From efdc026114435fd0de982d3f07a1f8417ed276c5 Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Thu, 17 Jan 2008 15:37:35 +0000
Subject: [PATCH] Fixed the computation of terrain bounding volume so that it
 properly accounts for elevation layers

---
 include/osgTerrain/Layer             |  4 +-
 src/osgTerrain/Layer.cpp             | 62 +++++++++++++++++++---------
 src/osgTerrain/Terrain.cpp           | 19 +++++----
 src/osgWrappers/osgTerrain/Layer.cpp |  8 ++--
 4 files changed, 61 insertions(+), 32 deletions(-)

diff --git a/include/osgTerrain/Layer b/include/osgTerrain/Layer
index 290058d96..f93b848a0 100644
--- a/include/osgTerrain/Layer
+++ b/include/osgTerrain/Layer
@@ -160,7 +160,7 @@ class OSGTERRAIN_EXPORT Layer : public osg::Object
         /** Get modified count value. */
         virtual unsigned int getModifiedCount() const { return 0; }
 
-        virtual osg::BoundingSphere computeBound() const;
+        virtual osg::BoundingSphere computeBound(bool treatAsElevationLayer) const;
 
     protected:
 
@@ -333,7 +333,7 @@ class OSGTERRAIN_EXPORT ProxyLayer : public Layer
         virtual void setModifiedCount(unsigned int value);
         virtual unsigned int getModifiedCount() const;
 
-        virtual osg::BoundingSphere computeBound() const;
+        virtual osg::BoundingSphere computeBound(bool treatAsElevationLayer) const;
 
     protected:
 
diff --git a/src/osgTerrain/Layer.cpp b/src/osgTerrain/Layer.cpp
index b72c25e40..9c7cec6c0 100644
--- a/src/osgTerrain/Layer.cpp
+++ b/src/osgTerrain/Layer.cpp
@@ -34,32 +34,56 @@ Layer::~Layer()
 {
 }
 
-osg::BoundingSphere Layer::computeBound() const
+osg::BoundingSphere Layer::computeBound(bool treatAsElevationLayer) const
 {
     osg::BoundingSphere bs;
     if (!getLocator()) return bs;
-
-    osg::Vec3d v;
-    if (getLocator()->convertLocalToModel(osg::Vec3d(0.0,0.0,0.0), v))
-    {
-        bs.expandBy(v);
-    }
     
-    if (getLocator()->convertLocalToModel(osg::Vec3d(1.0,0.0,0.0), v))
+    if (treatAsElevationLayer)
     {
-        bs.expandBy(v);
-    }
+        osg::BoundingBox bb;
+        unsigned int numColumns = getNumColumns();
+        unsigned int numRows = getNumRows();
+        for(unsigned int r=0;r<numRows;++r)
+        {
+            for(unsigned int c=0;c<numColumns;++c)
+            {
+                float value = 0.0f;
+                bool validValue = getValidValue(c,r, value);
+                if (validValue) 
+                {
+                    osg::Vec3d ndc, v;
+                    ndc.x() = ((double)c)/(double)(numColumns-1), 
+                    ndc.y() = ((double)r)/(double)(numRows-1);
+                    ndc.z() = value;
 
-    if (getLocator()->convertLocalToModel(osg::Vec3d(1.0,1.0,0.0), v))
-    {
-        bs.expandBy(v);
+                    if (getLocator()->convertLocalToModel(ndc, v))
+                    {
+                        bb.expandBy(v);
+                    }
+                }
+            }
+        }
+        bs.expandBy(bb);
     }
-
-    if (getLocator()->convertLocalToModel(osg::Vec3d(0.0,1.0,0.0), v))
+    else
     {
-        bs.expandBy(v);
-    }
     
+        osg::Vec3d v;
+        if (getLocator()->convertLocalToModel(osg::Vec3d(0.5,0.5,0.0), v))
+        {
+            bs.center() = v;
+        }
+
+        if (getLocator()->convertLocalToModel(osg::Vec3d(0.0,0.0,0.0), v))
+        {
+            bs.expandBy(v);
+            
+            bs.radius() = (bs.center() - v).length();
+        }
+
+    }
+        
     return bs;
 }
 
@@ -431,8 +455,8 @@ unsigned int ProxyLayer::getModifiedCount() const
 }
 
 
-osg::BoundingSphere ProxyLayer::computeBound() const
+osg::BoundingSphere ProxyLayer::computeBound(bool treatAsElevationLayer) const
 {
-    if (_implementation.valid()) return _implementation->computeBound();
+    if (_implementation.valid()) return _implementation->computeBound(treatAsElevationLayer);
 }
 
diff --git a/src/osgTerrain/Terrain.cpp b/src/osgTerrain/Terrain.cpp
index 277aa5e6e..574ef7cfd 100644
--- a/src/osgTerrain/Terrain.cpp
+++ b/src/osgTerrain/Terrain.cpp
@@ -104,14 +104,19 @@ osg::BoundingSphere Terrain::computeBound() const
 {
     osg::BoundingSphere bs;
     
-    if (_elevationLayer.valid()) bs.expandBy(_elevationLayer->computeBound());
-
-    for(Layers::const_iterator itr = _colorLayers.begin();
-        itr != _colorLayers.end();
-        ++itr)
+    if (_elevationLayer.valid())
     {
-        if (itr->layer.valid()) bs.expandBy(itr->layer->computeBound());
+        bs.expandBy(_elevationLayer->computeBound(true));
     }
-
+    else
+    {
+        for(Layers::const_iterator itr = _colorLayers.begin();
+            itr != _colorLayers.end();
+            ++itr)
+        {
+            if (itr->layer.valid()) bs.expandBy(itr->layer->computeBound(false));
+        }
+    }
+    
     return bs;
 }
diff --git a/src/osgWrappers/osgTerrain/Layer.cpp b/src/osgWrappers/osgTerrain/Layer.cpp
index 738629947..888a660e1 100644
--- a/src/osgWrappers/osgTerrain/Layer.cpp
+++ b/src/osgWrappers/osgTerrain/Layer.cpp
@@ -555,9 +555,9 @@ BEGIN_OBJECT_REFLECTOR(osgTerrain::Layer)
 	          __unsigned_int__getModifiedCount,
 	          "Get modified count value. ",
 	          "");
-	I_Method0(osg::BoundingSphere, computeBound,
+	I_Method1(osg::BoundingSphere, computeBound, IN, bool, treatAsElevationLayer,
 	          Properties::VIRTUAL,
-	          __osg_BoundingSphere__computeBound,
+	          __osg_BoundingSphere__computeBound__bool,
 	          "",
 	          "");
 	I_SimpleProperty(const osg::Vec4 &, DefaultValue, 
@@ -693,9 +693,9 @@ BEGIN_OBJECT_REFLECTOR(osgTerrain::ProxyLayer)
 	          __unsigned_int__getModifiedCount,
 	          "Get modified count value. ",
 	          "");
-	I_Method0(osg::BoundingSphere, computeBound,
+	I_Method1(osg::BoundingSphere, computeBound, IN, bool, treatAsElevationLayer,
 	          Properties::VIRTUAL,
-	          __osg_BoundingSphere__computeBound,
+	          __osg_BoundingSphere__computeBound__bool,
 	          "",
 	          "");
 	I_SimpleProperty(const std::string &, FileName,