From e4e95a1d6069030bb3cc68804866001afbe5d2a2 Mon Sep 17 00:00:00 2001
From: Robert Osfield <robert@openscenegraph.com>
Date: Thu, 12 Jan 2006 22:43:36 +0000
Subject: [PATCH] Added support for tracking mouse movement and computing the
 intersection of the mouse position into texture coords.

---
 examples/osgmovie/osgmovie.cpp | 101 ++++++++++++++++++++++++++++++---
 1 file changed, 94 insertions(+), 7 deletions(-)

diff --git a/examples/osgmovie/osgmovie.cpp b/examples/osgmovie/osgmovie.cpp
index f603422bb..ad81b731e 100644
--- a/examples/osgmovie/osgmovie.cpp
+++ b/examples/osgmovie/osgmovie.cpp
@@ -13,8 +13,10 @@
 #include <osg/TexMat>
 #include <osg/CullFace>
 #include <osg/ImageStream>
+#include <osg/io_utils>
 
 #include <osgGA/TrackballManipulator>
+#include <osgGA/EventVisitor>
 
 osg::ImageStream* s_imageStream = 0;
 class PostSwapFinishCallback : public Producer::Camera::Callback
@@ -46,7 +48,7 @@ public:
 
     virtual void accept(osgGA::GUIEventHandlerVisitor& v) { v.visit(*this); }
 
-    virtual bool handle(const osgGA::GUIEventAdapter& ea,osgGA::GUIActionAdapter&);
+    virtual bool handle(const osgGA::GUIEventAdapter& ea,osgGA::GUIActionAdapter& aa, osg::Object*, osg::NodeVisitor* nv);
     
     virtual void getUsage(osg::ApplicationUsage& usage) const;
 
@@ -125,10 +127,95 @@ void MovieEventHandler::set(osg::Node* node)
 }
 
 
-bool MovieEventHandler::handle(const osgGA::GUIEventAdapter& ea,osgGA::GUIActionAdapter&)
+bool MovieEventHandler::handle(const osgGA::GUIEventAdapter& ea,osgGA::GUIActionAdapter& aa, osg::Object*, osg::NodeVisitor* nv)
 {
     switch(ea.getEventType())
     {
+        case(osgGA::GUIEventAdapter::MOVE):
+        case(osgGA::GUIEventAdapter::PUSH):
+        case(osgGA::GUIEventAdapter::RELEASE):
+        {
+            osgProducer::Viewer* viewer = dynamic_cast<osgProducer::Viewer*>(&aa);
+            osgUtil::IntersectVisitor::HitList hlist;
+            if (viewer->computeIntersections(ea.getX(),ea.getY(), nv->getNodePath().back(), hlist))
+            {
+                if (!hlist.empty())
+                {
+                    // use the nearest intersection                 
+                    osgUtil::Hit& hit = hlist.front();
+                    osg::Drawable* drawable = hit.getDrawable();
+                    osg::Geometry* geometry = drawable ? drawable->asGeometry() : 0;
+                    osg::Vec3Array* vertices = geometry ? dynamic_cast<osg::Vec3Array*>(geometry->getVertexArray()) : 0;
+
+                    if (vertices)
+                    {
+                        // get the vertex indices.
+                        const osgUtil::Hit::VecIndexList& vil = hit.getVecIndexList();
+                        
+                        if (vil.size()==3)
+                        {
+
+                            int i1 = vil[0];
+                            int i2 = vil[1];
+                            int i3 = vil[2];
+                            osg::Vec3 v1 = (*vertices)[i1];
+                            osg::Vec3 v2 = (*vertices)[i2];
+                            osg::Vec3 v3 = (*vertices)[i3];
+                            osg::Vec3 v = hit.getLocalIntersectPoint();
+                            osg::Vec3 p1 = hit.getLocalLineSegment()->start();
+                            osg::Vec3 p2 = hit.getLocalLineSegment()->end();
+                            
+                            osg::Vec3 p12 = p1-p2;
+                            osg::Vec3 v13 = v1-v3;
+                            osg::Vec3 v23 = v2-v3;
+                            osg::Vec3 p1v3 = p1-v3;
+                            
+                            osg::Matrix matrix(p12.x(), v13.x(), v23.x(), 0.0,
+                                               p12.y(), v13.y(), v23.y(), 0.0,
+                                               p12.z(), v13.z(), v23.z(), 0.0,
+                                               0.0,    0.0,    0.0,    1.0);
+                                               
+                            osg::Matrix inverse;
+                            inverse.invert(matrix);
+                            
+                            osg::Vec3 ratio = inverse*p1v3;
+
+                            // extract the baricentric coordinates.                            
+                            float r1 = ratio.y();
+                            float r2 = ratio.z();
+                            float r3 = 1.0f-r1-r2;
+
+                            osg::Array* texcoords = (geometry->getNumTexCoordArrays()>0) ? geometry->getTexCoordArray(0) : 0;
+                            osg::Vec2Array* texcoords_Vec2Array = dynamic_cast<osg::Vec2Array*>(texcoords);
+                            if (texcoords_Vec2Array)
+                            {
+                                // we have tex coord array so now we can compute the final tex coord at the point of intersection.                                
+                                osg::Vec2 tc1 = (*texcoords_Vec2Array)[i1];
+                                osg::Vec2 tc2 = (*texcoords_Vec2Array)[i2];
+                                osg::Vec2 tc3 = (*texcoords_Vec2Array)[i3];
+                                osg::Vec2 tc = tc1*r1 + tc2*r2 + tc3*r3;
+                                
+                                osg::notify(osg::NOTICE)<<"We hit tex coords "<<tc<<std::endl;
+                                
+                            }
+                            
+                            
+                        }
+                        else
+                        {
+                            osg::notify(osg::NOTICE)<<"Hit but insufficient indices to work with";
+                        }
+    
+                    }
+
+                } 
+            }
+            else
+            {
+                osg::notify(osg::NOTICE)<<"No hit"<<std::endl;
+            }
+            break;
+        }
         case(osgGA::GUIEventAdapter::KEYDOWN):
         {
             if (ea.getKey()=='s')
@@ -190,6 +277,7 @@ bool MovieEventHandler::handle(const osgGA::GUIEventAdapter& ea,osgGA::GUIAction
         default:
             return false;
     }
+    return false;
 }
 
 void MovieEventHandler::getUsage(osg::ApplicationUsage& usage) const
@@ -257,11 +345,6 @@ int main(int argc, char** argv)
     // set up the value with sensible default event handlers.
     viewer.setUpViewer(osgProducer::Viewer::STANDARD_SETTINGS);
 
-    // register the handler to add keyboard and mosue handling.
-    MovieEventHandler* meh = new MovieEventHandler();
-    viewer.getEventHandlerList().push_front(meh);
-
-
     // get details on keyboard and mouse bindings used by the viewer.
     viewer.getUsage(*arguments.getApplicationUsage());
 
@@ -343,8 +426,12 @@ int main(int argc, char** argv)
         // nothing loaded.
         return 1;
     }
+    
+    
 
     // pass the model to the MovieEventHandler so it can pick out ImageStream's to manipulate.
+    MovieEventHandler* meh = new MovieEventHandler();
+    geode->setEventCallback(meh);
     meh->set(geode.get());
 
     // report any errors if they have occured when parsing the program aguments.