NotifyLogger: Shifted the class from flightgear to simgear.

This is to allow the code to be reused in the flightgear test suite.

simgear/debug/CMakeLists.txt

@@ -1,7 +1,7 @@
 
 include (SimGearComponent)
 
-set(HEADERS debug_types.h logstream.hxx BufferedLogCallback.hxx)
+set(HEADERS debug_types.h logstream.hxx BufferedLogCallback.hxx OsgIoCapture.hxx)
 set(SOURCES logstream.cxx BufferedLogCallback.cxx)
 
-simgear_component(debug debug "${SOURCES}" "${HEADERS}")
+simgear_component(debug debug "${SOURCES}" "${HEADERS}")

simgear/debug/OsgIoCapture.hxx

@@ -0,0 +1,45 @@
+#include <cstring>
+
+#include <osg/Notify>
+
+using namespace osg;
+
+
+/**
+ * merge OSG output into our logging system, so it gets recorded to file,
+ * and so we can display a GUI console with renderer issues, especially
+ * shader compilation warnings and errors.
+ */
+class NotifyLogger : public osg::NotifyHandler
+{
+public:
+    // note this callback will be invoked by OSG from multiple threads.
+    // fortunately our Simgear logging implementation already handles
+    // that internally, so we simply pass the message on.
+    virtual void notify(osg::NotifySeverity severity, const char* message) {
+        // Detect whether a osg::Reference derived object is deleted with a non-zero
+        // reference count. In this case trigger a segfault to get a stack trace.
+        if (strstr(message, "the final reference count was")) {
+            // as this is going to segfault ignore the translation of severity and always output the message.
+            SG_LOG(SG_GL, SG_ALERT, message);
+            int* trigger_segfault = 0;
+            *trigger_segfault     = 0;
+            return;
+        }
+        SG_LOG(SG_GL, translateSeverity(severity), message);
+    }
+
+private:
+    sgDebugPriority translateSeverity(osg::NotifySeverity severity) {
+        switch (severity) {
+            case osg::ALWAYS:
+            case osg::FATAL:      return SG_ALERT;
+            case osg::WARN:       return SG_WARN;
+            case osg::NOTICE:
+            case osg::INFO:       return SG_INFO;
+            case osg::DEBUG_FP:
+            case osg::DEBUG_INFO: return SG_DEBUG;
+            default:              return SG_ALERT;
+        }
+    }
+};