From a7ba138dc7493d4c6bf10e54dad71069af578f2e Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Tue, 31 Mar 2015 16:23:43 +0000
Subject: [PATCH] Introduced osg::Camera::resize(..) method and associated enum
 thus:

        enum ResizeMask
        {
            RESIZE_VIEWPORT=1,
            RESIZE_ATTACHMENTS=2,
            RESIZE_PROJECTIONMATRIX=4,
            RESIZE_DEFAULT=RESIZE_VIEWPORT|RESIZE_ATTACHMENTS
        };

        /** Resize, to the specified width and height, the viewport, attachments and projection matrix according to the resizeMask provided.
          * Note, the adjustment of the projection matrix is done if the RESIZE_PROJECTIONMATRIX mask to set and according to the rules specified in the ProjectionResizePolicy. */
        void resize(int width, int height, int resizeMask=RESIZE_DEFAULT);



git-svn-id: http://svn.openscenegraph.org/osg/OpenSceneGraph/trunk@14811 16af8721-9629-0410-8352-f15c8da7e697
---
 examples/osgdistortion/osgdistortion.cpp | 14 ++------
 include/osg/Camera                       | 13 ++++++++
 src/osg/Camera.cpp                       | 41 ++++++++++++++++++++++++
 3 files changed, 56 insertions(+), 12 deletions(-)

diff --git a/examples/osgdistortion/osgdistortion.cpp b/examples/osgdistortion/osgdistortion.cpp
index c32877d60..feb088ee7 100644
--- a/examples/osgdistortion/osgdistortion.cpp
+++ b/examples/osgdistortion/osgdistortion.cpp
@@ -108,13 +108,6 @@ public:
     {
     }
 
-    void resizeRTTCamera(osg::Camera* camera,unsigned int width, unsigned int height)
-    {
-        camera->setViewport(0, 0, width, height);
-
-        camera->resizeAttachments(width, height);
-    }
-
     virtual bool handle(const osgGA::GUIEventAdapter& ea, osgGA::GUIActionAdapter& aa, osg::Object* object, osg::NodeVisitor* nv)
     {
         osg::Camera* camera = dynamic_cast<osg::Camera*>(object);
@@ -130,11 +123,8 @@ public:
             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();
-
-            resizeRTTCamera(camera, width, height);
+            // reset the Camera viewpoer and associated Texture's to make sure it tracks the new window size.
+            camera->resize(ea.getWindowWidth(), ea.getWindowHeight());
         }
         return false;
     }
diff --git a/include/osg/Camera b/include/osg/Camera
index 98cb7b282..84e49f1f0 100644
--- a/include/osg/Camera
+++ b/include/osg/Camera
@@ -430,6 +430,19 @@ class OSG_EXPORT Camera : public Transform, public CullSettings
         void resizeAttachments(int width, int height);
 
 
+        enum ResizeMask
+        {
+            RESIZE_VIEWPORT=1,
+            RESIZE_ATTACHMENTS=2,
+            RESIZE_PROJECTIONMATRIX=4,
+            RESIZE_DEFAULT=RESIZE_VIEWPORT|RESIZE_ATTACHMENTS
+        };
+
+        /** Resize, to the specified width and height, the viewport, attachments and projection matrix according to the resizeMask provided.
+          * Note, the adjustment of the projection matrix is done if the RESIZE_PROJECTIONMATRIX mask to set and according to the rules specified in the ProjectionResizePolicy. */
+        void resize(int width, int height, int resizeMask=RESIZE_DEFAULT);
+
+
         /** Explicit control over implicit allocation of buffers when using FBO.
          Implicit buffers are automatically substituted when user have not attached such buffer.
 
diff --git a/src/osg/Camera.cpp b/src/osg/Camera.cpp
index 975ea5dee..e0f2637f4 100644
--- a/src/osg/Camera.cpp
+++ b/src/osg/Camera.cpp
@@ -481,6 +481,47 @@ void Camera::resizeAttachments(int width, int height)
     }
 }
 
+void Camera::resize(int width, int height, int resizeMask)
+{
+    if (getViewport())
+    {
+        double previousWidth = getViewport()->width();
+        double previousHeight = getViewport()->height();
+        double newWidth = width;
+        double newHeight = height;
+
+        if ((previousWidth!=newWidth) || (previousHeight!=newHeight))
+        {
+            if ((resizeMask&RESIZE_PROJECTIONMATRIX)!=0 && (getProjectionResizePolicy()!=FIXED))
+            {
+                double widthChangeRatio = newWidth / previousWidth;
+                double heigtChangeRatio = newHeight / previousHeight;
+                double aspectRatioChange = widthChangeRatio / heigtChangeRatio;
+                if (aspectRatioChange!=1.0)
+                {
+                    switch(getProjectionResizePolicy())
+                    {
+                        case(HORIZONTAL): getProjectionMatrix() *= osg::Matrix::scale(1.0/aspectRatioChange,1.0,1.0); break;
+                        case(VERTICAL): getProjectionMatrix() *= osg::Matrix::scale(1.0, aspectRatioChange,1.0); break;
+                        case(FIXED): break;
+                    }
+                }
+            }
+
+            if ((resizeMask&RESIZE_VIEWPORT)!=0)
+            {
+                setViewport(0,0,width, height);
+            }
+        }
+    }
+
+    if ((resizeMask&RESIZE_ATTACHMENTS)!=0)
+    {
+        resizeAttachments(width, height);
+    }
+}
+
+
 void Camera::createCameraThread()
 {
     if (!_cameraThread)