Added osgSim::OverlayNode setup in osgsimulation, and added preliminary test

code to the osgSim::OverlayNode to test osgsimulation/the architecture.

src/osgSim/OverlayNode.cpp

@@ -28,6 +28,7 @@ public:
 
     virtual void operator()(osg::Node*, osg::NodeVisitor* nv)
     {
+        osg::notify(osg::NOTICE)<<"Oddddd stuff"<<std::endl;
         _node->accept(*nv);
     }
     
@@ -35,7 +36,7 @@ public:
 };
 
 OverlayNode::OverlayNode():
-    _textureUnit(0)
+    _textureUnit(1)
 {
     init();
 }
@@ -50,15 +51,46 @@ OverlayNode::OverlayNode(const OverlayNode& copy, const osg::CopyOp& copyop):
 
 void OverlayNode::init()
 {
-    _camera = new osg::CameraNode;
+    unsigned int tex_width = 1024;
+    unsigned int tex_height = 1024;
+    
+    osg::Texture2D* texture = new osg::Texture2D;
+    texture->setTextureSize(tex_width, tex_height);
+    texture->setInternalFormat(GL_RGBA);
+    texture->setFilter(osg::Texture2D::MIN_FILTER,osg::Texture2D::LINEAR);
+    texture->setFilter(osg::Texture2D::MAG_FILTER,osg::Texture2D::LINEAR);
+    texture->setWrap(osg::Texture2D::WRAP_S,osg::Texture2D::CLAMP_TO_BORDER);
+    texture->setWrap(osg::Texture2D::WRAP_T,osg::Texture2D::CLAMP_TO_BORDER);
+    texture->setBorderColor(osg::Vec4(1.0f,1.0f,1.0f,1.0f));
+   
+    _texture = texture;
+
+    // set up the render to texture camera.
+    {
+
+        // create the camera
+        _camera = new osg::CameraNode;
+
+        _camera->setClearColor(osg::Vec4(1.0f,0.5f,0.5f,1.0f));
+
+        // set viewport
+        _camera->setViewport(0,0,tex_width,tex_height);
+
+        // set the camera to render before the main camera.
+        _camera->setRenderOrder(osg::CameraNode::PRE_RENDER);
+
+        // tell the camera to use OpenGL frame buffer object where supported.
+        _camera->setRenderTargetImplmentation(osg::CameraNode::FRAME_BUFFER_OBJECT);
+
+        // attach the texture and use it as the color buffer.
+        _camera->attach(osg::CameraNode::COLOR_BUFFER, _texture.get());
+    }
 
     _texgenNode = new osg::TexGenNode;
-    _texgenNode->setTextureUnit(_textureUnit);
-
-    _texture = new osg::Texture2D;
 
     _mainSubgraphStateSet = new osg::StateSet;
-    _mainSubgraphStateSet->setTextureAttributeAndModes(_textureUnit, _texture.get(), osg::StateAttribute::ON);
+
+    setOverlayTextureUnit(1);
 }
 
 
@@ -77,14 +109,55 @@ void OverlayNode::traverse(osg::NodeVisitor& nv)
         return;
     }
     
+    
     unsigned int contextID = cv->getState()!=0 ? cv->getState()->getContextID() : 0;
 
     // if we need to redraw then do cull traversal on camera.
     if (!_textureObjectValidList[contextID])
     {
+        osg::Vec3 _position(0,0,0);
+
+        // now compute the camera's view and projection matrix to point at the shadower (the camera's children)
+        osg::BoundingSphere bs;
+        for(unsigned int i=0; i<_camera->getNumChildren(); ++i)
+        {
+            bs.expandBy(_camera->getChild(i)->getBound());
+        }
+
+        if (!bs.valid())
+        {
+            osg::notify(osg::WARN) << "bb invalid"<<_camera.get()<<std::endl;
+            return;
+        }
+
+        float centerDistance = (_position-bs.center()).length();
+
+        float znear = centerDistance-bs.radius();
+        float zfar  = centerDistance+bs.radius();
+        float zNearRatio = 0.001f;
+        if (znear<zfar*zNearRatio) znear = zfar*zNearRatio;
+
+        float top   = (bs.radius()/centerDistance)*znear;
+        float right = top;
+
+        _camera->setReferenceFrame(osg::CameraNode::ABSOLUTE_RF);
+        _camera->setProjectionMatrixAsFrustum(-right,right,-top,top,znear,zfar);
+        _camera->setViewMatrixAsLookAt(_position,bs.center(),osg::Vec3(0.0f,1.0f,0.0f));
+
+        // compute the matrix which takes a vertex from local coords into tex coords
+        // will use this later to specify osg::TexGen..
+        osg::Matrix MVPT = _camera->getViewMatrix() * 
+                           _camera->getProjectionMatrix() *
+                           osg::Matrix::translate(1.0,1.0,1.0) *
+                           osg::Matrix::scale(0.5f,0.5f,0.5f);
+
+        _texgenNode->getTexGen()->setMode(osg::TexGen::EYE_LINEAR);
+        _texgenNode->getTexGen()->setPlanesFromMatrix(MVPT);
+
+
         _camera->accept(*cv);
         
-        _textureObjectValidList[contextID] = 1;
+//        _textureObjectValidList[contextID] = 1;
     }
     
     
@@ -103,7 +176,13 @@ void OverlayNode::traverse(osg::NodeVisitor& nv)
 
 void OverlayNode::setOverlaySubgraph(osg::Node* node)
 {
+    if (_overlaySubgraph == node) return;
+
     _overlaySubgraph = node;
+
+    _camera->removeChild(0, _camera->getNumChildren());
+    _camera->addChild(node);
+
     dirtyOverlayTexture();
 }
 
@@ -114,10 +193,14 @@ void OverlayNode::dirtyOverlayTexture()
 
 void OverlayNode::setOverlayTextureUnit(unsigned int unit)
 {
-    if (_textureUnit==unit) return;
-    
-    _texgenNode->setTextureUnit(unit);
+    _textureUnit = unit;
+
+    _texgenNode->setTextureUnit(_textureUnit);
     
     _mainSubgraphStateSet->clear();
     _mainSubgraphStateSet->setTextureAttributeAndModes(_textureUnit, _texture.get(), osg::StateAttribute::ON);
+    _mainSubgraphStateSet->setTextureMode(_textureUnit, GL_TEXTURE_GEN_S, osg::StateAttribute::ON);
+    _mainSubgraphStateSet->setTextureMode(_textureUnit, GL_TEXTURE_GEN_T, osg::StateAttribute::ON);
+    _mainSubgraphStateSet->setTextureMode(_textureUnit, GL_TEXTURE_GEN_R, osg::StateAttribute::ON);
+    _mainSubgraphStateSet->setTextureMode(_textureUnit, GL_TEXTURE_GEN_Q, osg::StateAttribute::ON);
 }