Added perlimnary support for reading the DISPLAY variable.

src/osg/GraphicsContext.cpp

@@ -59,6 +59,18 @@ GraphicsContext* GraphicsContext::createGraphicsContext(Traits* traits)
         return 0;    
 }
 
+GraphicsContext::ScreenIdentifier::ScreenIdentifier():
+    displayNum(0),
+    screenNum(0) {}
+
+GraphicsContext::ScreenIdentifier::ScreenIdentifier(int in_screenNum):
+    displayNum(0),
+    screenNum(in_screenNum) {}
+
+GraphicsContext::ScreenIdentifier::ScreenIdentifier(const std::string& in_hostName,int in_displayNum, int in_screenNum):
+    hostName(in_hostName),
+    displayNum(in_displayNum),
+    screenNum(in_screenNum) {}
 
 std::string GraphicsContext::ScreenIdentifier::displayName() const
 {
@@ -67,6 +79,60 @@ std::string GraphicsContext::ScreenIdentifier::displayName() const
     return ostr.str();
 }
 
+void GraphicsContext::ScreenIdentifier::readDISPLAY()
+{
+    const char* ptr = 0;
+    if ((ptr=getenv("DISPLAY")) != 0)
+    {
+        setScreenIdentifier(ptr);
+    }
+}
+
+void GraphicsContext::ScreenIdentifier::setScreenIdentifier(const std::string& displayName)
+{
+    std::string::size_type colon = displayName.find_last_of(':');
+    std::string::size_type point = displayName.find_last_of('.');
+    
+    if (point!=std::string::npos && 
+        colon==std::string::npos && 
+        point < colon) point = std::string::npos;
+
+    if (colon==std::string::npos)
+    {
+        hostName = "";
+    }
+    else
+    {
+        hostName = displayName.substr(0,colon);
+    }
+    
+    std::string::size_type startOfDisplayNum = (colon==std::string::npos) ? 0 : colon+1;
+    std::string::size_type endOfDisplayNum = (point==std::string::npos) ?  displayName.size() : point;
+
+    if (startOfDisplayNum<endOfDisplayNum)
+    {
+        displayNum = atoi(displayName.substr(startOfDisplayNum,endOfDisplayNum-startOfDisplayNum).c_str());
+    }
+    else
+    {
+        displayNum = -1;
+    }
+
+    if (point!=std::string::npos && point+1<displayName.size())
+    {
+        screenNum = atoi(displayName.substr(point+1,displayName.size()-point-1).c_str());
+    }
+    else
+    {
+        screenNum = -1;
+    }
+
+#if 0    
+    osg::notify(osg::NOTICE)<<"   hostName ["<<hostName<<"]"<<std::endl;
+    osg::notify(osg::NOTICE)<<"   displayNum "<<displayNum<<std::endl;
+    osg::notify(osg::NOTICE)<<"   screenNum "<<screenNum<<std::endl;
+#endif
+}
 
 class ContextData
 {

src/osgViewer/View.cpp

@@ -266,13 +266,24 @@ void View::setUpViewAcrossAllScreens()
     double fovy, aspectRatio, zNear, zFar;        
     _camera->getProjectionMatrixAsPerspective(fovy, aspectRatio, zNear, zFar);
 
-    unsigned int numScreens = wsi->getNumScreens();
+    osg::GraphicsContext::ScreenIdentifier si;
+    si.readDISPLAY();
+    
+    // displayNum has not been set so reset it to 0.
+    if (si.displayNum<0) si.displayNum = 0;
+    
+    unsigned int numScreens = wsi->getNumScreens(si);
     if (numScreens==1)
     {
+        if (si.screenNum<0) si.screenNum = 0;
+    
         unsigned int width, height;
-        wsi->getScreenResolution(osg::GraphicsContext::ScreenIdentifier(0), width, height);
+        wsi->getScreenResolution(si, width, height);
 
         osg::ref_ptr<osg::GraphicsContext::Traits> traits = new osg::GraphicsContext::Traits;
+        traits->hostName = si.hostName;
+        traits->displayNum = si.displayNum;
+        traits->screenNum = si.screenNum;
         traits->x = 0;
         traits->y = 0;
         traits->width = width;
@@ -336,10 +347,15 @@ void View::setUpViewAcrossAllScreens()
     
         for(unsigned int i=0; i<numScreens; ++i)
         {
+            si.screenNum = i;
+        
             unsigned int width, height;
-            wsi->getScreenResolution(osg::GraphicsContext::ScreenIdentifier(i), width, height);
+            wsi->getScreenResolution(si, width, height);
 
             osg::ref_ptr<osg::GraphicsContext::Traits> traits = new osg::GraphicsContext::Traits;
+            traits->hostName = si.hostName;
+            traits->displayNum = si.displayNum;
+            traits->screenNum = si.screenNum;
             traits->screenNum = i;
             traits->x = 0;
             traits->y = 0;
@@ -410,6 +426,10 @@ void View::setUpViewInWindow(int x, int y, int width, int height, unsigned int s
     osg::DisplaySettings* ds = _displaySettings.valid() ? _displaySettings.get() : osg::DisplaySettings::instance();
 
     osg::ref_ptr<osg::GraphicsContext::Traits> traits = new osg::GraphicsContext::Traits;
+
+    traits->readDISPLAY();
+    if (traits->displayNum<0) traits->displayNum = 0;
+    
     traits->screenNum = screenNum;
     traits->x = x;
     traits->y = y;
@@ -471,11 +491,21 @@ void View::setUpViewOnSingleScreen(unsigned int screenNum)
 
     osg::DisplaySettings* ds = _displaySettings.valid() ? _displaySettings.get() : osg::DisplaySettings::instance();
 
+    osg::GraphicsContext::ScreenIdentifier si;
+    si.readDISPLAY();
+    
+    // displayNum has not been set so reset it to 0.
+    if (si.displayNum<0) si.displayNum = 0;
+
+    si.screenNum = screenNum;
+
     unsigned int width, height;
-    wsi->getScreenResolution(osg::GraphicsContext::ScreenIdentifier(screenNum), width, height);
+    wsi->getScreenResolution(si, width, height);
 
     osg::ref_ptr<osg::GraphicsContext::Traits> traits = new osg::GraphicsContext::Traits;
-    traits->screenNum = screenNum;
+    traits->hostName = si.hostName;
+    traits->displayNum = si.displayNum;
+    traits->screenNum = si.screenNum;
     traits->x = 0;
     traits->y = 0;
     traits->width = width;