add PlaneNode::set_clip_effect

panda/src/collide/collisionPolygon.cxx

@@ -613,13 +613,20 @@ test_intersection_from_line(const CollisionEntry &entry) const {
   if (cpa != (ClipPlaneAttrib *)NULL) {
     // We have a clip plane; apply it.
     Points new_points;
-    apply_clip_plane(new_points, cpa, entry.get_into_node_path().get_net_transform());
+    if (apply_clip_plane(new_points, cpa, entry.get_into_node_path().get_net_transform())) {
+      // All points are behind the clip plane.
+      if (!point_is_inside(p, _points)) {
+        return NULL;
+      }
+
+    } else {
       if (new_points.size() < 3) {
         return NULL;
       }
       if (!point_is_inside(p, new_points)) {
         return NULL;
       }
+    }
 
   } else {
     // No clip plane is in effect.  Do the default test.
@@ -682,13 +689,20 @@ test_intersection_from_ray(const CollisionEntry &entry) const {
   if (cpa != (ClipPlaneAttrib *)NULL) {
     // We have a clip plane; apply it.
     Points new_points;
-    apply_clip_plane(new_points, cpa, entry.get_into_node_path().get_net_transform());
+    if (apply_clip_plane(new_points, cpa, entry.get_into_node_path().get_net_transform())) {
+      // All points are behind the clip plane.
+      if (!point_is_inside(p, _points)) {
+        return NULL;
+      }
+
+    } else {
       if (new_points.size() < 3) {
         return NULL;
       }
       if (!point_is_inside(p, new_points)) {
         return NULL;
       }
+    }
 
   } else {
     // No clip plane is in effect.  Do the default test.
@@ -753,13 +767,20 @@ test_intersection_from_segment(const CollisionEntry &entry) const {
   if (cpa != (ClipPlaneAttrib *)NULL) {
     // We have a clip plane; apply it.
     Points new_points;
-    apply_clip_plane(new_points, cpa, entry.get_into_node_path().get_net_transform());
+    if (apply_clip_plane(new_points, cpa, entry.get_into_node_path().get_net_transform())) {
+      // All points are behind the clip plane.
+      if (!point_is_inside(p, _points)) {
+        return NULL;
+      }
+
+    } else {
       if (new_points.size() < 3) {
         return NULL;
       }
       if (!point_is_inside(p, new_points)) {
         return NULL;
       }
+    }
 
   } else {
     // No clip plane is in effect.  Do the default test.
@@ -1165,24 +1186,22 @@ apply_clip_plane(CollisionPolygon::Points &new_points,
   bool all_in = true;
 
   int num_planes = cpa->get_num_on_planes();
-  if (num_planes > 0) {
+  bool first_plane = true;
+
+  for (int i = 0; i < num_planes; i++) {
     NodePath plane_path = cpa->get_on_plane(0);
     PlaneNode *plane_node = DCAST(PlaneNode, plane_path.node());
+    if ((plane_node->get_clip_effect() & PlaneNode::CE_collision) != 0) {
       CPT(TransformState) new_transform = 
         net_transform->invert_compose(plane_path.get_net_transform());
       
       Planef plane = plane_node->get_plane() * new_transform->get_mat();
+      if (first_plane) {
+        first_plane = false;
         if (!clip_polygon(new_points, _points, plane)) {
           all_in = false;
         }
-
-    for (int i = 1; i < num_planes; i++) {
-      NodePath plane_path = cpa->get_on_plane(0);
-      PlaneNode *plane_node = DCAST(PlaneNode, plane_path.node());
-      CPT(TransformState) new_transform = 
-        net_transform->invert_compose(plane_path.get_net_transform());
-      
-      Planef plane = plane_node->get_plane() * new_transform->get_mat();
+      } else {
         Points last_points;
         last_points.swap(new_points);
         if (!clip_polygon(new_points, last_points, plane)) {
@@ -1190,6 +1209,7 @@ apply_clip_plane(CollisionPolygon::Points &new_points,
         }
       }
     }
+  }
 
   if (!all_in) {
     compute_vectors(new_points);

panda/src/display/graphicsStateGuardian.cxx

@@ -1431,7 +1431,8 @@ do_issue_clip_plane() {
   for (int li = 0; li < num_on_planes; li++) {
     NodePath plane = new_attrib->get_on_plane(li);
     nassertv(!plane.is_empty() && plane.node()->is_of_type(PlaneNode::get_class_type()));
-
+    PlaneNode *plane_node = (PlaneNode *)plane.node();
+    if ((plane_node->get_clip_effect() & PlaneNode::CE_visible) != 0) {
       num_enabled++;
 
       // Clipping should be enabled before we apply any planes.
@@ -1505,6 +1506,7 @@ do_issue_clip_plane() {
           << "Failed to bind " << plane << " to id.\n";
       }
     }
+  }
 
   // Disable all unused planes
   for (i = 0; i < cur_max_planes; i++) {

panda/src/pgraph/planeNode.I

@@ -134,6 +134,34 @@ get_priority() const {
   return _priority;
 }
  
+////////////////////////////////////////////////////////////////////
+//     Function: PlaneNode::set_clip_effect
+//       Access: Published
+//  Description: Specifies the sort of things this plane will actually
+//               clip (when it is used as a clip plane).  This is a
+//               bitmask union of ClipEffect values.  If it includes
+//               CE_visible, then it will clip visible geometry; if it
+//               includes CE_collision, then it will clip collision
+//               polygons.  If it includes neither bit, it will still
+//               affect culling, but objects will either be wholly
+//               behind the clipping plane, or wholly present.
+////////////////////////////////////////////////////////////////////
+INLINE void PlaneNode::
+set_clip_effect(int clip_effect) {
+  _clip_effect = clip_effect;
+}
+
+////////////////////////////////////////////////////////////////////
+//     Function: PlaneNode::get_clip_effect
+//       Access: Published
+//  Description: Returns the clip_effect bits for this clip plane.
+//               See set_clip_effect().
+////////////////////////////////////////////////////////////////////
+INLINE int PlaneNode::
+get_clip_effect() const {
+  return _clip_effect;
+}
+
 ////////////////////////////////////////////////////////////////////
 //     Function: PlaneNode::get_sort_seq
 //       Access: Public, Static

panda/src/pgraph/planeNode.cxx

@@ -75,7 +75,8 @@ fillin(DatagramIterator &scan, BamReader *) {
 PlaneNode::
 PlaneNode(const string &name, const Planef &plane) :
   PandaNode(name),
-  _priority(0)
+  _priority(0),
+  _clip_effect(~0)
 {
   set_cull_callback();
 
@@ -94,6 +95,7 @@ PlaneNode::
 PlaneNode(const PlaneNode &copy) :
   PandaNode(copy),
   _priority(copy._priority),
+  _clip_effect(copy._clip_effect),
   _cycler(copy._cycler)
 {
 }
@@ -316,6 +318,7 @@ write_datagram(BamWriter *manager, Datagram &dg) {
   PandaNode::write_datagram(manager, dg);
   manager->write_cdata(dg, _cycler);
   dg.add_int32(_priority);
+  dg.add_uint8(_clip_effect);
 }
 
 ////////////////////////////////////////////////////////////////////
@@ -350,4 +353,10 @@ fillin(DatagramIterator &scan, BamReader *manager) {
   PandaNode::fillin(scan, manager);
   manager->read_cdata(scan, _cycler);
   _priority = scan.get_int32();
+
+  if (manager->get_file_minor_ver() < 9) {
+    _clip_effect = ~0;
+  } else {
+    _clip_effect = scan.get_uint8();
+  }
 }

panda/src/pgraph/planeNode.h

@@ -65,6 +65,13 @@ PUBLISHED:
   INLINE void set_priority(int priority);
   INLINE int get_priority() const;
 
+  enum ClipEffect {
+    CE_visible    = 0x0001,
+    CE_collision  = 0x0002,
+  };
+  INLINE void set_clip_effect(int clip_effect);
+  INLINE int get_clip_effect() const;
+
 public:
   INLINE static UpdateSeq get_sort_seq();
 
@@ -77,6 +84,7 @@ private:
   // so, and cycling it makes it difficult to synchronize with the
   // ClipPlaneAttribs.
   int _priority;
+  int _clip_effect;
   static UpdateSeq _sort_seq;
 
   // This is the data that must be cycled between pipeline stages.

panda/src/putil/bam.h

@@ -36,7 +36,7 @@ static const unsigned short _bam_major_ver = 6;
 // Bumped to major version 5 on 5/6/05 for new Geom implementation.
 // Bumped to major version 6 on 2/11/06 to factor out PandaNode::CData.
 
-static const unsigned short _bam_minor_ver = 8;
+static const unsigned short _bam_minor_ver = 9;
 // Bumped to minor version 1 on 3/12/06 to add Texture::_compression.
 // Bumped to minor version 2 on 3/17/06 to add PandaNode::_draw_control_mask.
 // Bumped to minor version 3 on 3/21/06 to add Texture::_ram_images.
@@ -45,6 +45,7 @@ static const unsigned short _bam_minor_ver = 8;
 // Bumped to minor version 6 on 2/5/07 to change GeomPrimitive::_num_vertices.
 // Bumped to minor version 7 on 2/15/07 to change SliderTable.
 // Bumped to minor version 8 on 5/12/07 to change GeomVertexArrayData::_data.
+// Bumped to minor version 9 on 5/15/07 to add PlaneNode::_clip_effect.
 
 
 #endif