From 4b4cd13d310af3c3287cae1c5d2f5b717d74ad98 Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Sat, 23 Jul 2016 16:33:39 +0100
Subject: [PATCH] Implemented lighter weight setting of the
 CurrentVertexArrayState and introduced GlobalVertexArrayState.

---
 include/osg/State            | 15 +++++++++++++--
 include/osg/VertexArrayState |  2 +-
 src/osg/Drawable.cpp         |  8 +-------
 src/osg/State.cpp            |  8 ++++----
 src/osg/VertexArrayState.cpp |  2 ++
 5 files changed, 21 insertions(+), 14 deletions(-)

diff --git a/include/osg/State b/include/osg/State
index ae8bc0cf0..c530562be 100644
--- a/include/osg/State
+++ b/include/osg/State
@@ -500,12 +500,22 @@ class OSG_EXPORT State : public Referenced
         void dirtyAllAttributes();
 
 
+        struct SetCurrentVertexArrayStateProxy
+        {
+            SetCurrentVertexArrayStateProxy(osg::State& state, VertexArrayState* vas):_state(state) { _state.setCurrentVertexArrayState(vas); }
+            ~SetCurrentVertexArrayStateProxy() { _state.setCurrentToGloabalVertexArrayState(); }
+            osg::State& _state;
+        };
+
 
         /** Set the CurrentVetexArrayState object that take which vertex arrays are bound.*/
         void setCurrentVertexArrayState(VertexArrayState* vas) { _currentVertexArrayState = vas; }
 
         /** Get the CurrentVetexArrayState object that take which vertex arrays are bound.*/
-        VertexArrayState* getCurrentVertexArrayState() const { return _currentVertexArrayState.get(); }
+        VertexArrayState* getCurrentVertexArrayState() const { return _currentVertexArrayState; }
+
+        /** Set the getCurrentVertexArrayState to the GloabalVertexArrayState.*/
+        void setCurrentToGloabalVertexArrayState() { _currentVertexArrayState = _globalVertexArrayState.get(); }
 
 
         /** disable the vertex, normal, color, tex coords, secondary color, fog coord and index arrays.*/
@@ -1780,7 +1790,8 @@ class OSG_EXPORT State : public Referenced
         GraphicsContext*            _graphicsContext;
         unsigned int                _contextID;
 
-        osg::ref_ptr<VertexArrayState> _currentVertexArrayState;
+        osg::ref_ptr<VertexArrayState>  _globalVertexArrayState;
+        VertexArrayState*               _currentVertexArrayState;
 
         bool                            _shaderCompositionEnabled;
         bool                            _shaderCompositionDirty;
diff --git a/include/osg/VertexArrayState b/include/osg/VertexArrayState
index 97e35bcd8..093323ee7 100644
--- a/include/osg/VertexArrayState
+++ b/include/osg/VertexArrayState
@@ -153,7 +153,7 @@ public:
 public:
 
 
-        osg::GLBufferObject* getGLBufferObject(osg::Array* array);
+        // osg::GLBufferObject* getGLBufferObject(osg::Array* array);
 
         osg::ref_ptr<osg::GLExtensions> _ext;
 
diff --git a/src/osg/Drawable.cpp b/src/osg/Drawable.cpp
index 41abb15d4..36aac7d73 100644
--- a/src/osg/Drawable.cpp
+++ b/src/osg/Drawable.cpp
@@ -629,18 +629,12 @@ void Drawable::draw(RenderInfo& renderInfo) const
             _vertexArrayStateList[contextID] = vas = setUpVertexArrayState(renderInfo, true);
         }
 
-        //state.pushVAO(localVAO);
-        osg::ref_ptr<VertexArrayState> previous_vas = state.getCurrentVertexArrayState();
-
-        state.setCurrentVertexArrayState(vas);
+        State::SetCurrentVertexArrayStateProxy setVASProxy(state, vas);
 
         vas->bindVertexArrayObject();
 
         drawInner(renderInfo);
 
-        // state.popVAO();
-        state.setCurrentVertexArrayState(previous_vas);
-
         return;
     }
 #endif
diff --git a/src/osg/State.cpp b/src/osg/State.cpp
index b625cee99..8fcaa8764 100644
--- a/src/osg/State.cpp
+++ b/src/osg/State.cpp
@@ -140,8 +140,7 @@ State::State():
     _gpuTimestamp = 0;
     _timestampBits = 0;
 
-
-
+    _currentVertexArrayState = 0;
 }
 
 State::~State()
@@ -986,8 +985,9 @@ void State::initializeExtensionProcs()
     GLExtensions::Set(_contextID, _glExtensions.get());
 
 #ifdef USE_VERTEXARRAYSTATE
-    _currentVertexArrayState = new VertexArrayState(_glExtensions.get());
-    _currentVertexArrayState->assignAllDispatchers();
+    _globalVertexArrayState = new VertexArrayState(_glExtensions.get());
+    _globalVertexArrayState->assignAllDispatchers();
+    setCurrentToGloabalVertexArrayState();
 #endif
 
     setGLExtensionFuncPtr(_glClientActiveTexture,"glClientActiveTexture","glClientActiveTextureARB");
diff --git a/src/osg/VertexArrayState.cpp b/src/osg/VertexArrayState.cpp
index eae4109cb..52cf3be1d 100644
--- a/src/osg/VertexArrayState.cpp
+++ b/src/osg/VertexArrayState.cpp
@@ -345,6 +345,7 @@ VertexArrayState::VertexArrayState(osg::GLExtensions* ext):
 {
 }
 
+#if 0
 osg::GLBufferObject* VertexArrayState::getGLBufferObject(osg::Array* array)
 {
     if (_ext->isBufferObjectSupported && array->getBufferObject())
@@ -356,6 +357,7 @@ osg::GLBufferObject* VertexArrayState::getGLBufferObject(osg::Array* array)
         return 0;
     }
 }
+#endif
 
 void VertexArrayState::generateVretexArrayObject()
 {