SoSurroundScale Class Reference
[Nodes]

The SoSurroundScale class is used to automatically scale geometry to surround other geometry. More...

#include <Inventor/nodes/SoSurroundScale.h>

Inheritance diagram for SoSurroundScale:

SoTransformation SoNode SoFieldContainer SoBase

List of all members.

Public Member Functions

 SoSurroundScale (void)
void invalidate (void)
virtual void doAction (SoAction *action)
void setDoingTranslations (const SbBool val)
SbBool isDoingTranslations (void)

Static Public Member Functions

static void initClass (void)

Public Attributes

SoSFInt32 numNodesUpToContainer
SoSFInt32 numNodesUpToReset

Protected Member Functions

virtual ~SoSurroundScale ()
virtual void callback (SoCallbackAction *action)
virtual void GLRender (SoGLRenderAction *action)
virtual void getBoundingBox (SoGetBoundingBoxAction *action)
virtual void getMatrix (SoGetMatrixAction *action)
virtual void pick (SoPickAction *action)
void updateMySurroundParams (SoAction *action, const SbMatrix &inv)
void setIgnoreInBbox (const SbBool val)
SbBool isIgnoreInBbox (void)

Protected Attributes

SbVec3f cachedScale
SbVec3f cachedInvScale
SbVec3f cachedTranslation
SbBool cacheOK
SbBool doTranslations


Detailed Description

The SoSurroundScale class is used to automatically scale geometry to surround other geometry.

This node calculates a transformation (a translation and a scale) which will, when the node is traversed, be appended to the current model matrix, making a default cube placed directly to the right of this node in the graph surround geometry to the right of the container branch this node is on. The container is specified by the field SoSurroundScale::numNodesUpToContainer.

When calculating the bounding box to be surrounded, the bounding box action will be applied to the container node, and the bounding box calculations will be reset after traversing the node specified by the field SoSurroundScale::numNodesUpToReset.

Here's a complete, stand-alone example which sets up am SoTrackballDragger (connected to a cube), uses an SoSurroundScale node to make it auto-scale to the size of the high cube and translates it an offset to one side of the cube:

  #include <Inventor/Qt/SoQt.h>
  #include <Inventor/Qt/viewers/SoQtExaminerViewer.h>
  #include <Inventor/draggers/SoTrackballDragger.h>
  #include <Inventor/nodes/SoAntiSquish.h>
  #include <Inventor/nodes/SoSeparator.h>
  #include <Inventor/nodes/SoCube.h>
  #include <Inventor/nodes/SoSurroundScale.h>
  #include <Inventor/nodes/SoRotation.h>
  #include <Inventor/nodes/SoTranslation.h>


  int
  main(int argc, char **argv)
  {
    QWidget * window = SoQt::init(argv[0]);
    if (window == NULL) exit(1);

    SoSeparator * root = new SoSeparator;
    root->ref();

    SoSeparator * surroundsep = new SoSeparator;
    root->addChild(surroundsep);

    SoTranslation * translation = new SoTranslation;
    translation->translation = SbVec3f(12, 0, 0);
    surroundsep->addChild(translation);

    SoSurroundScale * ss = new SoSurroundScale;
    ss->numNodesUpToReset = 1;
    ss->numNodesUpToContainer = 2;
    surroundsep->addChild(ss);

    SoAntiSquish * antisquish = new SoAntiSquish;
    antisquish->sizing = SoAntiSquish::BIGGEST_DIMENSION;
    surroundsep->addChild(antisquish);

    SoTrackballDragger * dragger = new SoTrackballDragger;
    surroundsep->addChild(dragger);

    SoRotation * rotation = new SoRotation;
    rotation->rotation.connectFrom(& dragger->rotation);
    root->addChild(rotation);

    SoCube * cube = new SoCube;
    cube->height = 10.0f;
    root->addChild(cube);

    SoQtExaminerViewer * viewer = new SoQtExaminerViewer(window);
    viewer->setSceneGraph(root);
    viewer->setViewing(FALSE);
    viewer->setDecoration(FALSE);
    viewer->show();

    SoQt::show(window);
    SoQt::mainLoop();

    delete viewer;
    root->unref();

    return 0;
  }

It might be easier to see how the SoSurroundScale node works in the above example by looking at the actual scenegraph:

  #Inventor V2.1 ascii

  Separator {
     Separator {
        Translation {
           translation 12 0 0
        }
        SurroundScale {
           numNodesUpToContainer 2
           numNodesUpToReset 1
        }
        AntiSquish {
           sizing BIGGEST_DIMENSION
        }
        DEF +0 TrackballDragger {
        }
     }
     Rotation {
        rotation 0 0 1  0 =
        USE +0          . rotation
     }
     Cube {
        height 10
     }
  }

This node is internally used by manipulators to make it possible for them to scale their dragger's geometry to match the scenegraph geometry it is modifying, as is demonstrated above (but outside of the context of a manipulator).

It is also generally useful for application programmers who want any particular piece of geometry surround other geometry of unknown or changing extent.

SoSurroundScale nodes in the scenegraph is often paired up with SoAntiSquish nodes to get uniform scaling along all three principal axes.

See also:
SoAntiSquish

Constructor & Destructor Documentation

SoSurroundScale::SoSurroundScale ( void   ) 

Constructor.

SoSurroundScale::~SoSurroundScale (  )  [protected, virtual]

Destructor.


Member Function Documentation

void SoSurroundScale::initClass ( void   )  [static]

Sets up initialization for data common to all instances of this class, like submitting necessary information to the Coin type system.

Reimplemented from SoTransformation.

void SoSurroundScale::invalidate ( void   ) 

Invalidates the cached transformation, forcing a recalculation to be done the next time this node is traversed.

void SoSurroundScale::doAction ( SoAction action  )  [virtual]

This function performs the typical operation of a node for any action.

Reimplemented from SoNode.

void SoSurroundScale::setDoingTranslations ( const SbBool  val  ) 

Sets whether the translation part of the transformation should be ignored or not. Default behavior is to translate.

SbBool SoSurroundScale::isDoingTranslations ( void   ) 

Returns whether the translation part of the transformation should be ignored or not.

See also:
setDoingTranslations()

void SoSurroundScale::callback ( SoCallbackAction action  )  [protected, virtual]

Action method for SoCallbackAction.

Simply updates the state according to how the node behaves for the render action, so the application programmer can use the SoCallbackAction for extracting information about the scene graph.

Reimplemented from SoNode.

void SoSurroundScale::GLRender ( SoGLRenderAction action  )  [protected, virtual]

Action method for the SoGLRenderAction.

This is called during rendering traversals. Nodes influencing the rendering state in any way or who wants to throw geometry primitives at OpenGL overrides this method.

Reimplemented from SoNode.

void SoSurroundScale::getBoundingBox ( SoGetBoundingBoxAction action  )  [protected, virtual]

Action method for the SoGetBoundingBoxAction.

Calculates bounding box and center coordinates for node and modifies the values of the action to encompass the bounding box for this node and to shift the center point for the scene more towards the one for this node.

Nodes influencing how geometry nodes calculates their bounding box also overrides this method to change the relevant state variables.

Reimplemented from SoNode.

void SoSurroundScale::getMatrix ( SoGetMatrixAction action  )  [protected, virtual]

Action method for SoGetMatrixAction.

Updates action by accumulating with the transformation matrix of this node (if any).

Reimplemented from SoNode.

void SoSurroundScale::pick ( SoPickAction action  )  [protected, virtual]

Action method for SoPickAction.

Does common processing for SoPickAction action instances.

Reimplemented from SoNode.

void SoSurroundScale::updateMySurroundParams ( SoAction action,
const SbMatrix inv 
) [protected]

Calculates the translation and scale needed to make a default cube surround geometry to the right of the branch this node is on.

void SoSurroundScale::setIgnoreInBbox ( const SbBool  val  )  [protected]

Sets whether bounding box calculations in SoGetBoundingBoxAction should be affected by this node.

Default is to ignore our bounding box calculations.

SbBool SoSurroundScale::isIgnoreInBbox ( void   )  [protected]

Returns the value of the flag that decides whether bounding box calculations in SoGetBoundingBoxAction should be affected by this node.

See also:
setIgnoreInBbox()


Member Data Documentation

SoSFInt32 SoSurroundScale::numNodesUpToContainer

Number of nodes in the path counting from this and "upwards" to the container node.

SoSFInt32 SoSurroundScale::numNodesUpToReset

Number of nodes in the path counting from this and "upwards" to the node where we will reset the bounding box value.

SoSurroundScale::cachedScale [protected]

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

SoSurroundScale::cachedInvScale [protected]

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

SoSurroundScale::cachedTranslation [protected]

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

SoSurroundScale::cacheOK [protected]

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

SoSurroundScale::doTranslations [protected]

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


The documentation for this class was generated from the following files:
Generated on Sat Nov 10 03:30:12 2007 for Coin by  doxygen 1.5.3-20071008