From 3326c26a60bbd38058fa160ec75aaf90a4411f55 Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Tue, 2 Jun 2009 09:20:20 +0000
Subject: [PATCH] Merged from svn/trunk : "Fixed handling of case where the    
       master and the slave camera are placed on the same          
 GraphisContext, or when the master camera and slave camera are          
 assigned to different Camers. Note normally one doesn't mix           master
 with GraphicsContexts and slave cameras so neither case is           common."

---
 src/osg/GraphicsContext.cpp | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/src/osg/GraphicsContext.cpp b/src/osg/GraphicsContext.cpp
index 4a5098403..46e66de3f 100644
--- a/src/osg/GraphicsContext.cpp
+++ b/src/osg/GraphicsContext.cpp
@@ -819,6 +819,7 @@ void GraphicsContext::resizedImplementation(int x, int y, int width, int height)
             osg::View* view = camera->getView();
             osg::View::Slave* slave = view ? view->findSlaveForCamera(camera) : 0;
 
+
             if (slave)
             {
                 if (camera->getReferenceFrame()==osg::Transform::RELATIVE_RF)
@@ -849,6 +850,29 @@ void GraphicsContext::resizedImplementation(int x, int y, int width, int height)
                     case(osg::Camera::VERTICAL): camera->getProjectionMatrix() *= osg::Matrix::scale(1.0, aspectRatioChange,1.0); break;
                     default: break;
                 }
+
+                osg::Camera* master = view ? view->getCamera() : 0;
+                if (view && camera==master)
+                {
+                    for(unsigned int i=0; i<view->getNumSlaves(); ++i)
+                    {
+                        osg::View::Slave& child = view->getSlave(i);
+                        if (child._camera.valid() && child._camera->getReferenceFrame()==osg::Transform::RELATIVE_RF)
+                        {
+                            // scale the slaves by the inverse of the change that has been applied to master, to avoid them be
+                            // scaled twice (such as when both master and slave are on the same GraphicsContexts) or by the wrong scale
+                            // when master and slave are on different GraphicsContexts.
+                            switch(policy)
+                            {
+                                case(osg::Camera::HORIZONTAL): child._projectionOffset *= osg::Matrix::scale(aspectRatioChange,1.0,1.0); break;
+                                case(osg::Camera::VERTICAL): child._projectionOffset *= osg::Matrix::scale(1.0, 1.0/aspectRatioChange,1.0); break;
+                                default: break;
+                            }
+                        }
+                    }
+                }
+
+
             }
 
         }