SoBoundingBoxCache(3) Coin SoBoundingBoxCache(3)NAME
SoBoundingBoxCache -
The SoBoundingBoxCache class is used to cache bounding boxes.
SYNOPSIS
#include <Inventor/caches/SoBoundingBoxCache.h>
Inherits SoCache.
Public Member Functions
SoBoundingBoxCache (SoState *state)
virtual ~SoBoundingBoxCache ()
void set (const SbXfBox3f &boundingbox, SbBool centerset, const SbVec3f ¢erpoint)
const SbXfBox3f & getBox () const
const SbBox3f & getProjectedBox () const
SbBool isCenterSet () const
const SbVec3f & getCenter () const
SbBool hasLinesOrPoints (void) const
Static Public Member Functions
static void setHasLinesOrPoints (SoState *state)
Additional Inherited Members
Detailed Description
The SoBoundingBoxCache class is used to cache bounding boxes.
Constructor &; Destructor Documentation
SoBoundingBoxCache::SoBoundingBoxCache (SoState *state)
Constructor with state being the current state.
SoBoundingBoxCache::~SoBoundingBoxCache () [virtual]
Destructor.
Member Function Documentation
void SoBoundingBoxCache::set (const SbXfBox3f &boundingbox, SbBoolcenterset, const SbVec3f ¢erpoint)
Sets the data for this cache. boundingBox is the node's bounding box, centerSet and centerPoints specifies the center of the geometry
inside boundingBox.
const SbXfBox3f & SoBoundingBoxCache::getBox (void) const
Returns the bounding box for this cache.
const SbBox3f & SoBoundingBoxCache::getProjectedBox (void) const
Returns the projected bounding box for this cache.
SbBool SoBoundingBoxCache::isCenterSet (void) const
Returns whether the center of the bounding box was set in the SoBoundingBoxCache::set() method.
See also:
SoBoundingBoxCache::getCenter()
const SbVec3f & SoBoundingBoxCache::getCenter (void) const
Returns the center of the bounding box. Should only be used if SoBoundingBoxCache::isCenterSet() returns TRUE.
void SoBoundingBoxCache::setHasLinesOrPoints (SoState *state) [static]
Sets the flag returned from SoBoundingBoxCache::hasLinesOrPoints() to TRUE for all open bounding box caches.
The reason bounding box caches keep a lines-or-points flag is to make it known to client code if the shape(s) they contain have any of
these primitives -- or are rendered with these primitives. The reason this is important to know for the client code is because it might
need to add an 'epsilon' slack value to the calculated bounding box to account for smoothing / anti-aliasing effects in the renderer, so
lines and points graphics is not accidently clipped by near and far clipping planes, for instance.
This method is a static method on the class. It will upon invocation scan through the state stack and set the flag for all open
SoBoundingBoxCache elements. It has been made to work like this so it can easily be invoked on all current bounding box cache instances
from the SoShape-type nodes using lines and / or point primitives.
See also:
hasLinesOrPoints()
SbBool SoBoundingBoxCache::hasLinesOrPoints (void) const
Return TRUE if the hasLinesOrPoints flag has been set.
See also:
setHasLinesOrPoints()
Author
Generated automatically by Doxygen for Coin from the source code.
Version 3.1.3 Wed May 23 2012 SoBoundingBoxCache(3)
Check Out this Related Man Page
SoCache(3) Coin SoCache(3)NAME
SoCache -
The SoCache class is the superclass for all internal cache classes.
It organizes reference counting to make it possible to share cache instances. It also organizes a list of elements that will affect the
cache. If any of the elements have changed since the cache was created, the cache is invalid.
SYNOPSIS
#include <Inventor/caches/SoCache.h>
Inherited by SoBoundingBoxCache, SoConvexDataCache, SoGLRenderCache, SoNormalCache, SoPrimitiveVertexCache, and SoTextureCoordinateCache.
Public Member Functions
SoCache (SoState *const state)
void ref (void)
void unref (SoState *state=NULL)
void addElement (const SoElement *const elem)
virtual void addCacheDependency (const SoState *state, SoCache *cache)
virtual SbBool isValid (const SoState *state) const
const SoElement * getInvalidElement (const SoState *const state) const
void invalidate (void)
Protected Member Functions
virtual void destroy (SoState *state)
virtual ~SoCache ()
Detailed Description
The SoCache class is the superclass for all internal cache classes.
It organizes reference counting to make it possible to share cache instances. It also organizes a list of elements that will affect the
cache. If any of the elements have changed since the cache was created, the cache is invalid.
The cache element test algorithm in Coin works like this:
Every element that is read before it's written when a cache is created is stored in the SoCache's element list. This is done to detect when
something outside the cache changes.
Example: you have a SoCoordinate3 node outside an SoSeparator, but an SoIndexedFaceSet inside the SoSeparator. If the SoSeparator creates a
cache, SoIndexedFaceSet will read SoCoordinateElement, and since SoCoordinateElement hasn't been set after the cache was opened, the cache
stores that element in the cache's list of element dependencies.
At the next frame, the SoSeparator will test if the cache is valid, and will then test all dependency elements. If one of the elements
doesn't match, the cache is not valid and can't be used.
That's the basics. There are some steps you have to do when creating a cache to make the cache dependencies work. Basically you have to do
it like this:
SbBool storedinvalid = SoCacheElement::setInvalid(FALSE);
state->push();
SoMyCache * cache = new SoMyCache(state);
cache->ref();
SoCacheElement::set(state, cache);
buildMyCache();
state->pop();
SoCacheElement::setInvalid(storedinvalid);.fi
First you reset and store the old value of the cache invalid-flag. Then you push the state so that the cache can detect when something outside the cache is changed (and to be able to change the cache element). Next, you create the cache - don't forget to ref it. Finally, set the current cache in the cache element and build the cache. After building the cache, you pop the state and restore the invalid-cache flag.
When building the cache, all elements that are read will be copied into the cache (using SoElement::copyMatchInfo()), and these copied elements are used to test the validity of the cache (in SoCache::isValid()).
You don't have to manually add element dependencies. They will automatically be picked up when creating the cache. This is handled in SoElement::getConstElement().
If you want the cache to be invalidated when some field inside your node is changed, it's common to overload the notify()-method, and call SoCache::invalidate() whenever the notify()-method for your node is called. See for instance SoShape::notify().
Also, don't delete the cache in your notify() method. Wait until the next time the cache is needed before unref-ing the old cache.
Constructor &; Destructor Documentation
SoCache::SoCache (SoState *conststate)
Constructor with state being the current state.
SoCache::~SoCache () [protected], [virtual]
Destructor
Member Function Documentation
void SoCache::ref (void)
Increases the reference count by one.
void SoCache::unref (SoState *state = NULL)
Decreases the reference count by one. When the reference count reaches zero, the cache is deleted. The SoCache::destroy() method is called
before the destructor is called.
void SoCache::addElement (const SoElement *constelem)
Adds elem to the list of elements this cache depends on.
void SoCache::addCacheDependency (const SoState *state, SoCache *cache) [virtual]
Adds dependencies from cache to this cache.
SbBool SoCache::isValid (const SoState *state) const [virtual]
Return TRUE if this cache is valid, FALSE otherwise.
Reimplemented in SoGLRenderCache.
const SoElement * SoCache::getInvalidElement (const SoState *conststate) const
Returns the element that caused the invalidation. Returns NULL if the cache is valid, or if the cache was not invalidated bacause of an
element.
void SoCache::invalidate (void)
Forces a cache to be invalid.
void SoCache::destroy (SoState *state) [protected], [virtual]
Can be overridden by subclasses to clean up before they are deleted. Default method does nothing.
Reimplemented in SoGLRenderCache.
Author
Generated automatically by Doxygen for Coin from the source code.
Version 3.1.3 Wed May 23 2012 SoCache(3)