# SoCallbackAction Class Reference
[Actions]

`#include <Inventor/actions/SoCallbackAction.h>`

Inheritance diagram for SoCallbackAction:

List of all members.

## Detailed Description

The SoCallbackAction class invokes callbacks at specific nodes.

This action has mechanisms for tracking traversal position and traversal state. In combination with the ability to pass geometry primitives to callback actions set by the user, this does for instance make it rather straightforward to extract the geometry of a scene graph.

You should be able to use this action for most of your "simple" traversal needs, instead of cooking up your own code, as the SoCallbackAction is rather flexible.

A common use of this action is to extract geometry of non-primitive shapes as triangles. A full-fledged example that demonstrates this on a scenegraph with two spheres follows:

       #include <Inventor/SoDB.h>
       #include <Inventor/SoPrimitiveVertex.h>
       #include <Inventor/actions/SoCallbackAction.h>
       #include <Inventor/nodes/SoCoordinate3.h>
       #include <Inventor/nodes/SoIndexedFaceSet.h>
       #include <Inventor/nodes/SoSeparator.h>
       #include <Inventor/nodes/SoShape.h>
       #include <Inventor/nodes/SoSphere.h>
       #include <Inventor/nodes/SoTranslation.h>

       static SoCoordinate3 * coord3 = NULL;
       static SoIndexedFaceSet * ifs = NULL;

       static int coord3idx = 0;

       static void
       triangle_cb(void * userdata, SoCallbackAction * action,
                   const SoPrimitiveVertex * v1,
                   const SoPrimitiveVertex * v2,
                   const SoPrimitiveVertex * v3)
       {
         const SbVec3f vtx[] = { v1->getPoint(), v2->getPoint(), v3->getPoint() };
         const SbMatrix mm = action->getModelMatrix();

         SbVec3f vx[3];
         for (int j=0; j < 3; j++) { mm.multVecMatrix(vtx[j], vx[j]); }

         // (This is sub-optimal -- should scan for the same vertex
         // coordinates already being present in the SoCoordinate3
         // node. We'll get lots of duplicate coordinates from this.)
         coord3->point.setNum(coord3->point.getNum() + 3);
         coord3->point.setValues(coord3idx, 3, vx);

         int32_t indices[] = { coord3idx, coord3idx + 1, coord3idx + 2, -1 };
         coord3idx += 3;

         int oldsize = ifs->coordIndex.getNum();
         ifs->coordIndex.setNum(oldsize + 4);
         ifs->coordIndex.setValues(oldsize, 4, indices);

         // (Note that it would likely be desirable to grab normal vectors,
         // materials and / or texture coordinates in a real-world
         // application. How to do this is not shown by the above code,
         // but it is not much different from the extraction of vertex
         // coordinates.)
       }

       int
       main(void)
       {
         SoDB::init();

         SoSeparator * root = new SoSeparator;
         root->addChild(new SoSphere);
         SoTranslation * trans = new SoTranslation;
         trans->translation.setValue(10, 0, 0);
         root->addChild(trans);
         SoSphere * ss = new SoSphere;
         ss->radius = 3;
         root->addChild(ss);

         root->ref();

         coord3 = new SoCoordinate3;
         coord3->point.setNum(0);
         ifs = new SoIndexedFaceSet;
         ifs->coordIndex.setNum(0);

         SoCallbackAction ca;
         ca.addTriangleCallback(SoShape::getClassTypeId(), triangle_cb, NULL);
         ca.apply(root);

         root->unref();

         // [the generated SoCoordinate3 and SoIndexedFaceSet nodes would now
         // typically be used in a scenegraph in a viewer, or written to disk
         // or something]

         return 0;
       }

## Public Types

typedef Response | SoCallbackActionCB (void *userdata, SoCallbackAction *action, const SoNode *node)
enum | Response { CONTINUE, ABORT, PRUNE }

## Public Member Functions

| SoCallbackAction (void)
| SoCallbackAction (const SbViewportRegion &vp)
virtual | ~SoCallbackAction ()
void | setViewportRegion (const SbViewportRegion &vp)
void | addPreCallback (const SoType type, SoCallbackActionCB *cb, void *userdata)
void | addPostCallback (const SoType type, SoCallbackActionCB *cb, void *userdata)
void | addPreTailCallback (SoCallbackActionCB *cb, void *userdata)
void | addPostTailCallback (SoCallbackActionCB *cb, void *userdata)
void | addTriangleCallback (const SoType type, SoTriangleCB *cb, void *userdata)
void | addLineSegmentCallback (const SoType type, SoLineSegmentCB *cb, void *userdata)
void | addPointCallback (const SoType type, SoPointCB *cb, void *userdata)
SoDecimationTypeElement::Type | getDecimationType (void) const
float | getDecimationPercentage (void) const
float | getComplexity (void) const
SoComplexity::Type | getComplexityType (void) const
int32_t | getNumCoordinates (void) const
const SbVec3f & | getCoordinate3 (const int index) const
const SbVec4f & | getCoordinate4 (const int index) const
SoDrawStyle::Style | getDrawStyle (void) const
unsigned short | getLinePattern (void) const
float | getLineWidth (void) const
float | getPointSize (void) const
const SbName & | getFontName (void) const
float | getFontSize (void) const
SoLightModel::Model | getLightModel (void) const
const SbVec3f & | getLightAttenuation (void) const
void | getMaterial (SbColor &ambient, SbColor &diffuse, SbColor &specular, SbColor &emission, float &shininess, float &transparency, const int index=0) const
SoMaterialBinding::Binding | getMaterialBinding (void) const
uint32_t | getNumNormals (void) const
const SbVec3f & | getNormal (const int index) const
SoNormalBinding::Binding | getNormalBinding (void) const
int32_t | getNumProfileCoordinates (void) const
const SbVec2f & | getProfileCoordinate2 (const int index) const
const SbVec3f & | getProfileCoordinate3 (const int index) const
const SoNodeList & | getProfile (void) const
SoShapeHints::VertexOrdering | getVertexOrdering (void) const
SoShapeHints::ShapeType | getShapeType (void) const
SoShapeHints::FaceType | getFaceType (void) const
float | getCreaseAngle (void) const
int32_t | getNumTextureCoordinates (void) const
const SbVec2f & | getTextureCoordinate2 (const int index) const
const SbVec3f & | getTextureCoordinate3 (const int index) const
const SbVec4f & | getTextureCoordinate4 (const int index) const
SoTextureCoordinateBinding::Binding | getTextureCoordinateBinding (void) const
const SbColor & | getTextureBlendColor (void) const
const unsigned char * | getTextureImage (SbVec2s &size, int &numcomps) const
const unsigned char * | getTextureImage (SbVec3s &size, int &numcomps) const
const SbMatrix & | getTextureMatrix (void) const
SoTexture2::Model | getTextureModel (void) const
SoTexture2::Wrap | getTextureWrapS (void) const
SoTexture2::Wrap | getTextureWrapT (void) const
SoTexture2::Wrap | getTextureWrapR (void) const
const SbMatrix & | getModelMatrix (void) const
SoUnits::Units | getUnits (void) const
float | getFocalDistance (void) const
const SbMatrix & | getProjectionMatrix (void) const
const SbMatrix & | getViewingMatrix (void) const
const SbViewVolume & | getViewVolume (void) const
const SbViewportRegion & | getViewportRegion (void) const
SoPickStyle::Style | getPickStyle (void) const
int32_t | getSwitch (void) const
Response | getCurrentResponse (void) const
void | invokePreCallbacks (const SoNode *const node)
void | invokePostCallbacks (const SoNode *const node)
void | invokeTriangleCallbacks (const SoShape *const shape, const SoPrimitiveVertex *const v1, const SoPrimitiveVertex *const v2, const SoPrimitiveVertex *const v3)
void | invokeLineSegmentCallbacks (const SoShape *const shape, const SoPrimitiveVertex *const v1, const SoPrimitiveVertex *const v2)
void | invokePointCallbacks (const SoShape *const shape, const SoPrimitiveVertex *const v)
SbBool | shouldGeneratePrimitives (const SoShape *shape) const
virtual SoNode * | getCurPathTail (void)
void | setCurrentNode (SoNode *const node)

## Static Public Member Functions

void | initClass (void)

## Protected Member Functions

virtual void | beginTraversal (SoNode *node)

## Friends

class | SoCallbackActionP

## Member Typedef Documentation

Response SoCallbackAction::SoCallbackActionCB

| Callback functions need to be of this type. node is at the current traversal point in the scene graph.

## Member Enumeration Documentation

enum SoCallbackAction::Response

Response values for callback function.

Enumeration values:

  CONTINUE | Continue traversal as usual.
  ABORT | Abort traversal.
  PRUNE | Don't do traversal of neither the current node (if returning from a pre-traversal callback) nor its children.

## Constructor & Destructor Documentation

SoCallbackAction::SoCallbackAction | ( | void |  | ) |

| Default constructor. Will set the viewport to a standard viewport with size 640x512.

SoCallbackAction::SoCallbackAction | ( | const SbViewportRegion & | vp | ) |

| Constructor which lets you specify the viewport. This constructor is an extension versus the Open Inventor API.

SoCallbackAction::~SoCallbackAction | ( |  | ) | `[virtual]`

| Destructor.

## Member Function Documentation

void SoCallbackAction::initClass | ( | void |  | ) | `[static]`

| Initializes the run-time type system for this class, and sets up the enabled elements and action method list. Reimplemented from SoAction. Reimplemented in SoVectorizeAction, and SoVectorizePSAction.

void SoCallbackAction::setViewportRegion | ( | const SbViewportRegion & | vp | ) |

| Sets the viewport region for this action. When set, the viewport element is initialized right before a traversal starts, making it the current viewport. This method is an extension versus the Open Inventor API.

void SoCallbackAction::addPreCallback | ( | const SoType | type,
|  | SoCallbackActionCB * | cb,
|  | void * | userdata
| ) |

| Set a function cb to call before every node of type is traversed. cb will be called with userdata.

void SoCallbackAction::addPostCallback | ( | const SoType | type,
|  | SoCallbackActionCB * | cb,
|  | void * | userdata
| ) |

| Set a function cb to call after every node of type has been traversed. cb will be called with userdata.

void SoCallbackAction::addPreTailCallback | ( | SoCallbackActionCB * | cb,
|  | void * | userdata
| ) |

| Set a function cb to call before the tail of a path is traversed. cb will be called with userdata.

void SoCallbackAction::addPostTailCallback | ( | SoCallbackActionCB * | cb,
|  | void * | userdata
| ) |

| Set a function cb to call after the tail of a path has been traversed. cb will be called with userdata.

void SoCallbackAction::addTriangleCallback | ( | const SoType | type,
|  | SoTriangleCB * | cb,
|  | void * | userdata
| ) |

| Set a function cb to call when traversing a node of type which generates triangle primitives for rendering. cb will be called with userdata.

void SoCallbackAction::addLineSegmentCallback | ( | const SoType | type,
|  | SoLineSegmentCB * | cb,
|  | void * | userdata
| ) |

| Set a function cb to call when traversing a node of type which generates line primitives for rendering. cb will be called with userdata.

void SoCallbackAction::addPointCallback | ( | const SoType | type,
|  | SoPointCB * | cb,
|  | void * | userdata
| ) |

| Set a function cb to call when traversing a node of type which generates single point primitives for rendering. cb will be called with userdata.

SoDecimationTypeElement::Type SoCallbackAction::getDecimationType | ( | void |  | ) | const

| Returns current decimation type setting.

float SoCallbackAction::getDecimationPercentage | ( | void |  | ) | const

| Returns current decimation percentage setting.

float SoCallbackAction::getComplexity | ( | void |  | ) | const

| Returns current complexity setting.

SoComplexity::Type SoCallbackAction::getComplexityType | ( | void |  | ) | const

| Returns current complexity type setting.

int32_t SoCallbackAction::getNumCoordinates | ( | void |  | ) | const

| Returns current number of coordinates in the state.

const SbVec3f & SoCallbackAction::getCoordinate3 | ( | const int | index | ) | const

| Returns a coordinate triplet from the current state pool of coordinates.

const SbVec4f & SoCallbackAction::getCoordinate4 | ( | const int | index | ) | const

| Returns a coordinate quartuplet from the current state pool of coordinates.

SoDrawStyle::Style SoCallbackAction::getDrawStyle | ( | void |  | ) | const

| Returns current draw style setting.

unsigned short SoCallbackAction::getLinePattern | ( | void |  | ) | const

| Returns current line pattern setting.

float SoCallbackAction::getLineWidth | ( | void |  | ) | const

| Returns current line width setting.

float SoCallbackAction::getPointSize | ( | void |  | ) | const

| Returns current point size setting.

const SbName & SoCallbackAction::getFontName | ( | void |  | ) | const

| Returns current fontname setting.

float SoCallbackAction::getFontSize | ( | void |  | ) | const

| Returns current fontsize setting.

SoLightModel::Model SoCallbackAction::getLightModel | ( | void |  | ) | const

| Returns current lightmodel setting.

const SbVec3f & SoCallbackAction::getLightAttenuation | ( | void |  | ) | const

| Returns current light attenuation setting.

void SoCallbackAction::getMaterial | ( | SbColor & | ambient,
|  | SbColor & | diffuse,
|  | SbColor & | specular,
|  | SbColor & | emission,
|  | float & | shininess,
|  | float & | transparency,
|  | const int | index = 0
| ) | const

| Returns current material settings.

SoMaterialBinding::Binding SoCallbackAction::getMaterialBinding | ( | void |  | ) | const

| Returns current materialbinding setting.

uint32_t SoCallbackAction::getNumNormals | ( | void |  | ) | const

| Returns current number of normals in the state.

const SbVec3f & SoCallbackAction::getNormal | ( | const int | index | ) | const

| Returns the normal vectors at index from the current state.

SoNormalBinding::Binding SoCallbackAction::getNormalBinding | ( | void |  | ) | const

| Returns current normalbinding setting.

int32_t SoCallbackAction::getNumProfileCoordinates | ( | void |  | ) | const

| Returns current number of profile coordinates in the state.

const SbVec2f & SoCallbackAction::getProfileCoordinate2 | ( | const int | index | ) | const

| Returns current number of SbVec2f profile coordinates in the state.

const SbVec3f & SoCallbackAction::getProfileCoordinate3 | ( | const int | index | ) | const

| Returns current number of SbVec3f profile coordinates in the state.

const SoNodeList & SoCallbackAction::getProfile | ( | void |  | ) | const

| Returns current list of profile nodes.

SoShapeHints::VertexOrdering SoCallbackAction::getVertexOrdering | ( | void |  | ) | const

| Returns current vertexordering shapehint setting.

SoShapeHints::ShapeType SoCallbackAction::getShapeType | ( | void |  | ) | const

| Returns current shapetype hint setting.

SoShapeHints::FaceType SoCallbackAction::getFaceType | ( | void |  | ) | const

| Returns current facetype hint setting.

float SoCallbackAction::getCreaseAngle | ( | void |  | ) | const

| Returns current creaseangle setting.

int32_t SoCallbackAction::getNumTextureCoordinates | ( | void |  | ) | const

| Returns current number of texture coordinates in the traversal state.

const SbVec2f & SoCallbackAction::getTextureCoordinate2 | ( | const int | index | ) | const

| Returns SbVec2f texture coordinate at index from the texture coordinate pool of the traversal state.

const SbVec3f & SoCallbackAction::getTextureCoordinate3 | ( | const int | index | ) | const

Returns SbVec3f texture coordinate at index from the texture coordinate pool of the traversal state.

This function is an extension for Coin, and it is not available in the original SGI Open Inventor v2.1 API.

Since:
  Coin 2.0

const SbVec4f & SoCallbackAction::getTextureCoordinate4 | ( | const int | index | ) | const

| Returns SbVec4f texture coordinate at index from the texture coordinate pool of the traversal state.

SoTextureCoordinateBinding::Binding SoCallbackAction::getTextureCoordinateBinding | ( | void |  | ) | const

| Returns current texturecoordinate binding setting.

const SbColor & SoCallbackAction::getTextureBlendColor | ( | void |  | ) | const

| Returns current texture blend color setting.

const unsigned char * SoCallbackAction::getTextureImage | ( | SbVec2s & | size,
|  | int & | numcomps
| ) | const

| Returns current texture image settings.

const unsigned char * SoCallbackAction::getTextureImage | ( | SbVec3s & | size,
|  | int & | numcomps
| ) | const

Returns current 3D texture image settings.

This function is an extension for Coin, and it is not available in the original SGI Open Inventor v2.1 API.

Since:
  Coin 2.0

const SbMatrix & SoCallbackAction::getTextureMatrix | ( | void |  | ) | const

| Returns current texture transformation matrix setting.

SoTexture2::Model SoCallbackAction::getTextureModel | ( | void |  | ) | const

| Returns current texturemapping model setting.

SoTexture2::Wrap SoCallbackAction::getTextureWrapS | ( | void |  | ) | const

| Returns current texture wrapping setting for the `S` coordinate.

SoTexture2::Wrap SoCallbackAction::getTextureWrapT | ( | void |  | ) | const

| Returns current texture wrapping setting for the `T` coordinate.

SoTexture2::Wrap SoCallbackAction::getTextureWrapR | ( | void |  | ) | const

Returns current texture wrapping setting for the `R` coordinate.

This function is an extension for Coin, and it is not available in the original SGI Open Inventor v2.1 API.

Since:
  Coin 2.0

const SbMatrix & SoCallbackAction::getModelMatrix | ( | void |  | ) | const

| Returns current model matrix.

SoUnits::Units SoCallbackAction::getUnits | ( | void |  | ) | const

| Returns current units setting.

float SoCallbackAction::getFocalDistance | ( | void |  | ) | const

| Returns current camera focal distance setting.

const SbMatrix & SoCallbackAction::getProjectionMatrix | ( | void |  | ) | const

| Returns current projection matrix.

const SbMatrix & SoCallbackAction::getViewingMatrix | ( | void |  | ) | const

| Returns current viewing matrix.

const SbViewVolume & SoCallbackAction::getViewVolume | ( | void |  | ) | const

| Returns current view volume setting.

const SbViewportRegion & SoCallbackAction::getViewportRegion | ( | void |  | ) | const

| Returns current viewport region setting. This method is an extension versus the Open Inventor API.

SoPickStyle::Style SoCallbackAction::getPickStyle | ( | void |  | ) | const

| Returns current pickstyle setting.

int32_t SoCallbackAction::getSwitch | ( | void |  | ) | const

| Returns last SoSwitch::whichChild setting during the traversal.

SoCallbackAction::Response SoCallbackAction::getCurrentResponse | ( | void |  | ) | const

| This API member is considered internal to the library, as it is not likely to be of interest to the application programmer.

void SoCallbackAction::invokePreCallbacks | ( | const SoNode *const | node | ) |

| This API member is considered internal to the library, as it is not likely to be of interest to the application programmer. Invoke all "pre traversal" callbacks.

void SoCallbackAction::invokePostCallbacks | ( | const SoNode *const | node | ) |

| This API member is considered internal to the library, as it is not likely to be of interest to the application programmer. Invoke all "post traversal" callbacks.

void SoCallbackAction::invokeTriangleCallbacks | ( | const SoShape *const | shape,
|  | const SoPrimitiveVertex *const | v1,
|  | const SoPrimitiveVertex *const | v2,
|  | const SoPrimitiveVertex *const | v3
| ) |

| This API member is considered internal to the library, as it is not likely to be of interest to the application programmer. Invoke all "triangle generation" callbacks.

void SoCallbackAction::invokeLineSegmentCallbacks | ( | const SoShape *const | shape,
|  | const SoPrimitiveVertex *const | v1,
|  | const SoPrimitiveVertex *const | v2
| ) |

| This API member is considered internal to the library, as it is not likely to be of interest to the application programmer. Invoke all "line segment generation" callbacks.

void SoCallbackAction::invokePointCallbacks | ( | const SoShape *const | shape,
|  | const SoPrimitiveVertex *const | v
| ) |

| This API member is considered internal to the library, as it is not likely to be of interest to the application programmer. Invoke all "point" callbacks.

SbBool SoCallbackAction::shouldGeneratePrimitives | ( | const SoShape * | shape | ) | const

| This API member is considered internal to the library, as it is not likely to be of interest to the application programmer. Check from the shape nodes whether or not to generate primitives from the complex shapes. If there are no callbacks attached to the node types, making the primitives would only be a waste of CPU.

SoNode * SoCallbackAction::getCurPathTail | ( | void |  | ) | `[virtual]`

| Returns the current tail of the traversal path for the callback action. Reimplemented from SoAction.

void SoCallbackAction::setCurrentNode | ( | SoNode *const | node | ) |

| Used from nodes during traversal to keep a current node pointer in the action.

void SoCallbackAction::beginTraversal | ( | SoNode * | node | ) | `[protected, virtual]`

This virtual method is called from SoAction::apply(), and is the entry point for the actual scenegraph traversal.

It can be overridden to initialize the action at traversal start, for specific initializations in the action subclasses inheriting SoAction.

Default method just calls traverse(), which any overridden implementation of the method must do too (or call SoAction::beginTraversal()) to trigger the scenegraph traversal.

Reimplemented from SoAction.

The documentation for this class was generated from the following files:

- SoCallbackAction.h
- SoCallbackAction.cpp