
>
> osgText::Text* text = new osgText::Text;
> geode->addDrawable( text );
> text->setFont(timesFont);
> std::stringstream ss;
>
> ss<<"width:"<<traits->width<<"Height:"<<traits->height<<std::endl;
> std::string str;
> ss>>str;
> std::wstring wstr(str.begin(), str.end());
> text->setText( wstr.data() );
> text->setPosition(position);
> }
> //////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
> --
> Xiaodong Wu
> 吴晓东
> "'Xiao' means the time and the view when the sun rises and 'dong'
> means the east in Chinese"
> _______________________________________________
> osg-users mailing list
> osg-users@lists.openscenegraph.org
> http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
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