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SoSurroundScale.3coin2

NAME

SoSurroundScale -

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.

SYNOPSIS

#include <Inventor/nodes/SoSurroundScale.h>

Inherits SoTransformation.

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.

A way of thinking of the container node is that there exists a path from the root-node to the SoSurroundScale node. This path has a number of nodes in it. numNodesUpToContainer is the number of nodes in the path from the SoSurroundScale node towards the root node. When having counted numNodesUpToContainer from the SoSurroundScale node, you will have reached the container node. The container node is the seed-node that the bounding box is calculated from. All nodes lower than the seed-node will be a part of the bounding box unless they are closer to the SoSurroundScale node than numNodesUpToReset.

To make sure the node(s) that are to be scaled by the SoSurroundScale node aren't a part of the bounding box, the numNodesUpToReset is used. It is also the number of nodes up from the SoSurroundScale node towards the root node. The meaning of numNodesUpToReset is that nodes that are closer to the SoSurroundNode than the node at position numNodesUpToReset are not to be used for bounding box calculations.

Here's a complete, stand-alone example which sets up an SoTrackballDragger (connected to a cube), and 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 mydragger TrackballDragger {
         }
      }
      Rotation {
         rotation 0 0 1  0 =
         USE mydragger   . 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 are often paired up with SoAntiSquish nodes to get uniform scaling along all three principal axes, as has also been done in the above example.

FILE FORMAT/DEFAULTS:

     SurroundScale {
         numNodesUpToContainer 0
         numNodesUpToReset 0
     }
 
 

See also:

SoAntiSquish

Constructor & Destructor Documentation

SoSurroundScale::SoSurroundScale (void)Constructor.

References cacheOK, doTranslations, numNodesUpToContainer, and numNodesUpToReset.

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.

Referenced by SoInteraction::init().

void SoSurroundScale::invalidate (void)Invalidates the cached transformation, forcing a recalculation to be done the next time this node is traversed.

References cacheOK.

Referenced by SoTransformBoxDragger::invalidateSurroundScaleCB(), SoTabBoxDragger::invalidateSurroundScaleCB(), SoJackDragger::invalidateSurroundScaleCB(), SoCenterballDragger::kidFinishCB(), and SoCenterballDragger::kidStartCB().

void SoSurroundScale::doAction (SoAction * action) [virtual]This function performs the typical operation of a node for any action.

Reimplemented from SoNode.

References cachedScale, cachedTranslation, cacheOK, doTranslations, SoAction::getState(), and updateMySurroundParams().

Referenced by callback(), getBoundingBox(), GLRender(), and pick().

void SoSurroundScale::setDoingTranslations (const SbBool val)Sets whether the translation part of the transformation should be ignored or not. Default behavior is to translate.

References doTranslations.

Referenced by SoCenterballDragger::getBoundingBox(), and SoCenterballDragger::getMatrix().

SbBool SoSurroundScale::isDoingTranslations (void)Returns whether the translation part of the transformation should be ignored or not.

See also:

setDoingTranslations()

References doTranslations.

Referenced by SoCenterballDragger::getBoundingBox(), and SoCenterballDragger::getMatrix().

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.

References doAction().

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.

References doAction().

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.

References doAction(), and isIgnoreInBbox().

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.

References cachedScale, cachedTranslation, cacheOK, doTranslations, SoGetMatrixAction::getInverse(), SoGetMatrixAction::getMatrix(), SbMatrix::multLeft(), SbMatrix::multRight(), SbMatrix::setScale(), SbMatrix::setTranslate(), and updateMySurroundParams().

void SoSurroundScale::pick (SoPickAction * action) [protected, virtual]Action method for SoPickAction.

Does common processing for SoPickAction action instances.

Reimplemented from SoNode.

References doAction().

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.

References SoAction::apply(), cachedInvScale, cachedScale, cachedTranslation, cacheOK, SoPath::copy(), SoFieldContainer::get(), SoGetBoundingBoxAction::getBoundingBox(), SbBox3f::getCenter(), SoAction::getCurPath(), SoFullPath::getLength(), SbBox3f::getSize(), SoAction::getState(), SoState::isElementEnabled(), SbBox3f::isEmpty(), isIgnoreInBbox(), numNodesUpToContainer, numNodesUpToReset, SoDebugError::postWarning(), SoBase::ref(), setIgnoreInBbox(), SoGetBoundingBoxAction::setResetPath(), SbVec3f::setValue(), and SoBase::unref().

Referenced by doAction(), and getMatrix().

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.

Referenced by updateMySurroundParams().

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()

Referenced by getBoundingBox(), and updateMySurroundParams().

Member Data Documentation

SoSFInt32 SoSurroundScale::numNodesUpToContainerNumber of nodes in the path counting from this and 'upwards' to the container node.

Referenced by SoCenterballManip::SoCenterballManip(), SoHandleBoxManip::SoHandleBoxManip(), SoJackManip::SoJackManip(), SoSurroundScale(), SoTabBoxManip::SoTabBoxManip(), SoTrackballManip::SoTrackballManip(), SoTransformBoxManip::SoTransformBoxManip(), SoTransformerManip::SoTransformerManip(), and updateMySurroundParams().

SoSFInt32 SoSurroundScale::numNodesUpToResetNumber of nodes in the path counting from this and 'upwards' to the node where we will reset the bounding box value.

Referenced by SoCenterballManip::SoCenterballManip(), SoHandleBoxManip::SoHandleBoxManip(), SoJackManip::SoJackManip(), SoSurroundScale(), SoTabBoxManip::SoTabBoxManip(), SoTrackballManip::SoTrackballManip(), SoTransformBoxManip::SoTransformBoxManip(), SoTransformerManip::SoTransformerManip(), and updateMySurroundParams().

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.

Referenced by doAction(), getMatrix(), and updateMySurroundParams().

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.

Referenced by updateMySurroundParams().

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.

Referenced by doAction(), getMatrix(), and updateMySurroundParams().

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.

Referenced by doAction(), getMatrix(), invalidate(), SoSurroundScale(), and updateMySurroundParams().

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.

Referenced by doAction(), getMatrix(), isDoingTranslations(), setDoingTranslations(), and SoSurroundScale().

Author

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