From 890aea95371156adaf1ab72dfd09400973d5fede Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Fri, 20 Mar 2015 17:58:34 +0000
Subject: [PATCH] Added event handle to alter the RTT Camera's dimensions to
 follow the windows resizes.

git-svn-id: http://svn.openscenegraph.org/osg/OpenSceneGraph/trunk@14806 16af8721-9629-0410-8352-f15c8da7e697
---
 examples/osgdistortion/osgdistortion.cpp | 54 ++++++++++++++++++++++++
 1 file changed, 54 insertions(+)

diff --git a/examples/osgdistortion/osgdistortion.cpp b/examples/osgdistortion/osgdistortion.cpp
index 6cba18fb7..b3181c632 100644
--- a/examples/osgdistortion/osgdistortion.cpp
+++ b/examples/osgdistortion/osgdistortion.cpp
@@ -100,6 +100,58 @@ struct CommandLineOptions
      }
 };
 
+
+class WindowResizedHandler : public osgGA::GUIEventHandler
+{
+public:
+    WindowResizedHandler()
+    {
+    }
+
+    virtual bool handle(const osgGA::GUIEventAdapter& ea, osgGA::GUIActionAdapter& aa, osg::Object* object, osg::NodeVisitor* nv)
+    {
+        osg::Camera* camera = dynamic_cast<osg::Camera*>(object);
+        if (!camera) return false;
+
+        const osg::FrameStamp* fs = nv->getFrameStamp();
+
+        if (ea.getEventType()==osgGA::GUIEventAdapter::RESIZE)
+        {
+            OSG_NOTICE<<"Window resized event context="<<ea.getGraphicsContext()<<" frameNumber = "<<fs->getFrameNumber()<<std::endl;
+            OSG_NOTICE<<"   WindowX="<<ea.getWindowX()<<std::endl;
+            OSG_NOTICE<<"   WindowY="<<ea.getWindowY()<<std::endl;
+            OSG_NOTICE<<"   WindowWidth="<<ea.getWindowWidth()<<std::endl;
+            OSG_NOTICE<<"   WindowHeight="<<ea.getWindowHeight()<<std::endl;
+
+            // reset the Camera and associated Texture's to make sure it tracks the new window size.
+            int width = ea.getWindowWidth();
+            int height = ea.getWindowHeight();
+            camera->setViewport(0, 0, width, height);
+            camera->setRenderingCache(0);
+
+            osg::Camera::BufferAttachmentMap& cbam = camera->getBufferAttachmentMap();
+            for(osg::Camera::BufferAttachmentMap::iterator itr = cbam.begin();
+                itr != cbam.end();
+                ++itr)
+            {
+                osg::Camera::Attachment& attachment = itr->second;
+                if (attachment._texture.get())
+                {
+                    osg::Texture2D* texture2D = dynamic_cast<osg::Texture2D*>(attachment._texture.get());
+                    if (texture2D)
+                    {
+                        OSG_NOTICE<<"Resetting Texture size"<<std::endl;
+                        texture2D->setTextureSize(width, height);
+                        texture2D->dirtyTextureObject();
+                    }
+                }
+            }
+        }
+        return false;
+    }
+
+};
+
 osg::Node* createDistortionSubgraph(CommandLineOptions& options, osg::Node* subgraph, const osg::Vec4& clearColour)
 {
     osg::Group* distortionNode = new osg::Group;
@@ -141,6 +193,8 @@ osg::Node* createDistortionSubgraph(CommandLineOptions& options, osg::Node* subg
         camera->addChild(subgraph);
 
         distortionNode->addChild(camera);
+
+        camera->addEventCallback(new WindowResizedHandler());
    }
 
     // set up the hud camera