Provided by: libcoin60-doc_3.1.3-2_all bug

NAME

       SoCullElement -

       The SoCullElement class is used internally for render and pick culling.

       The element holds all planes the geometry should be inside, and keeps a bitflag to signal
       which planes need to be tested.

SYNOPSIS

       #include <Inventor/elements/SoCullElement.h>

       Inherits SoElement.

   Public Member Functions
       virtual void init (SoState *state)
       virtual void push (SoState *state)
       virtual SbBool matches (const SoElement *elt) const
       virtual SoElement * copyMatchInfo (void) const

   Static Public Member Functions
       static void initClass (void)
       static void setViewVolume (SoState *state, const SbViewVolume &vv)
       static void addPlane (SoState *state, const SbPlane &newplane)
       static SbBool cullBox (SoState *state, const SbBox3f &box, const SbBool transform=TRUE)
       static SbBool cullTest (SoState *state, const SbBox3f &box, const SbBool transform=TRUE)
       static SbBool completelyInside (SoState *state)

   Protected Member Functions
       virtual ~SoCullElement ()

Detailed Description

       The SoCullElement class is used internally for render and pick culling.

       The element holds all planes the geometry should be inside, and keeps a bitflag to signal
       which planes need to be tested.

       This element is an extension for Coin, and is not available in the original Open Inventor.

       The maximum number of planes in this element is 32, which should be more than enough,
       since the view frustum is represented by 6 planes, and the maximum number of OpenGL
       clipping planes is typically 6 or 8.

       This element is designed for fast culling, and will not do optimal view frustum culling; a
       box might not be culled even though it is outside the view frustum. The assumption is that
       the view frustum is small compared to the world model. The element simply records all
       planes to be culled against, and the graph is not culled until it is completely outside
       one of the planes.

       SoCullElement is not active for other actions than SoGLRenderAction. It's possible to
       enable it for SoCallbackAction by updating it in a post camera callback though. Do
       something like this:

         static SoCallbackAction::Response
         camera_cb(void * data, SoCallbackAction * action, const SoNode * node)
         {
           SoState * state = action->getState();
           SoCullElement::setViewVolume(state, SoViewVolumeElement::get(state));
           return SoCallbackAction::CONTINUE;
         }

         [...]
         SoCallbackAction cba(myviewport);
         cba.addPostCallback(SoCamera::getClassTypeId(), camera_cb, NULL);

         .fi

       When the view volume is set in SoCullElement in the post camera callback, SoCallbackAction will perform culling on Separators and other nodes in the same way as SoGLRenderAction.

Constructor & Destructor Documentation

   SoCullElement::~SoCullElement () [protected, virtual] The destructor.

Member Function Documentation

   void SoCullElement::initClass (void) [static] Initialize relevant common data for all
       instances, like the type system.
       Reimplemented from SoElement.

   void SoCullElement::setViewVolume (SoState *state, const SbViewVolume &vv) [static] Sets the
       current view volume. In effect, this adds six planes to the list of culling planes. If a
       view volume has already been set, the old view volume planes are overwritten by the new
       ones. The view volume must be in the world coordinate systems.
   void SoCullElement::addPlane (SoState *state, const SbPlane &newplane) [static] Add plane
       geometry must be inside. The plane must be in the world coordinate system.
   SbBool SoCullElement::cullBox (SoState *state, const SbBox3f &box, const SbBooltransform =
       TRUE) [static] Cull against box. If transform is TRUE, the box is assumed to be in object
       space, and will be transformed into world space using the model matrix. Returns TRUE if
       box is outside one of the planes, and updates the element to detect when geometry is
       completely inside all planes.
   SbBool SoCullElement::cullTest (SoState *state, const SbBox3f &box, const SbBooltransform =
       TRUE) [static] Cull against box. If transform is TRUE, the box is assumed to be in object
       space, and will be transformed into world space using the model matrix. Returns TRUE if
       box is outside one of the planes. This method will not update the element state, just
       perform a cull test against active planes.
   SbBool SoCullElement::completelyInside (SoState *state) [static] Returns TRUE if the current
       geometry is completely inside all planes. There is no need to do a cull test if this is
       the case.
   SoElement * SoCullElement::copyMatchInfo (void) const [virtual] This function creates a copy
       of the element that contains enough information to enable the matches() function to work.
       Used to help with scenegraph traversal caching operations.

       Implements SoElement.

Author

       Generated automatically by Doxygen for Coin from the source code.