From 77d4705182a3fe89bb6195a3052f9f6836eba853 Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Wed, 6 Sep 2017 16:53:54 +0100
Subject: [PATCH] Added KeyHandler for toggling "SIGNED_DISTANCE_FIELD" and
 "OUTLINE" #pragma(tic) shader defines to control the different shader paths.

Keys to press are 'd' for toggle SIGNED_DISTANCE_FIELD and 'o' for OUTLINE.
---
 examples/osgfont/osgfont.cpp | 57 +++++++++++++++++++++++++++++++++++-
 1 file changed, 56 insertions(+), 1 deletion(-)

diff --git a/examples/osgfont/osgfont.cpp b/examples/osgfont/osgfont.cpp
index 55f893f36..3e70be384 100644
--- a/examples/osgfont/osgfont.cpp
+++ b/examples/osgfont/osgfont.cpp
@@ -182,7 +182,61 @@ osgText::Text* createLabel(const std::string& l, TextSettings& settings, unsigne
     return label;
 }
 
+class KeyHandler : public osgGA::GUIEventHandler
+{
+public:
 
+    KeyHandler() {}
+
+    ~KeyHandler() {}
+
+    bool handle(const osgGA::GUIEventAdapter& ea, osgGA::GUIActionAdapter& aa)
+    {
+        osgViewer::View* view = dynamic_cast<osgViewer::View*>(&aa);
+        if (!view) return false;
+
+#if 1
+        osg::StateSet* stateset = view->getSceneData()->getOrCreateStateSet();
+#else
+        osg::StateSet* stateset = view->getCamera()->getOrCreateStateSet();
+#endif
+        switch(ea.getEventType())
+        {
+            case(osgGA::GUIEventAdapter::KEYUP):
+            {
+                if (ea.getKey()=='d')
+                {
+                    toggleDefine(stateset, "SIGNED_DISTANCE_FIELD");
+                    return true;
+                }
+                else if (ea.getKey()=='o')
+                {
+                    toggleDefine(stateset, "OUTLINE");
+                    return true;
+                }
+                break;
+            }
+            default:
+                break;
+        }
+        return false;
+    }
+
+    void toggleDefine(osg::StateSet* stateset, const std::string& define)
+    {
+        osg::StateSet::DefinePair* dp = stateset->getDefinePair(define);
+        if (dp)
+        {
+            OSG_NOTICE<<"Disabling "<<define<<std::endl;
+            stateset->removeDefine(define);
+        }
+        else
+        {
+            OSG_NOTICE<<"Enabling "<<define<<std::endl;
+            stateset->setDefine(define);
+        }
+    }
+};
 
 
 int main(int argc, char** argv)
@@ -191,9 +245,10 @@ int main(int argc, char** argv)
     osgViewer::Viewer viewer(args);
 
 
-    viewer.addEventHandler( new osgGA::StateSetManipulator(viewer.getCamera()->getOrCreateStateSet()) );
+    viewer.addEventHandler(new osgGA::StateSetManipulator(viewer.getCamera()->getOrCreateStateSet()));
     viewer.addEventHandler(new osgViewer::StatsHandler());
     viewer.addEventHandler(new osgViewer::WindowSizeHandler());
+    viewer.addEventHandler(new KeyHandler());
 
     TextSettings settings;
     settings.backgroundColor = viewer.getCamera()->getClearColor();