Further work on PlaneIntersector

2006-11-29 14:21:59 +00:00
parent 35cb04437d
commit ab7d1ecc42
6 changed files with 314 additions and 168 deletions
--- a/src/osgUtil/PlaneIntersector.cpp
+++ b/src/osgUtil/PlaneIntersector.cpp
@@ -21,6 +21,127 @@

 using namespace osgUtil;

+namespace PlaneIntersectorUtils
+{
+
+    struct TriangleIntersection
+    {
+        osg::Vec3d v[2];
+    };
+
+    typedef std::list<TriangleIntersection> TriangleIntersections;
+
+    struct TriangleIntersector
+    {
+
+        osg::Plane _plane;
+        osg::Polytope _polytope;
+        bool _hit;
+
+        TriangleIntersections _intersections;
+
+        TriangleIntersector()
+        {
+            _hit = false;
+        }
+
+        void set(const osg::Plane& plane, const osg::Polytope& polytope)
+        {
+            _plane = plane;
+            _polytope = polytope;
+            _hit = false;
+        }
+
+        inline void operator () (const osg::Vec3& v1,const osg::Vec3& v2,const osg::Vec3& v3, bool)
+        {
+        
+            double d1 = _plane.distance(v1);
+            double d2 = _plane.distance(v2);
+            double d3 = _plane.distance(v3);
+            
+            unsigned int numBelow = 0;
+            unsigned int numAbove = 0;
+            unsigned int numOnPlane = 0;
+            if (d1<0) ++numBelow;
+            else if (d1>0) ++numAbove;
+            else ++numOnPlane;
+        
+            if (d2<0) ++numBelow;
+            else if (d2>0) ++numAbove;
+            else ++numOnPlane;
+        
+            if (d3<0) ++numBelow;
+            else if (d3>0) ++numAbove;
+            else ++numOnPlane;
+            
+            // trivially discard triangles that are completely one side of the plane
+            if (numAbove==3 || numBelow==3) return;
+            
+            _hit = true;
+
+            if (numOnPlane==3)
+            {
+                // triangle lives wholy in the plane
+                osg::notify(osg::NOTICE)<<"3"<<std::endl;
+                return;
+            }
+
+            if (numOnPlane==2)
+            {
+                // one edge lives wholy in the plane
+                osg::notify(osg::NOTICE)<<"2"<<std::endl;
+                return;
+            }
+
+            if (numOnPlane==1)
+            {
+                // one point lives wholy in the plane
+                osg::notify(osg::NOTICE)<<"1"<<std::endl;
+                return;
+            }
+
+            TriangleIntersection ti;
+            unsigned int numIntersects = 0;
+
+            if (d1*d2 < 0.0)
+            {
+                // edge 12 itersects
+                double div = 1.0 / (d2-d1);
+                ti.v[numIntersects++] = v1* (d2*div) - v2 * (d1*div);
+            }
+
+            if (d2*d3 < 0.0)
+            {
+                // edge 23 itersects
+                double div = 1.0 / (d3-d2);
+                ti.v[numIntersects++] = v2* (d3*div) - v3 * (d2*div);
+            }
+
+            if (d1*d3 < 0.0)
+            {
+                if (numIntersects<2)
+                {
+                    // edge 13 itersects
+                    double div = 1.0 / (d3-d1);
+                    ti.v[numIntersects++] = v1* (d3*div) - v3 * (d1*div);
+                }
+                else
+                {
+                    osg::notify(osg::NOTICE)<<"!!! too many intersecting edges found !!!"<<std::endl;
+                }
+                 
+            }
+
+            osg::notify(osg::NOTICE)<<"ti.v1="<<ti.v[0]<<" ti.v2="<<ti.v[1]<<std::endl;
+            
+            _intersections.push_back(ti);
+
+        }
+
+    };
+
+}
+

 ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 //
@@ -101,18 +222,32 @@ void PlaneIntersector::leave()

 void PlaneIntersector::intersect(osgUtil::IntersectionVisitor& iv, osg::Drawable* drawable)
 {
-    osg::notify(osg::NOTICE)<<"PlaneIntersector::intersect(osgUtil::IntersectionVisitor& iv, osg::Drawable* drawable)"<<std::endl;
+    // osg::notify(osg::NOTICE)<<"PlaneIntersector::intersect(osgUtil::IntersectionVisitor& iv, osg::Drawable* drawable)"<<std::endl;

-    if ( !_plane.intersect( drawable->getBound() ) ) return;
+    if ( _plane.intersect( drawable->getBound() )!=0 ) return;
    if ( !_polytope.contains( drawable->getBound() ) ) return;

-    osg::notify(osg::NOTICE)<<"Succed PlaneIntersector::intersect(osgUtil::IntersectionVisitor& iv, osg::Drawable* drawable)"<<std::endl;
+    // osg::notify(osg::NOTICE)<<"Succed PlaneIntersector::intersect(osgUtil::IntersectionVisitor& iv, osg::Drawable* drawable)"<<std::endl;
+
+    osg::TriangleFunctor<PlaneIntersectorUtils::TriangleIntersector> ti;
+    ti.set(_plane,_polytope);
+    drawable->accept(ti);
+
+    if (ti._hit)
+    {
+        Intersection hit;
+        hit.nodePath = iv.getNodePath();
+        hit.drawable = drawable;
+
+        insertIntersection(hit);
+
+        osg::notify(osg::NOTICE)<<std::endl<<"++++++++++++ Found intersections +++++++++++++++++++++++++"<<std::endl<<std::endl;
+    }
+    else
+    {
+        osg::notify(osg::NOTICE)<<std::endl<<"------------ No intersections -------------------------"<<std::endl<<std::endl;
+    }

-    Intersection hit;
-    hit.nodePath = iv.getNodePath();
-    hit.drawable = drawable;
-    
-    insertIntersection(hit);
 }