Added support for setting the maximum number of graphics contexts that the

OSG has to maintian.

src/osg/DisplaySettings.cpp

@@ -3,9 +3,28 @@
 #include <algorithm>
 
 using namespace osg;
-
 using namespace std;
 
+class DisplaySettingsPtr
+{
+    public:
+        DisplaySettingsPtr() : _ptr(0L) {}
+        DisplaySettingsPtr(DisplaySettings* t): _ptr(t) {}
+        DisplaySettingsPtr(const DisplaySettingsPtr& rp):_ptr(rp._ptr) { }
+        ~DisplaySettingsPtr() { if (_ptr) delete _ptr; _ptr=0L; }
+
+        inline DisplaySettings* get() { return _ptr; }
+
+        DisplaySettings* _ptr;
+};
+
+DisplaySettings* DisplaySettings::instance()
+{
+    static DisplaySettingsPtr s_displaySettings = new DisplaySettings;
+    return s_displaySettings.get();
+}
+
+
 DisplaySettings::DisplaySettings(const DisplaySettings& vs):Referenced()
 {
     copy(vs);
@@ -15,7 +34,8 @@ DisplaySettings::~DisplaySettings()
 {
 }
 
-DisplaySettings& DisplaySettings::operator = (const DisplaySettings& vs)
+ 
+ DisplaySettings& DisplaySettings::operator = (const DisplaySettings& vs)
 {
     if (this==&vs) return *this;
     copy(vs);
@@ -34,6 +54,8 @@ void DisplaySettings::copy(const DisplaySettings& vs)
     _depthBuffer = vs._depthBuffer;
     _minimumNumberAlphaBits = vs._minimumNumberAlphaBits;
     _minimumNumberStencilBits = vs._minimumNumberStencilBits;
+
+    _maxNumOfGraphicsContexts = vs._maxNumOfGraphicsContexts;
 }
 
 void DisplaySettings::merge(const DisplaySettings& vs)
@@ -63,6 +85,12 @@ void DisplaySettings::setDefaults()
     _depthBuffer = true;
     _minimumNumberAlphaBits = 0;
     _minimumNumberStencilBits = 0;
+    
+    #ifdef __sgi
+    _maxNumOfGraphicsContexts = 4;
+    #else
+    _maxNumOfGraphicsContexts = 1;
+    #endif
 }
 
 void DisplaySettings::readEnvironmentalVariables()
@@ -118,6 +146,11 @@ void DisplaySettings::readEnvironmentalVariables()
     {
         _screenHeight = atof(ptr);
     }
+
+    if( (ptr = getenv("OSG_MAX_NUMBER_OF_GRAPHICS_CONTEXTS")) != 0)
+    {
+        _maxNumOfGraphicsContexts = atof(ptr);
+    }
 }
 
 void DisplaySettings::readCommandLine(std::vector<std::string>& commandLine)

src/osg/Drawable.cpp

@@ -15,6 +15,8 @@ Drawable::DeletedDisplayListCache Drawable::s_deletedDisplayListCache;
 
 Drawable::Drawable()
 {
+    _globjList.resize(DisplaySettings::instance()->getMaxNumberOfGraphicsContexts(),0);
+
     _bbox_computed = false;
 
     // Note, if your are defining a subclass from drawable which is

src/osg/Texture.cpp

@@ -18,6 +18,9 @@ Texture::DeletedTextureObjectCache Texture::s_deletedTextureObjectCache;
 
 Texture::Texture()
 {
+    _handleList.resize(DisplaySettings::instance()->getMaxNumberOfGraphicsContexts(),0);
+    _modifiedTag.resize(DisplaySettings::instance()->getMaxNumberOfGraphicsContexts(),0);
+
     _textureUnit = 0;
 
     _wrap_s    = CLAMP;
@@ -189,12 +192,10 @@ void Texture::apply(State& state) const
         }
         else  if (_image.valid() && _image->data())
         {
-            // pad out the modified tag list, if required.
-            while (_modifiedTag.size() <= contextID)
-                _modifiedTag.push_back(0);
+            uint& modifiedTag = getModifiedTag(contextID);
 
             if (_subloadMode == AUTO ||
-                (_subloadMode == IF_DIRTY && _modifiedTag[contextID] != _image->getModifiedTag()))
+                (_subloadMode == IF_DIRTY && modifiedTag != _image->getModifiedTag()))
             {
                 glBindTexture( GL_TEXTURE_2D, handle );
                 glTexSubImage2D(GL_TEXTURE_2D, 0,
@@ -203,7 +204,7 @@ void Texture::apply(State& state) const
                                 (GLenum) _image->pixelFormat(), (GLenum) _image->dataType(),
                                 _image->data());
                 // update the modified flag to show that the image has been loaded.
-                _modifiedTag[contextID] = _image->getModifiedTag();
+                modifiedTag = _image->getModifiedTag();
             }
         }
     }
@@ -240,12 +241,8 @@ void Texture::applyImmediateMode(State& state) const
     // current OpenGL context.
     const uint contextID = state.getContextID();
 
-    // pad out the modified tag list, if required.
-    while (_modifiedTag.size() <= contextID)
-        _modifiedTag.push_back(0);
-
     // update the modified tag to show that it is upto date.
-    _modifiedTag[contextID] = _image->getModifiedTag();
+    getModifiedTag(contextID) = _image->getModifiedTag();
 
 
     if (_subloadMode == OFF)

src/osgDB/Registry.cpp

@@ -32,6 +32,13 @@ class RegistryPtr
         Registry* _ptr;
 };
 
+Registry* Registry::instance()
+{
+    static RegistryPtr s_nodeFactory = new Registry;
+    return s_nodeFactory.get();
+}
+
+
 // definition of the Registry
 Registry::Registry()
 {
@@ -63,11 +70,6 @@ Registry::~Registry()
 }
 
 
-Registry* Registry::instance()
-{
-    static RegistryPtr s_nodeFactory = new Registry;
-    return s_nodeFactory.get();
-}
 
 void Registry::readCommandLine(std::vector<std::string>& commandLine)
 {