SoCallback(3IV)

NAME
SoCallback — provides custom behavior during actions

INHERITS FROM
SoBase > SoFieldContainer > SoNode > SoCallback

SYNOPSIS
#include <Inventor/nodes/SoCallback.h>

typedef void
SoCallbackCB(void *userData, SoAction *action)

Methods from class SoCallback:

SoCallback()
void
setCallback(SoCallbackCB *func, void *userData = NULL)
static SoType
getClassTypeId()

Methods from class SoNode:

void
setOverride(SbBool state)
SbBool
isOverride() const
SoNode *
copy(SbBool copyConnections = FALSE) const
virtual SbBool
affectsState() const
static SoNode *
getByName(const SbName &name)
static int
getByName(const SbName &name, SoNodeList &list)

Methods from class SoFieldContainer:

void
setToDefaults()
SbBool
hasDefaultValues() const
SbBool
fieldsAreEqual(const SoFieldContainer *fc) const
void
copyFieldValues(const SoFieldContainer *fc, SbBool copyConnections = FALSE)
SbBool
set(const char *fieldDataString)
void
get(SbString &fieldDataString)
virtual int
getFields(SoFieldList &resultList) const
virtual SoField *
getField(const SbName &fieldName) const
SbBool
getFieldName(const SoField *field, SbName &fieldName) const
SbBool
isNotifyEnabled() const
SbBool
enableNotify(SbBool flag)

Methods from class SoBase:

void
ref()
void
unref() const
void
unrefNoDelete() const
void
touch()
virtual SoType
getTypeId() const
SbBool
isOfType(SoType type) const
virtual void
setName(const SbName &name)
virtual SbName
getName() const

DESCRIPTION
This node provides a general mechanism for inserting callback functions into a scene graph. The callback function registered with the node is called each time the node is traversed while performing any scene graph action. The callback function is passed a pointer to the action being performed and a user data pointer registered with the callback function. You can use this node to make nonstandard OpenGL calls while rendering. If you do, be careful not to interfere with Inventor's use of OpenGL.

If you use a callback node for GL rendering, you should be careful to follow render caching rules. If your callback node can make different rendering calls each time it is traversed, it cannot be cached. In such a case, the node should invalidate any open caches, as in the following example:

void
myCallbackFunc(void *d, SoAction *action) {
    if (action->isOfType(SoGLRenderAction::getClassTypeId())) {
	// Make my custom GL calls
	((MyClass *) d)->myRender();

	// Invalidate the state so that a cache is not made
	SoCacheElement::invalidate(action->getState());
    }
}

METHODS

SoCallback()
Creates a callback node with default settings.

void
setCallback(SoCallbackCB *func, void *userData = NULL)
Sets pointer to callback function and user data. By default, the function pointer in the node is NULL and does nothing.

static SoType
getClassTypeId()
Returns type identifier for this class.

ACTION BEHAVIOR
SoGLRenderAction, SoBoundingBoxAction, SoPickAction
Calls the specified callback function for all actions.

FILE FORMAT/DEFAULTS
Callback {
}

SEE ALSO
SoAction, SoCallbackAction, SoEventCallback