From ffbc1167de4d3761a4c7574add76db50e3098901 Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Mon, 13 Mar 2017 11:44:34 +0000
Subject: [PATCH] Added lazy state updating for vertex array object
 binding/unbinding

---
 include/osg/State               | 14 +++++++++++++-
 include/osg/VertexArrayState    |  4 ----
 src/osg/Drawable.cpp            |  8 ++++++--
 src/osg/Geometry.cpp            |  4 +++-
 src/osg/State.cpp               |  1 +
 src/osgTerrain/GeometryPool.cpp |  4 +++-
 6 files changed, 26 insertions(+), 9 deletions(-)

diff --git a/include/osg/State b/include/osg/State
index 4560bccf6..b79420dfd 100644
--- a/include/osg/State
+++ b/include/osg/State
@@ -563,7 +563,7 @@ class OSG_EXPORT State : public Referenced
 
 
         void setCurrentPixelBufferObject(osg::GLBufferObject* pbo) { _currentPBO = pbo; }
-        const GLBufferObject* getCurrentPixelBufferObject() { return _currentPBO; }
+        const GLBufferObject* getCurrentPixelBufferObject() const { return _currentPBO; }
 
         inline void bindPixelBufferObject(osg::GLBufferObject* pbo)
         {
@@ -590,6 +590,17 @@ class OSG_EXPORT State : public Referenced
             _currentPBO = 0;
         }
 
+
+        void setCurrentVertexArrayObject(GLuint vao) { _currentVAO = vao; }
+        GLuint getCurrentVertexArrayObject() const { return _currentVAO; }
+
+        inline void bindVertexArrayObject(const VertexArrayState* vas) { bindVertexArrayObject(vas->getVertexArrayObject()); }
+
+        inline void bindVertexArrayObject(GLuint vao) { if (_currentVAO!=vao) { _glExtensions->glBindVertexArray(vao); _currentVAO = vao; } }
+
+        inline void unbindVertexArrayObject() { if (_currentVAO!=0) { _glExtensions->glBindVertexArray(0); _currentVAO = 0; } }
+
+
         typedef std::vector<GLushort> IndicesGLushort;
         IndicesGLushort _quadIndicesGLushort[4];
 
@@ -1248,6 +1259,7 @@ class OSG_EXPORT State : public Referenced
         unsigned int                    _currentActiveTextureUnit;
         unsigned int                    _currentClientActiveTextureUnit;
         GLBufferObject*                 _currentPBO;
+        GLuint                          _currentVAO;
 
 
         inline ModeMap& getOrCreateTextureModeMap(unsigned int unit)
diff --git a/include/osg/VertexArrayState b/include/osg/VertexArrayState
index d7f99c269..cfd8dae86 100644
--- a/include/osg/VertexArrayState
+++ b/include/osg/VertexArrayState
@@ -164,10 +164,6 @@ public:
 
         void deleteVertexArrayObject();
 
-        inline void bindVertexArrayObject() const { _ext->glBindVertexArray (_vertexArrayObject); }
-
-        inline void unbindVertexArrayObject() const { _ext->glBindVertexArray (0); }
-
         GLuint getVertexArrayObject() const { return _vertexArrayObject; }
 
 
diff --git a/src/osg/Drawable.cpp b/src/osg/Drawable.cpp
index 3f8d381ae..857e4546d 100644
--- a/src/osg/Drawable.cpp
+++ b/src/osg/Drawable.cpp
@@ -642,7 +642,7 @@ void Drawable::draw(RenderInfo& renderInfo) const
 
         State::SetCurrentVertexArrayStateProxy setVASProxy(state, vas);
 
-        vas->bindVertexArrayObject();
+        state.bindVertexArrayObject(vas);
 
         drawInner(renderInfo);
 
@@ -652,7 +652,11 @@ void Drawable::draw(RenderInfo& renderInfo) const
     }
 
     // TODO, add check against whether VAO is active and supported
-    if (state.getCurrentVertexArrayState()) state.getCurrentVertexArrayState()->bindVertexArrayObject();
+    if (state.getCurrentVertexArrayState())
+    {
+        //OSG_NOTICE<<"state.getCurrentVertexArrayState()->getVertexArrayObject()="<< state.getCurrentVertexArrayState()->getVertexArrayObject()<<std::endl;
+        state.bindVertexArrayObject(state.getCurrentVertexArrayState());
+    }
 
 
 #ifdef OSG_GL_DISPLAYLISTS_AVAILABLE
diff --git a/src/osg/Geometry.cpp b/src/osg/Geometry.cpp
index 60cfc5b8b..715375ed0 100644
--- a/src/osg/Geometry.cpp
+++ b/src/osg/Geometry.cpp
@@ -820,9 +820,11 @@ void Geometry::compileGLObjects(RenderInfo& renderInfo) const
 
             State::SetCurrentVertexArrayStateProxy setVASProxy(state, vas);
 
-            vas->bindVertexArrayObject();
+            state.bindVertexArrayObject(vas);
 
             drawVertexArraysImplementation(renderInfo);
+
+            state.unbindVertexArrayObject();
         }
     }
     else
diff --git a/src/osg/State.cpp b/src/osg/State.cpp
index 3162d6561..43eed6cb6 100644
--- a/src/osg/State.cpp
+++ b/src/osg/State.cpp
@@ -89,6 +89,7 @@ State::State():
     _currentClientActiveTextureUnit=0;
 
     _currentPBO = 0;
+    _currentVAO = 0;
 
     _isSecondaryColorSupported = false;
     _isFogCoordSupported = false;
diff --git a/src/osgTerrain/GeometryPool.cpp b/src/osgTerrain/GeometryPool.cpp
index 905d156aa..c7fb3c5f8 100644
--- a/src/osgTerrain/GeometryPool.cpp
+++ b/src/osgTerrain/GeometryPool.cpp
@@ -861,10 +861,12 @@ void SharedGeometry::compileGLObjects(osg::RenderInfo& renderInfo) const
 
             osg::State::SetCurrentVertexArrayStateProxy setVASProxy(state, vas);
 
-            vas->bindVertexArrayObject();
+            state.bindVertexArrayObject(vas);
 
             if (vbo_glBufferObject) vas->bindVertexBufferObject(vbo_glBufferObject);
             if (ebo_glBufferObject) vas->bindElementBufferObject(ebo_glBufferObject);
+
+            state.unbindVertexArrayObject();
         }
 
     }